AJR:174, June 2000 1613 Abdominal Sonography in Examination of Children with Blunt Abdominal Trauma OBJECTIVE. The objective of our study was to evaluate abdominal sonography for the detection of fluid and organ injury in children with blunt abdominal trauma. SUBJECTS AND METHODS. Fifty-one consecutive children with blunt abdominal trauma requiring abdominal CT were prospectively examined with sonography. Sonograms and CTs were independently evaluated by two radiologists for fluid and organ injury; CT ex- aminations were considered abnormal if either was identified. Differences in CT interpreta- tion were settled by a third observer. Using CT as the truth standard, we calculated the sensitivity, specificity, and negative predictive value of sonography for both observers. Agree- ment of the sonographic interpretations was evaluated using kappa statistic. RESULTS. In 33.3% of patients, CT revealed fluid, organ injury, or both. The sensitivity and specificity of sonography when detection of fluid was the sole parameter evaluated was 58.8% and 79.4%, respectively, for observer 1 and 47.1% and 79.4%, respectively, for ob- server 2. In contrast, the sensitivity and specificity of sonography when detection of both fluid and organ injury was evaluated was 64.7% and 79.4%, respectively, for observer 1 and 70.6% and 70.6%, respectively, for observer 2. The negative predictive value of sonography was 79.4% and 75.0% with evaluation limited to detection of fluid and 81.8% and 82.8% with evaluation of fluid and organ abnormality for observers 1 and 2 , respectively. Agreement was excellent for sonographic identification of fluid ( κ = 0.82) but poor for detection of organ in- jury (κ = 0.34). CONCLUSION. The low sensitivity and negative predictive value of sonography when assessing for either fluid alone or fluid and organ injury suggest that a normal screening sonography alone in the setting of blunt abdominal trauma fails to confidently exclude the presence of an intraabdominal injury. ach year approximately 600,000 children in the United States are hospitalized for trauma-related in- juries [1], and approximately 20–30% of these injuries involve the abdomen. Most abdominal injuries in children are caused by blunt, rather than penetrating, trauma. After blunt abdomi- nal injury, children who are hemodynamically stable frequently undergo contrast-enhanced CT of the abdomen and pelvis. Abdominal and pelvic CT are performed because of the diffi- culty in determining whether an abdominal in- jury is present after physical examination and laboratory analysis. Because up to 80% of CT scans obtained in this setting have normal find- ings [2], it has been proposed that screening with abdominal sonography might be an alter- nate rapid, cost-effective, and radiation expo- sure–free means of excluding abdominal injury [2–5]. However, others believe that CT should remain the study of choice because of its increased sensitivity for the detection of in- trabdominal injuries in children after blunt trauma [6–10]. The purpose of this prospective study was to directly compare sonography with CT for the detection of intraabdominal in- jury with both techniques performed on the same trauma patients. Additionally, the accu- racy of abdominal sonography after blunt ab- dominal trauma in children concomitantly undergoing abdominal CT was assessed. This study format allowed us to determine the sen- sitivity and specificity of sonography for de- tection of intraabdominal fluid alone and of both fluid and organ injury using CT as the truth standard. Ellen C. Benya 1 Jennifer E. Lim-Dunham 2,3 Orlando Landrum 2 Mindy Statter 4,5 Received July 6, 1999; accepted after revision November 2, 1999. 1 Department of Radiology, Children’s Memorial Hospital, 2300 Children’s Plaza, Chicago, IL 60614. Address correspondence to E. C. Benya. 2 Department of Radiology, University of Chicago Children’s Hospital, 5841 S. Maryland Ave., Chicago, IL 60637. 3 Present address: Department of Radiology, Loyola University Medical Center, 2160 S. First St., Maywood, IL 60153. 4 Department of Surgery, University of Chicago Children’s Hospital, Chicago, IL 60637. 5 Present address: 7129 Jahnke Rd., Richmond, VA 23225. AJR 2000;174:1613–1616 0361–803X/00/1746–1613 © American Roentgen Ray Society E Downloaded from www.ajronline.org by 52.73.204.196 on 05/17/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved