Multi Detector CT

What is Computed Tomography?

Computed Tomography (also known as CT or CAT scan) uses special x-ray equipment to obtain image data from different angles of the body. The information is then computer processed yielding exquisite high resolution cross-sectional images (or “slices”) of body tissues and organs. CT is especially useful because it can simultaneously show many different types of tissue including the lungs, heart, bones, soft tissues, muscle and blood vessels. Contrast material is sometimes given by intravenous injection to make the area of interest more visible on the images.

How is CT used in diagnostics?

Because CT provides detailed, cross-sectional views of all types of tissue, CT is one of the best tools for studying the lungs, bowel, liver, spleen, pancreas, kidneys and other internal organs of the abdomen and pelvis.It is often the preferred method for diagnosing and staging different types of cancers, including lung, liver and pancreatic cancer, since the images allow a physician to confirm the presence of a tumor and to measure its size, precise location, and the extent to which the tumor may have spread. CT examinations are often used to plan and properly administer radiation treatments for tumors, to guide biopsies and other minimally invasive procedures, and to plan surgery and determine surgical respectability. CT can clearly show even very small bones, as well as surrounding tissues such as muscle and blood vessels, making it invaluable in diagnosing spinal problems and abnormalities of the extremities and other skeletal structures. CT also plays a significant role in the detection of vascular diseases that can lead to stroke, kidney failure, or even death.

What can a person expect during the CT procedure?

The first step is for the CT Technologist to correctly position the patient on the CT table. The patient will be told to lie still, usually on his or her back. The table slowly passes through the center of a large, donut shaped x-ray machine. The patient might hear whirring sounds during the procedure as the x-ray tube and detectors rotate. Patients may also be asked to hold their breath for certain studies to prevent movement within the pictures. The patient will be alone in the scan room during the actual CT scan, but the technologist will always be able to see and hear the patient and communicate with them from the control room. The study typically takes between 15 to 30 minutes, depending on the type of study. Under certain circumstances, as when evaluating blood vessels, the patient will have iodine containing contrast material injected into an arm or hand vein shortly before scanning begins. He or she may feel a flush of heat or a metallic taste in the mouth, usually lasting no more than a minute or two. In addition, oral contrast may be administered for up to 1-1 ˝ hours prior to the scan in order to help visualize the stomach, intestines and large bowel.

What are some of the common uses for a CT Study?

CT Chest: Used to evaluate the lungs, especially to investigate more closely findings detected on conventional chest x-rays. Also used to evaluate the heart, aorta and coronary arteries to detect aneurysms and blockages that may lead to heart disease.

CT Abdomen and Pelvis: Used to accurately diagnose the many causes of abdominal pain, such as appendicitis, diverticulitis, pancreatitis, and ovarian cysts. Also used to detect and stage primary and metastatic tumors of the internal organs. A specialized study, virtual colonography, can help detect colonic polyps and early colon cancers before they are symptomatic.

CT Brain: Used in detecting skull fractures and brain injuries in patients with trauma, identifying stroke and intracranial bleeding, evaluating headache, detecting brain tumors, non-invasively assessing for aneurysms and arteriovenous malformations, identifying inflammation or tumors in the sinuses and ears, detecting diseases or malformations of the skull.

CT Spine: Used to detect disc herniations, arthritis and narrowing of the spinal canal which may cause nerve injury, identifying fractures of the vertebrae in patients with trauma or osteoporosis, assessing for metastatic disease to the spine in cancer patients.

CT Angiography: Uses x-rays to non-invasively visualize blood flow in arterial vessels throughout the body. CT Angiography can used to evaluate the pulmonary arteries for blood clots, visualize blood flow in the arteries supplying the kidneys, identify aneurysms and dissections of the aorta and other major blood vessels, identify small aneurysms or arteriovenous malformations inside the brain, detect atherosclerotic blockages in the coronary arteries and arteries to the legs and arms.