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Dictionary of Radiology Words

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Radiology of the Hip

- AP view:
    - patient is supine with the foot internally rotated 15 deg to obtain best views of the femoral neck;
    - central beam is directed toward the femoral head;
    - X-ray tube should be positioned 100 cm from focal plane of film cassette to yield an image at 20% magnification, corresponding
          to the magnification incorporated in the templates;
          - tape measure will allow accurate assessment of radiographic magnification;



- Lateral View:
    - surgical lateral view:
          - this view should be obtained on all patients suspected of having a hip fracture or dislocation;
          - do not order a frog leg lateral in any patient suspected of having a hip fracture or dislocation)
          - patient is supine; the opposite hip is flexed and abducted;
          - cassette is placed against the lateral aspect of the affected hip;
          - central beam is directed horizontally toward the groin with about 20 degree of cephalic tilt;
    - frogleg lateral view:
          - do not order a frog leg lateral in any patient suspected of having hip fracture or dislocation);
          - patient is supine w/ knees flexed, soles of feet together, and the thighs maximally abducted;
          - central beam is directed vertically or with a 10 to 15 deg cephalic tilt to a point slightly above pubic symphysis;

         

Radiographic Processing

• Correct processing of radiographs is a key factor in good radiography. Correct processing is not an expensive procedure; however an understanding of basic fundamentals and needs is required to avoid unnecessary that might destroy the detail of a radiograph. The first consideration will be x-ray film and its processing.

• The latent image produced when a radiographic film is exposed to a beam of X-ray can be visualized and examined only after the film has been suitably processed in the dark room .

• However, the most detailed and careful radiographic technique in the X-ray room can be wasted unless it is matched by similar high standards in the dark room. It is essential that the dark room should be suitably maintained and used. 

• The exposed film is removed from the cassette in a safely lighted dark room and placed in stainless steel processing frame. It is then immersed in a tank of developer which completes the reduction of the exposed grains of silver halide, and makes the image visible.

• After a specified time the film is taken out of the developer, rinsed in water and then immersed in the fixer bath. This solution removes the undeveloped emulsion.

• The image can be inspected in white light. after 10 minutes in the fixer bath the film is washed in running water for half an hou, to remove the processing chemicals and then hung up to dry.

 Details of radiographic processing:

Storing unexposed x-ray film it should be stored in cool dry place protected from radiation in upright position.

Loading the X-ray film

• The X-ray film should be correctly positioned within the cassette by touching only the corners.

• The central portion should never be touched. Then the cassette should be closed and locked.

Storing x-ray cassettes

• Loaded x-ray cassettes should be stored in an upright position in cool dry place within the dark room.

Removing the x-ray film from the cassette

• The processing room should be darkened except for the safe light. Great care must be taken in removing the x-ray film from the cassette to prevent damage of the intensifying screens. The workers fingers should not touch the screens of the cassette. Rubbing the film across the end of the cassette must be avoided to avoided black pressure scratches on the developed radiograph.

Developing X-Ray Film

• The processing solutions should be stirred before processing the film. The x-ray film should be placed in the developing solution and agitated briefly to remove any air bubbles.

• It should be left in the developer for five minutes, if the tem­perature is 68° F. If the temperature varies from 68° F the developing time should be varied accordingly. Below 60° F, developing chemical are quite sluggish casing under development and inadequate fixation.

• A bone 75°f developing chemical work too rapidly causing fogging and too much softening the emulsion chemicals.

 Time-Temperature Variations for Film Developing

Temperature degrees	60	62	64	66	68	70	72	74	76
Time in minutes	9	7^1/2	6^1/2	5^1/2	5	4	3^1/2	3^1/4	3

• The developing chemicals reduce the exposed silver halides in the emulsion to me­tallic silver, which is black. The increase in intensity of light from the intensifying screens causes more of the silver halides to turn to metallic silver, thus giving the various shades of gray and black on the developed radio­graph.

• Two forms of developing chemicals are used, one a liquid and the other a powder. Liquid chemicals are more convenient, the powder variety may disseminate powder dust throughout the room.

• The developing solution should be tightly covered when not in use to reduce oxida­tion. The solution should be discarded and replaced after three months of use because oxidation and accumulation of gelatin sludge and other impurities will cause poor development. A more practical method of determining it the developing solution should be discarded is to notice the color. As the solution weakens it first turns yellow, then brown. When it turns brown, indicating exhaustion, it should be replaced.

• X-ray film should be quickly removed from the developer and, in one motion placed into the post-developer water rinse. The developing solution should not be allowed to drip from the film back into the developer tank. The developing solution on the film will be nearly exhausted and a certain amount of developer should be removed each time to reduce the level so that developer replenisher solution may be added periodically. This keeps the developer at the proper level and at the correct chemical strength.

• Reloading the Cassette:

• During the time that the x-ray film is in the developer the cassettes should be reloaded as previously described.

• Post-development Rinse

• The post-development rinse, which ordinarily will take 30 seconds, should be circulating clean water. The rinsing process can be shortened by continually agitating the film. After the rinse is completed the film should be drained to prevent excess dilution of the fixer.

• Clearing and fixing X-ray Film

•  After its removal from the rinse, x-ray film should be placed in the fixing solution and agitated for 15 seconds. This helps prevent streaking and staining of the finished radiograph and hastens the fixation process.

• The temperature range for fixation should be the same as that for development, with 68° F optimum. The developing and fixing solutions should have the same tempera­tures to avoid unevenness of development and reticulation of the final radiograph.

• Final Washing of the Radiograph

• Adequate washing prevents discoloration it should be performed in running water at 68 F. washing for 20 minutes is adequate.

•  Drying the radiograph

• The radiograph may be dried in open air or in an automatically heated, circulating air dryer fresh fixer solution hastens drying. If temperature of fixation is above 75^o F, drying time will he markedly slower due to swelling of the emulsion.

• Storing Radiographs: 

• Processed radiographs should have the corners cut off and be placed in a properly labeled envelope. The envelope should be stored in an up­right position in a storage bin. A numbering system should be used so that radiographs can be easily found.

• Automatic processing

• Reliable short time automatic processors are available. It should be 90-seconds processor because the reliability and reproducibility is as good as these for the slower processors.

• Where large number of radiographs have to be handled, automatic processing reduces the time and labor needed and results in a consistent end product . However, the cost of the initial equipment, of maintenance and the increased amount of chemicals required would seldom justify its use in veterinary practice.

•  Hanging x-ray film

• X- ray film should be grasped only at the corners and inserted into the clips of the film hangers and locked in place. The upper corner of the film grasped and a Hached to the top clips. The film now ready to be placed in the developing tank.

• The clips of the film hanger should be cleaned periodically to prevent an accumulation of chemicals that may rundown on the film during processing and cause streaks.    

• Manufacturers specify the correct type.

• Two forms of safe-light can be used in the radiographic dark room.

• Direct: a diffused light shines directly over the work point, such as the dry and wet bench.

• Indirect: the filtered light is directed up to the ceiling where it is reflected over the room.

• Safe-light efficiency: Safe-lights should be placed so that the work of the dark room can be done without fumbling . where the dry and wet benches are separate , a small direct wall light should be provided for each.

Dark Room Equipments

Film cassettes:

• A cassette is alight-tight metal container which is designed to hold the x-ray film and intensifying screens in close contact.

• The front face which is of aluminum or plastic, faces the tube while the other side have a sheet of lead to absorbed back-scatter screens and cassettes are of course made in various sizes to correspond with standard film sizes.

Mounting intensifying screens in the cassette

• Intensifying screens should be never be loose but must be properly mounted into the cassette.

• Because certain adhesives interact with the screens it is advisable to use only the double-sided tape provided by the manufacturers.

The care of cassettes

• Do not drop them on a hard floor

• Do not trap the edges of the screens when the cassette is closed

• Cassettes should be kept clean and there is always the danger of blood or urine leaking to the inside of the cassette. When a cassette must be placed in a dirty situation put it in a plastic bag.

 Check for contrast

• Good contrast between screens and the film in the cassette is vitally important. If radiographs should areas with loss definition, check the cassette.

Dry Bench

• The dry bench is where the cassette are unloaded and recharged with fresh film. It must be impossible for splashes of developer to reach the dry bench surface.

• The top of the dry bench must be large enough to accommodate the largest cassette in use when opened out.

• The top surface should be either of wood or linoleum. Plastic laminates are not recommended because they hold static charges of electricity which can cause marks on films.

• It is usual to store film boxes, especially those in current use , beneath the dry bench , either in a cupboard ( protected if near an X-ray set ) or in a film hopper.

• The processing frames should hang above the bench , cash size on its appropriate. There are two designs of processing frame– the channel type and the clip type.

Wet Bench

• The wet bench is where the processing of the films is carried out . It is possible to process the individual films in flat dishes but the method has a number of disadvantages and is not be recommended.

• The usual method is to use a set of  tanks holding developer ,rinse water and fixer , and a larger tank for washing the films.

Heaters

• Standardized processing requires the developer to be at the optimum temperature of 20c (68 f).

• The heater is put into the developer and the current switched on. On an average, the temperature will be raised by 1 degree per minute. In very cold weather it is also desirable to heat the fixer.

Washing Tank

• The washing tank should be at least four times larger than the developer tank, with a supply of cold water constantly circulating through it, via a rubber hose, when films are being washed.

 Drying

• Films can be dried by removing them from the channel hanger, attaching a film clip, and hanging on a tensioned wire strung up in a dust-ree place.

Safe-lighting

• X-ray film before processing is sensitive to white light; it must only be handled under safe-lighting.

• A safe-light is a box containing a low wattage bulb behind a specified filter. This is a sheet of dyed gelatin between glass.

Two forms of safe light can be used in the radiographic dark room:

• Direct: A diffuse light shines direct over the work point such as the dry and wet bench.

• Indirect: the filtered light is directed up to the ceiling where it is reflected over the room.

Safe light efficiency

• Safe light should be placed so that the work of the dark room can be done without fumbling. Where the dry and wet benches are separate, a small direct wall light should be provided for each.

 Processing room and equipment

•  A radiographic processing room must capable of being made completely dark. The room must be kept clean and it should not be used for other purposes. A red, orange or yellow safe light may be used.

• The arrangement of the dark room should provide easy accessibility during processing a bench for loading and unloading cassettes should be placed at one side of the room and the processing tanks at the opposite side the bench should be some distance from the processing tanks.

• Immediately above or below the bench there should be space for storing film hangers. Unexposed x-ray film and cassettes should be stored in a cool dry place such as the processing room.

