Padormo F, Cawley P, Dillon L, Hughes E, Almalbis J, Robinson J, Maggioni A, Botella MDLF, Cromb D, Price A, Arlinghaus L, Pitts J, Luo T, Zhang D, Deoni SCL, Williams S, Malik S, O′Muircheartaigh J, Counsell SJ, Rutherford M, Arichi T, Edwards AD, Hajnal JV. In vivo T
1 mapping of neonatal brain tissue at 64 mT.
Magn Reson Med 2023;
89:1016-1025. [PMID:
36372971 PMCID:
PMC10099617 DOI:
10.1002/mrm.29509]
[Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/14/2022] [Accepted: 10/11/2022] [Indexed: 11/16/2022]
Abstract
PURPOSE
Ultralow-field (ULF) point-of-care MRI systems allow image acquisition without interrupting medical provision, with neonatal clinical care being an important potential application. The ability to measure neonatal brain tissue T1 is a key enabling technology for subsequent structural image contrast optimization, as well as being a potential biomarker for brain development. Here we describe an optimized strategy for neonatal T1 mapping at ULF.
METHODS
Examinations were performed on a 64-mT portable MRI system. A phantom validation experiment was performed, and a total of 33 in vivo exams were acquired from 28 neonates with postmenstrual age ranging from 31+4 to 49+0 weeks. Multiple inversion-recovery turbo spin-echo sequences were acquired with differing inversion and repetition times. An analysis pipeline incorporating inter-sequence motion correction generated proton density and T1 maps. Regions of interest were placed in the cerebral deep gray matter, frontal white matter, and cerebellum. Weighted linear regression was used to predict T1 as a function of postmenstrual age.
RESULTS
Reduction of T1 with postmenstrual age is observed in all measured brain tissue; the change in T1 per week and 95% confidence intervals is given by dT1 = -21 ms/week [-25, -16] (cerebellum), dT1 = -14 ms/week [-18, -10] (deep gray matter), and dT1 = -35 ms/week [-45, -25] (white matter).
CONCLUSION
Neonatal T1 values at ULF are shorter than those previously described at standard clinical field strengths, but longer than those of adults at ULF. T1 reduces with postmenstrual age and is therefore a candidate biomarker for perinatal brain development.
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