Feasibility of reducing Angiofil® concentration in multiphase postmortem CT angiography and implications for iodine consumption and environmental sustainability : an observational study

Background Postmortem CT angiography (PMCTA) is widely used in forensic medicine to evaluate the vascular system before autopsy. The contrast mixture of 3,500 ml paraffin and 210 ml Angiofil ® , originally proposed by Grabherr et al. for multiphase postmortem CT angiography (MPMCTA) approach, provides reliable global vascular opacification. Recent advances in CT detector technology, image reconstruction techniques, and growing environmental concerns have encouraged the investigation of alternative contrast-agent dilutions aimed to reduce iodine consumption. The aim of this observational study was to explore whether lower Angiofil ® concentrations could be used while preserving adequate vascular visualization and diagnostic image quality. Methods Thirty cases were evaluated using four progressively diluted Angiofil ® –paraffin mixtures containing 200 ml, 180 ml, 150 ml, and 120 ml of Angiofil ® in 3,500 ml of paraffin. Contrast enhancement was quantified by measuring Hounsfield units (HU) within regions of interest (ROIs) placed in the ascending thoracic aorta and compared with a clinical case. Image quality was independently assessed by an experienced forensic radiologist based on opacification of the ascending thoracic aorta. In addition, a dedicated evaluation of coronary artery lumen and wall visualization was performed. Results The mixture containing 200 ml of Angiofil ® showed no relevant improvement in image quality compared with the original dilution. A mixture containing 180 ml of Angiofil ® allowed excellent vascular assessment in individuals with a BMI > 35 kg/m², whereas 150 ml of Angiofil ® provided optimal image quality in individuals with a BMI ≤ 35 kg/m². The 120 ml mixture remained diagnostically acceptable in most cases but produced photon-starvation artifacts in individuals with high muscle mass or a BMI > 33 kg/m², limiting vascular assessment. Conclusion Adjusting the Angiofil ® –paraffin mixture according to body morphology using 180 ml of Angiofil ® for individuals with a BMI > 35 kg/m² and 150 ml for those with a BMI ≤ 35 kg/m² maintains excellent vascular visualization while substantially reducing iodine consumption. This optimization supports more environmentally sustainable PMCTA practice without compromising diagnostic image quality.