CT Scans are special X-Ray tests that produce cross sectional images of the body using X-Ray and a Computer. It can be performed on any part of the body from head to toe. The information provided by CT scan is far more than that from a chest X-Ray.
Pregnant women should not undergo CT scan.

During the test, you lie on a table that is attached to the CT scanner, which is a large doughnut shaped machine. The area to be examined passes through the machine. The CT scanner sends large number of X-Ray beams through the body which are picked up by sensors and the images are computer processed to finally provide cross sectional images of the part examined.

CT scan uses a large number of X-Ray beams which criss-cross the body to acquire minutest details inside of the body. It entails lot of X-Ray exposure. A typical CT scan of the chest is equal to 500-600 Chest X-rays in terms of radiation exposure.

CT scan of the chest can detect most minor of abnormalities in the lungs. Pneumonia, Tuberculosis, Cancers, Fluid around the lungs, air around the lungs and a host of diseases affecting the organs examined can be detected by the CT scan. It is currently the most commonly performed and most sensitive test for detailed evaluation of various chest diseases.

Low Dose CT Scan is currently the only investigation which has proved useful in early detection of lung cancer -much before even the symptoms develop. A big trial in US has shown 20% reduction in lung Cancer related death rates by the use of low dose CT scan in “susceptible population”. Persons above the age of 45 years with over 20 years history of smoking stand to benefit from screening for lung cancer by low dose CT scan.