• The processing equipment include a developing tank of sufficient size to contain a 14x17 inch x-ray film an  intermediate wash tank and  a fixer tank.

• Processing tanks should be cleaned periodically, usually at every changes of solution. Sodium hypochlorite (Clorox) diluted in 4 parts of water is recommended for stainless-steel and hard-rubber tanks. These tanks should be scrubbed with a fiber brush.

Dark Room Layout

• The latent image produced when a radiographic film is exposed to a beam of X-ray can be visualized and examined only after the film has been suitably processed in the dark room. However, the most detailed and careful radiographic technique in the X-ray room can be wasted unless it is matched by similar high standard in the dark room.

• It is essential that the dark room should be suitably constructed and that the processing solutions should be suitable maintained and used.

• A room should be set aside as a permanent dark room, ideally with a floor area of not less than 8X6 ft (2.6 X  2 m). Although individual circumstances must dictate where a dark room is to be sited, the following points might be borne in mind:

• The room must be capable of being made completely lightproof.

• It should not be damp or subjected to extreme of temperature.

• Water and electrical outlets should be provided.

• A room should be set aside as a permanent dark room with sufficient space to accommodate a dry bench (3 x 2), a wet bench and a sink.

• Too large room is as undesirable as small room.

• Dark room should be near the x-ray examination area.

• The room must be capable of being made completely light proof to avoid film fog and  should be well ventilated.

• The wall should be constructed of solid concrete (15 cm thick), have a lead box inside to store boxes of unexposed films currently in use.

• Sufficient running water and electrical outlet should be provided

• The walls and roof should be painted by white or cream enamel as such a paint acts as a good reflecting surface fore safe light.

• X-ray rotating warning light in hallway switched "on" signaling that x-ray machine is operating.

 

Radiologic Anatomy Review Images 2

Lumbar/Sacral Spine AP	Lumbar/Sacral Spine AP	Thoracic/Lumbar Spine Oblique	Spine
Chest AP	Thorax	Neck Spine Lateral	Neck Spine PA
Upper Extremity	Hand/Wrist	Hand Arteriogram	Forearm/Wrist Lateral Oblique
Forearm Arteriogram	Elbow, Lateral	Elbow PA	Elbow AP
Thorax/Manubrium	Thorax/Aortic Arch	Computerized Tomograms (CT's)	Shoulder AP
Thorax/Great Vessels and Bronchi	Heart	Abdomen/Crura and Spleen	Abdomen/Coeliac Axis
Thorax/Pulmonary Trunk	Root of Neck	Thoracic Inlet	Superior Mediastinum

 

Radiologic Anatomy Review Images 1

Scoliosis

Scoliosis occurs relatively frequently in the general population, and its frequency depends upon the magnitude of the curve being described. Scoliosis of greater than 25 degrees has been reported in about 1.5/1000 persons in the United States. Most curves can be treated nonoperatively if they are detected before they become too severe. However, 60 % of curvatures in rapidly growing prepubertal children will progress. Therefore, scoliosis screening is done in schools across America and several other countries. This screening is probably not necessary until the fifth grade. Beyond that point, boys and girls should be examined every 6 - 9 months. Generally, curvatures less than 30 degrees will not progress after the child is skeletally mature. Once this has been established, scoliosis screening and monitoring can usually be stopped. However, with greater curvatures, the curvature may progress at about 1 degree per year in adults. In this population, monitoring should be continued.

patient with thoracic scoliosis, convex to the right, bridged by a Harrington rod and bone graft along the concave side of the spine

If scoliosis is neglected, the curves may progress dramatically, creating significant physical deformity and even cardiopulmonary problems with especially severe curves. Currently, scoliosis is treated successfully by special braces, electrical stimulation, surgery, or by combinations of these three techniques.

Generally, scoliosis is treated by orthopedic surgeons with special training in spinal problems. However, radiographic scoliosis examinations are ordered by a wide variety of other physicians, most of whom look toward the radiologist as the local musculoskeletal expert, after the orthopedist. Therefore, one must know how to read these films and how to dictate a coherent and helpful interpretation of them.

A sample dictation of a typical examination is shown below:

Standing AP and lateral views of the entire spine demonstrate an arcuate thoracolumbar scoliosis with a rightward convexity. No associated vertebral abnormalities are noted. Using the Cobb technique, and measuring from the top of the T9 and the bottom of the L3 vertebral bodies, this angle measures approximately 27 degrees. The apex of the curve is at the T12 vertebral body and demonstrates grade 3 out of 4 rotation to the right. Lateral bending films show persistence of the curvature with bending to the right and increased curvature with bending to the left. This indicates that the thoracolumbar curve is structural and major. The iliac apophyses are complete along the iliac crests, but have not yet fused with the ilium, indicating that the patient has not yet reached skeletal maturity.

The remainder of this chapter will discuss the rationale behind each of the parts of this sample dictation.

The normal thoracolumbar spine is relatively straight in the sagittal plane and has a double curve in the coronal plane. As shown below, the thoracic spine in convex posteriorly (kyphosis) and the lumbar spine is convex anteriorly (lordosis). Normally there should be no lateral curvature of the spine.

normal spine demonstrating the normal thoracic kyphosis and lumbar lordosis

Scoliosis is a complicated deformity that is characterized by both lateral curvature and vertebral rotation. As the disease progresses, the vertebrae and spinous processes in the area of the major curve rotate toward the concavity of the curve. On the concave side of the curve, the ribs are close together. On the convex side, they are widely separated.

As the vertebral bodies rotate, the spinous processes deviate more and more to the concave side and the ribs follow the rotation of the vertebrae. The posterior ribs on the convex side are pushed posteriorly, causing the characteristic rib hump seen in thoracic scoliosis. The anterior ribs on the concave side are pushed anteriorly.

typical distortion of vertebra and ribs in thoracic scoliosis as seen from below

Scoliosis also causes pathologic changes in the vertebral bodies and intervertebral discs, as shown below.

coronal view of a scoliotic spine: the vertebrae and intervertebral discs are decreased in height on the concave side

Scoliosis has many causes, and a brief differential diagnosis is listed in the outline below:

Classification of scoliosis

• Nonstructural scoliosis
  • postural scoliosis
  • compensatory scoliosis

• Transient structural scoliosis
  • sciatic scoliosis
  • hysterical scoliosis>
  • inflammatory scoliosis

• Structural scoliosis
  • idiopathic (70 - 80 % of all cases)
  • congenital
  • neuromuscular
    • poliomyelitis
    • cerebral palsy
    • syringomyelia
    • muscular dystrophy
    • amyotonia congenita
    • Friedreich's ataxia
  • neurofibromatosis
  • mesenchymal disorders
    • Marfan's syndrome
    • Morquio's syndrome
    • rheumatoid arthritis
    • osteogenesis imperfecta
    • certain dwarves
  • trauma
    • fractures
    • irradiation
    • surgery

Idiopathic genetic scoliosis accounts for about 80 % of all cases of the disorder, and has a strong female predilection (7:1). It can be subclassified into infantile, juvenile and adolescent types, depending upon the age of onset. The most common of these is adolescent scoliosis, which by itself is by far the most common type of idiopathic scoliosis in the United States.

Scoliosis can result from congenital vertebral anomalies, as shown below. Discovery of these anomalies should prompt a workup for other associated cardiac, genitourinary or vertebral anomalies.

vertebral anomalies causing scoliosis

Other causes of scoliosis are occasionally seen, especially due to trauma, neurofibromatosis or associated with one of the neuromuscular disorders.

Radiographic assessment of the scoliosis patient

The radiographic assessment of the scoliosis patient begins with erect anteroposterior and lateral views of the entire spine (occiput to sacrum). In addition, the examination should include a lateral view of the lumbar spine to look for the presence of spondylolysis or spondylolisthesis (prevalence in the general population is about 5 %). The scoliotic curve is then measured from the AP view. The most commonly used method (used by the Scoliosis Research Society, the U. S. Air Force, and everyone I've ever worked with) is the Cobb method. The Cobb method has several advantages over other methods, including the fact that it is more likely to be consistent even when the patient is measured by several different examiners. An alternative system, known as the Risser-Ferguson method, is used far less commonly.

One must first determine what type of curvature is present. The curvature may be acute, such as seen with a fracture or hemivertebra. More often, it is smooth and arcuate, as shown below. The presence of any vertebral or rib anomalies should be reported. Scoliosis is generally described as to the location of the curve or curves, as shown below.

patterns of scoliosis

One should also describe whether the convexity of the curve points to the right or left. If there is a double curve, each curve must be described and measured.

To use the Cobb method, one must first decide which vertebrae are the end-vertebrae of the curve. These end-vertebrae are the vertebrae at the upper and lower limits of the curve which tilt most severely toward the concavity of the curve. Once these vertebrae have been selected, one then draws a line along the upper endplate of the upper body and along the lower endplate of the lower body as shown below.

Cobb method for measurement of scoliosis

If the endplates cannot be easily seen, these lines can be drawn along the top or bottom or the pedicles. The angle of interest is simply the angle between these two lines. However, with minor degrees of scoliosis, these two lines will probably intersect off the film somewhere, like downtown Seattle. Therefore, a useful theorem from high school geometry is used to help measure this angle. If one constructs perpendicular lines to these first two lines, these perpendicular lines will intersect on the film and will have the same angle between them as exists between the first two lines. When reporting this angle, it is important to mention that one is using the Cobb method and also which end vertebrae were chosen for the measurement. This latter data is especially important, since once chosen, the same levels should be used from then on to measure curvature on follow-up films. This information should be in the radiographic report, since it becomes part of the patient's chart and therefore lasts far longer than the radiographs, which are often recycled after 5 years or so.

Once one has measured the angle of curvature, one may then estimate the degree of rotation of the vertebra at the apex of the curve by looking at the relation of the pedicles to midline.

measurement of rotational component of scoliosis

Prior to surgery, a set of lateral bending films are often taken to assess the rigidity or flexibility of the curves. In the illustration below, the thoracic curve is the major curve and the lumbar curve is simply a compensatory curvature. This is shown by the lateral bending films.

bending films may help to differentiate structural from nonstructural curves

A further goal of the radiographic examination is to determine the physiological or skeletal maturity of the patient. As mentioned above, once skeletal maturity has been reached, curvature below 30 degrees do not progress. Therefore, one may at this time consider discontinuing followup examinations in this population, and scoliosis screening in the general population of children.

