Liver fibrosis detection and staging: a comparative study of T1ρ MR imaging and 2D real-time shear-wave elastography

Abstract

Purpose: To compare the results of T1ρ MR imaging and 2D real-time shear-wave elastography (SWE) for liver fibrosis detection and staging.

Methods: Twenty-nine rabbit models of CCl₄-induced liver fibrosis were established and six untreated rabbits served as controls. T1ρ MR imaging and 2D real-time SWE examination were performed at 2, 4, 6, 8, 10, and 12 weeks. T1ρ values and liver stiffness (LS) values were measured. Fibrosis was staged according to the METAVIR scoring system. Correlation test was performed among T1ρ values, LS values, and fibrosis stage. Receiver operating characteristic (ROC) analysis was performed for assessing diagnostic performance of T1ρ and SWE in detection of no fibrosis (F0), substantial fibrosis (≥ F2), severe fibrosis (≥ F3), and cirrhosis (F4).

Results: There was moderate positive correlation between fibrosis stage and T1ρ values (r = 0.566; 95% CI 0.291-0.754; P < 0.0001), and LS value (r = 0.726; 95% CI 0.521-0.851; P = 0.003). T1ρ values showed moderate positive correlations with LS values [r = 0.693; 95% confidence interval (CI) 0.472-0.832; P < 0.0001]. Areas Under ROC (AUROCs) were 0.861 (95% CI 0.705-0.953) for SWE and 0.856 (95% CI 0.698-0.950) for T1ρ (P = 0.940), 0.906 (95% CI 0.762-0.978) for SWE and 0.849 (95% CI 0.691-0.946) for T1ρ (P = 0.414), 0.870 (95% CI 0.716-0.958) for SWE and 0.799 (95% CI 0.632-0.913) for T1ρ (P = 0.422), and 0.846 (95% CI 0.687-0.944) for SWE and 0.692 (95% CI 0.517-0.835) for T1ρ (P = 0.137), when diagnosing liver fibrosis with ≥ F1, ≥ F2, ≥ F3, and F4, respectively. There was moderate positive correlation between inflammatory activity and T1ρ values (r = 0.520; 95% CI 0.158-0.807; P = 0.013).

Conclusion: T1ρ imaging has potential for liver fibrosis detection and staging with good diagnostic capability similar to that of ultrasonography elastography.

Keywords: Liver fibrosis; Magnetic resonance imaging; T1ρ relaxation elastography; Ultrasonography.

Fig. 1

A For T1ρ value measurement, ROI was manually drawn conforming to the liver margins but excluding major blood vessels. B For LS value measurement, a round ROI was placed in the box on the gray-scale US image in the right liver lobe

Fig. 2

T1ρ (A) and LS values (B) increased with the severity of liver fibrosis

Fig. 3

Youden plot graph shows a significant positive correlation between T1ρ and LS values (r = 0.693; 95% CI 0.472–0.832; P < 0.0001)

Fig. 4

F0 (A–C). A T1ρ map, with T1ρ value measurement of 48.98 ms; B SWE, with LS value measurement of 8.19 kPa; and Masson trichrome-staining slices (C ×100), no fibrosis. F1 (D–F). D T1ρ map, with T1ρ value measurement of 66.04 ms; E SWE, with LS value measurement of 15.08 kPa; and Masson trichrome-staining slices (F ×100), stage F1 portal and periportal fibrosis. F2 (G–I). G T1ρ map, with T1ρ value measurement of 67.85 ms; H SWE, with LS value measurement of 16.67 kPa; and Masson trichrome-staining slices (I ×100), stage F2 fibrosis with few septa. F3 (J–L). J T1ρ map, with T1ρ value measurement of 92.43 ms; K SWE, with LS value measurement of 19.60 kPa; and Masson trichrome-staining slices (L ×100), stage F3 fibrosis with bridging and F4 (M–O). M T1ρ map, with T1ρ value measurement of 105.76 ms; N SWE, with LS value measurement of 26.21 kPa; and Masson trichrome-staining slices (O ×100), stage F4 fibrosis with overt cirrhosis and nodule formation

Fig. 5

ROC curves of T1ρ and SWE for liver fibrosis staging. A F0 versus F1–F4; B F0–F1 versus F2–F4; C F0–F2 versus F3–F4; D F0–F3 versus F4