Very soon, our teaching hospital, located in a village in central India, shall use a new computed tomography (CT) equipment for obtaining high-quality radiologic images. The previous CT scanner- it had served us well for 10 years – was living a borrowed life. The hospital, therefore decided to invest into a new CT scanner.

The new CT scanner would surely change the way we make diagnoses, choose therapies and predict disease-related uncertainties. No one can deny that CT scanners- they have entered into a presbyopic age now- have helped us pick the strokes, cancers, infections, inflammations, and degenerations with reasonably good accuracy. Our radiology consultants and residents have every reason to be visibly excited. Then why should I sound a bit skeptical when it is time to celebrate?

For several reasons. I think that the risks, benefits, and costs of CT are often not publicly discussed by the doctors. Patients naively believe that the state of the art technology can reveal almost everything that their doctors wished to see, and once detected, these faults can easily be fixed. We cannot blame patients for such a wishful thinking. The glamour and the glitter of the technology can be very seducing. The images that a CT generates look too good to disbelieve them. The problem is with the healthcare professionals- they make no efforts to correct these wrong impressions. There are three reasons which should make the medical professionals realize that all is not well with the CT. Let me explain them.

First, many patients are being subjected to CT scans for wrong reasons. They need careful history and structured physical examination- and not a CT scan- to either rule in a disorder or exclude it. For example, tension headaches and migraines account for most headaches in primary care, but waiting halls of CT centers are occupied by patients with such headaches, whose cause can be easily and accurately diagnosed by a history alone. Less than 1 percent of patients with severe headaches- and normal neurological exam- have serious brain disorders and therefore, are unlikely to be benefitted by CT scans. And yet, CT head is routinely ordered by doctors as a screening test to confirm or rule out serious brain disorders. Take head injuries, a common reason for referral for a CT scan. A recent BMJ article teaches how to reduce use of CT scans in minor head injuries. Only 1 of 10 patients judged to have mild head injury has a clinically important finding on CT scan, and only 1 of 100 such patients require a neurosurgery. Patients at risk can be easily identified if doctors apply clinical decision rules on them- a task that requires no more than few minutes. And yet, almost every patient, regardless of the severity of head injury undergoes a mandatory CT scan in every hospital where such an equipment exists. Similalry, patients presenting with aching necks and stiff backs- a common problem in primary care- routinely undergo neuroimaging despite substantial evidence that imaging them is unnecessary, and is a waste of time, efforts and money. Researchers have shown that on CT imaging of the lumbar spine, a quarter of healthy people without backache have herniated discs and half the healthy backs have anatomical changes that are reported as significant by the radiologists. When orthopedic surgeons try to fix these findings, they are, according to the New England Journal of Medicine article, actually raping the lumbar spine!

Second, CT scans often discover unexpected –and irrelevant- findings. When patients alarmed by these findings seek medical consultation, doctors do not know how to interpret or address them. Radiologists frequently report asymptomatic healed ischemic infarcts in elderly people, degenerative changes in cervical and lumbar spines and adrenal gland tumors- appropriately called incidentalomas- which not only confuse the doctors, but also frighten the patients. Jerome Groopman quotes Dr. Terry Light in his book, “You can see so many things on an MRI, but nothing that’s clearly responsible for the symptoms. So you begin to go around and around. The hateful part of MRIs – I mean they can be a wonderful technology-but they find abnormalities in everybody. More often than not, I am stuck trying to figure whether the MRI abnormality is responsible for the pain. That is the really hard part.”

Third, CT scans, instead of saving a life, can cut it short. Rebecca Smith-Bindman questions the safety of CT technology in his very readable NEJM article. The author says that patients receive 100 to 500 times more radiation from CT scans than they do from conventional radiography and run a 1 in 50 risk of developing CT-generated cancer— a risk played down by the industry and the medical profession. The irony is that patients with benign headaches, minor head injuries, aching necks and stiff backs- the very people who frequently find their way into CT rooms, are not even aware of these risks- probably because their doctors are either as ignorant or do not have time to explain pluses and minuses. Let the CT specialists count the number of patients who visit their center, after they have prominently displayed this warning at their reception desk: “Of the 100 people examined by our CT scanner, two might eventually develop a CT-induced cancer.” Only patients will brave hearts will submit their heads for CT screening after they read this warning.

Finally, CT equipment is expensive. It costs about 15 million rupees to acquire a decent CT scanner and about 2 million rupees every year to maintain the equipment. My radiologist friend tells me that if they bill Rs. 2000 for a scan, and scan 10 heads, chests or bellies every day, they will have to wait for five years before they recover the cost of a machine- and by then the technology turns obsolete. Because it will be difficult to generate this number by a clean and honest practice, most doctors who own CT equipment promote the technology by inventing new indications for CT scanning, by cleverly placed stories in the newspapers, by lecturing in events organized by equipment manufacturers and social clubs, and by offering commissions to the doctors. “Half the patients who receive CT scans in my clinic,” he says, “do not need this test” but I do not refuse, for, I have to keep referring doctors and patients happy. Even in teaching hospitals, the very institutes where scientific evidence, and not commerse, should guide the use of diagnostic tests, CT scans are ordered indiscriminately and inappropriately. The worth of a radiology department is measured not by the number of unnecessary tests that it could avoid but by the number of CT scans the radiologists did. The more, the better. Hospital managers, morbidly obsessed with numbers and infatuated with technology can harm evidence-based healthcare. And when commerse impacts science, the art of medicine dies a unwept death.

Can we inject a bit of science when we order CT scans? Can we go back to history and physical examination before we hastily scribble a request for a CT scan? Can we invest some time with our patients explaining them that for several common disorders CT scans are not worth the time, money and efforts it takes to generate the images.

An image-shattering task for health professionals!