Spontaneous perforation of the common bile duct: an uncommon complication of primary sclerosing cholangitis.

OBJECTIVES: To describe the MR features and prognosis of patients with an uncommon complication of primary sclerosing cholangitis (PSC) characterized by a spontaneous perforation of the common bile duct (CBD) resulting in a peri-biliary collection and a pseudo-cystic appearance of the CBD. METHODS: A single-center cohort of 263 patients with PSC who had at least two MRIs between 2003 and 2022 and a minimum follow-up of 1 year was retrospectively analyzed. MRI data (characteristics of CBD perforation and MR features of PSC) and clinical data were assessed. Analysis of survival without liver transplantation according to type of PSC (classical or CBD spontaneous perforation) was performed according to the Kaplan-Meier method and the curves were compared using the Log-Rank test. RESULTS: A total of nine (3.4%) PSC patients (5 males) had perforation of the CBD with a median age at diagnosis of 18 years compared to 33 years for the control group (p = 0.019). The peri-biliary collections were variable in appearance (fusiform or pedunculated), with a diameter ranging from 5 to 54 mm. All nine patients showed intra- and extra-hepatic bile duct involvement, dysmorphia, and high ANALI scores. The clinical course was characterized by numerous complications in most patients, and five patients (56%) underwent liver transplantation at a median time of 5 years from diagnosis, compared to 40 patients (16%) in the control group (p = 0.02). CONCLUSION: The spontaneous perforation of the common bile duct is an uncommon complication of primary sclerosing cholangitis that affects young patients and is associated with a poor prognosis. CLINICAL RELEVANCE STATEMENT: This uncommon complication of primary sclerosing cholangitis with perforation of the common bile duct resulting in a peri-biliary collection and a pseudo-cystic appearance of the common bile duct is characterized by a poor prognosis in younger patients. KEY POINTS: • Among 263 patients with primary sclerosing cholangitis (PSC), nine patients (3.6%) had an uncommon complication characterized on MRI by perforation of the common bile duct (CBD). • This perforation of the CBD was responsible in all nine cases for the formation of a peri-biliary collection, giving a pseudo-cystic appearance to the CBD. • The spontaneous perforation of the common bile duct is an uncommon complication of primary sclerosing cholangitis that affects young patients with a poor prognosis.

Deep learning for automatic bowel-obstruction identification on abdominal CT.

RATIONALE AND OBJECTIVES: Automated evaluation of abdominal computed tomography (CT) scans should help radiologists manage their massive workloads, thereby leading to earlier diagnoses and better patient outcomes. Our objective was to develop a machine-learning model capable of reliably identifying suspected bowel obstruction (BO) on abdominal CT. MATERIALS AND METHODS: The internal dataset comprised 1345 abdominal CTs obtained in 2015-2022 from 1273 patients with suspected BO; among them, 670 were annotated as BO yes/no by an experienced abdominal radiologist. The external dataset consisted of 88 radiologist-annotated CTs. We developed a full preprocessing pipeline for abdominal CT comprising a model to locate the abdominal-pelvic region and another model to crop the 3D scan around the body. We built, trained, and tested several neural-network architectures for the binary classification (BO, yes/no) of each CT. F1 and balanced accuracy scores were computed to assess model performance. RESULTS: The mixed convolutional network pretrained on a Kinetics 400 dataset achieved the best results: with the internal dataset, the F1 score was 0.92, balanced accuracy 0.86, and sensitivity 0.93; with the external dataset, the corresponding values were 0.89, 0.89, and 0.89. When calibrated on sensitivity, this model produced 1.00 sensitivity, 0.84 specificity, and an F1 score of 0.88 with the internal dataset; corresponding values were 0.98, 0.76, and 0.87 with the external dataset. CONCLUSION: The 3D mixed convolutional neural network developed here shows great potential for the automated binary classification (BO yes/no) of abdominal CT scans from patients with suspected BO. CLINICAL RELEVANCE STATEMENT: The 3D mixed CNN automates bowel obstruction classification, potentially automating patient selection and CT prioritization, leading to an enhanced radiologist workflow. KEY POINTS: • Bowel obstruction's rising incidence strains radiologists. AI can aid urgent CT readings. • Employed 1345 CT scans, neural networks for bowel obstruction detection, achieving high accuracy and sensitivity on external testing. • 3D mixed CNN automates CT reading prioritization effectively and speeds up bowel obstruction diagnosis.

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.

Chyluria: non-enhanced MR lymphography.

