High Frame Rate Contrast-enhanced Ultrasound Helps Differentiate Malignant and Benign Focal Liver Lesions

Background and Aims:This study aimed to evaluate the diagnostic performance of high frame rate contrast-en-hanced ultrasound(H-CEUS)of focal liver lesions(FLLs).Methods:From July 2017 to June 2019,conventional con-trast-enhanced ultrasound(C-CEUS)and H-CEUS were per-formed in 78 patients with 78 nodules.The characteristics of C-CEUS and H-CEUS in malignant and benign groups and the differences between different lesion sizes(1-3 cm,3-5 cm,or>5 cm)of C-CEUS and H-CEUS were examined.The diagnostic performance of C-CEUS and H-CEUS was ana-lyzed.The chi-square test or Fisher’s exact test was used to assess inter-group differences.The receiver operating characteristic curve was plotted to determine the diagnostic performance of C-CEUS and H-CEUS.Results:There were significant differences in the enhancement area,fill-in direc-tion and vascular architecture between C-CEUS and H-CEUS for both benign and malignant lesions(all p=0.000-0.008),but there were no significant differences in washout results(p=0.566 and p=0.684,respectively).For lesions 1-3 cm in size,the enhancement area,fill-in direction,and vascular architecture on C-CEUS and H-CEUS were significantly dif-ferent(all p=0.000),unlike for lesions 3-5 cm or>5 cm in size.For differentiation of malignant from benign FLLs in the 1-3 cm group,H-CEUS showed sensitivity,specific-ity,accuracy,and positive and negative predictive values of 92.86%,95.0%,96.3%,90.48%and 93.75%,respectively,which were higher than those for C-CEUS(75.0%,70.0%,77.78%,66.67%and 72.91%,respectively).Conclusions:H-CEUS provided more vascular information which could help differentiate malignant from benign FLLs,especially for lesions 1-3 cm in size.