Chronic hepatitis B: correlation of abnormal features on T2-weighted imaging and dynamic contrast-enhanced imaging with hepatic histopathology

Computed Tomography and Magnetic Resonance Imaging Signs of Chronic Liver Rejection: A Case-Control Study

OBJECTIVE

In liver transplantation, chronic rejection is still poorly studied. This study aimed to investigate the role of imaging in its recognition.

METHODS

This study is a retrospective observational case-control series. Patients with histologic diagnosis of chronic liver transplant rejection were selected; the last imaging examination (computed tomography or magnetic resonance imaging) before the diagnosis was evaluated. At least 3 controls were selected for each case; radiological signs indicative of altered liver function were analyzed. χ 2 Test with Yates correction was used to compare the rates of radiologic signs in the case and control groups, also considering whether patients suffered chronic rejection within or after 12 months. Statistical significance was set at P < 0.050.

RESULTS

A total of 118 patients were included in the study (27 in the case group and 91 in the control group). Periportal edema was appreciable in 19 of 27 cases (70%) and in 6 of 91 controls (4%) ( P < 0.001); ascites and hepatomegaly were present in 14 of 27 cases (52%) and 12 of 27 cases (44%), respectively, and in 1 of 91 controls (1%) ( P < 0.001); splenomegaly was present in 13 of 27 cases (48%) and in 8 of 91 controls (10%) ( P < 0.001); and biliary tract dilatation was present in 13 of 27 cases (48%) and in 11 of 91 patients controls (5%) ( P < 0.001). In the controls, periportal edema was significantly less frequent beyond 12 months after transplant (1% vs 11%; P = 0.020); the other signs after 12 months were not significant.

CONCLUSIONS

The identification of periportal edema, biliary dilatation, ascites, and hepatosplenomegaly can serve as potential warning signs of ongoing chronic liver rejection. It is especially important to investigate periportal edema if it is present 1 year or more after orthotopic liver transplantation.

T2-weighted imaging and dynamic contrast‑enhanced imaging in predicting the prognosis in patients with acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a syndrome with high 28- and 90-day mortality rates. Magnetic resonance imaging (MRI) has been widely used to diagnose and evaluate liver disease. Our purpose is to determine the value of the imaging features derived from Gd-DTPA-enhanced MRI for predicting the poor outcome of patients with ACLF and develop a clinically practical radiological score.

METHODS

This retrospective study comprised 175 ACLF patients who underwent Gd-DTPA-enhanced abdominal MRI from January 2017 to December 2021. The primary end-point was 90-day mortality. Imaging parameters, such as diffuse hyperintense of the liver on T2WI, patchy enhancement of the liver at the arterial phase, uneven enhancement of the liver at the portal vein phase, gallbladder wall edema, periportal edema, ascites, esophageal and gastric varix, umbilical vein patefac, portal vein thrombosis, and splenomegaly were screened. Cox proportional hazard regression models were used to evaluate prognostic factors and develop a prediction model. The accuracy of the model was evaluated by receiver operating characteristic (ROC) curves.

RESULTS

During the follow-up period, 31 of the 175 ACLF patients died within 90 days. In the multivariate analysis, three imaging parameters were independently associated with survival: diffuse hyperintense on T2WI (p = 0.007; HR = 3.53 [1.40-8.89]), patchy enhancement at the arterial phase (p = 0.037; HR = 2.45 [1.06-5.69]), moderate ascites (vs. mild) (p = 0.006; HR = 4.12 [1.49-11.36]), and severe ascites (vs. mild) (p = 0.005; HR = 4.29 [1.57-11.71]). A practical radiological score was proposed, based on the presence of diffuse hyperintense (7 points), patchy enhancement (5 points), and ascites (6, 8, and 8 points for mild, moderate, and severe, respectively). Further analysis showed that a cut-off at 14 points was optimum to distinguish high-risk (score > 14) from the low-risk group (score ≤ 14) for 90-day survival and demonstrated a mean area under the ROC curve of 0.774 in ACLF patients.

CONCLUSIONS

Gd-DTPA-enhanced MR imaging features can predict poor outcomes in patients with ACLF, based on which we proposed a clinically practical radiological score allowing stratification of the 90-day survival.

Development of an MRI-Based Radiomics-Clinical Model to Diagnose Liver Fibrosis Secondary to Pancreaticobiliary Maljunction in Children

BACKGROUND

Preoperative diagnosis of liver fibrosis in children with pancreaticobiliary maljunction (PBM) is needed to guide clinical decision-making and improve patient prognosis.

PURPOSE

To develop and validate an MR-based radiomics-clinical nomogram for identifying liver fibrosis in children with PBM.

STUDY TYPE

Retrospective.

POPULATION

A total of 136 patients with PBM from two centers (center A: 111 patients; center B: 25 patients). Cases from center A were randomly divided into training (74 patients) and internal validation (37 patients) sets. Cases from center B were assigned to the external validation set. Liver fibrosis was determined by histopathological examination.

FIELD STRENGTH/SEQUENCE

A 3.0 T (two vendors)/T1-weighted imaging and T2-weighted imaging.

