Who interprets the results and how do I get them?
CT, sometime called CAT scanning, uses special x-ray equipment to obtain images from different angles around the body, and then uses computer processing to show a cross-section of body tissues and organs.
CT is particularly useful because it can show several types of tissue lung, bone, soft tissue, and blood vessels with great clarity. Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders. CT of the body is a patient-friendly exam that involves minimal radiation exposure.
What are some indications of CT scan?
Because it provides detailed, cross-sectional views of all types of tissue, CT is one of the best tools for studying the chest and abdomen. It is often the preferred method for diagnosing different cancers, including lung, liver and pancreatic cancer. CT scan images allow doctors to confirm the presence of a tumor and to measure its size, precise location and the extent of the tumor’s involvement with nearby tissues. CT examinations are often used to plan and properly administer radiation treatments for tumors, and to guide biopsies and other minimally invasive procedures.
CT scan clearly shows even very small bones, as well as surrounding tissues such as muscle and blood vessels. This makes it invaluable for the diagnosis and treatment of problems and injuries to the hands, feet and other skeletal structures. CT images can also be used to measure bone mineral density for the detection of osteoporosis.
In cases of trauma, CT can quickly help the physician identify injuries to the liver, spleen, kidneys or other internal organs. CT also plays a significant role in the detection, diagnosis and treatment of vascular diseases that can lead to stroke, gangrene, or kidney failure.
How should I prepare for the procedure?
Wear comfortable, loose-fitting clothing. Metal objects can affect the image, so avoid clothing with zippers and snaps. Remove hairpins, jewelry, eyeglasses, hearing aids, and any removable dental work, depending on the part of your body that is being scanned. You may be asked not to eat or drink anything for one or more hours before the exam. Inform your doctor or x-ray technologist if there is any possibility that your are pregnant.
What does the equipment look like?
The CT scanner is a large, square machine with a hole in the center; it looks like a big doughnut. You will lie still on a table that can move up or down, and slide into and out from the center of the hole. Within the machine, an x-ray tube on a rotating circular frame with a detector on the opposite side moves around your body to produce the images. It may make clicking and whirring noises as the arm moves.
How is the procedure performed?
The technologist begins by positioning you on the CT Table. Your body may be supported by pillows to help you keep still and in the proper position during the procedure. As the study proceeds, the table will move slowly into the opening in the center of the CT scanner. Depending on the area of your body being examined, the increments of movement may be so small that they are almost undetectable or large enough that you will feel the sensation of motion.
A CT examination often requires the use of different contrast materials to enhance the visibility of certain tissues or blood vessels. The contrast material may be injected into your blood stream, given orally, or administered by enema, depending on the type of examination. Before administering the contrast material, the radiologist or technologist will ask whether you have any allergies, especially to medications or iodine, and whether you have history of diabetes, asthma, a heart condition, kidney problems or thyroid conditions. These conditions may indicate a higher risk of reaction to the contrast material or potential problems eliminating the material from your system after the exam. Nursing mothers should wait for 24 hours after contrast material is administered before resuming breastfeeding.
How does the procedure work?
In many ways, CT scanning works like other x-ray examinations. Very small, controlled amounts of x-ray radiation are passed through the body, and different tissues absorb the radiation at different rates. Each time the x-ray tube and detector make a 360-degree rotation and an x-ray passes through your body; the image of a thin section or slice is acquired. During each rotation, the detector records about 1,000 image slices.
A CT examination usually takes from 15 to 30 minutes. When the procedure is over, you may be asked to wait until the images are examined to determine if more images are needed.
What will I experience during the procedure?
CT scanning causes no pain, and with spiral CT, the need to lie still for any length of time is reduced. For different parts of the body, your preparation will vary. You may be asked to swallow a liquid contrast material that allows the radiologist to better see the stomach, small bowel and colon. Some patients find the taste mildly unpleasant, but most can easily tolerate it. Your exam may require the administration of the material by enema if your colon is the focus of the study. You will experience a sense of abdominal fullness and may feel an increasing need to expel the liquid. Be patient; the mild discomfort will not last long.
A contrast material is usually injected into a vein to better define the blood vessels and kidneys, and to accentuate the appearance between normal and abnormal tissue in organs such as the liver and spleen. Some people report feeling a flush of heat or a metallic taste in the back of the mouth. These sensations usually disappear within a minute or two. Others experience a mild itching sensation. Persistent itching accompanied by hives (small bumps on the skin) can be treated easily with medication.
In very 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, so tell the technologist immediately if you experience these symptoms. Fortunately, with the safety of modern contrast materials, these adverse effects are very rare.
You will be alone in the room during the procedure; however, the technologist can see, hear and speak with you at all times. For children, a parent may be allowed in the room with the child to alleviate fear, but may be required to wear a lead apron to prevent radiation exposure.
Who interprets the results and how do I get them?
A radiologist, who is a physician experienced in CT scan and other imaging examinations, will analyze the images, describe any abnormalities, and suggest a likely diagnosis. The radiologist will then send a signed report to your attending physician. Results can be obtained 12-24 hours after the procedure is completed.
Like other specialists, a radiologist must be a graduate of an accredited medical school, passed a licensing examination, and completed at least four years of residency. Radiologists are usually certified by either the Philippine Board of Radiology or the Philippine Osteopathic Board of Radiology.
The CT Scan Room is located at the Upper Ground Floor. For inquiries, please call us at (632) 771-9000 ext. 8133.