CT scan or Computerized Tomography or Computerized Axial Tomography (CAT Scan) makes use of computer-processed combinations of many X-ray measurements taken from different angles to produce three-dimensional images of the scanned area. In 1979 Nobel Prize for Physiology or Medicine was jointly awarded to Allan M Cormack and Godfrey N Hounsfield for development of CAT scan.
The first CT scan done on October 1st 1971 in a hospital in Wimbledon in London and was developed by an electrical engineer (G N Hounsfield). It was done for the brain. By 1998 the CT scan machines gradually improved-but could do scanning of the organs which do not move. The CT scanners were 4-8 slices. The first 16 slice machine was developed in 2002 – which make CT scanners more fast and accurate. But with this scanner also Radiologists were not able to see the coronary blockages as the heart was moving at a high speed.
The scientists made 32 slice scanners in the year 2005 and this is when the heart’s coronary arteries could be scanned by CT scan. This was the first time that without putting a catheter inside the body the blockages of the coronary arteries could be seen. The technology further evolved and in 2006 the 64 slice scanners were developed which could detect and measure the coronary blockages much more accurately.
After the development of 128 slice CT scanner, Cardiac Imaging becomes very easy and within 5 seconds the radiologists can detect very accurately the blockages in the coronary arteries with a high-resolution picture. These images can be rotated, dissected and studied individually. With the use of advanced software, the image qualities can be further improved in 128 slice scanners – making the machines equal to 500 slice scanners.
The latest scanner as on 2018 are 320 slice scans and using dual-source cameras the scanners have become 640 slice CT scanners. The advantages of dual-source cameras are that they can scan the heart in half a second (less than half a heartbeat) and are very useful when the heart rate is very high and the patient cannot hold their breath for long.
Since heart disease is a most common and most fatal disease of the world and India – and is detectable only after the blocks have crossed 70% by symptoms and TMT (Exercise Stress Test) – CT coronary scan is the best way to diagnose heart disease in very early stage. Millions of heart attacks and deaths can be prevented by using this test. It has already replaced the crude method of inserting a tube in the body to diagnose heart blockages by 70%.
Is CT Angiography painful?
A CT angiogram is not painful. The table you lie on may feel hard, and the room may be cool. It may be hard to lie still during the test. If you are having CT coronary angiography, the area where the intravenous line is placed will be numbed beforehand, so you should not feel any pain. After the procedure is over, you may feel some pain where the catheter was inserted. If you feel any discomfort, ask the nurse or doctor for some pain relief.