Abstract:

Objective To develop a noninvasive technique for evaluating diaphragmatic invasion using routine preoperative dynamic enhanced MDCT. Methods This retrospective study involved 90 patients with histopathologically proven hepatocellular carcinoma and in whom multiphasic MDCT indicated that the tumor was close to the diaphragm. The length of the interface between the primary tumor and neighboring structures（arch distance） as well as the maximum tumor diameter were measured from the images， and the ratio of arch distance to maximum tumor diameter was calculated. Ratios were analyzed using receiver operating characteristic （ROC） curves. Results In 3 phases of dynamic contrast-enhanced MDCT（plain，arterial and venous），the ratio of arch distance to maximum tumor diameter was significantly higher for lesions showing diaphragmatic invasion than for those not showing diaphragmatic invasion. The area under the ROC curve for diagnosing diaphragmatic invasion was 0.893 in the venous phase，0.769 in the arterial phase and 0.814 in the plain phase.With a cut-off of 1.07，using the technique in the venous phase allowed diagnosis of diaphragmatic invasion with a sensitivity of 89.2% and specificity of 84.9%. Conclusion Measurement of the ratio of arch distance to maximum tumor diameter in the venous phase of MDCT is a simple and effective noninvasive technique for detecting diaphragmatic invasion.

Key words: Liver neoplasm, Computed tomography, Diaphragm, Diaphragmatic invasion, Diagnosis