Several methods can be used to estimate skeletal maturity. A single AP view of the left hand and wrist can be compared to standards in the Greulich and Pyle hand atlas. Since the iliac crests are usually present on a scoliosis study, they provide a convenient index of skeletal maturity. When the iliac crest apophyses meet the sacroiliac junction and firmly seal to the ilium, maturation is nearly complete.

determination of skeletal maturity

One can also look for evidence of maturation in the vertebral bodies themselves at the endplates, as shown below. When the plates blend in with the vertebral bodies to form a solid union, maturation is complete.

determination of vertebral maturity

Intravenous Pyelogram

What is an Intravenous Pyelogram (IVP)?

An intravenous pyelogram (IVP) is an x-ray examination of the kidneys, ureters and urinary bladder that uses contrast material.

An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.

When a contrast material is injected into the patient's arm, it travels through the blood stream and collects in the kidneys and urinary tract, turning these areas bright white. An IVP allows the radiologist to view and assess the anatomy and function of the kidneys and lower urinary tract.

What are some common uses of IVP studies?

An intravenous pyelogram examination helps the physician assess abnormalities in the urinary system, as well as how quickly and efficiently the patient's system is able to handle waste.

The exam is used to help diagnose symptoms such as blood in the urine or pain in the side or lower back.

The IVP exam can enable the radiologist to detect problems within the urinary tract resulting from:

• kidney stones
• enlarged prostate
• tumors in the kidney, ureters or urinary bladder.

How should I prepare for the procedure?

Your doctor will give you detailed instructions on how to prepare for your IVP study.

You will likely be instructed not to eat or drink after midnight on the night before your exam. You may also be asked to take a mild laxative (in either pill or liquid form) the evening before the procedure.

You should inform your physician of any medications you are taking and if you have any allergies, especially to contrast material. Also inform your doctor about recent illnesses or other medical conditions.

You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy because radiation can be harmful to the fetus. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.

What does the x-ray equipment look like?

The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room or in a nearby room. When used for viewing images in real time (called fluoroscopy), the image intensifier (which converts x-rays into a video image) is suspended over a table on which the patient lies. When used for taking still pictures, a drawer under the table holds the x-ray film or image recording plate that captures the images.

How does the procedure work?

X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special image recording plate.

Fluoroscopy uses a continuous x-ray beam to create a sequence of images that are projected onto a fluorescent screen, or television-like monitor. When used with a contrast material, which clearly defines the area being examined by making it appear bright white, this special x-ray technique makes it possible for the physician to view internal organs in motion. Still images are also captured and stored either on film or electronically on a computer.

In the IVP exam, iodine injected through a vein in the arm collects in the kidneys, ureters and bladder, giving these areas a bright white and sharply defined appearance on the x-ray images.

X-ray images are maintained as hard film copy (much like a photographic negative) or, more likely, as a digital image that is stored electronically. These stored images are easily accessible and are sometimes compared to current x-ray images for diagnosis and disease management.

How is the procedure performed?

This examination is usually done on an outpatient basis.

The patient is positioned on the table and still x-ray images are taken. The contrast material is then injected, usually in a vein in the patient's arm, followed by additional still images.

The patient must hold very still and may be asked to keep from breathing for a few seconds while the x-ray picture is taken to reduce the possibility of a blurred image. The technologist will walk behind a wall or into the next room to activate the x-ray machine.

As the contrast material is processed by the kidneys a series of images is taken to determine the actual size of the kidneys and to capture the urinary tract in action as it begins to empty. The technologist may apply a compression band around the body to better visualize the urinary structures leading from the kidney.

When the examination is complete, the patient will be asked to wait until the technologist determines that the images are of high enough quality for the radiologist to read.

An IVP study is usually completed within an hour. However, because some kidneys empty at a slower rate the exam may last up to four hours.

What will I experience during and after the procedure?

The IVP is a painless procedure.

You will feel a minor sting as the iodine is injected into your arm. Some patients experience a flush of warmth, a mild itching sensation and a metallic taste in their mouth as the iodine begins to circulate throughout their body. These common side effects usually disappear within a minute or two and are harmless. Itching that persists or is accompanied by hives, can be easily treated with medication. In rare cases, a patient may become short of breath or experience swelling in the throat or other parts of the body. These can be indications of a more serious reaction to the contrast material that should be treated promptly. Tell the radiologist immediately if you experience these symptoms.

During the imaging process, you may be asked to turn from side to side and to hold several different positions to enable the radiologist to capture views from several angles. Near the end of the exam, you may be asked to empty your bladder so that an additional x-ray can be taken of your urinary bladder after it empties.

The contrast material used for IVP studies will not discolor your urine or cause any discomfort when you urinate. If you experience such symptoms after your IVP exam, you should let your doctor know immediately.

Who interprets the results and how do I get them?

A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you.

What are the benefits vs. risks?

Benefits

• Imaging of the urinary tract with IVP is a minimally invasive procedure with rare complications.
• IVP images provide valuable, detailed information to assist physicians in diagnosing and treating urinary tract conditions from kidney stones to cancer.
• An IVP can often provide enough information about kidney stones and obstructions to direct treatment with medication and avoid more invasive surgical procedures.
• The imaging process is fast, painless and less expensive than alternatives such as computed tomography (CT) and magnetic resonance imaging (MRI).
• No radiation remains in a patient's body after an x-ray examination.
• X-rays usually have no side effects.

Risks

• There is always a slight chance of cancer from radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
• The effective radiation dose from this procedure is about 1.6 mSv, which is about the same as the average person receives from background radiation in six months. See the Safety page for more information about radiation dose.
• Contrast materials used in IVP studies can cause adverse reactions in some people.
• Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

A Word About Minimizing Radiation Exposure

Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.

State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures those parts of a patient's body not being imaged receive minimal radiation exposure.

What are the limitations of IVP studies?

An IVP shows details of the inside of the urinary tract including the kidneys, ureters and bladder. Computed tomography (CT) or magnetic resonance imaging (MRI) may add valuable information about the functioning tissue of the kidneys and surrounding structures nearby the kidneys, ureters and bladder.

IVP studies are not usually indicated for pregnant women.

Myelography

What is Myelography?

Myelography is an imaging examination that shows the passage of contrast material in the space around the spinal cord (the subarachnoid space) using a real-time form of x-ray (radiography) called fluoroscopy, in which organs can be seen over many seconds (rather than in the static image called an x-ray or radiograph).

An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.

Fluoroscopy makes it possible to see internal organs in motion. When the contrast material is injected into the subarachnoid space, the radiologist is able to view and evaluate the status of the spinal cord, nerve roots, and intervertebral disks. By this means, myelography provides a very detailed picture (myelogram) of the spinal cord and spinal column. The radiologist views the passage of contrast material as it is flowing using fluoroscopy but also takes permanent static (unmoving) pictures, called x-rays or radiographs, of the contrast material around the spinal cord and nerve roots in order to document abnormalities. In most cases, the myelogram is followed by a computed tomography (CT) scan to better define abnormalities.

What are some common uses of the procedure?

Magnetic resonance imaging (MRI) is often the first imaging exam done to evaluate the spinal cord and nerve roots. However, on occasion, a patient has medical devices, such as a cardiac pacemaker, that prevent him or her from undergoing MRI. Sometimes, myelography is performed in conjunction with MRI to better define abnormalities.

Myelography is most commonly used to detect abnormalities of the spinal cord, the spinal canal, the spinal nerve roots and the blood vessels that supply the spinal cord, including:

• to show whether herniations of the material between the vertebral bodies, termed the intervertebral disks, are pushing on nerve roots or the spinal cord.
• to depict a condition that often accompanies degeneration of the bones and soft tissues surrounding the spinal canal, termed spinal stenosis. In this condition, the spinal canal narrows as the surrounding tissues enlarge due to the development of bony spurs (osteophytes) and the adjacent ligaments.

Myelography can also be used to assess the following conditions when MR imaging cannot be performed, or in addition to MRI:

• tumors
• infection
• inflammation of the arachnoid membrane that covers the spinal cord
• spinal lesions caused by disease or trauma

A myelogram can show whether surgical treatment is promising in a given case and, if it is, can help in planning surgery.

How should I prepare for the procedure?

Your physician will give you detailed instructions on how to prepare for your myelogram.

You should inform your physician of any medications you are taking and if you have any allergies, especially to contrast material. Also inform your doctor about recent illnesses or other medical conditions.

Specifically, the physician needs to know if (1) you are taking medications that need to be stopped a few days before the procedure and (2) if you have a history of contrast reaction to the contrast material used for the myelogram.

Some drugs should be stopped one or two days before myelography. They include certain antipsychotic medications, antidepressants, blood thinners, and drugs—especially metformin—that are used to treat diabetes. However, the most important medication that must be stopped is blood thinners (anticoagulants). If you are taking blood thinners, you should speak with your physician about alternative methods of maintaining anticoagulation while you are undergoing a myelogram. At times, that procedure entails taking intravenous blood thinners such as heparin and stopping the intravenous infusion a few hours before undergoing the myelogram.

Many drugs used to treat seizures are not indicated before a myelogram. Therefore, it is also important that medical staff know in advance if you have a seizure disorder and they can help you plan to stop taking the seizure medications a few days before the myelogram. Although reactions to the contrast material used in the myelogram are extremely uncommon, you should inform your physician if you have had a severe allergic reaction to contrast material or medication. In addition, please mention if you have any allergies to other, non-medical, substances or have a history of asthma. In those instances, you will be watched especially carefully to check for a reaction when injecting the contrast material. Allergy to iodine-containing substances can be especially risky. Usually patients are advised to increase their fluid intake the day before a scheduled myelogram, as it is important to be well hydrated. Solid foods are avoided for several hours before the exam, but fluids may be continued.

You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy because radiation can be harmful to the fetus. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.

Unless you are to spend the night in hospital, you should arrange to have a relative or friend take you home.

What does the equipment look like?

The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room or in a nearby room. When used for viewing images in real time (called fluoroscopy), the image intensifier (which converts x-rays into a video image) is suspended over a table on which the patient lies. When used for taking still pictures, a drawer under the table holds the x-ray film or image recording plate that captures the images.

How does the procedure work?

X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special image recording plate.

Fluoroscopy uses a continuous x-ray beam to create a sequence of images that are projected onto a fluorescent screen, or television-like monitor. When used with a contrast material, which clearly defines the area being examined by making it appear bright white, this special x-ray technique makes it possible for the physician to view internal organs in motion. Still images are also captured and stored either on film or electronically on a computer.

X-ray images are maintained as hard film copy (much like a photographic negative) or, more likely, as a digital image that is stored electronically. These stored images are easily accessible and are sometimes compared to current x-ray images for diagnosis and disease management.

How is the procedure performed?

