Optimal pressure for mimicking clinical breath holding inspiratory CT in the deceased for VPMCT

• Published in: Forensic imaging (Online) Vol. 32; p. 200530
• Main Authors: Jakobsen, Søren Reinhold, Boel, Lene Warner Thorup, Gascho, Dominic, Thali, Michael, Hansen, Kasper
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-03-2023
• Subjects: Consolidations; Forensic imaging; Ground glass opacities; Lung volume; Stereology; Lung volume; Ground glass opacities; Stereology; Forensic imaging; Consolidations
• ISSN: 2666-2256; 2666-2256
• DOI: 10.1016/j.fri.2022.200530

•The effect of increasing ventilation pressure on postmortem changes was examined.•Quantitative analysis showed maximum positive effect of inflation at 30 cmH2O.•A simple cost-efficient inflation device was used for reliable and reproducible VPMCT.
Ventilated PMCT (VPMCT) has been reported to provide better quality of pulmonary structures in PMCT in adults and children. However, there are no consensus regarding optimal inflation pressure, and the practical use of VPMCT is still limited by cost of ventilation equipment. Here, we describe a simple and cost-efficient inflation-device for VPMCT and investigate optimal inflation pressure.
To elucidate the effect of different ventilation pressures on total lung volume and the volume of ground glass opacities (GGO), air-filled tissue, consolidations, and bronchi in VPMCT.
A precise inflation device was assembled using standard components: a back-pressure regulator, a water manometer and silicone tubing. Each case had PMCT performed at 0, 10, 20, 30 and 40 cmH2O pressure. Volumes were measured using stereology.
14 cases were enrolled in the study. The total lung volume increased significantly by 3612 mL (median) from 0 to 30 cmH2O (p = 0.001). The volume of consolidations was significantly reduced by 455.86 mL (median) between 0 and 30 cmH2O (p = 0.001). A significant reduction of GGO-volume of 133 mL (median) was observed at the pressure interval 30–40 cmH2O (p = 0.031), but not at lower pressures.
The constructed inflation device allowed precise and reproducible inflation of the lungs in deceased humans. We found a maximum effect of inflation at 30 cmH2O. At further inflation pressure, only the volume of GGOs decreased , but the effect was minor. For mimicking an in vivo breath-hold scan in PMCT we recommend inflation pressure of 30 cmH2O.
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