Malignant hepatic tumors: Changes on MRI after hepatic arterial chemoembolization - Preliminary findings

This study describes the MR appearances of malignant hypervascular liver le sions pre- and post-hepatic-arterial chemoembolization, with correlation to serial imaging and clinical responses, Eight patients with malignant hyper vascular liver lesions underwent pretreatment and posttreatment MR examinat ion on a 1.5-T MR imager. MR sequences included T1-weighted spoiled gradien t echo (SGE), T2-weighted fat-suppressed spin echo or turbo spin echo, and dynamic gadolinium-enhanced SGE images. AU patients underwent pretreatment, initial posttreatment, and subsequent posttreatment MR studies, The histol ogy of primary tumors included various types of hepatocellular carcinoma (H CC) (four patients: fibrolamellar HCC [one patient], HCC [two patients], mi xed HCC/cholangiocarcinoma [one patient]) and liver metastases (four patien ts: untyped islet cell tumor [two patients], gastrinoma [one patient], carc inoid [one patient]), Response to chemoembolization was determined by three assessments: MR response, serial imaging response, and clinical response. The appearance of MR response to chemoembolization was determined based on the correlation with clinical and serial imaging response. The MR response of lesions that showed good clinical response included: increase in signal intensity on T1-weighted images (three patients), decrease in signal intens ity on Ta-weighted images (three patients), and negligible or minimal enhan cement on immediate postgadolinium images (four patients) after chemoemboli zation, The most marked change in lesion appearance was observed in lesions less than or equal to 1 cm, which had intense homogeneous enhancement on p retreatment MR studies and negligible enhancement on initial posttreatment MR examinations. MR response of lesions that showed moderate clinical respo nse demonstrated a variety of lesion appearances from substantial change to minimal change. MR response of lesions that showed poor clinical response demonstrated no change in lesion appearances compared with the pretreatment MR study. Our results demonstrated change in appearance of liver lesions b etween pre- and post-hepatic-arterial chemoembolization MR studies. MR resp onse correlated with response determined by serial imaging studies and clin ical findings.