This examination is usually done on an outpatient basis.

As the patient lies face-down on the examination table, the radiologist will use the fluoroscope, which projects radiographic images in a movie-like sequence onto a monitor, to visualize the spine and determine the best place to inject the contrast material.

The contrast material usually is injected into the lower lumbar spine, because it is considered easier and safer. Occasionally, if it is deemed safer or more useful, the contrast material will be injected into the upper cervical spine.

At the site of the injection, the skin will be cleaned and numbed with a local anesthetic. Depending on the location of the puncture, the patient will be positioned on their side, on their abdomen, or in a sitting position as the needle is inserted. In some cases, patients will be placed in a sitting position. If needed, a small amount of cerebrospinal fluid will be withdrawn for laboratory studies. The contrast material is then injected and the x-ray table is slowly tilted so that contrast material will run up and down the spine and surround the nerve roots that are next to the spinal cord.

The radiologist will monitor the flow of contrast with fluoroscopy, focusing on the area of the patient’s symptoms. At this point, additional x-ray images will be taken by the technologist; it is important to remain still to reduce the possibility of blurred images.

A computed tomography (CT) scan is frequently performed immediately after myelography while contrast material is still present in the spinal canal. This combination of imaging studies is known as CT myelography.

A myelography examination is usually completed within 30 to 60 minutes. A CT scan will add another 30-60 minutes to the total examination time.

What will I experience during and after the procedure?

You will feel a brief sting when local anesthetic is injected, and slight pressure as the spinal needle is inserted. Positioning the needle can occasionally cause a sharp pain.

During the exam, you will be asked to lay as still as possible while the table is tilted at different angles. A foot rest and straps or supports will keep you from sliding out of position. You may find the face-down position uncomfortable or that it causes you difficulty breathing deeply or swallowing. However, you should not have to maintain this position for very long.

Rarely, headache, flushing, or nausea may follow contrast injection. Seizures are possible, but also are rare.

Some facilities have patients stay in a recovery area resting with the head elevated at a 30° to 45° angle for as long as four hours. You may be encouraged to take fluids at this time to help eliminate contrast material from your body and to prevent headache.

Following your myelogram, you should refrain from strenuous physical activity and from bending over for one to two days.

You should notify your health professional if you experience fever higher than 100.4°F, excessive nausea or vomiting, severe headache for more than 24 hours, neck stiffness, or numbness in your legs. You should also report if you have trouble urinating or moving your bowels.

Who interprets the results and how do I get them?

A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you.

What are the benefits vs. risks?

Benefits

• Myelography is relatively safe and painless.
• When a contrast material is injected into the space surrounding the spinal cord, it allows the radiologist to view outlines of the different areas of the spine that usually are not visible or distinguishable on x-rays.
• No radiation remains in a patient's body after an x-ray examination.
• X-rays usually have no side effects.

Risks

• There is always a slight chance of cancer from radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
• The effective radiation dose from this procedure is about 4 mSv, which is about the same as the average person receives from background radiation in 16 months. See the Safety page for more information about radiation dose.
• Although it is uncommon, headache due to the needle puncture following myelography is one risk. The headache, when it occurs, usually begins when the patient begins to sit upright or stand. One of the common features of this type of headache is that it is improved when the patient lays flat. When present, the headache usually begins within 2-3 days after the procedure. Rest while laying on one’s back and increased fluid intake readily relieve mild headaches, but more severe headaches may call for medication. In rare circumstances some patients continue to experience spinal headaches, which may necessitate a special procedure to stop leakage of cerebrospinal fluid from the puncture site.
• Adverse reactions to injection of contrast material during a myelogram are infrequent and usually mild in nature, including itching, rash, sneezing, nausea, or anxiety. The development of hives or wheezing may require treatment with medication. More severe reactions involving the heart or lungs are rare.
• Other rare complications of myelography include nerve injury from the spinal needle and bleeding around the nerve roots as they enter or exit the spinal cord. In addition, the membrane covering the spinal cord may become inflamed or infected. Seizures are a very uncommon complication of myelography.
• There is a very small risk that contrast material will block the spinal canal, which can make surgery necessary.
• Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

A Word About Minimizing Radiation Exposure

Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.

State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures those parts of a patient's body not being imaged receive minimal radiation exposure.

What are the limitations of Myelography?

• The most significant limitation of myelography is that it only sees inside the spinal canal and the very proximal nerve roots. Abnormalities outside these areas may be better imaged with MRI.
• Myelography usually is avoided during pregnancy because of the potential risk to the baby.
• The findings may not be accurate if the patient moves during the exam.
• It may be difficult to inject contrast material in patients with structural defects of the spine or some forms of spinal injury.
• Myelography cannot be done if the injection site is infected.

Brain Tumors

Brain Tumors Overview

A brain tumor is a group of abnormal cells that grows in or around the brain. Tumors can directly destroy healthy brain cells. They can also indirectly damage healthy cells by crowding other parts of the brain and causing inflammation, brain swelling and pressure within the skull.

Brain tumors are either malignant or benign. A malignant tumor, also called brain cancer, grows rapidly and often invades or crowds healthy areas of the brain. Benign brain tumors do not contain cancer cells. They look normal under a microscope and are usually slow growing.

Brain tumors fall into two different categories: primary or metastatic. Primary brain tumors begin within the brain. A metastatic tumor is formed when cancer cells located elsewhere in the body break away and travel to the brain. For this reason, metastatic brain tumors are always malignant, while primary brain tumors may be benign or malignant.

Brain tumors are classified based on where the tumor is located, the type of tissue involved, whether the tumor is benign or malignant, and other factors. If a tumor is determined malignant, the tumor cells are examined under a microscope to determine how malignant they are. Based on this analysis, tumors are rated, or graded, by their level of malignancy from least to most malignant. Factors that determine the tumor grade include how fast the cells are growing, how much blood is supplying the cells, the presence of dead cells in the middle of the tumor (necrosis), if the cells are confined to a specific area, and how similar the cancerous cells are to normal cells.

The cause of primary brain tumors is unknown. Environmental and genetic factors may cause some brain tumors. Symptoms of a brain tumor include headaches, nausea, vomiting, seizures, behavior changes, memory loss, and vision or hearing problems.

What are my treatment options?

A variety of therapies are used to treat brain tumors. The type of treatment recommended depends on the size and type of the tumor, its growth rate, and the general health of the patient. Treatment options include surgery, radiation therapy, and chemotherapy, or a combination of these. This Web site focuses on radiation therapy for brain tumors.

In the past two decades, researchers have developed new techniques of delivering radiation that target the brain tumor while protecting nearby healthy tissues. These treatments include brachytherapy, intensity-modulated radiation therapy (IMRT) and radiosurgery.

Radiation therapy may be advised for tumors that are sensitive to this treatment. Conventional radiation therapy uses external beams of x-rays, gamma rays, or protons aimed at the tumor to kill cancer cells and shrink brain tumors. The therapy is usually given over a period of several weeks. Whole brain radiation therapy is an option in the case of multiple tumors.

New types of radiation therapy include:

• Brachytherapy utilizes radioactive seeds, which the doctor implants directly into the tumor. See Brachytherapy page.
• Hyperfractionation involves smaller doses of radiation two to three times a day, as opposed to a larger amount once a day.
• Stereotactic radiosurgery is a highly precise form of radiation therapy that directs narrow beams of radiation to the tumor from different angles. For this procedure, the patient wears a rigid head frame. Computed tomography (CT) or magnetic resonance imaging (MRI) help the doctor identify the tumor's exact location and a computer helps the doctor regulate the dose of radiation. See Stereotactic radiosurgery page.
• Intensity-modulated radiation therapy (IMRT) is an advanced mode of high-precision radiotherapy that utilizes computer-controlled x-ray accelerators to deliver precise radiation doses to a malignant tumor or specific areas within the tumor. The radiation dose is designed to conform to the three-dimensional (3-D) shape of the tumor by modulating—or controlling—the intensity of the radiation beam to focus a higher radiation dose to the tumor while minimizing radiation exposure to healthy cells. See IMRT page.

Surgery, also called surgical resection, is often indicated for primary brain tumors. A surgeon removes some or the entire tumor without causing severe damage to surrounding tissues. Surgery may also be used to reduce pressure within the skull (called intracranial pressure) and to relieve symptoms (called palliative treatment) in cases when the tumor cannot be removed.

Chemotherapy, or anticancer medications, may be recommended. The use of these drugs or chemicals to slow down or kill rapidly dividing cells can be used before, during, or after surgery to help destroy tumor cells and to prevent them from returning. Chemotherapy drugs may be taken by pill or by injection and are often used in combination. Drugs called radiosensitizers, which are believed to make radiation therapy more effective, may also be prescribed.

What happens during radiation therapy?

For conventional radiation therapy, your initial visit with the radiation oncologist is called a consultation. During this visit, the physician will review the history of your illness and perform a physical examination. Consultations with other members of your treatment team may also take place at this time.

After you and your physician(s) have decided on a course of treatment, you will begin the first phase—treatment planning. During this planning phase of your treatment, a radiation oncologist—a physician who specializes in radiation therapy—will simulate your radiation therapy treatment using either conventional radiographs (x-rays) or a computed tomography (CT) scan. These radiographic studies are used to plan the type and direction of radiation beams used to treat the cancer.

You will be asked to lie quietly on the treatment table during simulation, although no radiation therapy will be given at that point. Typically, treatment begins one to two days after your treatment planning session.

During your actual radiation therapy treatment, you will be asked to lie on the treatment table without moving. A radiation technologist will administer the treatment prescribed by the radiation oncologist. The treatment will last only a few minutes, and you will not feel anything. If you undergo stereotactic radiosurgery, you will wear a rigid head frame. In this procedure, a computed tomography (CT) scan or magnetic resonance imaging (MRI) will be used to help the doctor identify the tumor's exact location and a computer will regulate the dose of radiation as needed.

Treatment planning sessions and your first radiation therapy treatments may take an hour or two. Thereafter, treatments will usually last a few minutes and you will be in and out of the radiation department in 30 to 45 minutes for each session. Typically, treatments are given once or twice a day, five days a week for five to seven weeks.

For more information about specific radiation therapy procedures and equipment, visit the following pages:

• Brachytherapy
• Stereotactic Radiosurgery
• External Beam Therapy
• Intensity-Modulated Radiation Therapy
• Linear Accelerator
• Gamma Knife

What are possible side effects of radiation therapy?

The side effects of radiation therapy to the brain may not occur until two weeks after the start of your therapy. Many people experience hair loss but the amount varies from person to person. Hair usually grows back once therapy is finished.

