Three‐dimensional simultaneous brain T1, T2, and ADC mapping with MR Multitasking

• Published in: Magnetic resonance in medicine Vol. 84; no. 1; pp. 72 - 88
• Main Authors: Ma, Sen, Nguyen, Christopher T., Han, Fei, Wang, Nan, Deng, Zixin, Binesh, Nader, Moser, Franklin G., Christodoulou, Anthony G., Li, Debiao
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.07.2020
• Subjects: Brain; Brain cancer; Brain mapping; Brain tumors; Correlation coefficients; co‐registered and distortion‐free mapping; Diffusion; Distortion; Feasibility; In vivo methods and tests; low‐rank tensor imaging; Mapping; Medical imaging; MR Multitasking; Multitasking; Patients; Shot; simultaneous T1/T2/ADC quantification; Surgery; Tensors; Therapeutic applications; time‐resolved phase correction; Weighting
• ISSN: 0740-3194; 1522-2594; 1522-2594
• DOI: 10.1002/mrm.28092

Purpose To develop a simultaneous T1, T2, and ADC mapping method that provides co‐registered, distortion‐free images and enables multiparametric quantification of 3D brain coverage in a clinically feasible scan time with the MR Multitasking framework. Methods The T1/T2/diffusion weighting was generated by a series of T2 preparations and diffusion preparations. The underlying multidimensional image containing 3 spatial dimensions, 1 T1 weighting dimension, 1 T2‐preparation duration dimension, 1 b‐value dimension, and 1 diffusion direction dimension was modeled as a 5‐way low‐rank tensor. A separate real‐time low‐rank model incorporating time‐resolved phase correction was also used to compensate for both inter‐shot and intra‐shot phase inconsistency induced by physiological motion. The proposed method was validated on both phantom and 16 healthy subjects. The quantification of T1/T2/ADC was evaluated for each case. Three post‐surgery brain tumor patients were scanned for demonstration of clinical feasibility. Results Multitasking T1/T2/ADC maps were perfectly co‐registered and free from image distortion. Phantom studies showed substantial quantitative agreement (R2=0.999) with reference protocols for T1/T2/ADC. In vivo studies showed nonsignificant T1 (P = .248), T2 (P = .97), ADC (P = .328) differences among the frontal, parietal, and occipital regions. Although Multitasking showed significant differences of T1 (P = .03), T2 (P < .001), and ADC (P = .001) biases against the references, the mean bias estimates were small (ΔT1% < 5%, ΔT2% < 7%, ΔADC% < 5%), with all intraclass correlation coefficients greater than 0.82 indicating “excellent” agreement. Patient studies showed that Multitasking T1/T2/ADC maps were consistent with the clinical qualitative images. Conclusion The Multitasking approach simultaneously quantifies T1/T2/ADC with substantial agreement with the references and is promising for clinical applications.