Comparison of Radiographic, Ultrasound, and Magnetic Resonance Imaging for the Detection of Retained Stingray Barb: A Cadaveric Study.

INTRODUCTION: Stingray envenomations are a common marine animal injury for which it is important to identify and remove retained barbs to prevent secondary infection. The optimal imaging modality in stingray foreign body detection is not well characterized in the existing literature. In this study, we compared the accuracy of plain radiography, ultrasound, and magnetic resonance imaging (MRI) in detecting stingray barbs in the human foot and ankle. METHODS: This cadaveric study included a 1:1 randomization to the presence or absence of barbs in 24 sample injuries of human cadaveric foot and ankle specimens. Physicians trained in emergency medicine and radiology performed ultrasound examinations on each specimen and interpreted the presence or absence of a barb. Participants also interpreted x-ray images in the same manner. MRI scans were separately interpreted by a musculoskeletal radiology attending. Data were analyzed using McNemar's test. RESULTS: The 19 participants included 14 (74%) trained in emergency medicine and 5 (26%) trained in radiology. Forty-seven percent were residents, 42% faculty, and 11% fellows. X-ray was associated with the highest sensitivity of 94% for the identification of a retained barb, followed by MRI (83%) and ultrasound (70%). MRI was associated with the highest specificity of 100%, followed by x-ray (98%) and ultrasound (73%). CONCLUSIONS: Retained stingray barbs can lead to secondary infection after envenomation. In human cadaveric specimens, x-ray demonstrated the highest sensitivity, MRI demonstrated the highest specificity, and ultrasound demonstrated lower sensitivity and specificity.

Utility of Shunt Series in the Evaluation of Ventriculoperitoneal Shunt Dysfunction in Adults.

BACKGROUND: When patients present to emergency departments (EDs) with symptoms suspicious for ventriculoperitoneal shunt malfunction, evaluation often includes imaging of the shunt with both computed tomography (CT) of the head without contrast and a plain radiograph "shunt series" (SS). Recent literature has called into question the diagnostic value of the SS for the detection of ventriculoperitoneal shunt complications, suggesting that the plain radiographs provide redundant information and unnecessary exposure to radiation. OBJECTIVE: The aim of our study was to assess the frequency of abnormal SS plain radiography and head CT in the evaluation of shunt malfunction in all adult ED patients and to measure the association of abnormalities on CT and SS with surgical intervention. METHODS: We performed a retrospective chart review of all emergency department encounters at an urban level I trauma center between August 1, 2013 and October 3, 2018 in which an SS and head CT examination were performed within 24 h of each other. We described the results of imaging studies qualitatively and descriptive statistics were performed. RESULTS: Positive findings on CT were significantly associated with the decision to proceed to surgery. Positive findings on SS, however, were not significantly associated with the decision to proceed to surgery. CONCLUSIONS: The potential information gained from SS and convenience of ordering simultaneously with head CT does not appear to outweigh the risk of increased radiation exposure to the patient, the additional costs of the study, and the potential delay in time to head CT. These findings support the initial use of head CT in evaluation of shunt malfunction.