CT scans are known to be effective at finding pulmonary embolisms - sudden blockages in the arteries of the lungs. But according to The New York Times in an article this week, the scans also detect tiny embolisms that are harmless. These “harmless” detections lead to unnecessary surgery, expensive and potentially dangerous.
Prior to the introduction of the CT angiography test for pulmonary embolisms in 1998, patients inhaled radioisotopes and doctors imaged the blood and airflow patterns. Today’s CT angiographies have led to an 80 percent increase in the diagnoses in pulmonary embolisms.
While more complex and sensitive, CT scans are not necessarily safer than older tests. Like modern CT angiography, the radioisotope test exposed patients to a small but allegedly insignificant amount of radiation. The common treatment for pulmonary embolism is blood thinning medication - the leading cause of death among prescription drugs. And anticoagulation treatment may last the patient’s entire life.
But in order to avoid any appearance of malpractice, doctors would rather order the newer test. “There’s a lot of pressure to order the most advanced tests, no matter how small the problem,” said Dr. Renda Solymez Wiener, one of the study’s researchers and an assistant professor at Boston University. “We want to raise awareness that this kind of clinically insignificant embolisms can occur.” One way to do this is to integrate guidelines for these kinds of tests into hospital computers, according to Dr. David J. Brenner, Director of the Center for Radiological Research at Columbia University.
This finding presents a difficult decision for doctors. Pulmonary embolisms are potentially fatal - I shared with you a story about a man who died after doctors ignored his symptoms likely because he also just had hip replacement surgery. But anticoagulant drugs like warfarin are also very dangerous and taking the wrong dosage can also be fatal. If the drug is unnecessary, it should probably be avoided.
A Columbia University doctor had some sound advice in the Times article. “From the patient’s or parent’s perspective, it is completely appropriate to ask the physician, and discuss with him or her, why a CT scan is being ordered and what useful information will come from it.”