Chyluria is an uncommon medical condition resulting from an abnormal communication between the abdominal lymphatic system and the urinary tract, which results in the presence of chyle in the urine, making it appear milky white. Proper diagnosis is demonstrated by the concentration of urinary lipids. Worldwide, chyluria is most commonly associated with the parasite Wuchereria bancrofti. However, in Europe and North America, where the condition is rare, non-parasitic etiologies predominate. Identifying the cause and location of the uro-lymphatic communication is essential in guiding therapeutic management, but imaging the lymphatic channels remains a challenge. Magnetic resonance (MR) lymphography, a non-invasive free-breathing 3D high-resolution fast-recovery fast spin-echo sequence similar to that used for 3D MR cholangiopancreatography, may demonstrate the cause and location of an abnormal communication between the lymphatic system and urinary tract. In parasitic causes of chyluria, dilated lymphatics vessels communicating with the lymphatic system are demonstrated. In non-parasitic causes of chyluria channel type lymphatic malformations are the most common. Markedly dilated and dysplastic lymphatic vessels communicating with the urinary tract are demonstrated. In addition, other cystic or channel type lymphatic malformations such as thoracic, soft tissue or bone abnormalities may be observed. This review describes the abdominal lymphatic diseases leading to chyluria and presents the technique and images obtained with non-enhanced MR lymphography to enable radiologists in identifying and classifying uro-lymphatic fistulae.Critical relevance statement: Non-enhanced MR lymphography enables the identification and categorization of uro-lymphatic fistulae.

ERCP 2.0: Biliary 3D-reconstruction in patients with malignant hilar stricture.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) for malignant hilar strictures is challenging. The correlation between Magnetic resonance cholangiopancreatography (MRCP) and per ERCP 2D fluoroscopic images is not obvious. The aim of this study was to evaluate the feasibility and potential usefulness of MRCP-based handmade biliary 3D reconstruction in this setting. METHODS: Methods Patients who underwent MRCP followed by ERCP for biliary drainage of a malignant hilar stricture at our institution between 2018 and 2020 were reviewed. A handmade 3D segmentation using 3D slicer© (Kitware, France) was fashioned and reviewed with an expert radiologist. The primary outcome was the feasibility of biliary segmentation. RESULTS: A total of 16 patients were included. The mean age was 70.1 (+/- 8.6) years-old and 68.8% had hilar cholangiocarcinoma. Handmade segmentation was successful in all cases. The agreement between the MRCP interpretation and the 3D reconstruction was 37.5%, as per the Bismuth classification. 3D reconstruction available prior to ERCP could have helped guide for better stent placement in 11 cases (68.8%). CONCLUSIONS: MRCP-based biliary 3D segmentation-reconstruction, in patients with malignant hilar stricture is feasible and seems to provide a better anatomical understanding compared to MRCP and could help improve endoscopic management.

Protective potential of the gallbladder in primary sclerosing cholangitis.

Background & Aims: Gallbladder enlargement is common in patients with primary sclerosing cholangitis (PSC). The gallbladder may confer hepatoprotection against bile acid overload, through the sequestration and cholecystohepatic shunt of bile acids. The aim of this study was to assess the potential impact of the gallbladder on disease features and bile acid homeostasis in PSC. Methods: Patients with PSC from a single tertiary center who underwent liver MRI with three-dimensional cholangiography and concomitant analyses of serum bile acids were included. Gallbladder volume was measured by MRI and a cut-off of 50 ml was used to define gallbladder enlargement. Bile acid profiles and PSC severity, as assessed by blood tests and MRI features, were compared among patients according to gallbladder size (enlarged vs. normal-sized) or presence (removed vs. conserved). The impact of cholecystectomy was also assessed in the Abcb4 knockout mouse model of PSC. Results: Sixty-one patients with PSC, all treated with ursodeoxycholic acid (UDCA), were included. The gallbladder was enlarged in 30 patients, whereas 11 patients had been previously cholecystectomized. Patients with enlarged gallbladders had significantly lower alkaline phosphatase, a lower tauro-vs. glycoconjugate ratio and a higher UDCA vs. total bile acid ratio compared to those with normal-sized gallbladders. In addition, gallbladder volume negatively correlated with the hydrophobicity index of bile acids. Cholecystectomized patients displayed significantly higher aspartate aminotransferase and more severe bile duct strictures and dilatations compared to those with conserved gallbladder. In the Abcb4 knockout mice, cholecystectomy caused an increase in hepatic bile acid content and in circulating secondary bile acids, and an aggravation in cholangitis, inflammation and liver fibrosis. Conclusion: Altogether, our findings indicate that the gallbladder fulfills protective functions in PSC. Impact and implications: In patients with primary sclerosing cholangitis (PSC), gallbladder status impacts on bile acid homeostasis and disease features. We found evidence of lessened bile acid toxicity in patients with PSC and enlarged gallbladders and of increased disease severity in those who were previously cholecystectomized. In the Abcb4 knockout mouse model of PSC, cholecystectomy causes an aggravation of cholangitis and liver fibrosis. Overall, our results suggest that the gallbladder plays a protective role in PSC.

MRI restaging of rectal cancer: The RAC (Response-Anal canal-CRM) analysis joint consensus guidelines of the GRERCAR and GRECCAR groups.

