Repeatability of magnetic resonance fingerprinting T₁ and T₂ estimates assessed using the ISMRM/NIST MRI system phantom

Abstract

Purpose The purpose of this study was to evaluate accuracy and repeatability of T1 and T2 estimates of a Magnetic Resonance Fingerprinting (MRF) method using the ISMRM/NIST MRI system phantom. Methods The ISMRM/NIST MRI system phantom contains multiple compartments with standardized T1, T2 and proton density values. Conventional inversion-recovery spin echo and spin echo methods were used to characterize the T1 and T2 values in the phantom. The phantom was scanned using the MRF-FISP method over 34 consecutive days. The mean T1 and T2 values were compared to the values from the spin echo methods. The repeatability was characterized as the coefficient of variation (CV) of the measurements over 34 days. Results T1 and T2 values from MRF-FISP over 34 days showed a strong linear correlation with the measurements from the spin echo methods (R2 = 0.999 for T1, R2 = 0.996 for T2). The MRF estimates over the wide ranges of T1 and T2 values have less than 5% variation, except for the shortest T2 relaxation times where the method still maintains less than 8% variation. Conclusion MRF measurements of T1 and T2 are highly repeatable over time and across wide ranges of T1 and T2 values.

MR Fingerprinting of Adult Brain Tumors: Initial Experience

“…Recent studies have looked into improving on the MRF acquisition parameters to make them more robust, improving the reconstruction algorithms and acquiring newer quantitative parameters from this technique 26–28 . Given its multiparametric capabilities and repeatability, this technique holds the capability to become a useful MR imaging biomarker 29, 30 . Although the clinical applications and utility of this technique have not been assessed so far, the in-vivo quantitation data in healthy volunteers and in patients are emerging 31–33 .…”

Development of high‐resolution 3D MR fingerprinting for detection and characterization of epileptic lesions

“…When combined with diffusion, the MRF T 1 and T 2 values can differentiate prostate cancer from normal tissue and separate low‐grade from high/intermediate‐grade tumors . Because of the flexibility of the sequence design and signal modeling, confounding factors, such as slice profile imperfection, B0, and B1 inhomogeneities can be incorporated into the signal model, which has been shown to improve the accuracy and robustness of MRF scans and provide results with high repeatability . In a very recent study, 2D MRF was shown to improve detection of hippocampal sclerosis by multiparametric mapping of T 1 and T 2 values .…”

Magnetic resonance fingerprinting – An overview

“…Various sequences can be tailored to this MRF framework depending on the specific tissue properties that need to be measured, including T1, T2, M 0 , perfusion parameters, B 0 , B 1 , etc. Current MRF sequences have been shown to be repeatable[2,13,14]. MRF offers the possibility of bringing quantitative imaging into clinical routine, potentially allowing more precise and automated diagnosis and easier comparison between data acquired in different scans, at different times and in different locations.…”

“…Thus high quality individual time point images are explicitly not sought. Despite the significant undersampling, the signal evolution obtained from all the undersampled data can still be matched to the best corresponding MRF dictionary entry and the resulting quantitative maps have been shown to be highly accurate[2] and repeatable (Coefficient of variation of less than 5% for T1 and T2 values)[13]. It is therefore possible to “see through” image artifacts arising from the undersampling during the dictionary-matching step, as the errors are not coherent spatially or temporally [2].…”