Hepatocellular carcinoma treated with radio-frequency ablation: spectrum of imaging findings.
Contrast material-enhanced Doppler or gray-scale harmonic ultrasonography (US) may help determine the completeness or long-term therapeutic efficacy of radio-frequency (RF) ablation of hepatocellular carcinoma (HCC). Successfully treated HCC is devoid of vascularity at color or power Doppler US. When the tumor is not completely treated, residual viable tumor can be detected. These contrast-enhanced US techniques may also help identify residual tumor when performed during repeat RF ablation, when accurate localization of viable tumor is needed. To date, contrast-enhanced computed tomography (CT) has been the most widely used imaging modality in the evaluation of therapeutic response after RF ablation of HCC. At follow-up CT, successfully ablated lesions appear as low-attenuation areas with no foci of contrast enhancement either within or at the periphery of the treated lesion, whereas any foci of enhancement indicate residual or recurrent tumor. Reactive hyperemia in tissue surrounding the ablated lesion, iatrogenic arterioportal shunting, and small intralesional air pockets are frequently seen at immediate follow-up CT. Gadolinium-enhanced dynamic magnetic resonance imaging is also useful in assessing therapeutic response following RF ablation of HCC, particularly when CT findings are inconclusive. Familiarity with these imaging findings is helpful in this setting.
Kim
Seung Kwon
SK
Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul 135-710, South Korea.
Lim
Hyo Keun
HK
Kim
Young Han
YH
Lee
Won Jae
WJ
Lee
Soon Jin
SJ
Kim
Seung Hoon
SH
Lim
Jae Hoon
JH
Kim
Soo Ah
SA
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler