Is digital tomosynthesis or ultrasonography best for diagnosing urolithiasis?

Digital tomosynthesis (DT) performed “significantly” better than ultrasonography (USG) in detecting stones formed in the ureters—and it may become the preferred method of diagnosing urolithiasis.

Currently, unenhanced multi-detector computed tomography (MDCT) is considered the gold standard for detecting kidney stones, but the modality also delivers the highest radiation dose among imaging methods, according to a study published in the European Journal of Radiology.

“[T]here is a need for an imaging technique that can be used multiple times, involves minimal radiation risk while being reasonably sensitive and specific for detecting calculi,” wrote corresponding author Ajay Gulati, with the department of radio-diagnosis and imaging at the Postgraduate Institute of Medical Education and Research in India (PGIMER), and colleagues.

The prospective study included 66 patients who had underwent DT, USG and MDCT within 24 hours of each another. Two radiologists organized calculi according to their location and size.

Results showed no statistically significant difference between USG and DT in detecting urolithiasis. The sensitivity of DT (47.1 percent) lagged behind that of USG (50.9 percent) in detecting renal calculi. However, the sensitivity of DT in detecting ureteric calculi outperformed USG (74.9 percent and 39.2 percent, respectively).

“We are tempted to opine that DT may be preferred over USG for initial evaluation of patients with suspected ureteric calculi,” wrote Gulati et al. “However, considering the strength of ultrasound in demonstrating associated signs as hydoureteronephosis, we are still of the opinion, that both DT and USG should be used as complementary techniques in resolving these common clinical scenarios.”