Penetrating Colorectal Injuries: Diagnostic Performance of Multidetector CT with Trajectography

Abstract

Purpose To determine the diagnostic performance of multidetector computed tomography (CT) with trajectography for penetrating colorectal injuries. Materials and Methods This institutional review board-approved and HIPAA-compliant study was a 6-year blinded retrospective review by two independent readers of 182 consecutive patients who preoperatively underwent 40- or 64-row multidetector CT for penetrating torso trauma below the diaphragm and had surgically confirmed findings. Colorectal perforation was present in 42 patients. Trajectory analysis with postprocessing software was used for all studies. Additional signs evaluated were rectal contrast agent leak, collections of extruded fecal material, mural defect, wall thickening, abnormal enhancement, free fluid or stranding, and free air. The quality of the colorectal contrast agent administration was recorded. Sensitivity, specificity, predictive values, areas under the receiver operating characteristic curves (AUCs), and Cohen κ were determined. Results In patients with rectal contrast agent administration (n = 151), AUCs were 0.90-0.91, which indicated excellent accuracy. Trajectory was sensitive (88%-91%). For single wounds (n = 104), sensitivity of trajectory was 96% for both readers, but was only 80% for multiple wounds (n = 47). Contrast agent leak was highly specific (96%-98%), but insensitive (42%-46%). Improved diagnostic performance was observed in patients with poor colonic distension or opacification. Accuracy remained high (AUC, 0.86-0.99) in the group without rectal contrast agent administration (n = 31). Conclusion Trajectory had excellent sensitivity, while rectal contrast agent leak was specific but insensitive. Sensitivity of trajectory was lower for multiple wounds. Accuracy remained high in patients without rectal contrast agent administration. RSNA, 2016.

Accuracy of Preoperative MDCT in Patients With Penetrating Abdominal and Pelvic Trauma

“…1 Furthermore, studies have evaluated the use of CT tractography, which has proven itself as a more reliable indicator of bowel injury than leakage of enteric contrast, with sensitivities up to 96% and specificities of up to 78% compared to sensitivities of up to 46% and specificities of up to 98% for enteric contrast leakage. 10 In a study by Salim et al, it was found that single-contrast MDCT had an overall sensitivity of 100% and specificity of 81%. 4 Oral and rectal contrast use comes with its own limitations, of which the most significant setback is the time required for administration and transit of contrast, as it poses as a diagnostic delay.…”

Diagnostic performance of CT and the use of GI contrast material for detection of hollow viscus injury after penetrating abdominal trauma. Experience from a level 1 Nordic trauma center

“…Trajectography (i.e. the use of postprocessing software to evaluate wound tracts) is an emerging method for diagnosing GIT injury with reported excellent sensitivity while rectal contrast is reported as specific but insensitive for these injuries (13). Tractography has also been reported to perform better than conventional CT for detecting peritoneal violation (14).…”

Imaging Ballistic Injuries

“…In stable and semistable patients, CT is the gold standard of evaluation. Although there are numerous CT scanning protocols proposed in the literature, 25 -34 by consensus the authors of this article advocate the protocol in Table 1. Irrespective of how an institution chooses to image ballistic trauma patients, the authors of this article strongly discourage attempting to modify or institute a new protocol “on the fly.” We believe that if there is no dedicated missile trauma protocol available, you should use your institutions standard imaging protocols under direct radiologist supervision with the addition of delayed imaging an additional arterial phase or CT cystography based on the “at the scanner” radiologist review of the initial imaging.…”