In vivo T 1 mapping of neonatal brain tissue at 64 mT

• Published in: Magnetic resonance in medicine 2023-03, Vol.89 (3), p.1016-1025
• Main Authors: Padormo, Francesco, Cawley, Paul, Dillon, Louise, Hughes, Emer, Almalbis, Jennifer, Robinson, Joanna, Maggioni, Alessandra, Botella, Miguel De La Fuente, Cromb, Dan, Price, Anthony, Arlinghaus, Lori, Pitts, John, Luo, Tianrui, Zhang, Dingtian, Deoni, Sean C L, Williams, Steve, Malik, Shaihan, O Muircheartaigh, Jonathan, Counsell, Serena J, Rutherford, Mary, Arichi, Tomoki, Edwards, A David, Hajnal, Joseph V
• Format: Article
• Language: English
• Subjects: Adult; Brain - diagnostic imaging; Brain Mapping - methods; Cerebellum; Humans; Infant; Infant, Newborn; Linear Models; Magnetic Resonance Imaging - methods; White Matter
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.29509

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 T 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 T mapping at ULF. 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 to 49  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 T maps. Regions of interest were placed in the cerebral deep gray matter, frontal white matter, and cerebellum. Weighted linear regression was used to predict T as a function of postmenstrual age. Reduction of T with postmenstrual age is observed in all measured brain tissue; the change in T per week and 95% confidence intervals is given by dT  = -21 ms/week [-25, -16] (cerebellum), dT  = -14 ms/week [-18, -10] (deep gray matter), and dT  = -35 ms/week [-45, -25] (white matter). Neonatal T values at ULF are shorter than those previously described at standard clinical field strengths, but longer than those of adults at ULF. T reduces with postmenstrual age and is therefore a candidate biomarker for perinatal brain development.