Welle, Christopher L.

ABSTRACT Chronic liver disease (CLD) is a major cause of global morbidity and mortality, with outcomes closely linked to the severity of liver fibrosis. While liver biopsy has historically been the reference standard for fibrosis staging, its invasiveness, sampling variability and limited suitability for longitudinal monitoring have driven the widespread adoption of non‐invasive tests (NITs). Imaging‐based biomarkers, particularly elastography, now play a central role in the clinical assessment and care pathway design. This review focuses on imaging techniques for non‐invasive assessment of liver fibrosis, with emphasis on elastography techniques: vibration‐controlled transient elastography (VCTE), ultrasound‐based shear wave elastography (SWE) and magnetic resonance elastography (MRE). Technical principles, advantages, limitations and implementation considerations are discussed to support informed selection across clinical contexts. VCTE offers rapid point‐of‐care assessment with extensive validation for identifying advanced fibrosis but is limited by operator dependence, reduced repeatability and lack of anatomical information. SWE provides real‐time, radiologist‐controlled assessment with improved applicability in obesity and ascites, though intervendor variability and operator dependence remain challenges. MRE demonstrates the highest diagnostic accuracy, reproducibility and technical success, with assessment of larger liver volume and strong performance across etiologies, albeit with limited access due to the requirement of an MRI system. Adjunct MRI biomarkers, including proton‐density fat fraction and iron‐corrected T1 mapping, further enhance liver phenotyping by characterising steatosis and fibro‐inflammatory activity. Understanding the strengths and limitations of each technique is essential for radiologists supporting multidisciplinary CLD management and service implementation, particularly in evolving healthcare environments such as Australia.

Abstract Objectives: Radiologist participation in multidisciplinary tumor board can be time-consuming and demanding, requiring substantial preparation. Anecdotally radiologist participation is felt to help identify discrepancies in previous interpretations; however, there are limited data assessing the actual impact of their tumor board review on patient management. This prospective study aims to evaluate how the reinterpretation of outside imaging and review at hepatobiliary tumor board (HBTB) affects the diagnosis and management of patients with hepatobiliary neoplasms. Methods: This prospective analysis included all patients presented at the weekly HBTB between 6/13/2023 - 6/25/2024. One radiologist reviewed the available reports of outside imaging, the local reinterpretation of outside imaging, the updated local imaging, and documented conclusions from discussion of the case at HBTB. HBTB included 4 radiologists who had reviewed each case. Discrepancies (presence/absence, number, and reasons for) were recorded. When discrepancies occurred, the impact on patient management (5-point Likert scale) was determined by two of the radiologists present at the HBTB in consensus, with input from clinicians if needed. A six-month follow-up was performed to confirm suspected diagnoses. Results: 208 cases (128 males, 104 chronic liver disease patients) were presented at HBTB. Disagreements in the detection or characterization of lesions were found in 59/208 (28.4%) of cases. A change in management occurred in 38/59 (64.6%) of these discrepant cases. In cases with recorded discrepancies in which follow-up confirmation was available, the final interpretation was confirmed in 34/41 (82.9%) of cases. Conclusion: Our study found a discrepant interpretation in nearly one-third of cases presented at a weekly HBTB and a resultant change in management in 65% of those cases. These findings highlight the importance of reinterpretation of prior imaging studies and the presence of radiologists at HBTB to guide optimal patient management.

Background and Aims: Among those with primary sclerosing cholangitis (PSC), perihilar cholangiocarcinoma (pCCA) is often diagnosed at a late stage and is a leading source of mortality. Detection of pCCA in PSC when curative action can be taken is challenging. Our aim was to create a deep learning model that analyzed MRI to detect early-stage pCCA and compare its diagnostic performance with expert radiologists. Approach and Results: We conducted a multicenter, international, retrospective cohort study involving adults with large duct PSC who underwent contrast-enhanced MRI. Senior abdominal radiologists reviewed the images. All patients with pCCA had early-stage cancer and were registered for liver transplantation. We trained a 3D DenseNet-121 model, a form of deep learning, using MRI images and assessed its performance in a separate test cohort. The study included 398 patients (training cohort n=150; test cohort n=248). pCCA was present in 230 individuals (training cohort n=64; test cohort n=166). In the test cohort, the respective performances of the model compared to the radiologists were: sensitivity 87.9% versus 50.0%, p <0.001; specificity 84.1% versus 100.0%, p <0.001; area under receiving operating curve 86.0% versus 75.0%, p <0.001. Even when a mass was absent, the model had a higher sensitivity for pCCA than radiologists (91.6% vs. 50.6%, p <0.001) and maintained good specificity (84.1%). Conclusions: The 3D DenseNet-121 MRI model effectively detects early-stage pCCA in PSC patients. Compared to expert radiologists, the model missed fewer cases of cancer.

