Assessment of radiofrequency ablation margin by MRI-MRI image fusion in hepatocellular carcinoma

AIM:To investigate the feasibility and clinical value of magnetic resonance imaging(MRI)-MRI image fusion in assessing the ablative margin(AM) for hepatocellular carcinoma(HCC).METHODS:A newly developed ultrasound workstation for MRI-MRI image fusion was used to evaluate the AM of 62 tumors in 52 HCC patients after radiofrequency ablation(RFA).The lesions were divided into two groups:group A,in which the tumor was completely ablated and 5 mm AM was achieved(n = 32);and group B,in which the tumor was completely ablated but 5 mm AM was not achieved(n = 29).To detect local tumor progression(LTP),all patients were followed every two months by contrast-enhanced ultrasound,contrast-enhanced MRI or computed tomography(CT) in the first year after RFA.Then,the follow-up interval was prolonged to every three months after the first year.RESULTS:Of the 62 tumors,MRI-MRI image fusion was successful in 61(98.4%);the remaining case had significant deformation of the liver and massive ascites after RFA.The time required for creating image fusion and AM evaluation was 15.5 ± 5.5 min(range:8-22 min) and 9.6 ± 3.2 min(range:6-14 min),respectively.The follow-up period ranged from 1-23 mo(14.2 ± 5.4 mo).In group A,no LTP was detected in 32 lesions,whereas in group B,LTP was detected in 4 of 29 tumors,which occurred at 2,7,9,and 15 mo after RFA.The frequency of LTP in group B(13.8%;4/29) was significantly higher than that in group A(0/32,P = 0.046).All of the LTPs occurred in the area in which the 5 mm AM was not achieved.CONCLUSION:The MRI-MRI image fusion using an ultrasound workstation is feasible and useful for evaluating the AM after RFA for HCC.

Study of detection times for liver stiffness evaluation by shear wave elastography

AIM: To investigate enough valid measurements (VMs) to assess liver fibrosis in chronic hepatitis B patients (CHB).

Non-invasive assessment of liver fibrosis using twodimensional shear wave elastography in patients with autoimmune liver diseases

AIM To determine the diagnostic accuracy of two-dimensional shear wave elastography(2D-SWE) for the noninvasive assessment of liver fibrosis in patients with autoimmune liver diseases(AILD) using liver biopsy as the reference standard.METHODS Patients with AILD who underwent liver biopsy and 2D-SWE were consecutively enrolled. Receiver operating characteristic(ROC) curves were constructed to assess the overall accuracy and to identify optimal cut-off values.RESULTS The characteristics of the diagnostic performance were determined for 114 patients with AILD. The areas under the ROC curves for significant fibrosis, severe fibrosis, and cirrhosis were 0.85, 0.85, and 0.86, respectively, and the optimal cut-off values associated with significant fibrosis(≥ F2), severe fibrosis(≥ F3), and cirrhosis(F4) were 9.7 k Pa, 13.2 k Pa and 16.3 k Pa, respectively. 2D-SWE showed sensitivity values of 81.7% for significant fibrosis, 83.0% for severe fibrosis,and 87.0% for cirrhosis, and the respective specificity values were 81.3%, 74.6%, and 80.2%. The overall concordance rate of the liver stiffness measurements obtained using 2D-SWE vs fibrosis stages was 53.5%.CONCLUSION2D-SWE showed promising diagnostic performance for assessing liver fibrosis stages and exhibited high cut-off values in patients with AILD. Low overall concordance rate was observed in the liver stiffness measurements obtained using 2D-SWE vs fibrosis stages.