Comparison of point shear wave elastography and transient elastography in the evaluation of patients with NAFLD.

PURPOSE: To compare point shear wave elastography (pSWE, ElastPQ®) and transient elastography (TE) with Liver Biopsy in order to evaluate fibrosis stage in non-alcoholic fatty liver disease (NAFLD). METHODS: Our prospective study from September 2017 to October 2020 included 50 consecutively enrolled patients with NAFLD (52.2 ± 13.0 years, 32 male). All patients underwent clinical evaluation, B-mode ultrasound, pSWE, TE and liver biopsy in a single evaluation. The clinical, laboratory and liver biopsy data were compared with liver stiffness (LS) measurement obtained with pSWE and TE. TE and pSWE diagnostic accuracy for the diagnosis of the different fibrosis stages were evaluated using the area under receiver operating characteristic curve (AUROC). RESULTS: Only fibrosis stage was independently associated with TE and pSWE. The median liver stiffness measurement for fibrosis stages F0, F1, F2, F3, and F4 using TE was 4.8 (4.7-6.1) kPa, 5.5 (4.4-7.3) kPa, 7.7 (6.1-9.1) kPa, 9.9 (8.8-13.8) kPa, and 20.2 kPa, respectively. The corresponding median liver stiffness measurement using pSWE was 4.2 (4.0-4.8) kPa, 4.7 (4.2-5.8) kPa, 5.1 (4.1-6.9) kPa, 8.5 (5.2-13.3), and 15.1 kPa, respectively. The AUROC of TE for diagnosis of fibrosis stage F1, ≥ F2, ≥ F3, and F4 were 0.795, 0.867, 0.927, and 0.990, respectively. The corresponding AUROC of pSWE was 0.717, 0.733, 0.908, and 1.000, respectively. No association was observed with other histological parameters. CONCLUSION: TE was significantly better than pSWE for the diagnosis of fibrosis stage ≥ F2. No statistically significant differences were found between TE and pSWE AUROC of fibrosis stage ≥ F1, ≥ F3, and F4.

In vivo radiation dosimetry and image quality of turbo-flash and retrospective dual-source CT coronary angiography.

PURPOSE: To compare measured radiation dose (MD), estimated radiation dose (ED) and image quality in coronary computed tomography between turbo-flash (TFP) and retrospective protocol (RP) and correlate MD with size-specific dose estimates (SSDE). MATERIALS AND METHODS: In this prospective study, we selected 68 patients (mean age, 59.2 ± 9.7 years) undergoing 192 × 2 dual-source CT (SOMATOM Force, Siemens) to rule out coronary artery disease. Thirty-one underwent TFP and 37 RP. To evaluate in vivo MD, thermoluminescent dosimeters were placed, superficially, at thyroid and heart level, left breast areola and left hemi-thorax. MD in each site, and ED parameters, such as volume CT dose index (CTDIvol), SSDE, dose length product (DLP), effective dose (E), were compared between two protocols with a t test. Image quality was compared between two protocols. Inter-observer agreement was evaluated with a kappa coefficient (k). In each protocol, MD was correlated with SSDE using a Pearson coefficient (r). RESULTS: Comparing TFP and RP, MD at thyroid (1.43 vs. 2.58 mGy; p = 0.0408), heart (3.58 vs. 28.72 mGy; p < 0.0001), left breast areola (3.00 vs. 24.21 mGy; p < 0.0001) and left hemi-thorax (2.68 vs. 24.03 mGy; p < 0.0001), CTDIvol, SSDE, DLP and E were significantly lower. Differences in image quality were not statistically significant. Inter-observer agreement was good (k = 0.796) in TFP and very good (k = 0.817) in RP. MD and SSDE excellently correlated with TFP (r = 0.9298, p < 0.0001) and RP (r = 0.9753, p < 0.0001). CONCLUSIONS: With TFP, MD, CTDIvol, SSDE, DLP and E were significantly lower, than with RP. Image quality was similar between two protocols. MD correlated excellently with SSDE in each protocol.