Youe Ree Kim

Background: Accurate non-invasive assessment of liver fibrosis is needed in patients with chronic liver disease. Gadoxetic acid (Gd-EOB-DTPA)-enhanced hepatobiliary phase (HBP) magnetic resonance (MR) imaging reflects hepatocyte function and parenchymal heterogeneity, and the coefficient of variation (CV), which quantifies pixel-level signal inhomogeneity, has been proposed as a quantitative imaging biomarker of liver fibrosis. However, previous studies were retrospective, single-center, and lacked direct pathological validation. Objectives: To investigate the factors associated with CV on HBP images, evaluate the correlation between CV and pathologically confirmed liver fibrosis stage, and compare the diagnostic performance of CV with serum biomarkers, including the aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 (FIB-4), in a prospective multicenter setting. Methods: This prospective multicenter study was conducted between April 2017 and August 2020 at three medical centers. Ninety-nine participants who underwent Gd-EOB-DTPA-enhanced HBP T1-weighted MRI and liver biopsy or surgery were enrolled. CV was measured on HBP images, and the METAVIR fibrosis stage was used as the reference standard. Univariate and multivariable linear regression analyses, including an additional model adjusted for institution and pathology confirmation method, Welch’s analysis of variance with the Games–Howell post hoc test, Spearman’s rank correlation analysis, receiver operating characteristic (ROC) curve analysis with DeLong’s method for AUROC comparison, and intraclass correlation coefficient (ICC) analyses were performed. Results: Ninety-nine participants (64 men and 35 women; mean age, 55.5 ± 15.1 years) were enrolled. In multivariable linear regression analysis adjusted for institution and pathology confirmation method, pathologic fibrosis stage (B = 0.468; 95% CI, 0.358–0.578; p < 0.001) and serum albumin level (B = −0.341; p = 0.015) were independently associated with CV. Spearman’s correlation coefficient between CV and fibrosis stage was 0.74 (p < 0.001). The AUROCs of CV for significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) were 0.92, 0.88, and 0.86, respectively (all p < 0.001). CV outperformed APRI and FIB-4 across most fibrosis thresholds (p < 0.001 to p = 0.045), except for FIB-4 in the diagnosis of ≥F2 fibrosis (p = 0.09). The intra- and inter-observer ICC values were 0.94 and 0.84, respectively. Conclusions: In this prospective multicenter study with pathologically confirmed fibrosis stages, CV derived from Gd-EOB-DTPA-enhanced HBP MR images showed a strong correlation with liver fibrosis stage and higher diagnostic performance than APRI and FIB-4 across most fibrosis thresholds. Because CV can be calculated from routine clinical MRI acquisitions without additional hardware or blood tests, it may serve as a practical biomarker for non-invasive liver fibrosis assessment. However, because this study was conducted in a Korean cohort with predominantly hepatitis B virus-related liver disease, further validation in other ethnic groups and etiologies is needed.

Background: Crohn’s disease (CD) is a chronic disorder characterized by transmural bowel wall involvement and mesenteric changes, including inflammation and fibrosis. Although Magnetic Resonance Imaging (MRI)-based scoring systems have been proposed for the quantitative assessment of bowel wall changes in Magnetic Resonance enterography (MRE), there has been limited discussion regarding methods for the quantitative evaluation of mesenteric involvement. T1 mapping is an emerging MRI technique, potentially reflecting inflammation and fibrosis. This study aimed to assess the clinical utility of mesenteric T1 mapping in patients with CD. Methods: We retrospectively analyzed 71 adults with CD who underwent MRE from October 2024 to May 2025. Mesenteric native T1, post-contrast T1 relaxation times, their difference (ΔT1), and the extracellular volume (ECV) fraction were measured. Regions of interest were placed in mesenteric tissue adjacent to affected bowel segments, avoiding lymph nodes and artifacts. The Crohn’s Disease Activity Index (CDAI) was used to classify disease activity. Group differences and correlations with CDAI were evaluated. Results: Native T1 values were significantly higher in active CD than inactive disease (414.3 ms vs. 355.2 ms, p < 0.001). ΔT1 was also elevated in active disease (122.5 ms vs. 55.9 ms, p < 0.001), while post-contrast T1 and ECV did not differ significantly. Native T1 and ΔT1 showed significant positive correlations with CDAI (r = 0.53 and r = 0.46, respectively), while ECV had a weaker correlation (r = 0.27, p = 0.025). Conclusions: Mesenteric T1 mapping shows potential as a non-invasive biomarker of mesenteric involvement in CD. With further validation, mesenteric T1 mapping could enable more comprehensive disease assessment and improve the accuracy of clinical characterization in patients with Crohn’s disease.

