Age estimation by vertebral body observation using CT images

• Project/Area Number: 17K17643
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Legal medicine; Applied anthropology
• Research Institution: Chiba University (2019); The University of Tokyo (2017-2018)
• Principal Investigator: Chiba Fumiko 千葉大学, 大学院医学研究院, 講師 (90724972)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 法医学 / 法人類学 / 年齢推定 / 椎骨 / 胸椎 / 腰椎 / CT / computed tomography (CT) / 椎体 / 個人識別 / 骨棘 / 圧迫骨折 / 人類学

Outline of Final Research Achievements

The thoracic and lumbar vertebrae were observed using CT images, and the regression equations for age estimation were examined using the osteophytes of thoracic and lumbar vertebra. The degree of osteophyte formation; P, was classified into six grades, from 0 to 5, based on the length of the perpendicular line from the maximum osteophyte down to the vertebral edge. A single regression analysis to determine age with the sum of P in each vertebral body (score P) and maximum P (max P) showed a relatively good correlation.
The regression equation when “score P” was the explanatory variable were Y = 0.4124X + 31.169 (R2 = 0.7417) for males and Y = 0.5152X + 31.809 (R2 = 0.787) for females, and when “max P” was the explanatory variable were Y = 9.6855X + 21.334 (R2 = 0.7869) for males and Y = 9.9613X + 23.424 (R2 = 0.7849) for females.

Academic Significance and Societal Importance of the Research Achievements

現代日本人の胸椎・腰椎の骨棘をCTで観察し年齢推定式を検討した。CTを用いた検討はこれまでになく新規性が高いと同時に、解剖前CTが普及している本邦の法医実務においても有用性が期待できると考えられる。またmax Pによる回帰式は従来法と異なり最も骨棘が発達した1椎体の計測のみで年齢推定が可能である点は非常に簡便であると考えられる。さらに今回の検討では40歳代以上では骨棘形成の開始を認めるなど、推定式に加えて年齢推定の幅を狭めるためのカットオフ値としての有用性についても示唆された。