Addition to skeletal survey for child abuse improves rib fracture detection

Adding bilateral oblique rib radiographs to the skeletal survey for child abuse results in increased rib fracture detection and increased reader confidence, according to a study published in the April issue of the American Journal of Roentgenology.

An essential part of an evaluation of suspected child abuse is the skeletal survey. Rib fractures are the most common fracture in abused children, yet their detection is often radiographically challenging. In 2011, a recommendation for the routine oblique views of the ribs was added to the American College of Radiology’s appropriateness criteria guidelines for imaging in children under 2 years old with suspected physical abuse. Lead author Megan B. Marine, MD, of the Riley Hospital for Children in Indianapolis, and colleagues aimed to determine whether the addition of oblique views of the ribs increases rib fracture detection.

The researchers identified 212 patients under the age of 2 who underwent a skeletal survey for suspected child abuse from January 2003 to July 2011 and had at least one rib fracture. These patients were then age-matched with control subjects without fractures. Two randomized radiographic series of the ribs were performed: one contained two views and the other contained four views that included the right and left oblique.

Results revealed that the sensitivity and specificity of the two-view series were 81 percent and 91 percent, respectively. Sensitivity and specificity for detection of posterior rib fractures were 74 percent and 92 percent, respectively. Data indicated good agreement between observers for the detection of rib fractures in both series, with average kappa values of 0.70 for the two-view and 0.78 for the four-view. Confidence significantly increased for the four-view series.

“Adding bilateral oblique rib radiographs to the skeletal survey for child abuse results in significantly increased (19%) rib fracture detection. Therefore, the new ACR Society of Pediatric Radiology practice guideline of addition of bilateral oblique views of the ribs is justified,” Marine and colleagues concluded.