Low-Dose CT Scans for Kidney Stone Detection

Kidney stones are a common—and often excruciating—medical condition that affects more and more Americans every year. Incidence has more than doubled (3.8% to 8.8%) since the 1970s.

There are different kinds of kidney stones, each of which causes significant suffering for the patient when the stones (made of hard deposits of calcium, phosphates or uric acid) get stuck during their passage from the kidney to the ureter on the way to the bladder. Unfortunately, people who’ve had kidney stones once are 50% more likely to get one in the future.

To diagnose kidney stones, doctors usually order a CT scan. But repeated scans can cause a buildup of radiation. "This radiation exposure is not something that you get and it washes out of your system," says urologist Dinesh Singh, MD. "Radiation exposure is cumulative, so the more CT scans you have, the more radiation exposure you get.” This can cause health problems, including even the development of cancer, he notes.  

This concern inspired Dr. Singh to explore potential ways to reduce radiation exposure for kidney stone patients. Now, Dr. Singh has demonstrated in clinical studies that kidney stones can still be identified when scans use far less radiation. In fact, even after reducing the radiation in the scans by 87% (compared to a full-dose, standard CT scan), Dr. Singh and his colleagues didn't miss any clinical findings. Dr. Singh says he hopes the low-dose radiation will eventually become standard for kidney stone patients. 

"It's an area where research became part of everyday practice," he says, "[Research is] making our understanding of medicine better, and making the patients' lives better by applying some of these techniques or new drugs or new technologies to improve their care.”

To learn more, visit Yalemedicine.org.