We often hear the names of different health imaging techniques, but may not fully understand how they work or what kind of image the produce. Diagnostic imaging techniques help find the cause of an injury or illness. These tools allow specialists to “see” inside your body, providing a “picture” of your bones, organs, muscles, tendons, nerves and/or cartilage. With this image, the specialist can find any abnormalities, and provide the proper treatment to fix or cure it.
Common Diagnostic Imaging Techniques
The following provides a quick insight on three of the more common imaging techniques, the X-Ray, CT Scan and MRI.
X-rays (radiographs) are the most common and widely available technique. The part of your body being pictured is positioned between the X-ray machine and photographic film while the machine briefly sends electromagnetic waves (radiation) through your body, exposing the film to reflect your internal structure. Bones, tumors and other dense matter appear white or light because they absorb the radiation. Less dense soft tissues and breaks in bone let radiation pass through, making these parts look darker on the X-ray film. Sometimes, to make certain organs stand out in the picture, you are given barium sulfate or a dye. If you have a fracture in one limb, your doctor may want a comparison X-ray of your uninjured limb. The images are ready quickly. X-rays may not show as much detail as an image produced using newer, more powerful techniques.
Computed Tomography (CT):
Computed tomography (CT) is a imaging tool that combines X-rays with computer technology to produce a more detailed, cross-sectional image of your body. A CT scan lets your doctor see the size, shape, and position of structures that are deep inside your body, such as organs, tissues, or tumors. You lie as motionless as possible on a table that slides into the center of the cylinder-like CT scanner. The process is painless. An X-ray tube slowly rotates around you, taking many pictures from all directions. A computer combines the images to produce a clear, two-dimensional view on a television screen. You may need a CT scan if you have a problem with a small, bony structure or if you have severe trauma to the brain, spinal cord, chest, abdomen, or pelvis. As with a regular X-ray, sometimes you may be given barium sulfate or a dye to make certain parts of your body show up better. A CT scan costs more and takes more time than a regular X-ray, and it is not always available in small hospitals and rural areas.
Magnetic Resonance Imaging (MRI):
Magnetic resonance imaging (MRI) is another imaging technique that produces cross-sectional images of your body. Unlike CT scans, MRI works without radiation. The MRI tool uses magnetic fields and a sophisticated computer to take high-resolution pictures of your bones and soft tissues. You lie as motionless as possible on a table that slides into the tube-shaped MRI scanner. The MRI creates a magnetic field around you and then pulses radio waves to the area of your body to be pictured. The radio waves cause your tissues to resonate. A computer records the rate at which your body’s various parts (tendons, ligaments, nerves, etc.) give off these vibrations, and translates the data into a detailed, two-dimensional picture. An MRI may help your doctor to diagnose your torn knee ligaments and cartilage, torn rotator cuffs, herniated disks, hip and pelvic problems, and other problems. An MRI may take 30 to 90 minutes. It is not available at all hospitals.