Visualizing the hepatic vascular architecture using superb microvascular imaging in patients with hepatitis C virus: A novel technique

Abstract

Aim: To identify the hepatic vascular architecture of patients with hepatitis C virus (HCV) using superb microvascular imaging (SMI) and investigate the use of SMI in the evaluation of liver fibrosis.

Methods: SMI was performed in 100 HCV patients. SMI images were classified into five types according to the vascular pattern, and these patterns were compared with the fibrosis stage. Moreover, the images were analyzed to examine vascularity by integrating the number of SMI signals in the region of interest ROI [number of vascular trees (VT)]. The number of VT, fibrosis stage, serum parameters of liver function, and CD34 expression were investigated.

Results: There was a significant difference between SMI distribution pattern and fibrosis stage (P < 0.001). The mean VT values in each of the fibrosis stages were as follows: 26.69 ± 7.08 in F0, 27.72 ± 9.32 in F1, 36.74 ± 9.23 in F2, 37.36 ± 5.32 in F3, and 58.14 ± 14.08 in F4. The VT showed excellent diagnostic ability for F4 [area under the receiver operator characteristic (AUROC): 0.911]. The VT was significantly correlated with the CD34 labeling index (r = 0.617, P < 0.0001).

Conclusion: SMI permitted the detailed delineation of the vascular architecture in chronic liver disease. SMI appears to be a reliable tool for noninvasively detecting significant fibrosis or cirrhosis in HCV patients.

Keywords: CD34; Chronic liver disease; Liver fibrosis; Number of vascular trees; Superb microvascular imaging; Ultrasound.

Figure 1

Superb microvascular imaging vascular patterns. Type I, clearly defined vessels with no irregularities; Type II, poor ramification and tapering of the main branches; Type III, mild tortuosity of the main branches and uneven branching; Type IV, moderate tortuosity and mild grouping of the main branches; and Type V, severe tortuosity and grouping of the main branches.

Figure 2

Distribution of the superb microvascular imaging patterns and fibrosis stages. Fisher’s exact probability test demonstrated a significant difference in the SMI pattern distribution and the fibrosis stage (P < 0.001). SMI: Superb microvascular imaging.

Figure 3

Vascular tree values for the different fibrosis stages in patients who underwent liver biopsy (A) and the receiver operating characteristic curve of the vascular tree for the prediction of F4 in all 100 patients. The VT values increased in proportion to the fibrosis stage (^aP < 0.001, ^cP < 0.01 by Kruskal-Wallis analysis). AUROC: Area under the receiver operating characteristic; VT: Vascular trees.

Figure 4

Superb microvascular imaging images and CD34 expressions at different fibrosis stages. A: SMI image; B: CD34 expression; C: Gomori trichrome staining. SMI: superb microvascular imaging.

Figure 5

Correlation between the vascular trees value and the CD34 labeling index. Spearman’s rank correlation coefficient. LI: Labeling index.