• Tom Hilbert, Tilman J Sumpf, Elisabeth Weiland, Jens Frahm, Jean-Philippe Thiran, Reto Meuli, Tobias Kober, and Gunnar Krueger.
• Advanced Clinical Imaging Technology (HC CEMEA SUI DI PI), Siemens Healthcare, Lausanne, Switzerland.
• J Magn Reson Imaging. 2018 Aug 1; 48 (2): 359-368.

BackgroundQuantitative T2 measurements are sensitive to intra- and extracellular water accumulation and myelin loss. Therefore, quantitative T2 promises to be a good biomarker of disease. However, T2 measurements require long acquisition times.PurposeTo accelerate T2 quantification and subsequent generation of synthetic T2 -weighted (T2 -w) image contrast for clinical research and routine. To that end, a recently developed model-based approach for rapid T2 and M0 quantification (MARTINI) based on undersampling k-space, was extended by parallel imaging (GRAPPA) to enable high-resolution T2 mapping with access to T2 -w images in less than 2 minutes acquisition time for the entire brain.Study TypeProspective cross-sectional study.Subjects/PhantomFourteen healthy subjects and a multipurpose phantom.Field Strength/SequenceCarr-Purcell-Meiboom-Gill sequence at a 3T scanner.AssessmentThe accuracy and reproducibility of the accelerated T2 quantification was assessed. Validations comprised MRI studies on a phantom as well as the brain, knee, prostate, and liver from healthy volunteers. Synthetic T2 -w images were generated from computed T2 and M0 maps and compared to conventional fast spin-echo (SE) images.Statistical TestsRoot mean square distance (RMSD) to the reference method and region of interest analysis.ResultsThe combination of MARTINI and GRAPPA (GRAPPATINI) lead to a 10-fold accelerated T2 mapping protocol with 1:44 minutes acquisition time and full brain coverage. The RMSD of GRAPPATINI increases less (4.3%) than a 10-fold MARTINI reconstruction (37.6%) in comparison to the reference. Reproducibility tests showed low standard deviation (SD) of T2 values in regions of interest between scan and rescan (<0.4 msec) and across subjects (<4 msec).Data ConclusionGRAPPATINI provides highly reproducible and fast whole-brain T2 maps and arbitrary synthetic T2 -w images in clinically compatible acquisition times of less than 2 minutes. These abilities are expected to support more widespread clinical applications of quantitative T2 mapping.Level Of Evidence2 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2018;48:359-368.© 2018 International Society for Magnetic Resonance in Medicine.

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