Geraldine Chang MD, Presenter: Nothing to Disclose

Lisa Clark MPH, PhD, Abstract Co-Author: Nothing to Disclose

Tanya Wolfson MS, Abstract Co-Author: Nothing to Disclose

Anthony Gamst PhD, Abstract Co-Author: Nothing to Disclose

Gavin Hamilton PhD, Abstract Co-Author: Research support, General Electric Company

Mark Bydder PhD, Abstract Co-Author: Research grant, General Electric Company

Michael Simca Middleton PhD, MD, Abstract Co-Author: Research Consultant, Siemens AG Research Consultant, Confirma, Inc Grant, General Electric Company Stockholder, General Electric Company Grant, Bayer AG Research Consultant, Merge Healthcare Research Consultant, Allergan, Inc Research Consultant, Merck & Co, Inc Research Consultant, Naviscan, Inc Speaker, SenoRx, Inc Speaker, C. R. Bard, Inc

Claude B. Sirlin MD, Abstract Co-Author: Research grant, Bayer AG Research grant, General Electric Company Research grant, Bracco Group Contract, Isis Pharmaceuticals, Inc Contract, Pfizer Inc Speaker Bureau, Bayer AG Consultant, Bayer AG Medical Advisory Board, Bayer AG Consultant, Merck & Co, Inc Medical Advisory Board, General Electric Company

To evaluate MR imaging (MRI)-determined proton density fat fraction (PDFF) reproducibility across two MR scanner platforms and, to confirm MRI-determined PDFF estimation accuracy using MR spectroscopy (MRS)-determined PDFF as reference standard.

This prospective, cross-sectional, crossover, observational pilot study was approved by an institutional review board. Twenty-one subjects gave written informed consent and underwent liver MRI and MRS at both 1.5T (Siemens Symphony scanner) and 3T (GE Signa Excite HD scanner). MRI-determined PDFF was estimated using an axial two-dimensional spoiled gradient-recalled echo sequence with low flip-angle to minimize T1 bias and six echo-times to permit correction of T2* and fat-water signal interference effects. MRS-determined PDFF was estimated using a Stimulated-echo Acquisition Mode sequence with long repetition time to minimize T1 bias and five echo-times to permit T2 correction. Reproducibility of MRI-determined PDFF on each scanner was assessed by correlation analysis; accuracy was assessed separately by linear regression analysis using MRS-determined PDFF as reference standard.

1.5T and 3T MRI-determined PDFF estimates were highly correlated (r=0.992). MRI-determined PDFF estimates were accurate at both 1.5T (regression slope/intercept = 0.958/-0.48) and 3T (slope/intercept = 1.020/0.925) against the MRS-determined PDFF reference.

MRI-determined PDFF estimation is reproducible and, using MRS-determined PDFF as reference standard, accurate across two MR scanner platforms at 1.5T and 3T.

Establishing reproducibility of MRI-determined PDFF is a necessary step in validating it as a reliable biomarker, which will then enable further obesity-related clinical and drug development research.

Chang, G, Clark, L, Wolfson, T, Gamst, A, Hamilton, G, Bydder, M, Middleton, M, Sirlin, C, Reproducibility of MR Imaging-determined Proton Density Fat Fraction (PDFF) across Different MR Scanner Platforms.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034550.html