Types Of Imaging Studies

 

What are the various types of imaging studies available?

Constant innovation in the world of Radiology means that there is an ever growing list of imaging studies available. Here are the popular types of studies commonly performed today :

• Angiography
  An angiogram is an imaging test that uses X-rays to look at your blood vessels. It is done to check for conditions such as:
  
  • Weak, stretched or enlarged portion of a blood vessel (aneurysm)
  • Narrowing of a blood vessel (stenosis)
  • Blockages
• Bone DEXA
  A bone scan is a radiology procedure used to look at the skeleton. It is done to find areas of physical and chemical changes in bone. A bone scan may also be used to see if treatment of certain conditions is working.
   
  A bone scan is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the scan to assist in the examination of the bones. The radioactive substance, called a radionuclide, or radioactive tracer, may either be increased or decreased in abnormal areas of bone.
  
  The radionuclide gives off a type of radiation, called gamma radiation. The gamma radiation is detected by a scanner. This processes the information into a picture of the bones.
  The areas where the radionuclide collects are called "hot spots." They may be a sign of conditions such as cancerous bone tumors and metastatic bone cancer. This is cancer that has spread from another site, such as the lungs, to the bones. Other conditions include those related to the bone. These include bone infection and bone injury not seen on regular X-rays.
  
  
• CT Scans
  Computed tomography (CT) of the body uses special x-ray equipment to help detect a variety of diseases and conditions. CT scanning is fast, painless, noninvasive and accurate. In emergency cases, it can reveal internal injuries and bleeding quickly enough to help save lives.
  
  Tell your doctor if there’s a possibility you are pregnant and discuss any recent illnesses, medical conditions, medications you’re taking, and allergies. You will be instructed not to eat or drink anything for a few hours beforehand. If you have a known allergy to contrast material, your doctor may prescribe medications to reduce the risk of an allergic reaction. These medications must be taken 12 hours prior to your exam. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown.
   
• MRI
  Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body. In many cases, MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan. MRI also may show problems that cannot be seen with other imaging methods.
  
  For an MRI test, the area of the body being studied is placed inside a special machine that contains a strong magnet. Pictures from an MRI scan are digital images that can be saved and stored on a computer for more study. The images also can be reviewed remotely, such as in a clinic or an operating room. In some cases, contrast material may be used during the MRI scan to show certain structures more clearly.
  
  You may be able to have an MRI with an open machine that doesn't enclose your entire body. But open MRI machines aren't available everywhere. The pictures from an open MRI may not be as good as those from a standard MRI machine.
  
  
• PET Scan
  A positron emission tomography (PET) scan is an imaging test that helps reveal how your tissues and organs are functioning. A PET scan uses a radioactive drug (tracer) to show this activity.
  
  The tracer may be injected, swallowed or inhaled, depending on which organ or tissue is being studied by the PET scan. The tracer collects in areas of your body that have higher levels of chemical activity, which often correspond to areas of disease. On a PET scan, these areas show up as bright spots.
  
  A PET scan is useful in revealing or evaluating several conditions, including some cancers, heart disease and brain disorders.
  
  
• Fluroscopy
  Fluoroscopy is a study of moving body structures--similar to an X-ray "movie." A continuous X-ray beam is passed through the body part being examined. The beam is transmitted to a TV-like monitor so that the body part and its motion can be seen in detail. Fluoroscopy, as an imaging tool, enables physicians to look at many body systems, including the skeletal, digestive, urinary, respiratory, and reproductive systems.
  
  Fluoroscopy may be performed to evaluate specific areas of the body, including the bones, muscles, and joints, as well as solid organs, such as the heart, lung, or kidneys.
  
  Other related procedures that may be used to diagnose problems of the bones, muscles, or joints include X-rays, myelography (myelogram), computed tomography (CT scan), magnetic resonance imaging (MRI), and arthrography.
  
  
• Mammogram
  A mammogram is a low-dose x-ray that allows specialists to look for changes in breast tissue. Screening mammograms are used to look for breast changes in women who do not appear to have breast problems. A diagnostic mammogram is used to get more information about breast changes in women who have breast symptoms or an abnormal screening mammogram.
  
  
• Myelography
  Myelography is an imaging examination that involves the introduction of a spinal needle into the spinal canal and the injection of contrast material in the space around the spinal cord and nerve roots (the subarachnoid space) using a real-time form of x-ray called fluoroscopy.
  
  When the contrast material is injected into the subarachnoid space, the radiologist is able to view and evaluate the status of the spinal cord, the nerve roots and the meninges. The meninges are the membranes which surround and cover the spinal cord and nerve roots. Myelography provides a very detailed picture (myelogram) of the spinal cord, nerve roots, subarachnoid space and spinal column. The radiologist views the passage of contrast material in real-time within the subarachnoid space as it is flowing using fluoroscopy but also takes permanent images, called x-rays or radiographs, of the contrast material around the spinal cord and nerve roots in order to document abnormalities involving or affecting these structures. In many of these cases, the myelogram may be followed by a computed tomography (CT) scan to better define the anatomy and any abnormalities.
  
  
• Ultrasound
  Ultrasound, also called sonography, uses sound waves to develop ultrasound images of what's going on inside the body. An instrument called a transducer emits high-frequency sound, inaudible to human ears, and then records the echoes as the sound waves bounce back to determine the size, shape, and consistency of soft tissues and organs.
  
  This information is relayed in real time to produce images on a computer screen. Ultrasound technicians, or sonographers, have special training in how to perform the test. Then a radiologist or your doctor will interpret the ultrasound images. This technology can help diagnose and treat certain conditions.
  
  
• X-Ray
  An X-ray is a quick, painless test that produces images of the structures inside your body — particularly your bones.
  
  X-ray beams pass through your body, and they are absorbed in different amounts depending on the density of the material they pass through. Dense materials, such as bone and metal, show up as white on X-rays. The air in your lungs shows up as black. Fat and muscle appear as shades of gray.
  
  For some types of X-ray tests, a contrast medium — such as iodine or barium — is introduced into your body to provide greater detail on the images.