With rapidly-advancing medical technology and ready sources of info from the Internet, more and more people are over-eager to submit to CT angiograms(CTA), also known as multi-slice CT of the heart(MSCT). The popular perception is that such scans will be able to diagnose heart disease and help to prevent heart attacks.
The popularity of CTA is largely due to the fact they are non-invasive and the machines are located in non-hospital settings like shopping-malls and office complexes. All a patient needs to do is to lie down, take and hold a deep breath, have a dye injected into a vein in the arm and the whole procedure can be over in a matter of less than 15 minutes. Soon, the patient is presented with colour copies of very graphic 3-D images of his heart, showing where there are blockages in the coronary arteries, if present.
To a certain extent, commercialism have crept in to boost the popularity of these scans. Many of these machines are physician-owned and consequently there may be over-utilisation in order to recoup the USD 1 million cost as quickly as possible.(It will take something like 3000 scans to pay off the machine cost)
What is not generally known is that CTAs use radiation to capture the images. A single heart-scan can expose you to as much as 21 millisieverts of radiation — equal to about 1,050 conventional chest X-rays!
Apart from this, the accuracy of these scans are both machine-dependent as well as operator-dependent. There is a learning curve for any new technology and experience is still being acquired to obtain the best interpretation.
Perhaps the most important factor that needs to be appreciated is that the chances of getting a total blockage (and a heart attack) is not always dependent on the severity of the blockage. This has been proven often as the most minor of blockages can lead to a total blockage in a matter of seconds, following a plaque rupture. So, even a CTA with minor blockages can be as disastrous as one with several severe blockages.
The dilemma facing healthcare providers recently received good coverage from the New York Times.
Even doctors are debating as to who should have one done. Therefore, it is important to appreciate that, while new technology will bring benefits, it must not be used indiscrimately.
It can then become a tool of questionable value that is used by impatient patients.