caa a22 4500 605494711 CHVBK 20210128100527.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s00261-015-0542-5 doi (NATIONALLICENCE)springer-10.1007/s00261-015-0542-5 Intra- and inter-examination repeatability of magnetic resonance spectroscopy, magnitude-based MRI, and complex-based MRI for estimation of hepatic proton density fat fraction in overweight and obese children and adults [Elektronische Daten] [Avishkar Tyagi, Omid Yeganeh, Yakir Levin, Jonathan Hooker, Gavin Hamilton, Tanya Wolfson, Anthony Gamst, Amir Zand, Elhamy Heba, Rohit Loomba, Jeffrey Schwimmer, Michael Middleton, Claude Sirlin] Purpose: Determine intra- and inter-examination repeatability of magnitude-based magnetic resonance imaging (MRI-M), complex-based magnetic resonance imaging (MRI-C), and magnetic resonance spectroscopy (MRS) at 3T for estimating hepatic proton density fat fraction (PDFF), and using MRS as a reference, confirm MRI-M and MRI-C accuracy. Methods: Twenty-nine overweight and obese pediatric (n=20) and adult (n=9) subjects (23 male, 6 female) underwent three same-day 3T MR examinations. In each examination MRI-M, MRI-C, and single-voxel MRS were acquired three times. For each MRI acquisition, hepatic PDFF was estimated at the MRS voxel location. Intra- and inter-examination repeatability were assessed by computing standard deviations (SDs) and intra-class correlation coefficients (ICCs). Aggregate SD was computed for each method as the square root of the average of first repeat variances. MRI-M and MRI-C PDFF estimation accuracy was assessed using linear regression with MRS as a reference. Results: For MRI-M, MRI-C, and MRS acquisitions, respectively, mean intra-examination SDs were 0.25%, 0.42%, and 0.49%; mean intra-examination ICCs were 0.999, 0.997, and 0.995; mean inter-examination SDs were 0.42%, 0.45%, and 0.46%; and inter-examination ICCs were 0.995, 0.992, and 0.990. Aggregate SD for each method was <0.9%. Using MRS as a reference, regression slope, intercept, average bias, and R 2, respectively, for MRI-M were 0.99%, 1.73%, 1.61%, and 0.986, and for MRI-C were 0.96%, 0.43%, 0.40%, and 0.991. Conclusion: MRI-M, MRI-C, and MRS showed high intra- and inter-examination hepatic PDFF estimation repeatability in overweight and obese subjects. Longitudinal hepatic PDFF change >1.8% (twice the maximum aggregate SD) may represent real change rather than measurement imprecision. Further research is needed to assess whether examinations performed on different days or with different MR technologists affect repeatability of MRS voxel placement and MRS-based PDFF measurements. Springer Science+Business Media New York, 2015 Proton density fat fraction nationallicence PDFF nationallicence Hepatic steatosis nationallicence Obesity nationallicence Intra-examination repeatability nationallicence Inter-examination repeatability nationallicence Magnitude-based MRI nationallicence Complex-based MRI nationallicence Magnetic resonance spectroscopy nationallicence Quantitative imaging biomarkers nationallicence Tyagi Avishkar Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Yeganeh Omid Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Levin Yakir Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Hooker Jonathan Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Hamilton Gavin Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Wolfson Tanya Computational and Applied Statistics Laboratory (CASL), SDSC - University of California, San Diego, La Jolla, CA, USA aut Gamst Anthony Computational and Applied Statistics Laboratory (CASL), SDSC - University of California, San Diego, La Jolla, CA, USA aut Zand Amir Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Heba Elhamy Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Loomba Rohit Division of Gastroenterology, Department of Medicine, University of California at San Diego, La Jolla, CA, USA aut Schwimmer Jeffrey Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Middleton Michael Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Sirlin Claude Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut Abdominal Imaging Springer US; http://www.springer-ny.com 40/8(2015-10-01), 3070-3077 0942-8925 40:8<3070 2015 40 261 https://doi.org/10.1007/s00261-015-0542-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00261-015-0542-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tyagi Avishkar Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Yeganeh Omid Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Levin Yakir Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Hooker Jonathan Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Hamilton Gavin Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Wolfson Tanya Computational and Applied Statistics Laboratory (CASL), SDSC - University of California, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Gamst Anthony Computational and Applied Statistics Laboratory (CASL), SDSC - University of California, San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Zand Amir Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Heba Elhamy Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Loomba Rohit Division of Gastroenterology, Department of Medicine, University of California at San Diego, La Jolla, CA, USA aut NATIONALLICENCE 700 1- Schwimmer Jeffrey Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Middleton Michael Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 700 1- Sirlin Claude Liver Imaging Group, MR3T Bydder Laboratory, Department of Radiology, University of California at San Diego, 408 Dickinson Street MC 8226, 92103-8226, San Diego, CA, USA aut NATIONALLICENCE 773 0- Abdominal Imaging Springer US; http://www.springer-ny.com 40/8(2015-10-01), 3070-3077 0942-8925 40:8<3070 2015 40 261