Noninvasive liver fibrosis assessment in chronic viral hepatitis C: agreement among 1D transient elastography, 2D shear wave elastography, and magnetic resonance elastography.

PURPOSE: To assess the agreement of one-dimensional transient elastography (1D-TE), two-dimensional shear wave elastography (2D-SWE), and magnetic resonance elastography (MRE) in a consecutive cohort of patients affected by hepatitis C virus (HCV) and to understand which patient-related factors are associated with disagreement. METHODS: Ninety-one consecutive patients with current or previous chronic HCV infection were enrolled between March 2017 and September 2018. We assessed the correlation between stiffness measurements expressed in kilopascals (kPa). After converting kPa values in three groups of increasing fibrosis burden using validated cut-off values, we assessed the agreement among the different techniques. Factors influencing inter-modality disagreement were examined by employing multivariate logistic regression analysis. RESULTS: Seventy-seven patients met the inclusion criteria and had reliable measurements by all stiffness imaging techniques. At the quantitative analysis, a strong correlation between stiffness measurements was found (Spearman's rho values ranging from 0.7 to 0.89 in all pairs of techniques). Complete concordance among MRE, 1D-TE, and 2D-SWE was found in 64.9% of patients, and the agreement was highest between MRE and 1D-TE, with κ value of 0.801. In only 2/77 patients (2.6%), there was complete disagreement. High body mass index (BMI) was the only factor significantly associated with inter-modality discordance. CONCLUSIONS: MRE, 1D-TE, and 2D-SWE assigned the majority of patients to the same fibrosis group. The agreement was at least good, and there was a strong correlation between kPa values in all three pairs of techniques. Highest agreement was found between MRE and 1D-TE. High BMI was associated with discordance among the techniques.

In vivo feasibility of real-time MR-US fusion imaging lumbar facet joint injections.

OBJECTIVES: Traditionally, facet joint injections (FJI) are performed under fluoroscopic or computed tomography (CT) guidance, mainly due to the deep anatomical location and the presence of bony landmarks. Fusion imaging technology, which couples the ultrasound scan with the corresponding CT or magnetic resonance (MR) image obtained from the diagnostic examination and reformatted in real time according to the ultrasound scanning plane, allows to combine the panoramic view and the elevated anatomical detail of MR or CT with the ease of use of ultrasound without patient exposure to ionizing radiation. METHODS: Thirty eight patients (24 females; mean age ± SD: 64 ± 9 years) received MR fusion-assisted ultrasound-guided FJI of 1 ml of a mixture of local anaesthetic and corticosteroid using a ultrasound machine (Logiq E9, GE Healthcare) equipped with a GPS-enhanced fusion imaging technology which couples real-time B-mode images with those of the previous recent diagnostic MR examination. Low-dose CT needle positioning confirmation was performed in the first 28 patients. Patients' pain was recorded using a visual analogue scale (VAS), at baseline and at 2, 4 and 8 weeks. RESULTS: All fusion imaging-guided injections were performed successfully. Out of 112, 96 FJI had optimal intra-articular needle positioning (accuracy: 85.7%). Patients VAS significantly decreases after the procedure with no differences among who received CT needle positioning control and who did not receive it. No major complications were observed. CONCLUSIONS: Ultrasound needle guidance with MR fusion assistance allows for safe and effective injection of degenerative facet joint disease.