ESGAR consensus statement on MR imaging in primary sclerosing cholangitis. Article: Ippolito D et al; Eur Radiol. 2025. DOI: 10.1007/s00330-025-11583-4. Primary sclerosing cholangitis (PSC) is a chronic, idiopathic fibroinflammatory disease of the intra- and extrahepatic bile ducts, leading to progressive cholestasis, fibrosis, and, in advanced stages, cirrhosis and liver failure [1,2]. Two clinical–radiological forms are recognized: large-duct PSC, characterized by typical cholangiographic abnormalities on MRCP or ERCP, and small-duct PSC, in which diagnosis requires liver biopsy [2,3]. In recent years, both the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD) have emphasized MRCP as the first-line imaging modality for PSC, discouraging diagnostic ERCP as a first approach, while reserving it for therapeutic or sampling purposes [4,5]. While previous documents had addressed MRI assessment and reporting in PSC, a practical, evidence-based guide defining how to perform, interpret, and structure MR/MRCP evaluation was still lacking [2]. The new ESGAR Consensus Statement fills this gap by providing operational recommendations and a structured reporting model aimed at improving diagnostic quality, consistency, and communication across clinical practice [6]. The consensus was developed through a Delphi process involving twelve international experts, with levels of evidence graded according to the Oxford Centre for Evidence-Based Medicine. Fifty-five statements were evaluated, of which 23 (41.8%) achieved complete agreement (score 5/5). Those formed the foundation for the structured reporting template proposed, complemented by statements which reached fair or slight consensus [6]. Among the statements reaching full agreement, MRCP is reaffirmed as the reference imaging technique for both diagnosis and follow-up of PSC. This examination should always precede any endoscopic intervention or stent placement, and in cases of inconclusive findings, it should be repeated, and an high-quality MRI at an expert center is recommended [6]. Minimum acquisition standards include a magnetic field strength of at least 1.5 T, and patient fasting for four hours to optimize gallbladder distension and reduce motion artifacts. The essential MRI protocol includes axial and coronal T2-weighted sequences for biliary wall and lumen evaluation, in-phase and opposed-phase or Dixon T1-weighted imaging for parenchymal assessment, 2D and/or 3D MRCP for comprehensive ductal mapping, and diffusion-weighted imaging (DWI) with multiple b-values to assess inflammatory activity and disease extent [2,3,7]. Three-dimensional MRCP provides higher spatial resolution and multiplanar reconstruction, while 2D MRCP remains valuable in patients with limited breath-hold capacity [7]. The use of contrast agents is not routinely required and should be reserved for lesion characterization or staging, as recommended by EASL and AASLD [4,5]. The consensus introduces reproducible criteria also for describing biliary abnormalities. Strictures should be reported as present or absent, localized or diffuse, and graded as high (≥ 75% caliber reduction) or low (< 75%). The length of the most severe stricture should be indicated, preferably on coronal images. Ductal wall thickening > 2 mm on T2-weighted or post-contrast T1-weighted images is considered abnormal, reflecting inflammation or fibrosis [6]. Beyond the biliary tree, evaluation should include parenchymal changes such as posterior segment atrophy, caudate lobe hypertrophy, and architectural distortion. Indirect signs of portal hypertension, including splenomegaly, collateral circulation, and varices, must be reported as markers of disease progression [3,4,6]. The pancreas should also be assessed to exclude features of autoimmune pancreatitis in the differential diagnosis, such as IgG4-related sclerosing cholangitis [6]. A structured assessment of PSC-related complications is also recommended. The report should describe signs of cholangitis—mural thickening, enhancement, and T2 hyperintensity—and findings suggestive of cholangiocarcinoma, such as new dominant strictures, mass-like or nodular lesions, or progressive ductal abnormalities [2,6]. Statements on surveillance achieved fair consensus (score 4/5), supporting annual MRI/MRCP for early detection of cholangiocarcinoma, fibrotic progression, and portal hypertension, consistent with current hepatology guidelines [4-6]. Other aspects of PSC imaging achieved partial or limited consensus, including the use of hepatobiliary contrast agents, negative oral contrast, and the precise definition of dominant strictures. Quantitative and functional MRI techniques—such as MR elastography, T1 mapping, MRCP+, and radiomics—were identified as areas of ongoing investigation that may enhance disease assessment once validated for clinical application [6]. | The structured reporting model proposed by ESGAR ensures that clinically relevant findings. Such as strictures, parenchymal changes, and complications, are consistently documented. This standardization improves interpretative clarity, diagnostic reproducibility, and communication between radiologists and clinicians, ultimately strengthening multidisciplinary management and research comparability across centres. References
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