By Brenda Tilke

A few decades ago, the autopsy rate in the U.S. was about 50%, but in recent years it has fallen as low as 15%. Reasons for the decrease include but are not limited to cultural and religious practices that make it difficult to obtain permission to perform an autopsy. Researchers in Boston and Jerusalem examined postmortem imaging alternatives to autopsies, particularly MR and CT. Their work was presented at the RSNA meeting in a scientific poster session this week.

A team of radiologists and pathologists at Boston University conducted MR studies with a 1.5-tesla system to discern the postmortem appearance of normal tissues (as determined by follow-up autopsy). Imaging techniques included coronal turboSTIR, body coil, 45-cm FOV, 8-mm mean slice thickness, and interslice gap of 0.5 mm. Axial T2-weighted fast field echo images with off-resonance magnetization transfer saturation were then acquired through the body. The total imaging time was less than 40 minutes.

Visceral organs had normal signal, according to the team. Ascites appeared only in patients with known premortem ascites. Small pleural effusions were seen in patients without premortem effusions, probably due to postmortem fluid accumulation in the pleural space. Brain scans showed preservation of the gray-white matter differentiation 12 hours after death.