ABSTRACT
PurposeWith the extensive use of percutaneous radiofrequency ablation (RFA) for the treatment of hepatic carcinoma (HC), the study of MRI findings and its clinical signiifcance after RFA of HC have important value and can improve the complete ablation rate.Materials and MethodsA retrospective analysis of post-procedure MRI ifndings of 79 patients (114 lesions) with HC were performed, the size of the lesion, the signal changes and enhancement condition were observed at the ifrst, fourth and seventh month after RFA; the two different ifndings of high signal ring on MRI T1WI and local recurrence rate were analyzed.ResultsOne month after RFA, peripheral region of RFA lesion showed high signal on T1WI, and slightly lower signal on T2WI, the size of lesions was slightly larger than pre-procedure, enhancement scan showed the thin homogeneous ring enhanced around the non-enhanced lesions; 4 months later, the size of lesions were relative stable and the periphery enhancement was weaken; 7 months later, the size of lesions were reduced and showed no enhancement. For recurrence lesions, the high signal ring was incomplete on TIWI, the incomplete area showed nodular enhancement on the arterial phase, and most of nodule showed slightly lower signal on the delay phase demonstrated a feature of quick wash-in and wash-out; 7 months after RFA, recurrence rate was 6.12% in patients with complete high signal ring and 43.75% in patients with incomplete high signal ring, the difference was statistically significant (P<0.05). The total survival rate and accumulated survival rate of the patients with complete high signal ring on T1WI were higher than the patients with incomplete ring, the difference was statistically signiifcant (P<0.05).ConclusionThere are characteristic ifndings of MRI examination of liver cancer after percutaneous RFA, observation of the integrity of high signal ring on T1WI image and ifnding of dynamic enhancement scan can early evaluate efifcacy of RFA guide the selection of treatment plan.