Zhu Ante, Reeder Scott B, Johnson Kevin M, Nguyen Sydney M, Golos Thaddeus G, Shimakawa Ann, Muehler Matthias R, Francois Christopher J, Bird Ian M, Fain Sean B, Shah Dinesh M, Wieben Oliver, Hernando Diego
Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin, USA.
Department of Radiology, University of Wisconsin, Madison, Wisconsin, USA.
J Magn Reson Imaging. 2020 Feb;51(2):580-592. doi: 10.1002/jmri.26849. Epub 2019 Jul 5.
3D chemical shift-encoded (CSE)-MRI techniques enable assessment of ferumoxytol concentration but are unreliable in the presence of motion.
To evaluate a motion-robust 2D-sequential CSE-MRI for R2* and B0 mapping in ferumoxytol-enhanced MRI of the placenta.
Prospective.
Pregnant rhesus macaques.
FIELD STRENGTH/SEQUENCE: 3.0T/CSE-MRI.
2D-sequential CSE-MRI was compared with 3D respiratory-gated CSE-MRI in placental imaging of 11 anesthetized animals at multiple timepoints before and after ferumoxytol administration, and in ferumoxytol phantoms (0 μg/mL-440 μg/mL). Motion artifacts of CSE-MRI in 10 pregnant women without ferumoxytol administration were assessed retrospectively by three blinded readers (4-point Likert scale). The repeatability of CSE-MRI in seven pregnant women was also prospectively studied.
Placental R2* and boundary B0 field measurements (ΔB0) were compared between 2D-sequential and 3D respiratory-gated CSE-MRI using linear regression and Bland-Altman analysis.
In phantoms, a slope of 0.94 (r = 0.99, concordance correlation coefficient ρ = 0.99), and bias of -4.8 s (limit of agreement [LOA], -41.4 s , +31.8 s ) in R2*, and a slope of 1.07 (r = 1.00, ρ = 0.99) and bias of 11.4 Hz (LOA -12.0 Hz, +34.8 Hz) in ΔB0 were obtained in 2D CSE-MRI compared with 3D CSE-MRI for reference R2* ≤390 s . In animals, a slope of 0.92 (r = 0.97, ρ = 0.98) and bias of -2.2 s (LOA -55.6 s , +51.3 s ) in R2*, and a slope of 1.05 (r = 0.95, ρ = 0.97) and bias of 0.4 Hz (LOA -9.0 Hz, +9.7 Hz) in ΔB0 were obtained. In humans, motion-impaired R2* maps in 3D CSE-MRI (Reader 1: 1.8 ± 0.6, Reader 2: 1.3 ± 0.7, Reader 3: 1.9 ± 0.6), while 2D CSE-MRI was motion-free (Reader 1: 2.9 ± 0.3, Reader 2: 3.0 ± 0, Reader 3: 3.0 ± 0). A mean difference of 0.66 s and coefficient of repeatability of 9.48 s for placental R2* were observed in the repeated 2D CSE-MRI.
2D-sequential CSE-MRI provides accurate R2* and B0 measurements in ferumoxytol-enhanced placental MRI of animals in the presence of respiratory motion, and motion-robustness in human placental imaging.
1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:580-592.
三维化学位移编码（CSE）磁共振成像（MRI）技术能够评估菲洛施托醇浓度，但在存在运动的情况下不可靠。
评估一种运动稳健的二维序列CSE-MRI，用于在菲洛施托醇增强的胎盘MRI中进行R2*和B0映射。
前瞻性研究。
怀孕的恒河猴。
场强/序列：3.0T/CSE-MRI。
在11只麻醉动物菲洛施托醇给药前后的多个时间点以及菲洛施托醇体模（0μg/mL - 440μg/mL）的胎盘成像中，将二维序列CSE-MRI与三维呼吸门控CSE-MRI进行比较。三位盲法阅片者对10名未使用菲洛施托醇的孕妇的CSE-MRI运动伪影进行回顾性评估（4分李克特量表）。还前瞻性研究了7名孕妇中CSE-MRI的可重复性。
使用线性回归和布兰德-奥特曼分析比较二维序列和三维呼吸门控CSE-MRI之间的胎盘R2*和边界B0场测量值（ΔB0）。
在体模中，对于参考R2*≤390 s，二维CSE-MRI与三维CSE-MRI相比，R2的斜率为0.94（r = 0.99，一致性相关系数ρ = 0.99），偏差为 - 4.8 s（一致性界限[LOA]， - 41.4 s， + 31.8 s），ΔB0的斜率为1.07（r = 1.00，ρ = 0.99），偏差为11.4 Hz（LOA - 12.0 Hz， + 34.8 Hz）。在动物中，R2的斜率为0.92（r = 0.97，ρ = 0.98），偏差为 - 2.2 s（LOA - 55.6 s， + 51.3 s），ΔB0的斜率为1.05（r = 0.95，ρ = 0.97），偏差为0.4 Hz（LOA - 9.0 Hz， + 9.7 Hz）。在人体中，三维CSE-MRI中的R2图受运动影响（阅片者1：1.8 ± 0.6，阅片者2：1.3 ± 0.7，阅片者3：1.9 ± 0.6），而二维CSE-MRI无运动影响（阅片者1：2.9 ± 0.3，阅片者2：3.0 ± 0，阅片者3：3.0 ± 0）。在重复的二维CSE-MRI中，观察到胎盘R2的平均差异为0.66 s，可重复性系数为9.48 s。
二维序列CSE-MRI在存在呼吸运动的情况下，能够在菲洛施托醇增强的动物胎盘MRI中提供准确的R2*和B0测量值，并且在人体胎盘成像中具有运动稳健性。
1技术效能：1期 《磁共振成像杂志》2020年；51：580 - 592。
