Monitoring SAR Metrics and Physiological Thermal Changes During Fetal Magnetic Resonance Imaging at 3T

Background: Monitoring SAR and body temperature changes during 3T MRI is crucial for fetal safety. Specific Absorption Rate (SAR), which measures energy absorbed by tissues and could potentially induce heating in pregnant patients. This study estimates SAR values in fetal MRI exams and correlates them with maternal temperature changes pre and post scan to assess thermal safety at 3.0 Tesla.  Methods: This prospective study involved 50 pregnant patients with gestational periods from 20 to 36 weeks who were referred for fetal MRI at 3.0 Tesla. The Mean SAR values ,the Pre & Post Scan body temperature changes and along with scan time per sequence per study were estimated, and analyzed for potential correlations.  Results: The ANOVA test was performed the mean SAR was 1.3 W/kg, with a pre and post scan temperature of 98.2°F and 97.3°F indicating (p ≥ 0.05) no statistically significant correlation between SAR values with respect to weight and temperature . The data based on total scan time while performing all three sequence, the result showed statically significance (p ≤ 0.05) ,only with the SAR value but not with the temperature difference(p ≥ 0.05) .  Conclusion: The current study HASTE sequences show higher SAR and involving minimal influence on whole-body temperature in fetal MRI. This study suggests MR technologists should apply SAR reducing strategies to limit scan time, ensuring safe and efficient fetal imaging at 3.0 Tesla.