CAT Scan

From Medical-Wiki

The CAT, or CT, Scan is a painless and non-invasive medical test that is routinely used for diagnostic purposes and for assisting in the placement of surgical instruments. It is an advanced cross-sectional imaging study that takes multiple images and combines them to view internal structures. These views give a greater clarity and representation of the soft tissue than X-rays. It has become the gold standard test for the detection of many disease processes and has been beneficial in the treatment of the neurological system.

1 How CAT Scans work
2 General CAT Scan Uses in Neuroradiology
3 CAT Scan in Trauma
4 Most Commonly Tested USMLE/Board Questions regarding CAT Scan
5 Benefits of CAT Scan
6 Risks of CAT Scan
7 References

How CAT Scans work

Much like plain films, CAT scans work by transmitting radiation throughout the body and subsequently absorbing the X-ray beams. However, in CAT scans there are numerous electronic detectors that pick up the waves while the table repositions the body to obtain multiple thin-slice images that are used to view three-dimensional images of the inside of the body[1]

CAT scans are often enhanced by the administration of contrast material, which can be either swallowed, given by enema, or injected through an intravenous line.

General CAT Scan Uses in Neuroradiology

Frontal view of Human Skull

The CAT scan has been indicated in the following common CNS conditions:

•Acute stroke

•Transient ischemic attack

•CNS infections in immunocompromised patients, such as those suffering from HIV

•Brain calcifications

•Fractures of the skull or facial bones

•Foreign bodies

•Chronic headache

CAT Angiography is a special kind of CAT scan that helps visualize blood vessels in the body, locating vessel aneurysms, atherosclerosis, arteriovenous malformation, aortic dissection, thrombosis, and in evaluation of the vessel wall for surgical procedures, including coronary bypass. This particular form of CAT scan has proven extremely beneficial to the field of neuroradiology- it is minimally invasive.

CAT Scan in Trauma

The CAT scan has evolved into the test of choice in trauma patients, a revolutionary advancement from the radiograph. It is relatively easy to interpret, reliable, and a suitable image may be obtained in a short time. Ultrafast CAT scanners can perform a head CAT scan in less than one minute.

The standard CAT scan performed in patients of traumatic injury is generally a noncontrast scan that spans from the base of the occiput to the top of the vertex in 5-mm increments.