Postmortem Changes in Skeletal Muscle Can Be Expressed by Hounsfield Unit Measurements in Postmortem Computed Tomography—A Murine Model Study

Purpose: The aim of the present study was to assess time-dependent changes in postmortem images of mouse skeletal muscle that were obtained with a small animal CT scanner. Materials and methods: Mice were euthanized and time-dependent changes in postmortem computed tomography (PMCT) images of skeletal muscle were recorded for 11 elapsed intervals: at the confirmed time of cardiac arrest, and at 0.5, 1, 2, 3, 6, 12, 24, 36, 48, and 72 hours after death. After acquiring PMCT images, skeletal muscle was removed and prepared for histological evaluation. Histological images and PMCT images of the skeletal muscle were then compared. Hounsfield unit (HU) measurements were obtained for the skeletal muscle PMCT images at each interval and time-dependent changes were examined. Results: Time-dependent changes were observed in histological images of skeletal muscle, but not in PMCT images. Time-dependent changes were detectable by HU values of skeletal muscle. Conclusion: Postmortem changes in skeletal muscle tissue appear as decreases in HU values on PMCT.