Multicenter Repeatability and Reproducibility of MR Fingerprinting in Phantoms and in Prostatic Tissue

Purpose To evaluate multicenter repeatability and reproducibility of T-1 and T-2 maps generated using MR fingerprinting (MRF) in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom and in prostatic tissues. Methods MRF experiments were performed on 5 different 3 Tesla MRI scanners at 3 different institutions: University Hospitals Cleveland Medical Center (Cleveland, OH), Brigham and Women's Hospital (Boston, MA) in the United States, and Diagnosticos da America (Rio de Janeiro, RJ) in Brazil. Raw MRF data were reconstructed using a Gadgetron-based MRF online reconstruction pipeline to yield quantitative T-1 and T-2 maps. The repeatability of T-1 and T-2 values over 6 measurements in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology MRI system phantom was assessed to demonstrate intrascanner variation. The reproducibility between the 4 clinical scanners was assessed to demonstrate interscanner variation. The same-day test-retest normal prostate mean T-1 and T-2 values from peripheral zone and transitional zone were also compared using the intraclass correlation coefficient and Bland-Altman analysis. Results The intrascanner variation of values measured using MRF was less than 2% for T-1 and 4.7% for T-2 for relaxation values, within the range of 307.7 to 2360 ms for T-1 and 19.1 to 248.5 ms for T-2. Interscanner measurements showed that the T-1 variation was less than 4.9%, and T-2 variation was less than 8.1% between multicenter scanners. Both T-1 and T-2 values in in vivo prostatic tissue demonstrated high test-retest reliability (intraclass correlation coefficient > 0.92) and strong linear correlation (R-2 > 0.840). Conclusion Prostate MRF measurements of T-1 and T-2 are repeatable and reproducible between MRI scanners at different centers on different continents for the above measurement ranges.