Comparison of ultrasound, computed tomography, and magnetic resonance imaging in detection of acute wooden foreign bodies in the canine manus

We evaluated the diagnostic sensitivity of ultrasound, nonenhanced computed tomography (CT) and nonenhanced magnetic resonance (MR) imaging in detecting wooden foreign bodies in the canine manus. Identical wooden splinters were manually inserted into 30 cadaver canine manus, and the limbs were evaluated using ultrasound, CT, and MR imaging by independent observers. All sites were rated as positive or negative for the presence of a foreign body, and observer certainty was scored on a 1-10 scale. Using receiver operating characteristic analysis, CT was the most accurate modality for detection of wooden foreign bodies overall and within each of the three individual regions, followed by ultrasound and MR imaging, respectively. Ultrasound evaluations were most limited in the metacarpal pad, where distal acoustic shadowing from the pad surface hindered evaluation of the tissues in some specimens.