Jeffrey N Stout1, Congyu Liao2, Borjan Gagoski3, Esra Abaci Turk3, Henry A Feldman4, Carolina Bibbo5, William H Barth6, Scott A Shainker7, Lawrence L Wald8, P Ellen Grant3, Elfar Adalsteinsson9. 1. Fetal and Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, 02115, USA. Electronic address: jeffrey.stout@childrens.harvard.edu. 2. Department of Radiology, Stanford University, Stanford, CA, 94305, USA. 3. Fetal and Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, 02115, USA. 4. Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, 02115, USA. 5. Brigham and Women's Hospital, Division of Maternal-Fetal Medicine, Boston, MA, 02115, USA. 6. Maternal-Fetal Medicine, Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, 02114, USA. 7. Maternal-Fetal Medicine, Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, 02115, USA. 8. Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, 02129, USA. 9. Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Abstract
INTRODUCTION: MR relaxometry has been used to assess placental exchange function, but methods to date are not sufficiently fast to be robust to placental motion. Magnetic resonance fingerprinting (MRF) permits rapid, voxel-wise, intrinsically co-registered T1 and T2 mapping. After characterizing measurement error, we scanned pregnant women during air and oxygen breathing to demonstrate MRF's ability to detect placental oxygenation changes. METHODS: The accuracy of FISP-based, sliding-window reconstructed MRF was tested on phantoms. MRF scans in 9-s breath holds were acquired at 3T in 31 pregnant women during air and oxygen breathing. A mixed effects model was used to test for changes in placenta relaxation times between physiological states, to assess the dependency on gestational age (GA), and the impact of placental motion. RESULTS: MRF estimates of known phantom relaxation times resulted in mean absolute errors for T1 of 92 ms (4.8%), but T2 was less accurate at 16 ms (13.6%). During normoxia, placental T1 = 1825 ± 141 ms (avg ± standard deviation) and T2 = 60 ± 16 ms (gestational age range 24.3-36.7, median 32.6 weeks). In the statistical model, placental T2 rose and T1 remained contant after hyperoxia, and no GA dependency was observed for T1 or T2. DISCUSSION: Well-characterized, motion-robust MRF was used to acquire T1 and T2 maps of the placenta. Changes with hyperoxia are consistent with a net increase in oxygen saturation. Toward the goal of whole-placenta quantitative oxygenation imaging over time, we aim to implement 3D MRF with integrated motion correction to improve T2 accuracy.
INTRODUCTION: MR relaxometry has been used to assess placental exchange function, but methods to date are not sufficiently fast to be robust to placental motion. Magnetic resonance fingerprinting (MRF) permits rapid, voxel-wise, intrinsically co-registered T1 and T2 mapping. After characterizing measurement error, we scanned pregnant women during air and oxygen breathing to demonstrate MRF's ability to detect placental oxygenation changes. METHODS: The accuracy of FISP-based, sliding-window reconstructed MRF was tested on phantoms. MRF scans in 9-s breath holds were acquired at 3T in 31 pregnant women during air and oxygen breathing. A mixed effects model was used to test for changes in placenta relaxation times between physiological states, to assess the dependency on gestational age (GA), and the impact of placental motion. RESULTS: MRF estimates of known phantom relaxation times resulted in mean absolute errors for T1 of 92 ms (4.8%), but T2 was less accurate at 16 ms (13.6%). During normoxia, placental T1 = 1825 ± 141 ms (avg ± standard deviation) and T2 = 60 ± 16 ms (gestational age range 24.3-36.7, median 32.6 weeks). In the statistical model, placental T2 rose and T1 remained contant after hyperoxia, and no GA dependency was observed for T1 or T2. DISCUSSION: Well-characterized, motion-robust MRF was used to acquire T1 and T2 maps of the placenta. Changes with hyperoxia are consistent with a net increase in oxygen saturation. Toward the goal of whole-placenta quantitative oxygenation imaging over time, we aim to implement 3D MRF with integrated motion correction to improve T2 accuracy.
Authors: Fuyixue Wang; Zijing Dong; Timothy G Reese; Berkin Bilgic; Mary Katherine Manhard; Jingyuan Chen; Jonathan R Polimeni; Lawrence L Wald; Kawin Setsompop Journal: Magn Reson Med Date: 2019-02-03 Impact factor: 4.668
Authors: Yun Jiang; Dan Ma; Kathryn E Keenan; Karl F Stupic; Vikas Gulani; Mark A Griswold Journal: Magn Reson Med Date: 2016-10-27 Impact factor: 4.668
Authors: Joëlle K Barral; Erik Gudmundson; Nikola Stikov; Maryam Etezadi-Amoli; Petre Stoica; Dwight G Nishimura Journal: Magn Reson Med Date: 2010-10 Impact factor: 4.668
Authors: Suneet P Chauhan; Everett F Magann; Dorota A Dohrety; Christopher S Ennen; Amy Niederhauser; John C Morrison Journal: Aust N Z J Obstet Gynaecol Date: 2008-04 Impact factor: 2.100
Authors: Yong Chen; Yun Jiang; Shivani Pahwa; Dan Ma; Lan Lu; Michael D Twieg; Katherine L Wright; Nicole Seiberlich; Mark A Griswold; Vikas Gulani Journal: Radiology Date: 2016-01-21 Impact factor: 11.105