The second most frequently reported side effect is a skin irritation. The skin around your ears and scalp may become dry, red or tender. It is important not to attempt to treat this side effect on your own, but rather to seek medical treatment as soon as it occurs. Fatigue is another possible side effect of radiation therapy. The best way to fight fatigue is to make sure to get adequate rest, eat a healthy diet, and rely on friends and family for support. Your normal energy levels should return about six weeks after you finish your therapy.

Edema, or swelling of the brain, is also prevalent among individuals undergoing radiation therapy to the brain. If you experience a headache or a feeling of pressure, report your symptoms to your oncologist. You may be prescribed medications to help reduce brain swelling, seizures or to control pain. When chemotherapy and radiation therapy are given at the same time, patients may experience more severe side effects. Your doctor can suggest ways to ease these uncomfortable symptoms.

Other possible side effects include:

• hearing problems
• nausea
• vomiting
• loss of appetite
• memory or speech problems
• headaches

What are some of the possible risks or complications?

Radiation is a powerful weapon against cancer cells, but sometimes it kills healthy brain tissue as well—a severe side effect called radiation necrosis. Necrosis can cause headaches, seizures, or even death in a small number of cases. However, the risk of necrosis has declined in recent years with the advent of the newer, targeted radiation therapies described above and the emergence of powerful imaging, brain mapping, and information technologies.

Other complications include:

• neurologic losses
• return of tumor growth

In children, radiation may damage the pituitary gland and other parts of the brain. This could cause learning problems or slow growth and development. Additionally, radiation during childhood increases the risk of developing tumors later in life. Researchers are studying chemotherapy as an alternative to radiation therapy in children with brain tumors.

What kind of treatment follow-up should I expect?

Regular follow-up treatment is extremely important after treatment for a brain tumor. Besides regular physical and neurological exams, you may need periodic magnetic resonance (MRI), computed tomography (CT) or positron emission tomography (PET) scans, blood tests or an endoscopy procedure. Your physician may also recommend home care, occupational or vocational therapy, pain management, physical therapy and participation in support groups.

This follow-up care will help your physician to:

• spot any sign that the tumor is returning
• monitor the health of your brain
• identify and treat the side effects of chemotherapy or radiation therapy
• detect the presence of other types of cancer at the earliest possible stage.

Are there any new developments in treating my disease?

Over the past decade, improvements in fractionated and hyperfractionated stereotactic radiotherapy are bringing new hope to patients with brain tumors, both in terms of survival and quality of life. A number of experimental drugs and therapies are also showing promise in clinical trials, including:

• Gene therapy involves the transfer of genetic material into a tumor cell, aiming to either destroy the cell or stop its growth.
• Angiogenesis inhibitors are drugs that interfere with the growth of blood vessels in the tumor, thus "starving" the tumor of the nutrients and oxygen it needs to grow. Treatment with these drugs is also called angiostatic therapy.

رادیو بیولوزی

اطلاعات اولیه

بدیهی است برای آن که اشعه بتواند روی مواد بیولوژیکی تاثیر بگذارد، بایستی انرژی اشعه بطور مستقیم یا غیر مستقیم به مواد بیولوژیکی و یا به موادی که در تبادل با آنها هستند، منتقل شود. تبادل می‌تواند اساسا فرایندهای فیزیکی مثل دیفوزیون یا انتشار یا تاثیرات الکتروستاتیکی ، یا فرایندهای شیمیایی مثل مهاجرت و فعالیت نمونه‌های تحریک شده به رادیکالها ، یونها و مولکولها و ... باشد.

تبادل در فرایندهای بیولوژیکی می‌تواند از طریق تغییر ماکرومولکول‌ها (مثل کروموزوم‌ها ، آنزیم‌ها ، آنتی بادیها) و میکروارگانیزمها (مثل ویروسها ، باکتریها و ...) به سلولها ، بافتها یا ارگانها باشد. وقتی که اشعه در یک نقطه آناتومیکی مثل A جذب شود، تاثیر بیولوژیکی می‌تواند در نقطه دیگری مثل B که در فاصله‌ای از نقطه A قرار دارد، ظاهر شود. این حالت تحت عنوان اثر در هدف دور (abscopal effect) ، خوانده می‌شود.

ارتباط رادیوبیولوژی با سایر علوم

رادیوبیولوژی یک علم چند موضوعی است که ابتدا از فیزیک شروع شده، به اکولوژی و همچنین بررسی قواعد تابش و علم اخلاق مربوط می‌شود.

• فیزیک : تاثیر اشعه روی سیستمهای بیولوژیکی از آن جهت به فیزیک مربوط می‌شود که در واقع مهمترین پارامترها مثل دوز جذب شده و آهنگ دوز جذب شده و ... مربوط به مبحث فیزیک است.
  
  
• شیمی : مهمترین مبحث مورد توجه از لحاظ شیمیایی ، رفتار و طبیعت واکنشهای واسطه‌ای شیمیایی است که ضمن تابش حاصل می‌شوند (شیمی تابش) و نتیجه آن ایجاد مولکولهای آزاد ، مهار کننده‌ها و تعدیل کننده‌های شیمیایی اثر اکسیژن و دوزیمتر شیمیایی است.
  
  
• بیوشیمی : تاثیر اشعه بر روی RNA ، DNA غشا سلول و ...
  
  
• بیولوژی و پزشکی : نتایج حاصله تابش اشعه روی سلولها ، سیستمهای بدن و بطور کلی تمام بدن.
  
  
• اکولوژی : اثرات اشعه در تعادل بین گونه‌های موجودات.
  
  
• اخلاق و سیاست

اهداف رادیوبیولوژی

اهداف نهایی رادیوبیولوژی بایستی توضیح همه وقایع و اثرات مهم و فرایندها از زمان انتقال اشعه تا مرحله نتایج بیولوژیکی انتهایی باشد. به علت آن که انتقال انرژی اشعه به مواد اساسا یک پدیده آماری است، بنابراین نمی‌توان اثرات اشعه را کاملا بطور قطعی بیان نمود و لذا ما در عمل ، محدود به یک نحو تاثیر متوسط یا یک توضیح تقریبی و احتمال وقوع نتایج خاصی هستیم.

• معمولا در رادیوبیولوژی بایستی از مقادیر ماکروسکوپی مثل دوز جذب شده و تندی دوز جذب شده شروع نمود. دوز جذب شده در مورد چگونگی توزیع میکروسکوپی دوز در ماده ، هیچگونه اطلاعی نمی‌دهد و لذا ما به یک کمیت دیگری احتیاج داریم که چگونگی جذب انرژی را در یک مقیاس میکروسکوپی مشخص نماید، مثلا LET در طول مسیر ذرات یونیزه کننده.
  
  
• آنچه در رادیوبیولوژی ، مورد بحث است، بررسی دوز جذب شده در مواد بیولوژیکی در بعد میکروسکوپی در حجم کوچکی همچون سلول و یا بخشی از سلول می‌باشد. برای این منظور بایستی چگونگی انتقال و ذخیره انرژی ذراتی چون الکترون ، پرتون و ... موقع عبور از داخل سلول را بدانیم. انرژی آزاد شده توسط یک ذره باردار در داخل ماده علاوه بر ایجاد یونیزاسیون و تحریک اتمها و مولکولها ، می‌تواند موجب ایجاد رادیکالهای آزاد که بسیار ناپایدار هستند، بشود. یونها و رادیکالها پس از مراحل مختلف روی اجزا حساس داخل سلول مثل DNA و دیگر اجزا سلولی تاثیر گذاشته و موجب مرگ سلول و یا ایجاد اثرات ناهنجار موتاسیون یا سرطان می‌شوند.
  
  
• اشعه می‌تواند موجب تاثیرات متعددی در سلولها شود. حساسترین سلولها به اشعه سریعتر تحت تاثیر واقع می‌شوند. رادیوبیولوژی علم بررسی تاثیرات اشعه بر روی سیستمهای بیولوژیکی می‌باشد. لذا مطالبی که مورد بحث این علم واقع می‌شود، از چگونگی جذب اشعه و سپس مراحل مختلف تاثیر اشعه در حیات سلول و نهایتا نتایج انتهایی حاصله از آن را مورد بحث قرار می‌دهد.

مراحل مختلف تاثیر اشعه

• مرحله تاثیر فیزیکی :
  
  این مرحله از موقع تابش اشعه به بدن شروع و به یونیزاسیون و تحریک اتمها و مولکولهای منتهی می‌شود. از لحاظ زمانی مدت این تاثیر حدود ثانیه می‌باشد.
  
  
• مرحله تاثیر فیزیوشیمیایی :
  
  محصولات اولیه حاصله از تابش اشعه به یک ماده موجب ایجاد محصولات ثانویه‌ای چون رادیکالهای شیمیایی می‌شود. مدت زمان ایجاد این رادیکالها حدود ثانیه می‌باشد.
  
  
• مرحله تاثیر شیمیایی :
  
  این مرحله به تاثیر رادیکالهای شیمیایی حاصله بر روی مولکولها و اتمها می‌باشد. مدت زمان این تاثیر حدود ثانیه می‌باشد.
  
  
• مرحله تاثیر بیولوژیکی :
  
  یونها و رادیکالهای حاصله در مراحل قبلی بر روی اجزای بیولوژیکی سلول و داخل سلولی تاثیر گذاشته و موجب تغییر در آنها می‌شوند. مدت زمان این تاثیر می‌تواند از ثانیه تا سالها باشد.

مراحل تاثیر بیولوژیکی

• اثر بر سلول :
  
  واحد موجود زنده ، سلول می‌باشد. تاثیرات بیولوژیکی اشعه بر روی یک موجود زنده پر سلولی در اثر تغییر در اجزا آن ، یعنی سلولها ، ظاهر می‌شود. تاثیر اشعه بر اجزا و مواد بین سلولها دارای اهمیت است. مطالعه اثر پرتوها بر روی موجودات تک سلولی نسبتا ساده است، لیکن این مطالعات در مورد موجودات پر سلولی بسیار مشکلتر است.
  
  
  • مرگ سلولی (Necrosis) : یکی از مهترین آثار پرتوهای یون ساز ، ایجاد مرگ سلولی است. از این خاصیت در رادیوتراپی استفاده می‌شود.
    
    
  • تاخیر در تقسیم سلولی : در اثر تابش اشعه به سلولها ، ممکن است دوز دریافت شده بوسیله سلول به حد کافی نباشد و موجب مرگ نشود و لیکن می‌تواند باعث تاخیر در تقسیم سلول شود. عمدتا این اثر در مورد سلولهایی اتفاق می‌افتد که نزدیک به شروع تقسیم هستند. در این گونه سلولها ، مرحله میتوز به تاخیر می‌افتد.
    
