Diffusion MRI ‐Based Fetal Thermometry Using Cerebrospinal Fluid: A Translational Feasibility Study
Year: 2026
Type: article
Abstract: BACKGROUND: Noninvasive fetal temperature assessment could improve MRI safety monitoring and provide insight into fetal physiology. Diffusion MRI is a potential approach because water diffusivity in free fluids is temperature dependent. However, the applicability of adult-derived diffusivity-temperature calibration to neonatal and fetal CSF remains uncertain. PURPOSE: To evaluate the feasibility of diffusion MRI for noninvasive estimation of a diffusion-derived proxy of fetal temperature in cerebrospinal fluid (CSF). STUDY TYPE: Prospective feasibility study. POPULATION/SUBJECTS: 11 preterm neonates (postmenstrual age, 30.0-40.6 weeks; 5 male, 6 female) underwent CSF diffusion MRI for translational validation, and 11 fetuses (gestational age, 27.6-37.6 weeks) underwent CSF diffusion MRI for in utero feasibility assessment. FIELD STRENGTH/SEQUENCE: 1.5T monopolar spin-echo echo-planar diffusion imaging for neonatal validation; 3T monopolar spin-echo echo-planar diffusion MRI for fetal imaging. ASSESSMENT: Temperature was derived from CSF apparent diffusion coefficients using an established diffusivity-temperature calibration. Neonatal estimates were compared with pre and postscan axillary temperatures. Monte Carlo simulations evaluated the effects of noise, gradient-amplitude scaling errors, and calibration uncertainty. STATISTICAL TESTS: Bland-Altman analysis, linear regression, descriptive statistics, Huber M-estimation, and Monte Carlo simulations were performed. Statistical significance for regression analyses was defined as p < 0.05. RESULTS: Diffusion-derived CSF temperatures agreed with axillary measurements within approximately ±1°C in 11 preterm neonates and showed Bland-Altman biases of 0.41°C and 0.50°C for mean diffusion-derived temperature compared with pre and postscan axillary measurements, respectively. In 11 fetuses, the CSF temperature estimates using the Huber M-estimator were 37.13°C ± 0.41°C (mean ± SD). Monte Carlo simulations revealed a decrease in the temperature SD from about 4.5°C at SNR = 30 to 1.6°C at SNR = 80. Gradient-amplitude scaling errors of ±8% resulted in approximately 6.5°C-7°C absolute temperature bias, which was reduced to ≤ 0.1°C after ideal effective b value correction. DATA CONCLUSION: Diffusion MRI enables feasible estimation of a diffusion-derived proxy of fetal temperature in CSF. TECHNICAL EFFICACY: Stage 1.
DOI: 10.1002/jmri.70614
Institution: Children's National
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,680
OpenAlex ID: W7225459729