Saskatoon Medical Imaging/Saskatoon Women's Imaging

Services provided: X-ray of abdomen, chest, limbs, spine, pelvis, etc.

Bone x-rays
Chest x-rays

What is Bone Radiography?

Radiography, x-ray as it is most commonly known, is the oldest and most frequently used form of medical imaging.  Professor Roentgen discovered x-rays more than a century ago.  They are used to produce diagnostic images of the human body on film or are converted to digital data and displayed on a computer screen.

X-ray imaging is the fastest and easiest way for a physician to view and assess bones. At least two images at different angles are taken and often more images are needed if the problem is around a joint (knee, elbow or wrist). X-rays play a key role in assessing for bone injuries, joint pain, and suspected bone masses or tumors.

Radiography involves exposing a part of the body to a small dose of radiation to produce an image of the internal structures on x-ray film. When x-rays penetrate the body, they are absorbed in varying amounts by the different tissues. Ribs, for example, will block much of the radiation and, therefore, appear white or light gray on the image. Fat tissue and air will appear darker because more radiation can pass through these tissues and expose the x-ray film.

How should I prepare for the bone x-ray procedure?

There is no special preparation required for most bone radiographs. Once you arrive, you may be asked to change into a gown before your examination. You will also be asked to remove jewelry, eyeglasses and any metal objects that could show up on the images and overlap important findings.

Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant.

What does the x-ray equipment look like?

Radiography equipment consists of a large, flat table.  The film may be in the form of a external cassette or in may be held in a drawer in the table of the x-ray machine.  The x-ray tube is usually suspended above the table so that it can be moved over the body to direct the x-rays at the area of interest.

How is the procedure performed?

The technologist positions the patient on the examination table, places a film holder (cassette) under the area of interest or under the table top in the area of the body part to be imaged. Sandbags or pillows may help the patient hold the proper position. Then the technologist steps behind a radiation barrier and asks the patient to hold very still without breathing for a few seconds. The radiographic equipment is activated, sending a beam of x-rays through the body to expose the film. The technologist then repositions the patient for another view, and the process is repeated. 

When your x-rays are completed you will be asked to wait until the technologist checks the images for adequate exposure and clinical usefulness.

What will I experience during the x-ray procedure?

X-ray imaging itself is painless, x-rays are a form electromagnetic radiation, and as such, create no detectable sensation.  You may experience some discomfort related to lying on the table, often a hard, cold surface. Sometimes, to get a clear image of an injury such as a possible fracture, you may be asked to hold an uncomfortable position for a short time. Any movement could blur the image and make it necessary to repeat the procedure to get a useful, clear picture.

What are current recommendations for bone x-rays?

Probably the most common use of bone radiographs is to assist the physician in identifying and treating fractures. X-ray images of the limbs, spine, joints and pelvis are performed in hospital emergency rooms, sports medicine centers, orthopedic clinics and physician offices. Images acquired can often demonstrate very subtle abnormalities and those produced after treatment ensure proper bone alignment and healing. Bone x-rays are essential tools in orthopedic surgery for such procedures as spinal repair, joint replacements and fracture management.

X-ray images can be used to diagnose and monitor the progression of degenerative diseases such as arthritis. They also play an important role in the detection and diagnosis of cancer, although usually computed tomography (CT) or magnetic resonance imaging (MRI) are better for determining the nature and the extent of cancer. X-rays can suggest the possibility of osteoporosis, but bone density determination for early loss of bone mineral is usually done on specialized, more sensitive equipment (bone densitometry).

What are the benefits vs. risks?

Benefits

• X-ray imaging is useful to diagnose bone injury and disease, such as fractures, bone infections, arthritis and cancer. 
• Because x-ray imaging is fast and easy, it is particularly useful in emergency diagnosis and treatment.
• X-ray equipment is relatively inexpensive and widely available in physician offices, ambulatory care centers, and other locations, making it convenient for both patients and physicians.

Risks

• Radiation exposure.  X-rays are a type of invisible electromagnetic radiation.  Modern x-ray techniques use only a fraction of the x-ray dose that was required in the early days of radiology.  This combined with very sensitive x-ray film results in minimal x-ray exposure.
• During a single x-ray exposure a patient is exposed to approximately 1/5 the annual radiation we are all exposed to from sources like the cosmic radiation from the sun and naturally occurring radioactive isotopes we encounter in our environment.  It is a low radiation dose.

What are the limitations of Bone Radiography?

X-ray images of bones are some of the most detailed images acquired in medical imaging, however, the useful information acquired pertains mostly to bone and very little can be learned about the surrounding tissues.  In the case of a knee injury, for example, an MRI will provide information about ligament tears, joint fluid or other problems in the region that x-rays are incapable of detecting.

Other imaging modalities, such as positron emission tomography (PET), nuclear medicine bone scanning or CT, may be more effective in diagnosing cancer spread to bone or to investigate primary bone tumors.  CT and MRI are especially useful for imaging the spine because beyond visualizing just the bones they can image the contents of the spinal canal to see the spinal cord and nerves, structures not seen on plain x-rays.

Sample Images

X-ray of Knee Replacement - frontal view	X-ray of Knee Replacement - side view	X-ray of the Neck Metal Plates and Screws are seen

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What is a Chest X-ray (Chest Radiography)?

The chest x-ray is one of the most commonly performed diagnostic imaging examinations. A chest x-ray is usually done for the evaluation of lungs, heart and remainder of the chest cavity. Pneumonia, heart failure, emphysema, lung cancer and other medical conditions can be detected on a chest x-ray.  Traditionally, chest x-rays have been taken prior to employment, prior to surgery or during immigration. The use of these "routine" chest x-rays is being re-evaluated because of a suspicion that they lack usefulness.  However, the chest x-ray remains a common and practical diagnostic examination.

