Vessel-Penetrating Sign in the Liver: MR Imaging Manifestations of Various Liver Pathologies

Kenji Matsuzaki¹, Mayumi Takeuchi¹, Masafumi Harada¹

Preserved intrahepatic vessels may be observed within various benign and malignant pathologies in the liver as "vessel-penetrating sign" (VPS) on imaging. MRI has an advantage to demonstrate vessels without the administration of contrast medium as flow voids on spin echo sequences with long TR; echo planar diffusion-weighted imaging, or as high signal intensity structures on gradient echo sequences with steady state free precession. The presence of VPS suggests infiltrative tumor growth, highly non-destructive tumors, mass formed by the aggregated malignant tumors, or benign tumor-like conditions. We present diagnostic imaging features of various liver lesions, which show VPS, with pathologic correlation.