Imaging findings of liver resection using a bipolar radiofrequency electrosurgical device-Initial observations.

Objective: To assess contrast-enhancedUS(CEUS),computed tomography(CT)and magnetic resonance (MR) imaging findings and serial changes of the treated area at follow-up in patients who under went liver resection using a bipolar radiofrequency electrosurgical device. Methods: Imaging findings of 27 patients with resected hepatocellular carcinomas(HCCs)(n = 24)and metastases (n = 3)(mean size:2.6cm),were retrospectively evaluated. Two readers assessed:the(a)presence, (b)thickness,(c)shapeand(d)echogenicity(CEUS)/attenuation(CT)/signalintensity(MRimaging) at coagulated site and the(e)presence of residual tumor of the bipolar radiofrequency electrosurgical device resection margin. Results: Follow-up was performed with either CT(n = 20)or MR imaging(n = 7)and repeated in 16 patients with CT(n = 7),MR imaging(n = 4),or both techniques(n = 5).Four patients also had a single CEUS examination. At first imaging follow-up a peripheral halo was depicted at resection site(100%).A fluid collection within the surgical area was found in 67% of patients. During the following imaging examinations a progressive involution of both findings was observed,respectively,in 81% and 62%of patients. Viable tissue was detected in three patients(11%). Conclusions: After liver resection with bipolar radiofrequency electrosurgical device successfully ablated tumor is demonstrated at imaging by an unenhancing partial linear peripheral halo,in most cases,surrounding a fluid collection reducing in size during follow-up.