Testing photogrammetry-based techniques for three-dimensional surface documentation in forensic pathology.

Area of Science:

• Forensic Pathology
• 3D Imaging Technologies
• Medical Documentation

Background:

• Forensic postmortem investigations can benefit from advanced 3D surface documentation techniques.
• Close-range photogrammetry and optical surface scanning are increasingly accessible and accurate.
• Current forensic practices have not fully integrated these 3D technologies.

Purpose of the Study:

• To evaluate digital camera-based photogrammetry and handheld optical surface scanning for 3D external body documentation in forensic pathology.
• To compare the feasibility, labor, and output quality of these two 3D techniques during postmortem examinations.

Main Methods:

• Two 3D documentation methods were tested: digital photogrammetry (Agisoft PhotoScan) and a handheld scanner (Vectra H1).
• Three subjects (one living, two deceased forensic cases) were documented using both methods.
• Data acquisition occurred pre-autopsy and during various autopsy stages, with subsequent 3D model generation and quantitative/visual assessment.

Main Results:

• Both techniques were easy to handle, equally laborious during data collection (approx. 20 min).
• Post-processing was time-intensive (up to 10h), with manual alignment needed for the handheld scanner.
• High-resolution, photorealistic 3D models were generated, but both methods struggled with body hair and reflective/moist surfaces.

Conclusions:

• Single-camera close-range photogrammetry and the Vectra H1 scanner are cost-effective solutions for postmortem body documentation.
• These 3D methods offer significant benefits for forensic pathology despite identified limitations.
• Further integration of 3D imaging in forensic medicine is recommended.