Ultrasound just as effective as CT in detecting kidney stones

The use of ultrasound to detect kidney stones is just as effective as CT, according to a study in the Sept. 18 issue of the New England Journal of Medicine.

"It's actually quite surprising that ultrasound is just as good as CT scanning when you look at patient outcomes," lead author Rebecca Smith-Bindman, of the University of California, San Francisco, told Reuters Health.

The large multicenter trial compared three groups of patients who were randomly assigned to receive either point-of-care ultrasound by an emergency physician, ultrasound by a radiologist, or an abdominal CT scan as their initial imaging study for suspected nephrolithiasis

The researchers compared the accuracy of the ultrasound and CT, as well as the 30-day incidence of any high-risk complications associated with delayed or missed diagnoses, and cumulative radiation exposure.

They found that there was no significant difference between ultrasound and CT regarding the sensitivity and specificity of the tests. They also found the incidence of high-risk diagnoses with complications in the first 30 days was low and didn't vary according to imaging methods. And the mean six-month cumulative radiation exposure was significantly lower in the groups undergoing ultrasound compared to the CT group.

There also was no significant difference in related serious adverse events across the three groups. Serious adverse events occurred in 12.4 percent of the patients assigned to point-of-care ultrasonography, 10.8 percent of those assigned to radiology ultrasonography, and 11.2 percent of those assigned to CT.

Smith-Bindman told Reuters that as the study progressed both physicians and patients became more comfortable with the idea of using ultrasound first, rather than CT, which has traditionally been the modality of choice for detecting kidney stones.

In January, FierceMedicalImaging reported that scientists at the University of Washington's Applied Physics Laboratory had developed a new device that allows doctors to use ultrasound to move kidney stones inside the body and help them pass naturally.

Researchers at the Children's Hospital at Montefiore in New York determined that the use of ultrasound as the first imaging option to detect appendicitis in children yields comparable results to CT and doesn't result in increased hospital stays, according to an article published last December in the American Journal of Roentgenology.

To learn more:
- see the study in New England Journal of Medicine
- read the Reuters Health article