Does oral radiocontrast affect image quality of abdominal sonography?

OBJECTIVE: Emergency Department patients with abdominal pain may require both an ultrasound (US) and computed tomography (CT) for an accurate diagnosis. Patients are often asked to drink oral radiocontrast while awaiting ultrasound, in order to better expedite a CT in the case of a non-diagnostic US. The impact of oral radiocontrast on US image quality has not been studied. We compared the quality of US images obtained before and after the ingestion of oral radiocontrast in healthy adult volunteers.

METHODS: This was a prospective study in which adult volunteer subjects underwent sonographic studies of the aorta, the right upper quadrant, the right lower quadrant, and the Focused Assessment with Sonography in Trauma (FAST) examination. Initial studies were performed prior to ingestion of oral radiocontrast, with subsequent imaging occurring at 1 and 2hour post-ingestion. All of the images from the sonographic exams were randomized and subsequently scored for quality by two emergency ultrasound fellowship trained emergency physicians with extensive experience in performing and interpreting US.

RESULTS: 638 images from 240 exams were obtained from 20 subjects at three time points. Six exams were not scored due to inadequate images. There were no significant differences in image quality for any of the US exam types after the ingestion of oral radiocontrast at 1 and 2h.

CONCLUSION: Ingestion of oral radiocontrast did not affect image quality of four common abdominal ultrasound examinations.