Congress:
ECR25
Poster Number:
C-11924
Type:
Poster: EPOS Radiographer (educational)
DOI:
10.26044/ecr2025/C-11924
Authorblock:
T. Asahara1, H. Hayashi2, S. Okada1, C. Yamaguchi1, N. Kimoto3, S. Goto2, R. Nishigami2, Y. Morimitsu1, T. Iguchi1; 1Okayama/JP, 2Kanazawa/JP, 3Fukuoka/JP
Disclosures:
Takashi Asahara:
Nothing to disclose
Hiroaki Hayashi:
Grant Recipient: JSPS Kakenhi, Japan, 24K03306
Shunsuke Okada:
Nothing to disclose
Chihiro Yamaguchi:
Nothing to disclose
Natsumi Kimoto:
Nothing to disclose
Sota Goto:
Nothing to disclose
Rina Nishigami:
Nothing to disclose
Yusuke Morimitsu:
Nothing to disclose
Toshihiro Iguchi:
Nothing to disclose
Keywords:
Forensic / Necropsy studies, Radiation physics, Radiographers, CT, CT-Quantitative, Experimental investigations, Physics, Forensics, Image verification
Learning objectives
In the field of dental forensic medicine, diagnoses have been made by qualitative exams. As shown in Fig. 1, the identification of unidentified individuals is carried out through direct visual investigation of the oral cavity and analysis of dental X-ray photographs to obtain the necessary information [1], but there are currently no quantitative indicators to support this information. Currently, photon counting CT (PCCT) is developed [2,3], and it is expected that diagnostic accuracy will be improved when quantitative diagnosis such as effective atomic number (Zeff) images can be put into practical use.
Fig 1: The concept of the present study. In forensic dental identification, the identity of the unidentified person is often confirmed by comparing the postmortem dental information with the antemortem treatment history. Information on artificial dental restorations is important for human identification. Quantitative images such as effective atomic number images can provide useful identification information.
<<Purpose>>
The purpose of this study is to demonstrate the usefulness of quantitative images for human identification in forensic dentistry. Using the application to forensic dentistry as an example, this presentation will demonstrate how quantitative analysis using photon counting detectors can revolutionize medical diagnostics.
Fig. 2 shows the difference between (a) qualitative diagnosis and (b) quantitative diagnosis. Qualitative diagnosis, which creates a shadow picture based on X-ray attenuation information, and quantitative diagnosis, which can analyze X-ray attenuation information based on physics theory to image the composition of substances, are different diagnostic methods.
Fig 2: Two approaches in image diagnosis. One is a structural evaluation based on anatomy (qualitative analysis), and another is a quantitative analysis, which can be derived from the X-ray attenuation analysis based on physics theory.
Fig. 3 is a conceptual diagram showing that qualitative diagnosis has been used for many years since Dr. Roentgen discovered X-rays in 1895. X-rays have been used for qualitative diagnosis even before the atomic model was theoretically constructed. With the development of PCCT in 2022, there are signs that quantitative diagnosis [4-8] will be applied to medicine.
Fig 3: Examples of the use of diagnostic X-rays from the discovery of X-rays to the present day. "Qualitative X-ray diagnosis" has been performed for many years, which began in medical use before Bohr's atomic model was elucidated. Currently, with the development of photon counting CT, "quantitative X-ray diagnosis" has become possible. Much research and development is needed to spread quantitative diagnosis to clinical examinations.