Understanding the imaging appearance of autoimmune disorders of the liver and biliary tract is important to guide further workup, suggest a particular diagnosis, monitor for disease progression or response to treatment, and evaluate for complications.

Dividing the interpretation of concurrently acquired chest and abdominal CT images between two radiologists has advantages, and the potential problems can be mitigated by awareness, defined expectations, and communication.

Encompassing a broad spectrum of abnormalities from diffuse liver disorders to focal liver lesions, hypointense findings on hepatobiliary phase MR images offer valuable diagnostic information, provide insight on the functional status of the liver, and aid in characterization of other imaging features.

Objectives: Determine whether the timing of transplantation affects patient mortality. Background: Neoadjuvant therapy and liver transplantation have emerged as an excellent treatment option for select patients with perihilar cholangiocarcinoma (pCCA). However, the optimal timing of transplantation is not known. Methods: We reviewed all patients registered for a standardized pCCA protocol between 1996 and 2020 at our center. After adjusting for confounders, we examined the association of waiting time with patient mortality in an intention-to-treat cohort (n=392) and those who received a liver transplant (n=256). Results: The median (interquartile range) time from registration to transplant or dropout was 5.74 (3.25–7.06) months. Compared with a short wait time (0–3 mo), longer waiting times did not affect all-cause mortality: (3–6 mo) hazard ratio (HR) 0.98; 95% CI: 0.52–1.84; (6–9 mo) HR: 0.80; 95% CI: 0.39–1.65; (9–12 mo) HR: 0.56; 95% CI: 0.26–1.22. Subgroups with a shorter waiting time had similar survival to those with long waiting times: living donor available HR: 0.97; 95% CI: 0.67–1.42; AB or B blood group HR: 0.93; 95% CI: 0.62–1.39. Longer waiting times were associated with decreased all-cause mortality after transplantation (HR: 0.92; 95% CI: 0.87–0.97). This benefit began after a 6-month waiting time minimum (HR: 0.53; 95% CI: 0.26–1.10) and increased further after 9 months (HR: 0.43 95% CI: 0.20–0.93). Waiting time was not associated with residual adenocarcinoma in the explant (odds ratio 0.99; 95% CI: 0.98–1.00). Conclusions: A waiting time of at least 6 months will optimize results with transplantation without affecting overall (intention-to-treat) patient survival.

Newer radiotherapy techniques, such as stereotactic body radiation, have been increasingly used as part of the treatment of cholangiocarcinomas, particularly as a bridge to liver transplantation. Although conformal, these high-dose therapies result in tissue injury in the peritumoral liver tissue. This retrospective study characterized the morphologic changes in the liver after stereotactic body radiation in a series of liver explant specimens with perihilar cholangiocarcinoma. The morphologic changes in the irradiated zone were compared against the nonirradiated background liver parenchyma to control for chemotherapy-related changes. Of the 21 cases studied, 16 patients (76.2%) had underlying primary sclerosing cholangitis, and 13 patients (61.9%) had advanced liver fibrosis. The average duration between completion of radiotherapy and liver transplantation was 33.4 weeks (range: 6.29 to 67.7). Twelve patients (57.1%) had no residual tumor in the liver. The most frequent histologic changes in the peritumoral irradiated liver tissue were sinusoidal congestion (100%), sinusoidal edematous stroma (100%), and hepatocellular atrophy (100%), followed by partial/complete occlusion of central veins (76.2%), sinusoidal cellular infiltrates (76.2%), and hepatocyte dropout (66.7%). The findings in the radiated areas were more extensive than in the background liver (P<0.01). Sinusoidal edematous stroma was striking and dominated the histologic findings in some cases. Over time, there was less sinusoidal congestion but more hepatocyte dropout (rs=−0.54, P=0.012 and rs=0.64, P=0.002, respectively). Uncommon findings, such as foam cell arteriopathy in the liver hilum, were also observed. In summary, postradiation liver specimens have distinctive morphologic findings.