Skin temperature increase after whole body postmortem magnetic resonance imaging

Abstract

• 1.5 T whole body postmortem magnetic resonance (PMMR) imaging was taken for 1 h. • The causes of skin temperature increase ( T inc ) after PMMR imaging was investigated. • Average specific absorption rates of PMMR imaging were within the safe range. • T inc is hardly influenced by radiofrequency heating but rather by room temperature. • 1.5 T whole body PMMR imaging for 1 h does not significantly warm up a cadaver. To investigate causes for skin temperature increase after whole body postmortem magnetic resonance (PMMR) imaging. 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. 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 ( R 2 = 0.388, P = 0.002), but did not correlate significantly with whole-body average SAR in all sequences ( R 2 = 0.032, P = 0.662 > 0.05). 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.