Bedside sonography in the emergency department demonstrated efficacy in identifying urinary stones, according to a review of 125 patient charts with CT and ultrasound results. The study was published in the Western Journal of Emergency Medicine. Overall sensitivity of ultrasound for detecting hydronephrosis was 78.4%, while sensitivity of a positive scan detecting hydronephrosis or visualized stones was 82.4%. Sensitivity was better for larger stones and a greater number of stones. The condition is usually diagnosed using non-contrast CT.