Development of an imaging evaluation method for sarcopenia using diffusion tensor imaging

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K09076
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56020:Orthopedics-related
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: Hara Yusuke 京都府立医科大学, 医学(系)研究科(研究院), 特任助教 (20795413)
• Co-Investigator(Kenkyū-buntansha): 城戸 優充 京都府立医科大学, 医学(系)研究科(研究院), 助教 (30729281) ; 生駒 和也 京都府立医科大学, 医学(系)研究科(研究院), 准教授 (50516044)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 拡散テンソル法(DTI) / 磁気共鳴画像法(MRI) / サルコペニア

Outline of Final Research Achievements

The optimal b-value of skeletal muscle in diffusion tensor imaging (DTI) was investigated. 12-week-old male SD rats (n=15) were used to model muscle dysfunction, and MR imaging and muscle strength measurements were performed before and 2, 4, and 8 weeks after model creation.The b-values were set to 100, 350, 500, and 1000s/mm2, and λ1, λ2, λ3, and FA were measured as DTI parameters. The ratios of DTI parameters (muscle dysfunction model group/control group) at each b-value were calculated, and the correlation between the calculated ratios and muscle strength was examined.
A negative correlation of r=0.36 was found between the ratio of λ1 and muscle strength at b-value=350s/mm2 (P<0.05). Other parameters showed no significant correlation with muscle strength.

Free Research Field

整形外科

Academic Significance and Societal Importance of the Research Achievements

本研究では，b値350s/mm2において足関節底屈筋力とλ1に負の相関があることを明らかにした．λ1では筋線維の方向と平行に水分子が拡散することが示された．b値が350s/mm2の際に，細胞内より細胞外の水分子の異方性がより顕著になるため，筋繊維の方向に平行な細胞外の水分子の拡散異方性が筋力に影響を与える可能性がある．筋力とλ1の負の相関は筋萎縮を示していることが推測された．筋萎縮に伴い，間質領域と間質領域内の水分子が増加した可能性がある．DTIの撮像においてb値を350s/mm2に設定することで，骨格筋の筋力を非侵襲的に測定することができ，臨床的に有用な指標となる可能性がある．