    
  • سیستم کروموزومی : مهمترین اثری که اشعه می‌تواند بر روی سلول بگذارد، تاثیر بر روی هسته سلول است و مهمترین بخش آن ، تاثیر بر روی کروموزومها می‌باشد. اشعه می‌تواند موجب افزایش احتمال موتاسیونهای مختلف شود. تغییرات ژنتیکی ممکن است در اثر یکی از موارد زیر باشد:
    
    
    • موتاسیون ژن : موتاسیون ژنی در اثر تغییر ساختمان DNA است. این می‌تواند موجب تغییرات ارثی شده و در نتیجه نسلهای بعدی تحت تاثیر آن واقع شوند.
      
      
    • تغییر تعدادی کروموزومها : خطاها در توزیع کروموزومها در حین تقسیم می‌تواند موجب تغییر در تکامل فردی شود که سلولهایش حامل کروموزوم اضافی یا کم باشند. در اکثر حالات کروموزوم اضافی موجب مرگ سلول می‌شود.
      
      
    • شکست کروموزوم
      
      
• اثر اشعه روی تمام بدن :
  
  تاثیر اشعه بر روی ارگانهای مختلف بدن را می‌توان در سه بخش بررسی کرد:
  
  
  • اثرات شدید که عمدتا مربوط به دوزهای زیاد با تندی دوز زیاد است. این گونه تابشها ، منجر به بیماری تابشی می‌گردد.
    
    
  • اثرات طولانی مدت که مربوط به حالت با دوزهای کم است. مثل ایجاد سرطانها در اثر تابش اشعه (سرطانزایی تابش).
    
    
  • اثرات ژنتیکی

اثرات زودرس اشعه

پس از یک تابش شدید اشعه به بدن مهمترین اثراتی که قابل مشاهده هستند، عبارتند از: تخریب ارگانهای خون ساز ، تاثیر روی سیستم گوارشی ، تاثیر روی مغز ، غدد تناسلی و پوست. علائم و عوارضی که با این بیماریها همراه هستند را علایم و عوارض شدید اشعه می‌نامند. بعضی از این عوارض به قرار زیر است:

بی‌اشتهایی ، سرگیجه ، استفراغ ، اسهال ، عرق زیاد ، اختلال در تنفس ، لرزش بدن و تب.

بایستی توجه داشت، ظهور عوارض و بیماریهای تابشی در افراد متفاوت نیاز به دوزهای متفاوت دارد، به خاطر آنکه واکنشهای افراد مختلف در مقابل اشعه متفاوت است.

اثر سرطانزایی اشعه

خاصیت سرطانزایی اشعه‌های یونیزان خیلی زود ، پس از کشف این پرتوها شناخته شد. تعیین رابطه بین دوز و وقوع سرطان در انسان به سادگی ، امکان‌پذیر نیست. در هر حال بعضی موارد وجود دارند که در طول زمانهای بسیار طولانی مشاهده شده‌اند و در نتیجه خاصیت سرطانزایی اشعه در انسانها به اثبات رسیده است. از انواع سرطانهای ایجاد شده بوسیله اشعه می‌توان به لوسمی‌ها ، سرطان تیروئید ، سرطان پستان ، سرطان استخوان ، سرطان پوست و ریه اشاره کرد.

چشم انداز

گسترش علم و تکنولوژی ، همراه با گسترش کاربرد اشعه‌های یونیزان می‌باشد. استفاده از اشعه‌های یونیزان در پزشکی جهت امور تشخیصی ، درمانی و تحقیقی امری اجتناب ناپذیر است و البته نه تنها این امر اجتناب ناپذیر است، بلکه استفاده از این پدیده هر روز ، رو به گسترش است. از طرف دیگر زیانبار بودن اشعه‌های یونیزان برای موجودات زنده و انسان امری اثبات شده می‌باشد.

لذا از یک طرف استفاده از این پدیده در امر بهبود زندگی و سلامت جامعه ضروری است و از طرف دیگر زیانبار بودن آن برای سلامت جامعه امری بدیهی می‌باشد. جوابی که در رفع این تناقص می‌توان ارائه نمود، استفاده کنترل شده و مطابق مقررات حفاظتی می‌باشد که در نتیجه در پرتو رعایت این مقررات می‌توان از این پدیده در جهت گسترش سلامت در جامعه و پیشگیری از گسترش زیانهای آن سود برد.

NetMedicine Radiology Library

Select from the following or scroll below to find the images you are interested in.

• Head/Face
• Neck
• Chest
• Abdomen
• Pelvis
• Spine
• Upper Extremity
• Lower Extremity

Head

Skull

• Lytic Lesions consistent with Multiple Myeloma .
  
• Left parietal skull fracture- 8 months old AP view, lateral view .

Facial Bones

• Acute Sinusitis
• Left zygomatic and lateral maxillary wall fractures
• Normal Waters view of the facial bones

Mandible

• Fracture of mandibular ramus (left side) - AP view

Nasal Bones

• Fracture of nasal bones
• Fracture of nasal bones and nasal maxillary spine

Neck

Soft tissue

• Submandibular soft tissue swelling from Ludwig's Angina - (lateral)
• Retropharyngeal Abscess - (lateral)

Cervical Spine (see spine)

Chest

• Pulmonary edema with cardiomegally and bilateral pleural effusions - (AP)
• Pulmonary edema with cardiomegally and ETT -(AP)
• Right first cervical rib - (AP). You can also see a close-up view .
• Left mediastinal mass with left pleural effusion
• Pneumocystis Carinii pneumonia- (AP)
• Mitral stenosis causing left atrial enlargement
• Bilateral lower lobe atelectasis
• Hiatal hernia -(PA)
• Hiatal hernia - (lateral)
• Tension pneumothorax -right sided-AP. The same patient's CXR 2 days later with incomplete re-expansion after tube thoracostomy.
• Pneumothorax (right-sided close up view)
• Empyema with air-fluid levels on the left side -(PA). The lateral view demonstrates lack of visualization of the left hemidiaphragm.
• Bullous Emphysema with large bilateral bullae -(PA)
• Pnuemomediastinum shown by small arrow-(AP). The patient is also intubated.
• Infiltrate of left upper lobe - (PA)
• Infiltrate of RUL and LUL - (AP)
• Thoracic aortic aneurysm (PA) . The lateral view is also quite impressive.
• Metastatic rib lesion (close-up view) . Notice the irregular outline of the involved rib compared to the others.
• Tuberculosis of RUL -(PA) . The lesion is also seen well on the lateral view .
• Multiple rib fractures on the right side with pulmonary contusion and hemothorax. There is a close up demonstrating the rib fractures.
• Situs Inversus (PA) . (this film is not reversed).
• Splenic hematoma demonstrating medial deviation of gastric bubble .
• Asbestosis-(PA) . There is also a lateral view .
• Hilar adenopathy-(PA) . Consistent with lymphoma or sarcoid.
• Left upper lobe nodule -(PA)
• Pneumoperitoneum on upright CXR.
  
• Fracture of mid sternum with anterior displacement, closeup .
  
• Frx left clavicle, 6 yo boy, close up .

Thoracic Spine (see spine)

Spine

Cervical

• Normal lateral c-spine view
• Normal AP view
• Normal AP odontoid view with slight rotation
• C1 fracture (Jefferson fx)
• C2 fracture of pars interarticularis (hangman's fx)
• C2 fracture with C2-C3 subluxation
• C2 pedicle fracture
• C6-C7 subluxation with jumped facet
• C7 spinous process fracture (clay shoveler's fx)

Thoracic-under construction

Lumbosacral-under construction

Abdomen

• Small bowel obstruction with multiple air fluid levels.

• Small bowel obstruction upright view with NGT in stomach. The supine view demonstrates the valvae of the small bowel well.
• Large and small bowel dilation . There is also a lateral decubitus view .
• Pneumointestinalis in a neonate. There is a close up view demonstrating the bowel wall air.
• Pneumobilia after passage of a gallstone. Take a good look at the liver where the biliary tract is outlined by air.

Pelvis

• Sacral fracture on left side
• Sacral fracture on left side with superior pubic ramus fracture
• Acetabular fracture on the left posterior lip
• Pubic symphysis widening with right sacroiliac joint widening .
• Pubic symphysis widening

Upper Extremities

Hand

• Metacarpal fracture-5th base
• Metacarpal fracture-5th base
• Metacarpal fracture 3rd, 4th heads . You can see the fracture better in a close up view .
• Proximal phalanx of thumb (nondisplaced) . Close up view shows this fracture more clearly.
• Middle phalanx of 2nd digit involving the articular surface. There is a close-up view .
• Distal phalanx of thumb torus fracture.
• PIP dislocation of 5th digit. There is a close up view .
  
• Frx 5th metacarpal head AP view, lateral view .

Wrist

• Radiocarpal dislocation (AP) . This is well demonstrated on the lateral view . There is also an oblique view .
• Perilunate dislocation (lateral) . There is also an AP view .
• Navicular (scaphoid) fracture.
• Navicular (scaphoid) fracture. -AP. There is a nice close up view . There is an oblique view as well.
• Radius fracture (distal) . It's subtle but you can see it next to the arrow here .
• Radius fracture (distal).
• Radius and ulna distal torus fracture (AP) . There is a lateral view .
  
• Navicular fracture, AP view, "navicular view".

 

Forearm

• Radius/Ulna midshaft greenstick fracture.
• Radius/Ulna distal diplaced fracture (AP) . There is a lateral view .

Elbow

• Intercondylar fracture, extending vertically-(AP) . It is not as obvious in the lateral view .
• Radial head fracture (lateral) . The AP view shows it well too.

Shoulder

Scapular fracture demonstrated on the lateral border.

Humeral surgical neck fracture, displaced. .

Posterior shoulder dislocation, axillary view, note the humeral head is not in the glenoid fossa, AP with internal rotation, note the small and false "joint space" as the humeral head sits behind the glenoid fossa, external rotation, Y view .

Lower Extremities

Hip

Intertrochanteric fracture-AP , close up , Lateral

Hip frx, infant with bone scan

Femur

Femoral shaft fracture

Knee

 

Patellar frx with disruption of the patellar ligament .

Tibial plateau fracture AP, oblique .

