Scaling up contrast-enhanced micro-CT imaging: Optimizing contrast and acquisition for large ex-vivo human samples
Daniël Docter, Melanie GMM Timmerman, Yousif Dawood, Jaco Hagoort, N. H. J. Lobé, Ernst van Heurn, Ramon R. Gorter, Karl Jacobs, Grzegorz Pyka, Greet Kerckhofs, Maurice J.B. van den Hoff, Bernadette S. de Bakker
Abstract
• Micro-CT imaging for forensic evaluation. • Micro-CT imaging for fetal research. • Micro-CT imaging for anatomical research. • Methodological considerations for imaging large samples through micro-CT imaging. Microfocus Computed Tomography (Micro-CT) is a novel method for non-destructive 3D imaging of samples, reaching microscale resolutions. While initially prominent in material sciences for small samples, micro-CT now gains significance in biological and medical studies. Here we present our utilization of micro-CT for imaging large ex-vivo human samples for anatomical and forensic research in three recent experiments and discuss the fundamentals of micro-CT imaging. For pelvic anatomical research, whole human pelvises were imaged to explore nerve anatomy around the prostate using various concentrations of buffered lugol (B-lugol). Advanced acquisition protocols were essential due to X-ray attenuation properties of the sample, which required higher energy for sufficient photon transmission. For fetal research, B-lugol stained fetuses of 20–24 gestational weeks underwent full body imaging. However, this led to challenging acquisition parameters and images of insufficient quality. Subsequent destaining yielded less dense, yet contrast-maintaining samples allowing higher quality images. Refined acquisition protocols with reduced energy improved image quality. For forensic research, explanted hyoid-larynx complexes were imaged. Micro-CT imaging showed potential in visualizing micro-fractures. The addition of B-lugol allowed for excellent soft tissue contrast and promising possibilities for forensic evaluation. In conclusion, micro-CT imaging accommodates a diversity of large ex-vivo human samples for anatomical and forensic purposes, though challenges arise with optimal soft tissue staining and acquisition protocols. We describe partial destaining as a new possibility to alleviate scanning issues to improve scan quality and highlight topics for future research. Micro-CT imaging is a promising new avenue for medical research and forensic evaluation.