ASSESSMENT

Clinical factors associated with liver fibrosis were evaluated. A total of 3562 radiomics features were extracted from segmented liver parenchyma. Maximum relevance minimum redundancy and least absolute shrinkage and selection operator were recruited to screen radiomics features. Based on the selected variables, multivariate logistic regression was used to construct the clinical model, radiomics model, and combined model. The combined model was visualized as a nomogram to show the impact of the radiomics signature and key clinical factors on the individual risk of developing liver fibrosis.

STATISTICAL TESTS

Mann-Whitney U and chi-squared tests were used to compare clinical factors. P < 0.05 was considered statistically significant in the final models.

RESULTS

Two clinical factors and four radiomics features were selected as they were associated with liver fibrosis in the training (AUC, 0.723, 0.927), internal validation (AUC, 0.718, 0.885), and external validation (AUC, 0.737, 0.865) sets. The radiomics-clinical nomogram yielded the best performance in the training (AUC, 0.977), internal validation (AUC, 0.921), and external validation (AUC, 0.878) sets, with good calibration (P > 0.05).

DATA CONCLUSION

Our radiomic-based nomogram is a noninvasive, accurate, and preoperative diagnostic tool that is able to detect liver fibrosis in PBM children.

EVIDENCE LEVEL

3.

TECHNICAL EFFICACY

Stage 2.

Identification of MRI features associated with injury type, severity, and prognosis in drug-induced liver injury

OBJECTIVES

To identify magnetic resonance imaging (MRI) features associated with injury type, severity, and liver transplantation (LT)/liver-related death (LRD) in drug-induced liver injury (DILI).

METHODS

The eligible DILI patients (2016 to 2020) who underwent contrast abdominal MRI within 3 months of onset were retrospectively analysed at Beijing Friendship Hospital, Capital Medical University. The MRI features independently associated with severity and prognosis were identified by backwards logistic regression. Unadjusted odds ratios (ORs) and 95% confidence intervals (CIs) are given.

RESULTS

The median age of 180 patients was 55.5 years, with 126 (70.0%) women. The injury types included hepatocellular (135 cases, 75.0%), mixed (23, 12.8%), and cholestatic (22, 12.2%). The proportion of periportal oedema in patients with hepatocellular and mixed injury was significantly higher than that in cholestatic injury (62.2%, 47.8% vs. 18.2%, p < 0.001). For severity, 157 (87.2%) patients had mild to moderate injury, and 23 (12.8%) had severe to fatal/LT. Irregularity of the liver surface (6.56 (95% CI, 1.27-22.84)), transient hepatic attenuation difference (THAD) (3.27 (95% CI, 1.14-9.36)), and splenomegaly (5.86 (95% CI, 1.96-17.53)) were independently associated with severity. Eight (4.4%) patients died/underwent LT. THAD (8.89 (95% CI, 1.35-58.43)), and ascites (64.63 (95% CI, 6.93-602.40)) were independently associated with LT/LRD. The prediction of the new model employing THAD and ascites for LT/LRD within 1 year was 0.959 (95% CI, 0.917-1.000).

CONCLUSIONS

Periportal oedema was associated with the type of injury. Irregularity of the liver surface, THAD, and splenomegaly were associated with severity. THAD and ascites may have potential clinical utility in predicting LT/LRD outcomes within 1 year.

KEY POINTS

• Contrast abdominal magnetic resonance imaging features can help clinicians evaluate the type of injury, severity, and poor prognosis of drug-induced liver injury. • Transient hepatic attenuation difference and ascites have potential clinical utility in the prediction of the poor prognosis of liver transplantation/liver-related death. • The new model predicting poor prognosis has a relatively high sensitivity of 0.875 and a high specificity of 0.919.

A novel radiomics signature based on T2-weighted imaging accurately predicts hepatic inflammation in individuals with biopsy-proven nonalcoholic fatty liver disease: a derivation and independent validation study

Background

Currently, there are no effective methods for assessing hepatic inflammation without resorting to histological examination of liver tissue obtained by biopsy. T2-weighted images (T2WI) are routinely obtained from liver magnetic resonance imaging (MRI) scan sequences. We aimed to establish a radiomics signature based on T2WI (T2-RS) for assessment of hepatic inflammation in people with nonalcoholic fatty liver disease (NAFLD).

Methods

A total of 203 individuals with biopsy-confirmed NAFLD from two independent Chinese cohorts with liver MRI examination were enrolled in this study. The hepatic inflammatory activity score (IAS) was calculated by the unweighted sum of the histologic scores for lobular inflammation and ballooning. One thousand and thirty-two radiomics features were extracted from the localized region of interest (ROI) in the right liver lobe of T2WI and, subsequently, selected by minimum redundancy maximum relevance and least absolute shrinkage and selection operator (LASSO) methods. The T2-RS was calculated by adding the selected features weighted by their coefficients.

Results

Eighteen radiomics features from Laplacian of Gaussian, wavelet, and original images were selected for establishing T2-RS. The T2-RS value differed significantly between groups with increasing grades of hepatic inflammation (P<0.01). The T2-RS yielded an area under the receiver operating characteristic (ROC) curve (AUROC) of 0.80 [95% confidence interval (CI): 0.71-0.89] for predicting hepatic inflammation in the training cohort with excellent calibration. The AUROCs of T2-RS in the internal cohort and external validation cohorts were 0.77 (0.61-0.93) and 0.75 (0.63-0.84), respectively.

Conclusions

The T2-RS derived from radiomics analysis of T2WI shows promising utility for predicting hepatic inflammation in individuals with NAFLD.