Tib/Fib

Massoneuve's fracture- Lateral view , Oblique view , full AP view , full Oblique view

Massoneuve's fracture- posterior tibial frx-Lateral view , AP view with widening of the syndesmosis , both frxs , close up of prox fib frx , close up of distal tibial frx , AP view of the distal leg

Tib/Fib fracture-AP , Lateral view

Tib/Fib fracture-AP distal , AP prox imal

Fibular fracture AP , Lateral

Tibial frx - displaced Salter II , AP

Ankle

Bimalleolar fracture

Trimalleolar fracture-ap , Lateral view

Ankle dislocation with distal fib frx, medial malleolar frx

Foot

Metatarsal fractures, of the distal 2nd, 3rd, 4th metatarsals (AP view) , Oblique view

Dancer's fracture, AP view , Oblique view , Lateral view

Lisfranc frx-Lateral view , Oblique view , AP view , close up

Metatarsal dislocation, first metatarsal-Lateral view , close up , AP view , close up AP

Fracture of cuboid-Oblique view , close up of oblique view

Fracture of the calcaneus-Lateral view , post op fixation- Lateral view

Metatarsal fracture, base of the 5th metatarsal- Oblique , close up

Calcaneus fracture - axial view , Lateral view

Metatarsal stress fracture- 4th metatarsal , close up

Calcaneal osteomyelitis , Close up

Fracture base of second metatarsal, AP view, close up view.

GI Thumbnails

Adynamic ileus 414 X 480 23 KB	Ca of cecum 414 X 480 18 KB	Ca of esophagus 300 X 480 14 KB	Carmens meniscus 640 X 446 25 KB
Carmens meniscus 189 X 240 6 KB	Cong Absence Diaphragm 408 X 480 17 KB	Cong Absence Diaphragm 380 X 480 18 KB	Crohns disease 346 X 480 19 KB
Duodenal atresia 380 X 480 15 KB	Hamptons line-ulcer 378 X 480 11 KB	Jackstone calculous 462 X 480 20 KB	Perforated rectum 384 X 480 17 KB
Perforated rectum 372 X 480 17 KB	Rectal ca 428 X 480 20 KB	SBO 372 X 480 20 KB	Sprue 378 X 480 18 KB
Amyloidosis 408 X 480 26 KB	Appendicolith 189 X 240 7 KB	Colonic polyps 180 X 281 11 KB	Scleroderma 100 X 131 3 KB

Diverticulitis 360 X 480 23 KB	Giardiasis 360 X 480 26 KB	Hypoalbuminemia 378 X 480 20 KB	Localized ileus-LUQ 322 X 480 16 KB
Lymphoma 100 X 118 3 KB	Ovarian ca mets 782 X 600 58 KB	Porcelain GB 178 X 240 8 KB	Small bowel obstruction 360 X 480 17 KB

Cardiac Images

ASD with PAH 430 X 480 19 KB	ASD 452 X 480 21 KB	Coarctation-figure3 sign 386 X 480 19 KB	Double aortic arch 225 X 240 8 KB
Ebsteins anomaly 640 X 476 23 KB	Hypolastic L Heart Syndrome 266 X 240 10 KB	L Ao Arch-Aberant RSCA 320 X 200 15 KB	Mitral Stenosis 448 X 480 20 KB
Multiple valve dz 264 X 240 9 KB	Pericardial effusion 424 X 480 16 KB	Persistent L SVC 320 X 230 17 KB	Pulmonary hypertension 450 X 480 24 KB
Pulmonary sling-lat 190 X 240 8 KB	R Ao Arch-Mirror image 396 X 480 16 KB	R Ao Arch Mirror image 410 X 480 21 KB	R Ao Arch-Aberrant LSCA 301 X 240 14 KB
R Ao Arch-mirror image 320 X 228 13 KB	Scimitar syndrome 193 X 240 7 KB	Scimitar syndrome 198 X 240 8 KB	TAPVR 237 X 240 9 KB

Tetralogy of Fallot 231 X 240 9 KB	VSD 548 X 480 24 KB	Ruptured AAA 420 X 346 30 KB	Holt-Oram Syndrome 800 X 546 32 KB

Bone Images

Ossification in scar 180 X 240 7 KB	Osteopetrosis 564 X 480 23 KB	Prostate ca mets 390 X 480 18 KB	RA 360 X 480 20 KB
Rugger Jersey spine 308 X 480 14 KB	Septic arthritis 378 X 480 16 KB	Sickle cell-skull 526 X 480 26 KB	Stasis periosititis 122 X 240 4 KB
Tumoral calcinosis 270 X 240 9 KB	Tumoral calcinosis 112 X 240 4 KB	Fong's 640 X 480 23 KB	Cleidocranial Dysostosis 584 X 480 25 KB
Holt-Oram Syndrome 800 X 546 32 KB	Jones Fracture 300 X 330 12 KB	Monteggia fracture-disclocation 300 X 223 9 KB	Multiple hereditary exostoses 358 X 480 17 KB
Multiple hereditary exostoses 366 X 480 15 KB	Salter 1 510 X 386 25 KB	Salter 2 179 X 485 10 KB	Salter 3 351 X 485 21 KB

Salter 4 431 X 466 15 KB	Smith's Fracture 240 X 247 12 KB

AVN-femur 528 X 480 40 KB	AVN-humerus 574 X 480 20 KB	Ischial avulsion 526 X 480 20 KB	Blastic met to L3 614 X 480 25 KB
Calcified hematoma 320 X 240 12 KB	Charcot joint 506 X 480 17 KB	Chincona cyst 168 X 240 6 KB	Chondrocalcinosis 344 X 480 14 KB
Chr venous insuffiency 180 X 240 6 KB	Chr venous insuffiency 182 X 240 8 KB	Dermatomyocitis 196 X 240 9 KB	DJD 640 X 480 27 KB
DJD 410 X 480 19 KB	Hangmans fx 360 X 480 16 KB	Hemophilac arthropathy 360 X 480 15 KB	DJD 318 X 480 15 KB
Lipohemarthrosis 640 X 284 13 KB	Ochronosis 122 X 240 6 KB	Ochronosis 166 X 240 5 KB	Ossification in scar 196 X 240 7 KB

Chest Images

Aspergilloma 433 X 460 15 KB	Atelectasis 486 X 480 21 KB	Atelectasis 378 X 480 18 KB	Atelectasis 458 X 480 23 KB
Br Ca cavitary 360 X 480 20 KB	Hamartoma 640 X 480 29 KB	Hamartoma 562 X 480 21 KB	Hydatid cyst 162 X 240 7 KB
Neurofibromatosis 640 X 480 26 KB	Neurofibromatosis 402 X 480 16 KB	Noncardiac pulmonary edema 608 X 480 29 KB	Osteochondroma 320 X 200 16 KB
Pancoast 334 X 480 16 KB	PTX-tension 224 X 240 7 KB	PTX-tension 246 X 240 8 KB	Pulmonary infarct 272 X 240 9 KB
Radiation fibrosis 536 X 480 21 KB	SPN-hamartoma 180 X 240 7 KB	SPN-hamartoma 198 X 240 7 KB	SPN-hamartoma 210 X 240 8 KB

Meconium aspiration syndrome 272 X 240 9 KB	Pneumonia-lingula 650 X 799 38 KB	Pneumonia-lingula 760 X 684 49 KB	Tension pneumothorax 197 X 240 8 KB

Hysterosalpingography

What is Hysterosalpingography؟

Hysterosalpingography, also called uterosalpingography, is an x-ray examination of a woman's uterus and fallopian tubes that uses a special form of x-ray called fluoroscopy and a contrast material.

An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.

Fluoroscopy is a special x-ray technique that makes it possible to see internal organs in motion. When the uterus and fallopian tubes are filled with a water-soluble contrast material, the radiologist is able to view and assess their anatomy and function.

What are some common uses of the procedure?

Hysterosalpingography is primarily used to examine women who have difficulty becoming pregnant by allowing the radiologist to evaluate the shape and structure of the uterus, the openness of the fallopian tubes, and any scarring within the peritoneal cavity.

The procedure can be used to investigate repeated miscarriages that result from congenital abnormalities of the uterus and to determine the presence and severity of these abnormalities, including:

• tumor masses or adhesions
• uterine fibroids

Hysterosalpingography is also used to monitor the effects of tubal surgery, including:

• tubal ligation
• the closure of the fallopian tubes in a sterilization procedure and a sterilization reversal
• the re-opening of the fallopian tubes following a sterilization or disease-related obstruction

How should I prepare for the procedure?

The hysterosalpingography procedure is best performed one week after menstruation but before ovulation to make certain that you are not pregnant during the exam.

This procedure should not be performed if you have an active inflammatory condition. You should notify your physician or technologist if you have a chronic pelvic infection or an untreated sexually transmitted disease at the time of the procedure.

On the night before the procedure, you will be asked to take a laxative or an enema to empty your bowels, so that the uterus and surrounding structures can be seen clearly.

Prior to the procedure, you may be given a mild sedative or over-the-counter medication to minimize any potential discomfort. Some physicians prescribe an antibiotic prior to and/or after the procedure.

You should inform your physician of any medications you are taking and if you have any allergies, especially to contrast material. Also inform your doctor about recent illnesses or other medical conditions.

You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy because radiation can be harmful to the fetus. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.

What does the equipment look like?

The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room or in a nearby room. When used for viewing images in real time (called fluoroscopy), the image intensifier (which converts x-rays into a video image) is suspended over a table on which the patient lies. When used for taking still pictures, a drawer under the table holds the x-ray film or image recording plate that captures the images.

How does the procedure work?

X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special image recording plate.

Fluoroscopy uses a continuous x-ray beam to create a sequence of images that are projected onto a fluorescent screen, or television-like monitor. When used with a contrast material, which clearly defines the area being examined by making it appear bright white, this special x-ray technique makes it possible for the physician to view internal organs in motion. Still images are also captured and stored either on film or electronically on a computer.

X-ray images are maintained as hard film copy (much like a photographic negative) or, more likely, as a digital image that is stored electronically. These stored images are easily accessible and are sometimes compared to current x-ray images for diagnosis and disease management.

How is the procedure performed?

This examination is usually done on an outpatient basis.

The patient is positioned on her back on the exam table, with her knees pulled to her chest or her feet held up with stirrups. A speculum is inserted into the vagina and the catheter is then inserted into the cervix. The speculum is removed and the patient is carefully situated underneath the fluoroscopy device. The contrast material then begins to fill the uterine cavity through the catheter and fluoroscopic images are taken.

In some cases, if certain abnormalities are encountered, the patient will be asked to rest and wait up to 30 minutes so that a delayed image can be obtained. This delayed image may provide clues to a patient's condition that the original images with contrast material do not. On occasion, an x-ray will be taken the next day to ensure that there is no scarring surrounding the ovaries.

