[Techniques for quantification of liver fat in risk stratification of diabetics]. / Techniken zur Leberfettquantifizierung bei der Risikostratifikation von Diabetikern.

CLINICAL/METHODICAL ISSUE: Fatty liver disease plays an important role in the development of type 2 diabetes. Accurate techniques for detection and quantification of liver fat are essential for clinical diagnostics. STANDARD RADIOLOGICAL METHODS: Chemical shift-encoded magnetic resonance imaging (MRI) is a simple approach to quantify liver fat content. METHODICAL INNOVATIONS: Liver fat quantification using chemical shift-encoded MRI is influenced by several bias factors, such as T2* decay, T1 recovery and the multispectral complexity of fat. PERFORMANCE: The confounder corrected proton density fat fraction is a simple approach to quantify liver fat with comparable results independent of the software and hardware used. ACHIEVEMENTS: The proton density fat fraction is an accurate biomarker for assessment of liver fat. PRACTICAL RECOMMENDATIONS: An accurate and reproducible quantification of liver fat using chemical shift-encoded MRI requires a calculation of the proton density fat fraction.

Feasibility of gadoxetate disodium-enhanced MR cholangiography in chronic cholestatic biliary disease.

AIM: To investigate the feasibility of gadoxetate disodium-enhanced magnetic resonance (MR) cholangiography in chronic obstructive cholestatic biliary disease in the clinical setting. MATERIALS AND METHODS: Twenty-three patients with dilated bile duct trees and ten volunteers underwent gadoxetate disodium-enhanced liver MR cholangiography and were enrolled in the present retrospective study. Gadoxetate disodium was given in a standardized manner as a bolus injection at a dose of 0.25 mmol/kg of body weight (0.1 ml/kg). Region of interest-based measurement of mean enhancement of the dilated bile ducts was performed in series before gadoxetate disodium administration and during hepatobiliary phases. RESULTS: Direct comparison of mean bile duct enhancement during hepatobiliary phases in the clinical imaging window between healthy volunteers [4.7 ± 2.2 arbitrary units (au)] and patients with dilated bile ducts (0.1 ± 0.3 au) revealed significantly lower or absent enhancement in dilated bile ducts (p = 0.001). CONCLUSION: Standard clinical gadoxetate disodium-enhanced MR cholangiography is not a reliable technique for the evaluation of the biliary trees, because of altered biliary gadoxetate disodium elimination in patients with chronic obstructive biliary diseases.