Hepatocellular Carcinoma:Evaluating Diaphragmatic Invasion By Measuring Arch Distance-To Maximum Tumor Diameter Ratios

Purpose To develop a noninvasive technique for evaluating diaphragmatic invasion by using routine preoperative dynamic enhanced MDCT.Methods Ninty patients with histopathologically proven hepatocellular carcinoma performed with multiphasic MDCT were retrospectively enrolled, of those MDCT images show the tumor closed to the diaphragm. The length of the interface between the primary tumor and neighboring structures (arch distance) and the maximum tumor diameter were measured on CT images, and arch distance-to-maximum tumor diameter ratios were calculated. The arch distance, diameter and the ratios was analyzed by receiver operating characteristic (ROC) curves. Results The arch distance, maximum tumor diameter and the arch distance-to-maximum tumor diameter ratios of lesions with diaphragmatic invasion was significantly higher than those lesions without diaphragmatic invasion in 3 phases of dynamic contrast enhanced MDCT. The area under the ROC curve for diagnose diaphragmatic invasion of arch distance, maximum tumor diameter and the arch distance-to-maximum tumor diameter ratios was 0.804,0.737,0.814 separately in unenhancement; 0.767,0.735,0.769 separately in arterious phase; 0.851,0.735, 0.893 separately in portal venous phase. With a cut-off at 1.07 of arch distance-to-maximum tumor diameter ratio in venous phase, sensitivity of 89.2% and specificity of 84.9%.Conclusion Measurement of the arch distance-to-maximum tumor diameter ratios in venous phase is a simple noninvasive technique with high performance for evaluating diaphragmatic invasion at MDCT.