Dinesh Singh, MD, discusses reducing radiation risk in kidney stone imaging

In this video, Dinesh Singh, MD, associate professor of urology, Endourology Chief, Urology; director of Laparoscopy & Endourology, Urology; and director of the Endourology Fellowship, Urology at Yale School of Medicine in New Haven, Connecticut, discusses growing concerns about radiation exposure in patients with kidney stone disease, emphasizing that awareness of this issue has emerged relatively recently.

Research over the past decade has shown that medical imaging, particularly CT scans, contributes meaningfully to long-term cancer risk. Large population models estimate that tens of thousands of cancers each year in the United States may be linked to radiation from diagnostic imaging. These cancers include not only blood malignancies such as leukemia but also solid tumors, including colorectal, bladder, and lung cancers.

Patients with kidney stones are especially vulnerable to cumulative radiation exposure because recurrence rates are high—about half will develop another stone. As a result, many undergo repeated imaging, with an average of 1 to 2 CT scans per patient and up to 10% receiving 5 or more scans. Singh notes that clinicians often focus on immediate diagnosis and treatment, particularly in emergency settings, without fully considering the long-term consequences of repeated radiation exposure that patients may experience years later.

At Yale, efforts have focused on reducing radiation exposure through research and protocol changes. Standard CT scans used to evaluate acute flank pain typically expose patients to approximately 10 to 12 millisieverts of radiation. A randomized study compared conventional CT scans with low-dose CT imaging in suspected kidney stone cases. The findings showed that low-dose CT scans were 100% sensitive for detecting ureteral stones larger than five millimeters—those most likely to require intervention. Smaller stones were occasionally missed, but these are usually managed conservatively with observation rather than surgery.

The study also addressed concerns about missing alternative diagnoses. Clinically significant findings overlooked by low-dose scans occurred in only about 2% to 3% of cases and would likely be identified with follow-up imaging if symptoms persisted. Singh concludes that increasing physician awareness and comfort with low-dose imaging is key to reducing unnecessary radiation while maintaining diagnostic accuracy and patient safety.