RESUMO
<p><b>OBJECTIVE</b>To explore the pathological basis of diffusion-weighted imaging (DWI) findings in hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE).</p><p><b>METHODS</b>DWI was performed in 15 patients with HCC treated by TACE within 24 - 48 hours before II-phase operation. The DWI findings of the liver lesions were analyzed and correlated with pathological findings including macroscopic observation, HE staining and immunohistochemical staining for bFGF.</p><p><b>RESULTS</b>(1) The viable tumor area showed mostly hypersignal intensity (12/15), whereas coagulative necrotic lesions showed hyposignal (8/15) or isosignal intensity (6/15). The ADC values of zones of viable tumor and necrosis in tumor were (1.42 +/- 0.16) x 10(-3) mm(2)/s and (1.58 +/- 0.18) x 10(-3) mm(2)/s, respectively. There was a significant difference of ADC values between the two zones (t = 2.618, P < 0.05). (2) There was a significant difference in ADC values of viable tumor between well and poorly differentiated tumors (t = -2.646, P < 0.05). The distinction of ADC values of the whole tumor was significant among tumors with different degree of necrosis (chi(2) = 7.236, P < 0.05). (3) A negative correlation was observed between bFGF protein expression index and ADC values of viable parts of the tumors in the study group (r = -0.552, P = 0.033).</p><p><b>CONCLUSION</b>DWI shows certain characteristic features of the HCC after TACE, and can be used to distinguish viable and necrotic tumor tissues in HCC after TACE.</p>