Purpose: This study assessed the use of liver stiffness (LS) and dispersion slope (DS) in classifying patients with chronic hepatitis B (CHB) by the necessity of antiviral treatment.Methods: A retrospective review examined 249 patients with CHB (male:female, 107:142; mean age, 53±14 years) between April 2018 and March 2022. Patients for whom treatment was indicated, termed group 1, exhibited either serum alanine transaminase (ALT) and aspartate aminotransferase levels not exceeding five times the upper limit of normal and LS >13 kPa, or hepatitis B virus DNA >2,000 IU/mL and ALT >40 IU/L. The remaining patients comprised group 2 (treatment not required). In subgroup analysis, patients with LS <13 kPa were further examined.Results: Overall, group 1 exhibited significantly higher LS (12.64±6.76 vs. 6.31±1.67 kPa, P<0.001) and DS (15.52±4.95 vs. 11.04±1.93 [m/s]/kHz, P<0.001) than group 2. In subgroup analysis, group 1 also demonstrated significantly higher values (LS: 8.05±2.12 vs 6.31±1.67 kPa, P<0.001, DS: 13.06±2.75 vs. 11.04±1.93 [m/s]/kHz, P<0.001). The areas under the curve (AUCs) for LS and DS in group 1 were 0.855 (95% confidence interval [CI], 0.80 to 0.90; P<0.001) and 0.810 (95% CI, 0.75 to 0.86; P<0.001), respectively. In subgroup analysis, the AUCs for LS and DS in group 1 were 0.751 (95% CI, 0.69 to 0.81; P<0.001) and 0.711 (95% CI, 0.64 to 0.77; P0.05).Conclusion: LS and DS assist in classifying patients with CHB by their need for antiviral treatment.

한솔, et al. J Korean Soc Radiol. 2023 Oct;84:e111. /Synapse/10.3348/jksr.2023.0036

Sarcopenia, a generalized loss of skeletal muscle mass that is primarily evident in the respiratory musculature, is associated with adverse outcomes in critically ill patients. However, the relationship between sarcopenia and ventilation-weaning outcomes has not yet been fully studied in patients with brain injuries. In this study, we examined the effect of reduced respiratory muscle mass on ventilation weaning in patients with brain injury. This observational study retrospectively reviewed the medical records of 73 patients with brain injury between January 2017 and December 2019. Thoracic skeletal muscle volumes were measured from thoracic CT images using the institute’s three-dimensional modeling software program of our institute. The thoracic skeletal muscle volumes index (TSMVI) was normalized by dividing muscle volume by the square of patient height. Sarcopenia was defined as a TSMVI of less than the 50th sex-specific percentile. Among 73 patients with brain injury, 12 (16.5%) failed to wean from mechanical ventilation. The patients in the weaning-failure group had significantly higher sequential organ failure assessment scores [7.8 ± 2.7 vs 6.1 ± 2.2, P = .022] and lower thoracic skeletal muscle volume indexes [652.5 ± 252.4 vs 1000.4 ± 347.3, P = .002] compared with those in the weaning-success group. In multivariate analysis, sarcopenia was significantly associated with an increased risk of weaning failure (odds ratio 12.72, 95% confidence interval 2.87–70.48, P = .001). Our study showed a significant association between the TSMVI and ventilation weaning outcomes in patients with brain injury.

