• Martijn A Cloos, Jakob Assländer, Batool Abbas, James Fishbaugh, James S Babb, Guido Gerig, and Riccardo Lattanzi.
• Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA.
• J Magn Reson Imaging. 2019 Sep 1; 50 (3): 810-815.

BackgroundQuantitative MRI can detect early changes in cartilage biochemical components, but its routine clinical implementation is challenging.PurposeTo introduce a novel technique to measure T1 and T2 along radial sections of the hip for accurate and reproducible multiparametric quantitative cartilage assessment in a clinically feasible scan time.Study TypeReproducibility, technical validation.Subjects/PhantomA seven-compartment phantom and three healthy volunteers.Field Strength/SequenceA novel MR pulse sequence that simultaneously measures proton density (PD), T1 , and T2 at 3 T was developed. Automatic positioning and semiautomatic cartilage segmentation were implemented to improve consistency and simplify workflow.AssessmentIntra- and interscanner variability of our technique was assessed over multiple scans on three different MR scanners.Statistical TestsFor each scan, the median of cartilage T1 and T2 over six radial slices was calculated. Restricted maximum likelihood estimation of variance components was used to estimate intrasubject variances reflecting variation between results from the two scans using the same scanner (intrascanner variance) and variation among results from the three scanners (interscanner variance).ResultsThe estimation error for T1 and T2 with respect to reference standard measurements was less than 3% on average for the phantom. The average interscanner coefficient of variation was 1.5% (1.2-1.9%) and 0.9% (0.0-3.7%) for T1 and T2 , respectively, in the seven compartments of the phantom. Total scan time in vivo was 7:13 minutes to obtain PD, T1 , and T2 maps along six radial hip sections at 0.6 × 0.6 × 4.0 mm3 voxel resolution. Interscanner variability for the in vivo study was 1.99% and 5.46% for T1 and T2 , respectively. in vivo intrascanner variability was 1.15% for T1 and 3.24% for T2 .Data ConclusionOur method, which includes slice positioning, model-based parameter estimation, and cartilage segmentation, is highly reproducible. It could enable employing quantitative hip cartilage evaluation for longitudinal and multicenter studies.Level Of Evidence1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:810-815.© 2018 International Society for Magnetic Resonance in Medicine.

22 keywords...

hide…