A clinically relevant liver injury grading system by CT, preliminary report

Current computed tomography (CT) grading scales are anatomic and do not reliably identify those liver injuries requiring intervention (surgery or angioembolization). We propose a clinically relevant CT grading system that could predict need for intervention. CT scans of 11 patients with hepatic injury were reviewed to establish criteria that correspond with intervention. Five features were identified that were associated with intervention: laceration in greater than or equal to three segments, laceration extending into the hilum, hemoperitoneum, active extravasation, and sentinel clot. Radiologists then evaluated the predictability of these criteria by analyzing 24 CT scans. Inter-observer agreement of the American Association for the Surgery of Trauma (AAST) grading system was compared to this new system. In the analysis of 24 CT scans, active extravasation and sentinel clot demonstrated the highest specificity for intervention. This new grading system had superior inter-observer agreement (k=0.56) as compared to the AAST grading system (k=0.47). Active extravasation and the presence of sentinel clot should form the foundation of a new liver grading system.