Postmortem imaging of antemortem myocardial ischaemia

Area of Science:

• Forensic pathology
• Cardiovascular imaging
• Postmortem diagnostics

Background:

• Accurate determination of antemortem myocardial ischemia is crucial in forensic investigations.
• Postmortem imaging (PMI) techniques offer potential for non-invasive assessment of cardiac conditions.
• Establishing the minimum time for reliable detection of myocardial ischemia using PMI is essential.

Purpose of the Study:

• To establish the minimum survival time required for the detection of antemortem myocardial ischemia using postmortem imaging (PMI) techniques.
• To evaluate the efficacy of MRI and CT angiography in identifying myocardial ischemic lesions at various postmortem intervals.

Main Methods:

• Nine pigs underwent induced myocardial ischemia via ligation of coronary arteries (LAD and/or RCA).
• Animals were euthanized at 30 minutes to 6 hours post-ligation, followed by PMI (MRI and CT angiography) 2-55 hours post-euthanasia.
• Myocardial signal intensity was measured, and hearts were analyzed histologically after coronary artery perfusion.

Main Results:

• MRI T2-weighted sequences detected left ventricular (LV) ischemic areas as hyperintense in all cases with ≥4 hours of ischemia, but none with <4 hours.
• Histological confirmation of ischemia was present in all animals after 4 hours.
• CT angiography successfully visualized arterial occlusion in all instances; right ventricular ischemia was inconsistently detected by MRI.

Conclusions:

• Left ventricular myocardial ischemia/infarction, at least 4 hours old, is detectable by T2-weighted postmortem MRI as hyperintense areas.
• Postmortem MRI demonstrates the highest sensitivity for detecting ischemic lesions within 24 hours after death.
• Right ventricular ischemia is not reliably detected by current PMI techniques, while CT angiography can confirm arterial occlusion.