Diagnosing Kidney Stones: Ultrasound’s Edge Over CT Scans

Using ultrasounds instead of computed tomography (CT) scans to diagnose urinary stone disease is safer and less costly, according to a new study.

Whenever kidney stones are suspected, the diagnosis is usually confirmed using imaging. CT scans have been increasingly tapped for this job to rule out other conditions. But data compiled from 15 U.S. medical centers found that this is not necessarily the best initial diagnostic test and that ultrasound might actually be the better choice.

In the study, patients who entered the emergency room with symptoms of kidney stones were randomly assigned to get a CT scan or an ultrasound. There were a total of 2,700 patients, aged 18 to 75.

Researchers monitored serious adverse events that occurred within 30 days of the diagnostic tests along with return emergency room visits and subsequent hospitalizations. No substantial differences emerged between patients who had a CT scan and those who received an ultrasound.

However, in comparing radiation exposure and imaging costs over a six-month period, scientists noted significant differences.

Average cumulative radiation exposures of patients who had an ultrasound were much lower (10.5 mSv for ultrasound done by an emergency room physician and 9.3 mSv when performed by a radiologist) than those who received a CT scan (17.5 mSv).

Ultrasound costs were also lower, averaging $150 and $200 when carried out by an emergency room physician and radiologist, respectively. CT scan costs averaged $300.

With the priority on patient safety and concerns over rising medical expenses, the study underscores the importance of minimizing cancer risks and providing cost-effective health care in kidney stone cases. And the key to it all just might be ultrasounds.