When the procedure is complete, the catheter will be removed and the patient will be allowed to sit up.

When the examination is complete, the patient will be asked to wait until the technologist determines that the images are of high enough quality for the radiologist to read.

The hysterosalpingogram is usually completed within 30 minutes.

What will I experience during and after the procedure?

This exam should cause only minor discomfort.

There may be slight discomfort when the catheter is placed and the contrast material is injected, but it should not last long. There may also be slight irritation of the peritoneum, causing generalized lower abdominal pain, but this should also be minimal and not long lasting.

Who interprets the results and how do I get them?

A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you.

What are the benefits vs. risks?

Benefits

• Hysterosalpingography is a minimally invasive procedure with rare complications.
• Hysterosalpingography is a relatively short procedure that can provide valuable information on a variety of abnormalities that cause infertility or problems carrying a fetus to term.
• No radiation remains in a patient's body after an x-ray examination.
• X-rays usually have no side effects.

Risks

• There is always a slight chance of cancer from radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
• The effective radiation dose from this procedure is about 1 mSv, which is about the same as the average person receives from background radiation in four months. See the Safety page for more information about radiation dose.
• In the event of a chronic inflammatory condition, pelvic infection or untreated sexually transmitted disease, be certain to notify the physician or technologist before the procedure to avoid worsening of infection.
• Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

A Word About Minimizing Radiation Exposure

Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.

State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures those parts of a patient's body not being imaged receive minimal radiation exposure.

What are the limitations of Hysterosalpingography?

Hysterosalpingography only sees the inside of the uterus and fallopian tubes. Abnormalities of the ovaries, wall of the uterus, and other pelvic structures may be evaluated with MRI or ultrasound. Infertility problems may be from causes not evaluated with hysterosalpingography, including, but not limited to, low or abnormal sperm count or the inability of a fertilized egg to implant in the uterus.

What is Mammography?

What is Mammography?

Mammography is a specific type of imaging that uses a low-dose x-ray system to examine breasts. A mammography exam, called a mammogram, is used to aid in the diagnosis of breast diseases in women.

An x-ray (radiograph) is a painless medical test that helps physicians diagnose and treat medical conditions. Radiography involves exposing a part of the body to a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest and most frequently used form of medical imaging.

Two recent enhancements to traditional mammography include digital mammography and computer-aided detection.

Digital mammography, also called full-field digital mammography (FFDM), is a mammography system in which the x-ray film is replaced by solid-state detectors that convert x-rays into electrical signals. These detectors are similar to those found in digital cameras. The electrical signals are used to produce images of the breast that can be seen on a computer screen or printed on special film similar to conventional mammograms. From the patient's point of view, digital mammography is essentially the same as the screen-film system.

See "Full-Field Digital Mammography: A Potential Alternative to the Traditional Film-Screen Technique?" under the News heading for more information on how FFDM works and its potential advantages.

Computer-aided detection (CAD) systems use a digitized mammographic image that can be obtained from either a conventional film mammogram or a digitally acquired mammogram. The computer software then searches for abnormal areas of density, mass, or calcification that may indicate the presence of cancer. The CAD system highlights these areas on the images, alerting the radiologist to the need for further analysis.

What are some common uses of the procedure?

Mammograms are used as a screening tool to detect early breast cancer in women experiencing no symptoms and to detect and diagnose breast disease in women experiencing symptoms such as a lump, pain or nipple discharge.

Screening Mammogram
Mammography plays a central part in early detection of breast cancers because it can show changes in the breast up to two years before a patient or physician can feel them. Current guidelines from the U.S. Department of Health and Human Services (HHS), the American Cancer Society (ACS), the American Medical Association (AMA) and the American College of Radiology (ACR) recommend screening mammography every year for women, beginning at age 40. Research has shown that annual mammograms lead to early detection of breast cancers, when they are most curable and breast-conservation therapies are available.

The National Cancer Institute (NCI) adds that women who have had breast cancer and those who are at increased risk due to a genetic history of breast cancer should seek expert medical advice about whether they should begin screening before age 40 and about the frequency of screening.

See the Breast Cancer page for information about breast cancer therapy.

Diagnostic Mammogram
Diagnostic mammography is used to evaluate a patient with abnormal clinical findings—such as a breast lump or lumps—that have been found by the woman or her doctor. Diagnostic mammography may also be done after an abnormal screening mammography in order to determine the cause of the area of concern on the screening exam.

How should I prepare for a mammogram?

Before scheduling a mammogram, the American Cancer Society (ACS) and other specialty organizations recommend that you discuss any new findings or problems in your breasts with your doctor. In addition, inform your doctor of any prior surgeries, hormone use, and family or personal history of breast cancer.

Do not schedule your mammogram for the week before your period if your breasts are usually tender during this time. The best time for a mammogram is one week following your period. Always inform your doctor or x-ray technologist if there is any possibility that you are pregnant.

The ACS also recommends you:

• Do not wear deodorant, talcum powder or lotion under your arms or on your breasts on the day of the exam. These can appear on the mammogram as calcium spots.
• Describe any breast symptoms or problems to the technologist performing the exam.
• If possible, obtain prior mammograms and make them available to the radiologist at the time of the current exam.
• Ask when your results will be available; do not assume the results are normal if you do not hear from your doctor or the mammography facility.

What does the Mammography equipment look like?

A mammography unit is a rectangular box that houses the tube in which x-rays are produced. The unit is used exclusively for x-ray exams of the breast, with special accessories that allow only the breast to be exposed to the x-rays. Attached to the unit is a device that holds and compresses the breast and positions it so images can be obtained at different angles.

How does the procedure work?

X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special image recording plate.

Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black.

X-ray images are maintained as hard film copy (much like a photographic negative) or, more likely, as a digital image that is stored electronically. These stored images are easily accessible and are sometimes compared to current x-ray images for diagnosis and disease management.

How is the procedure performed?

Mammography is performed on an outpatient basis.

During mammography, a specially qualified radiologic technologist will position your breast in the mammography unit. Your breast will be placed on a special platform and compressed with a paddle (often made of clear Plexiglas or other plastic). The technologist will gradually compress your breast.

Breast compression is necessary in order to:

• Even out the breast thickness so that all of the tissue can be visualized.
• Spread out the tissue so that small abnormalities won't be obscured by overlying breast tissue.
• Allow the use of a lower x-ray dose since a thinner amount of breast tissue is being imaged.
• Hold the breast still in order to eliminate blurring of the image caused by motion.
• Reduce x-ray scatter to increase sharpness of picture.
• The technologist will stand behind a glass shield during the x-ray exposure. You will be asked to change positions slightly between images. The routine views are a top-to-bottom view and an oblique side view. The process will be repeated for the other breast.

The patient must hold very still and may be asked to keep from breathing for a few seconds while the x-ray picture is taken to reduce the possibility of a blurred image. The technologist will walk behind a wall or into the next room to activate the x-ray machine.

When the examination is complete, the patient will be asked to wait until the technologist determines that the images are of high enough quality for the radiologist to read.

The examination process should take about 30 minutes.

What will I experience during and after the procedure?

You will feel pressure on your breast as it is squeezed by the compressor. Some women with sensitive breasts may experience discomfort. If this is the case, schedule the procedure when your breasts are least tender. Be sure to inform the technologist if pain occurs as compression is increased. If discomfort is significant, less compression will be used.

Who interprets the results and how do I get them?

A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will share the results with you.

You will also be notified of the results by the mammography facility.

What are the benefits vs. risks?

Benefits

• Imaging of the breast improves a physician's ability to detect small tumors. When cancers are small, the woman has more treatment options and a cure is more likely.
• The use of screening mammography increases the detection of small abnormal tissue growths confined to the milk ducts in the breast, called ductal carcinoma in situ (DCIS). These early tumors cannot harm patients if they are removed at this stage and mammography is the only proven method to reliably detect these tumors. It is also useful for detecting all types of breast cancer, including invasive ductal and invasive lobular cancer.
• No radiation remains in a patient's body after an x-ray examination.
• X-rays usually have no side effects.

Risks

• There is always a slight chance of cancer from radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
• The effective radiation dose from a mammogram is about 0.7 mSv, which is about the same as the average person receives from background radiation in three months. Federal mammography guidelines require that each unit be checked by a medical physicist every year to ensure that the unit operates correctly. See the Safety page for more information about radiation dose..
• False Positive Mammograms. Five percent to 15 percent of screening mammograms require more testing such as additional mammograms or ultrasound. Most of these tests turn out to be normal. If there is an abnormal finding a follow-up or biopsy may have to be performed. Most of the biopsies confirm that no cancer was present. It is estimated that a woman who has yearly mammograms between ages 40 and 49 has about a 30 percent chance of having a false-positive mammogram at some point in that decade and about a 7 percent to 8 percent chance of having a breast biopsy within the 10-year period. The estimate for false-positive mammograms is about 25 percent for women ages 50 or older.
• Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.

A Word About Minimizing Radiation Exposure

Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.

State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures those parts of a patient's body not being imaged receive minimal radiation exposure.

What are the limitations of Mammography?

Initial mammographic images themselves are not always enough to determine the existence of a benign or malignant disease with certainty. If a finding or spot seems suspicious, your radiologist may recommend further diagnostic studies.

Interpretations of mammograms can be difficult because a normal breast can appear differently for each woman. Also, the appearance of an image may be compromised if there is powder or salve on the breasts or if you have undergone breast surgery. Because some breast cancers are hard to visualize, a radiologist may want to compare the image to views from previous examinations. Not all cancers of the breast can be seen on mammography.

Breast implants can also impede accurate mammogram readings because both silicone and saline implants are not transparent on x-rays and can block a clear view of the tissues behind them, especially if the implant has been placed in front of, rather than beneath, the chest muscles. But the NCI says that experienced technologists and radiologists know how to carefully compress the breasts to improve the view without rupturing the implant.

When making an appointment for a mammogram, women with implants should ask if the facility uses special techniques designed to accommodate them. Before the mammogram is taken, they should make sure the technologist is experienced in performing mammography on patients with breast implants.

While mammography is the best screening tool for breast cancer available today, mammograms do not detect all breast cancers. Also, a small portion of mammograms indicate cancer is present when it is not (called a false-positive result).

Research is being done on a variety of breast imaging techniques that can contribute to the early detection of breast cancer and improve the accuracy in distinguishing non-cancerous breast conditions from breast cancers.

Computer-aided detection (CAD) systems and digital mammography are some of the new technologies under study.