Radiography involves exposing a part of the body to a small dose of radiation to produce an image of the internal structures on x-ray film. When x-rays penetrate the body, they are absorbed in varying amounts by different tissues. Ribs, for example, will block much of the radiation and, therefore, appear white or light gray on the image. Fat tissue and air will appear darker because more radiation can pass through them to expose the x-ray film.  Lung tissue absorbs very little radiation and appears quite dark on the images obtained.

Depending upon the type of image-recording medium, chest x-rays can be maintained as hard copy film for filing or as filmless digital data stored on a computer. Stored films or digital images may be used in the future as a source of comparison for any new x-rays acquired. Indeed, historical comparison films are often very important in the x-ray assessment process.

How should I prepare for the procedure?

There is no special preparation required for most bone radiographs. Once you arrive, you may be asked to change into a gown before your examination. You will also be asked to remove jewelry, eyeglasses and any metal objects that could show up on the images and overlap important findings.

Women should always inform their doctor or x-ray technologist if there is any possibility that they are pregnant.

What does the x-ray equipment look like?

The most common radiography equipment used for chest x-rays consists of a box-like apparatus containing the recording material, a film or a digital recording plate, against which the individual places his/her chest.  The x-ray tube, usually positioned about six feet away, delivers an x-ray beam only when the technologist triggers a switch.

In some instances, the radiography equipment consists of a large, flat table with a drawer that holds an x-ray film cassette or a digital recording plate. With this arrangement, the x-ray tube is suspended above the table.

How is the procedure performed?

Patients must remove their clothing, including any undergarments that may contain metal i.e. support bra, etc. Most medical centers will give the patient a gown to wear. Patients will also be asked to remove all metallic jewelry that may interfere with the x-rays. Normally, a frontal view is obtained, in which the patient stands with the chest pressed to the photographic plate, with hands on hips and elbows pushed forward. The technologist will ask the patient to be still and to take a deep breath and hold it. Breath-holding after a deep breath reduces the possibility of a blurred image and also enhances the quality of the x-ray image, since abnormalities in air-filled lungs are easier to see than in deflated lungs. Next, the technologist walks into a cubicle or small room to activate the radiographic equipment, which sends a beam of x-rays from the x-ray source through the patient's chest, to the recording medium (film cassette or digital detector). Some equipment is designed to accommodate patients who cannot stand for chest x-rays.

For a lateral view, the patient stands sideways to the photographic plate with arms elevated, and the process is repeated. Views from other angles may be obtained if the radiologist needs to evaluate additional areas of the chest.

When the chest x-rays are completed you will be asked to wait until the technologist checks the images for diagnostic quality. Ultimately, a radiologist will interpret the chest x-ray images.

What will I experience during the x-ray procedure?

X-ray imaging itself is painless, x-rays are a form electromagnetic radiation, and as such, create no detectable sensation.  The primary discomfort may come from the coldness of the recording plate. Individuals with arthritis or injuries to the chest, shoulders or arms may have discomfort trying to maintain position for the chest x-ray. In these circumstances, the technologist will assist you in finding a position that still ensures image quality.

What are the current recommendations for the chest x-ray?

A chest x-ray is typically performed as the first imaging test for symptoms of shortness of breath, a persistent cough, chest pain, chest injury or fever. Individuals with known or suspected medical conditions such as congestive heart failure or cancer may have chest x-rays to follow their response to treatment, or to determine if x-ray changes are present that would require a change in medical management.

What are the benefits vs. risks?

Benefits

• A physician may recommend a chest x-ray for a patient with shortness of breath, a bad or persistent cough, chest pain or a chest injury. In the instances of pneumonia, the site of pneumonia will appear white on the image.  The chest x-ray often capable of detecting the cause of your new signs or symptoms.  It is a fast, painless, easily obtainable test.
• Lung cancers and other tumours that spread to the lung may be visible on chest x-ray.
• Heart irregularities, such as fluid around the heart (pericardial effusion), an enlarged heart, or abnormal heart anatomy or heart failure may also be visible on a chest x-ray.
• Pleural effusions (fluid around the lungs) on one or both sides can be detected. Usually the cause of such fluid may be deduced from clinical data or other findings on the chest x-ray but it may be necessary to sample the fluid to determine its cause.

Risks

• X-rays are a type of invisible electromagnetic radiation.  Modern x-ray techniques use only a fraction of the x-ray dose that was required in the early days of radiology.  The use of modern x-ray film requires very small amounts of radiation to produce an optimal image.
• The chest x-ray is a very low exposure radiology examination. The effective radiation dose from this procedure is about 0.1 mSv, which is about the same as the average person receives from background radiation in 10 days.

What are the limitations of Chest Radiography?

The chest x-ray is a very useful examination, but has limitations. Some conditions of the chest will not show up on the image. Therefore, a normal chest x-ray does not necessarily rule out all problems in the chest. For example, patients with asthma can have a normal chest x-ray. There are some cancers that are too small or are too difficult to visualize and may not be identified. Blood clots to the lungs (pulmonary embolism) cannot be seen on chest x-rays and require different examinations.

A chest computed tomography (CT) may be requested to further clarify a finding seen on the chest x-ray or to look for an abnormality not visible on a chest x-ray in order to investigate a clinical problem. The degree of involvement of the lung, as well as the distribution of disease, and anatomic location may be better evaluated with chest CT, helping aid the diagnosis.

The chest x-ray and the physical examination should be correlated. The information each provides can give the physician a clearer understanding of the patient's condition.

Sample Images

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