PURPOSE: To develop guidelines by international experts to standardize data acquisition, image interpretation, and reporting in rectal cancer restaging with magnetic resonance imaging (MRI). MATERIALS AND METHODS: Evidence-based data and experts' opinions were combined using the RAND-UCLA Appropriateness Method to attain consensus guidelines. Experts provided recommendations for reporting template and protocol for data acquisition were collected; responses were analysed and classified as "RECOMMENDED" versus "NOT RECOMMENDED" (if ≥ 80% consensus among experts) or uncertain (if < 80% consensus among experts). RESULTS: Consensus regarding patient preparation, MRI sequences, staging and reporting was attained using the RAND-UCLA Appropriateness Method. A consensus was reached for each reporting template item among the experts. Tailored MRI protocol and standardized report were proposed. CONCLUSION: These consensus recommendations should be used as a guide for rectal cancer restaging with MRI.

Imaging of the biliary tract.

PURPOSE OF REVIEW: Magnetic resonance cholangiopancreatography (MRCP) has become the reference examination for the exploration of the biliary tract and has replaced endoscopic cholangiography for the analysis of the biliary tract because of its equivalent performance and its noninvasive character. RECENT FINDINGS: Based on the International Primary Sclerosing Cholangitis (PSC) Study Group recommendations for MR imaging in PSC, two protocols can be distinguished for the imaging of biliary tract: a basic protocol and a more complete protocol. It is essential to know the main pitfalls in order not to wrongly describe biliary anomalies. In addition to the excellent performance of MR imaging with MRCP in analyzing the anatomy and the anomalies of the biliary tree, complementary techniques have recently been developed. Several MR prognostic factors have been described. New hepato-specific contrast agents are now available for assessment of the general and segmental liver function. MR Elastography and Diffusion-weighted MR sequences are accurate to evaluate the degree of hepatic fibrosis. Finally, images obtained in MRCP can be postprocessed by a software that will analyze and model the biliary tree in order to quantitatively evaluate the biliary system. SUMMARY: Magnetic resonance imaging with its recent developments becomes by now an essential tool for the evaluation of biliary diseases.

JAK2V617F mutation drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm.

JAK2V617F mutation is associated with an increased risk for athero-thrombotic cardiovascular disease, but its role in aortic disease development and complications remains unknown. In a cohort of patients with myeloproliferative neoplasm, JAK2V617F mutation was identified as an independent risk factor for dilation of both the ascending and descending thoracic aorta. Using single-cell RNA-seq, complementary genetically-modified mouse models, as well as pharmacological approaches, we found that JAK2V617F mutation was associated with a pathogenic pro-inflammatory phenotype of perivascular tissue-resident macrophages, which promoted deleterious aortic wall remodeling at early stages, and dissecting aneurysm through the recruitment of circulating monocytes at later stages. Finally, genetic manipulation of tissue-resident macrophages, or treatment with a Jak2 inhibitor, ruxolitinib, mitigated aortic wall inflammation and reduced aortic dilation and rupture. Overall, JAK2V617F mutation drives vascular resident macrophages toward a pathogenic phenotype and promotes dissecting aortic aneurysm.

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.

Quantitative magnetic resonance cholangiopancreatography metrics are associated with disease severity and outcomes in people with primary sclerosing cholangitis.

Background & Aims: People with primary sclerosing cholangitis (PSC) have a variable and often progressive disease course that is associated with biliary and parenchymal changes. These changes are typically assessed by magnetic resonance imaging (MRI), including qualitative assessment of magnetic resonance cholangiopancreatography (MRCP). Our aim was to study the association of novel objective quantitative MRCP metrics with prognostic scores and patient outcomes. Methods: We performed a retrospective study including 77 individuals with large-duct PSC with baseline MRCP images, which were postprocessed to obtain quantitative measures of bile ducts using MRCP+™. The participants' ANALI scores, liver stiffness by vibration-controlled transient elastography, and biochemical indices were collected at baseline. Adverse outcome-free survival was measured as the absence of decompensated cirrhosis, liver transplantation (LT), or liver-related death over a 12-year period. The prognostic value of MRCP+-derived metrics was assessed by Cox regression modelling. Results: During a total of 386 patients-years, 16 cases of decompensation, 2 LTs, and 5 liver-related deaths were recorded. At baseline, around 50% of the patients were classified as being at risk of developing disease complications. MRCP+ metrics, particularly those describing the severity of bile duct dilatations, were correlated with all prognostic factors. Univariate analysis showed that MRCP+ metrics representing duct diameter, dilatations, and the percentage of ducts with strictures and/or dilatations were associated with survival. In a multivariable-adjusted analysis, the median duct diameter was significantly associated with survival (hazard ratio 10.9, 95% CI 1.3-90.3). Conclusions: MRCP+ metrics in people with PSC correlate with biochemical, elastographic, and radiological prognostic scores and are predictive of adverse outcome-free survival. Lay summary: In this study, we assessed in people with primary sclerosing cholangitis (PSC) the association of novel objective quantitative MRCP metrics automatically provided by a software tool (MRCP+) with prognostic scores and patient outcomes. We observed that MRCP+ metrics in people with PSC correlate with biochemical, elastographic, and radiological prognostic scores and are predictive of adverse outcome-free survival.