Skin temperature increase after whole body postmortem magnetic resonance imaging

Purpose: To investigate causes for skin temperature increase after whole body postmortem magnetic resonance (PMMR) imaging. Material and methods: We performed PMMR imaging using a 1.5 T clinical scanner on 28 deceased human adults. The corpses were kept in cold storage at 4 ℃ before MRI and the scan room was maintained at 23 ℃. Skin temperatures of corpses before and after MRI were measured and average specific absorption rates (SAR) of the measured points were calculated. Results: Average skin temperature before and after PMMR imaging was 11.8 ± 5.8 ℃ and 15.0 ± 5.1 ℃, respectively. Average skin temperature increase was 3.2 ± 1.4 ℃, and whole-body average SAR in all sequences was 0.97 ± 0.94 W/kg. The skin temperature increase correlated significantly with the difference between the average initial skin temperature before PMMR imaging and the room temperature (R² = 0.388, P = 0.002), but did not correlate significantly with whole-body average SAR in all sequences (R² = 0.032, P = 0.662 > 0.05). Conclusion: The skin temperature increase during whole body PMMR imaging is more likely influenced by room temperature than by RF energy-induced heating effect. RF heating effect in PMMR imaging is minimal, and it appears to be no significant issue to conduct 1.5 T PMMR imaging prior to autopsy.