Diagnostic value of magnetic resonance parametric mapping for non-invasive assessment of liver fibrosis in patients with primary sclerosing cholangitis.

BACKGROUND: Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease, characterized by bile duct inflammation and destruction, leading to biliary fibrosis and cirrhosis. The purpose of this study was to investigate the utility of T1 and T2 mapping parameters, including extracellular volume fraction (ECV) for non-invasive assessment of fibrosis severity in patients with PSC. METHODS: In this prospective study, patients with PSC diagnosis were consecutively enrolled from January 2019 to July 2020 and underwent liver MRI. Besides morphological sequences, MR elastography (MRE), and T1 and T2 mapping were performed. ECV was calculated from T1 relaxation times. The presence of significant fibrosis (≥ F2) was defined as MRE-derived liver stiffness ≥ 3.66 kPa and used as the reference standard, against which the diagnostic performance of MRI mapping parameters was tested. Student t test, ROC analysis and Pearson correlation were used for statistical analysis. RESULTS: 32 patients with PSC (age range 19-77 years) were analyzed. Both, hepatic native T1 (r = 0.66; P < 0.001) and ECV (r = 0.69; P < 0.001) correlated with MRE-derived liver stiffness. To diagnose significant fibrosis (≥ F2), ECV revealed a sensitivity of 84.2% (95% confidence interval (CI) 62.4-94.5%) and a specificity of 84.6% (CI 57.8-95.7%); hepatic native T1 revealed a sensitivity of 52.6% (CI 31.7-72.7%) and a specificity of 100.0% (CI 77.2-100.0%). Hepatic ECV (area under the curve (AUC) 0.858) and native T1 (AUC 0.711) had an equal or higher diagnostic performance for the assessment of significant fibrosis compared to serologic fibrosis scores (APRI (AUC 0.787), FIB-4 (AUC 0.588), AAR (0.570)). CONCLUSIONS: Hepatic T1 and ECV can diagnose significant fibrosis in patients with PSC. Quantitative mapping has the potential to be a new non-invasive biomarker for liver fibrosis assessment and quantification in PSC patients.

Routine bile collection for microbiological analysis during cholangiography and its impact on the management of cholangitis.

BACKGROUND: Antibiotic treatment of cholangitis is often insufficient because of inappropriate antibiotic use or bacterial resistance. OBJECTIVE: To evaluate the role of routine bile collection during endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography for microbiological analysis in the antibiotic management of cholangitis and to identify risk factors of bacteriobilia. DESIGN: Prospective, observational, diagnostic study. SETTING: Hannover Medical School, Hannover, Germany. PATIENTS AND INTERVENTION: This study involved 243 consecutive patients undergoing endoscopic retrograde cholangiography/percutaneous transhepatic cholangiography for biliary complications after orthotopic liver transplantation (27%), malignancy (27%), primary sclerosing cholangitis (15%), benign strictures (11%), and choledocholithiasis (8%). MAIN OUTCOME MEASUREMENTS: Microbiological examination of bile samples. RESULTS: Patients with biliary stents or who were receiving repeated interventions after orthotopic liver transplantation were at increased risk of bacteriobilia (P < .05). The rate of gram-positive monomicrobial infection was higher in patients with primary sclerosing cholangitis (P < .01). In 40 examinations, patients presented with preprocedural cholangitis although they were receiving antibiotics. According to bile culture results, the antibiotic treatment was modified to a more specific therapy in 72.5% of patients. In patients who developed cholangitis after endoscopic retrograde cholangiography (27 examinations), specific antibiotic treatment was started or refined in 67% of cases, based on bile culture results. LIMITATIONS: Contamination of samples during intervention cannot be totally excluded. CONCLUSION: Orthotopic liver transplantation, biliary stenting, and repeated interventions are risk factors of bacteriobilia. In our patients with primary sclerosing cholangitis, gram-positive monomicrobial infections were more common. A bile sample collected during cholangiography for microbiological analysis is a simple, potentially valuable, diagnostic tool in patients with cholangitis. Each center should recognize its own patterns of infection to ensure ideal targeted therapy.