Evaluation of hepatocellular carcinoma ablative margin using three-dimensional ultrasound-CT image fusion in a phantom study / 中华超声影像学杂志

ABSTRACT

Objective To design and construct a hepatocellular carcinoma(HCC) phantom,and assess the accuracy of three dimensional ultrasound (3DUS)-CT image fusion in evaluating ablative margin (AM).Methods The phantom was constructed by carrageenan gel and additives.A sphere-shaped HCC model surrounded by a 5 mm layer of AM model was embedded into a cylindrical-shaped ground substance model to form the phantom.After radiofrequency ablation (RFA),HCC model in the phantom was ablated into ablative lesion model.The ultrasound and CT image,macroscopic appearance and stability of the phantom were observed.Twenty-four phantoms were made and ablated into different ablative lesion models in which AM was achieved or not achieved.Outline the HCC and 5mm AM in the 3DCT image and fuse 3DCT image with the 3DUS image of the ablative lesion model to see whether the ablative area could cover the AM,as well as in which quadrant complete ablation of the AM had not been achieved and the maximal thickness of the unachieved AM.The result of the 3DUS-CT image fusion was compared with gross specimen.Results The ultrasound and CT image,macroscopic appearance and stability of the phantom met the demand of this study.The sensitivity,specificity and accuracy of 3DUS-CT image fusion were 93.8％,85.7％ and 91.3％respectively.The quadrant in which complete ablation of AM was not achieved matched with gross specimen.The maximal thickness of the unachieved AM measured by 3DUS-CT image fusion and gross specimen were (3.5 ± 2.0) mm and (3.2 ± 2.0) mm respectively,and no statistic difference was found between the two results.Conclusions The phantom made of carrageenan gel and additives was suitable for the evaluation of AM.3DUS-CT image fusion evaluation of AM was accurate.