It is well established that sarcopenic obesity (SO) is linked to many diseases such as metabolic and non-alcoholic fatty liver diseases, but there is little known about the relationship between SO and hepatic fibrosis progression in chronic liver disease. This study compared body composition contents in patients with non-obesity (NOb) and SO using abdominal magnetic resonance imaging and investigated the relationship between hepatic fibrosis and SO factors. This retrospective study enrolled 60 patients (28 NOb; 32 SO) from June 2014 to December 2020. Patients underwent histopathologic investigation where they classified fibrosis stages based on the Meta-analysis of Histological Data in Viral Hepatitis fibrosis scoring system. Muscle and fat areas at the third lumber vertebra level were assessed. The variation in the areas of muscle (MA), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) among fibrosis stages, and associations between hepatic fibrosis and SO factors, were analyzed. There were significant differences in SAT and VAT (p < 0.001), whereas there was no difference in MA (p = 0.064). There were significant differences in MA/SAT (p = 0.009), MA/VAT (p < 0.001), and MA/(SAT+VAT) (p < 0.001). In all the patients, hepatic fibrosis positively correlated with serum aspartate aminotransferase level (AST, R = 0.324; p = 0.025). Especially in SO patients, hepatic fibrosis closely correlated with body mass index (BMI, R = 0.443; p = 0.011), AST (R = 0.415; p = 0.044), VAT (R = 0.653; p < 0.001), MA/VAT (R = −0.605; p < 0.001), and MA/(SAT+VAT) (R = −0.416; p = 0.018). However, there was no association in NOb patients. This study demonstrated that SO patients had larger SAT and VAT than NOb patients. Hepatic fibrosis in SO positively correlated with body visceral fat composition in combination with BMI and AST level. These findings will be useful for understanding the relationship between the hepatic manifestation of fibrosis and body fat composition in sarcopenia and SO.

Purpose: This study compared the controlled attenuation parameter (CAP) to attenuation imaging (ATI) in the diagnosis of steatosis and transient elastography (TE) to two-dimensional shear wave elastography (2D-SWE) for the diagnosis of fibrosis in a prospectively constructed nonalcoholic fatty liver disease (NAFLD) patient cohort.Methods: Participants who underwent TE with CAP were included from a previously constructed NAFLD cohort with multiparametric ultrasound data. The degree of hepatic steatosis and stage of liver fibrosis were assessed. Diagnostic performance was evaluated using the area under the receiver operating characteristic curve (AUROC) for the grades of steatosis (S1-3) and fibrosis (F0-F4).Results: There were 105 participants. The distribution of hepatic steatosis grades (S0-S3) and liver fibrosis stages (F0-F4) was as follows: S0, n=34; S1, n=41; S2, n=22; S3, n=8; F0, n=63; F1, n=25; F2, n=5; F3, n=7; and F4, n=5. No significant difference was found between CAP and ATI in detecting ≥S1 (AUROC: 0.93 vs. 0.93, P=0.956) or ≥S2 (0.94 vs. 0.94, P=0.769). However, the AUROC of ATI in detecting ≥S3 was significantly higher than that of CAP (0.94 vs. 0.87, P=0.047). Regarding the detection of liver fibrosis, no significant difference was found between TE and 2D-SWE. The AUROCs of TE and 2D-SWE were as follows: ≥F1, 0.94 vs. 0.89 (P=0.107); ≥F2, 0.89 vs. 0.90 (P=0.644); ≥F3, 0.91 vs. 0.90 (P=0.703); and ≥F4, 0.88 vs. 0.92 (P=0.209).Conclusion: 2D-SWE and TE showed comparable diagnostic performance in assessing liver fibrosis, and ATI provided significantly better performance in detecting ≥S3 steatosis than CAP.

이승준, et al. J Korean Soc Radiol. 2023 May;84:e52. https://doi.org/10.3348/jksr.2022.0053

Kim H, et al. Investig Magn Reson Imaging. 2023 May;27:e7. https://doi.org/10.13104/imri.2022.1115