Effect of intravenous gadoxetate disodium and flip angle on hepatic proton density fat fraction estimation with six-echo, gradient-recalled-echo, magnitude-based MR imaging at 3T
Department
Radiology
Document Type
Article
Publication Title
Abdominal Radiology (New York)
Abstract
PURPOSE: The aim of the study was to determine in patients undergoing gadoxetate disodium (Gx)-enhanced MR exams whether proton density fat fraction (PDFF) estimation accuracy of magnitude-based multi-gradient-echo MRI (MRI-M) could be improved by using high flip angle (FA) on post-contrast images. MATERIALS AND METHODS: Thirty-one adults with known or suspected hepatic steatosis undergoing 3T clinical Gx-enhanced liver MRI were enrolled prospectively. MR spectroscopy (MRS), the reference standard, was performed before Gx to measure MRS-PDFF. Low (10°)- and high (50°)-flip angle (FA) MRI-M sequences were acquired before and during the hepatobiliary phase after Gx administration; MRI-PDFF was estimated in the MRS-PDFF voxel location. Linear regression parameters (slope, intercept, average bias, R ) were calculated for MRS-PDFF as a function of MRI-PDFF for each MRI-M sequence (pre-Gx low-FA, pre-Gx high-FA, post-Gx low-FA, post-Gx high-FA) for all patients and for patients with MRS-PDFF <10%. Regression parameters were compared (Bonferroni-adjusted bootstrap-based tests). RESULTS: Three of the four MRI-M sequences (pre-Gx low-FA, post-Gx low-FA, post-Gx high-FA) provided relatively unbiased PDFF estimates overall and in the low-PDFF range, with regression slopes close to 1 and intercepts and biases close to zero. Pre-Gx high-FA MRI overestimated PDFF in proportion to MRS-PDFF, with slopes of 0.72 (overall) and 0.63 (low-PDFF range). Based on regression bias closest to 0, the post-Gx high-FA sequence was the most accurate overall and in the low-PDFF range. This sequence provided statistically significant improvements in at least two regression parameters compared to every other sequence. CONCLUSION: In patients undergoing Gx-enhanced MR exams, PDFF estimation accuracy of MRI-M can be improved by using high-FA on post-contrast images.
First Page
1189
Last Page
1198
DOI
10.1007/s00261-016-0992-4
Volume
42
Issue
4
Publication Date
4-1-2017
Medical Subject Headings
Adult; Aged; Contrast Media (administration & dosage); Fatty Liver (diagnostic imaging); Female; Gadolinium DTPA (administration & dosage); Humans; Image Enhancement (methods); Magnetic Resonance Imaging (methods); Male; Middle Aged; Prospective Studies; Protons
PubMed ID
28028556
Recommended Citation
Park, C. C., Hamilton, G., Desai, A., Zand, K. A., Wolfson, T., Hooker, J. C., Costa, E., Heba, E., Clark, L., Gamst, A., Loomba, R., Middleton, M. S., & Sirlin, C. B. (2017). Effect of intravenous gadoxetate disodium and flip angle on hepatic proton density fat fraction estimation with six-echo, gradient-recalled-echo, magnitude-based MR imaging at 3T. Abdominal Radiology (New York), 42 (4), 1189-1198. https://doi.org/10.1007/s00261-016-0992-4