Focal loss of mural stratification as a radiological predictor for small bowel adenocarcinoma in Crohn's disease.

AIM: Patients with Crohn's disease (CD) are at higher risk of small bowel adenocarcinoma (SBA). We aimed to identify radiological predictors of SBA in CD. METHODS: We conducted a retrospective case-control study at two tertiary inflammatory bowel disease centers and identified CD patients diagnosed with SBA between 2003 and 2019. Patients were matched with up to four controls. Pre-operative imaging (magnetic resonance imaging (MRI) or computed tomography (CT)) were reviewed by three gastrointestinal radiologists. RESULTS: Nineteen patients with CD-associated SBA with a mean age of 54.9 and 32 matched controls were included. Mean length of small bowel involvement was 216 (± 188) mm in the SBA group versus 156 (± 167) mm in the control group (p = 0.76). Only 11.8 % of cases had a diagnosis of SBA made preoperatively. In univariate analysis, focal loss of mural stratification (odds ratio [OR], 11; 95%CI, 2.43-49.5, p = 0.002), and wall thickening (OR, 1.32; 95%CI, 1.05-1.66, p = 0.02) were significantly associated with SBA. After adjustment, focal loss of mural stratification was the only independent risk factor (OR, 11; 95 % CI, 2.43-49.5, p = 0.002). CONCLUSIONS: Focal loss of mural stratification was identified as a predictor of CD-associated SBA, which should be described in imaging reports and further validated.

A BCB4 variant is associated with hepatobiliary MR abnormalities in people with low-phospholipid-associated cholelithiasis syndrome.

Background & Aims: The low-phospholipid-associated cholelithiasis (LPAC) syndrome is a recently described peculiar form of cholelithiasis associated with the ATP-binding-cassette subfamily B, member 4 (ABCB4) gene deficiency. The purpose of our study was to analyse the relationship between magnetic resonance (MR) features and the genetic status of ABCB4 in people with LPAC syndrome. Methods: A total of 233 individuals with proven LPAC syndrome were enrolled between January 2003 and June 2018 in a retrospective single-centre study. Inclusion criteria included availability of clinical files, MR images, and genetic data. MR images were analysed by consensus among 3 senior radiologists blinded to the status of ABCB4 gene mutation. Results: A total of 125 individuals (mean age at first MR imaging 40.8 years; 66% females; 48% ABCB4 variant) were included. MR abnormalities were found in 61 (49%) of the 125 individuals. Forty (67%) of the 60 individuals with an ABCB4 gene variant had MR abnormalities as compared with 21 (33%) of the 65 individuals without an ABCB4 gene variant (odds ratio [OR] 4.1, 95% CI 1.9-9.5, p = 0.0001). Compared to individuals with no variant, individuals with an ABCB4 variant were more likely to show intrahepatic macrolithiasis (56 vs. 17%; OR 6.3, 95% CI 2.6-16.2, p <0.0001), bile duct dilatation (60 vs. 18%; OR 6.5, 95% CI 2.7-16.3, p <0.0001), and at least 1 MR feature of complication (35 vs. 15%; OR 2.9, 95% CI 1.1-7.8, p <0.05). Conclusions: ABCB4-related LPAC syndrome is associated with more frequent and severe hepatobiliary MR abnormalities. This finding strongly supports the major role of the ABCB4 gene in the pathogenesis of LPAC syndrome and highlights a genotype-phenotype association in this inherited disease with genetic heterogeneity. Lay summary: ABCB4-related LPAC syndrome associated with an ABCB4 gene variant demonstrates more frequent and severe hepatobiliary MR abnormalities. This finding supports the major role of the ABCB4 gene in the pathogenesis of LPAC syndrome.

Non-contrast MR lymphography of the lymphatic system of the liver.

This review shows the images obtained with non-contrast MR lymphography in different pathologic conditions affecting the liver. Non-contrast MR lymphography is obtained with a free-breathing 3D high spatial resolution fast-recovery fast spin-echo sequence similar to that used for 3D MR cholangiopancreatography. The liver is the largest lymph-producing organ generating approximately half of the body's lymphatic fluid and is the most important part of the lymphatic system from a functional point of view. Therefore, understanding the anatomy, physiology, and physiopathology of the lymphatics of the liver is important. However, its anatomy and pathology are relatively unknown because of the absence of commonly used imaging techniques. We describe the anatomy, the physiology, and the pathophysiology of the lymphatic system of the liver and the possibility of identifying dilated lymphatic vessels in various liver diseases and conditions. Disruption of normal lymphatic structure and function is observed in various disease conditions. Liver lymph flow is directly correlated with portal venous pressure. Therefore, a dilatation of liver lymphatics is observed in portal hypertension as well as in increased pressure in hepatic veins. After liver transplantation, ligation of lymphatic vessels at the hilum reduces chylous ascites and results in lymphatic dilatation which is easily observed. In severe long-standing biliary stenosis, dilated lymphatic vessels are commonly demonstrated with non-contrast MR lymphography. In hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and some metastases, lymphatic vessels are abundant in the immediate vicinity of the tumour. These various lymphatic abnormalities can be demonstrated with non-contrast MR lymphography.Key Points • Anatomy and pathology of the lymphatics of the liver are relatively unknown, partly because of lack of current imaging technique. • Non-contrast MR lymphography is obtained with a free-breathing 3D high spatial resolution fast spin-echo sequence similar to that used for 3D MR cholangiopancreatography. • Non-contrast MR lymphography may participate to the understanding of several abnormal liver conditions including portal hypertension, biliary diseases, and malignant hepatic tumours.

Predictive criteria of response to endoscopic treatment for severe strictures in primary sclerosing cholangitis.

BACKGROUND: The aim of this study was to identify predictive criteria of improvement after endoscopic treatment (ET) for severe strictures of extrahepatic bile ducts in patients with primary sclerosing cholangitis (PSC). METHODS: PSC patients who had at least one ET for severe stricture were included. Features of magnetic resonance cholangiography (MRC), performed before ET, were evaluated according to a standard model of interpretation, and a radiologic qualitative score of probability of improvement after ET was built. Score 3 (likely) was given in case of severe common bile duct (CBD) stricture with marked dilatation without severe strictures of upstream ducts, Score 1 (unlikely) was given in case of severe multiple strictures of secondary ducts without biliary dilatation and Score 2 (undeterminate) was given to an intermediate pattern. The response to ET was assessed at 2 months (T2-response) from the last ET and at 12 months (T12-response) from inclusion. RESULTS: Thirty-one patients were included. All had severe stricture (reduction ≥ 75% of the diameter) of CBD and 50% had severe stricture of right and/or left hepatic duct (LHD) at MRC before ET. According to the qualitative score, 16 patients had Score 3, 7 had Score 1 and 9 had Score 2. T12-response was obtained in 50% of patients. In univariate analysis, short LHD strictures, bilirubin, transaminases, pruritus and Score 3 were associated with T12-response. Increased bilirubin and transaminases were independent predictive factors of T12-response (HR 24, 95% CI: 3.4-170.4, P = 0.001 and 23.8, 95% CI: 3.4-169.4, P = 0.002, respectively). CONCLUSION: MRC, together with biochemical features, may contribute to identify the PSC patients who are likely to be improved after ET for severe strictures of extrahepatic bile ducts.