Association of Regional Muscle Thickness and Echo Intensity with Muscle Volume, Intramuscular Adipose Tissue, and Strength of the Quadriceps Femoris

Yoshihiro Fukumoto,1,2 Masashi Taniguchi,2 Tetsuya Hirono,2 Masahide Yagi,2 Momoko Yamagata,1,2 Ryusuke Nakai,3 Yosuke Yamada,4 Misaka Kimura,5 Noriaki Ichihashi2 1Faculty of Rehabilitation, Kansai Medical University, Hirakata, Japan; 2Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; 3Kyoto University Institute for the Future of Human Society, Kyoto, Japan; 4National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health, and Nutrition, Tokyo, Japan; 5Institute for Active Health, Kyoto University of Advanced Science, Kameoka, JapanCorrespondence: Yoshihiro Fukumoto, Faculty of Rehabilitation, Kansai Medical University, 18– 89 Uyamahigashicho, Hirakata City, Osaka, 573-1136, Japan, Tel +81-72-856-2307, Fax +81-72-856-2150, Email fukumoty@hirakata.kmu.ac.jpPurpose: This study aimed to investigate the association of muscle thickness (MT) and echo intensity (EI) obtained at different regions along the muscle length with muscle volume (MV), intramuscular adipose tissue (IntraMAT), and muscle strength of the quadriceps femoris (QF).Patients and Methods: A total of 135 community-dwelling adults (64 men and 71 women) participated in the study. Ultrasound scanning of the rectus femoris (RF) and vastus intermedius (VI) was performed at three locations (from mid- to distal thigh). The MT of the RF and VI and EI of the RF were measured. MRI-derived MV, IntraMAT, and muscle strength of the QF were measured.Results: The correlation between RF-MT and RF-MV weakened as scanning approached the distal thigh, and the difference between the coefficients for the scanning locations was significant for women. However, the correlation of VI-MT with VI-MV and that of the combined MT of RF and VI with the MV of the whole QF and muscle strength were comparable among the scanning locations for both sexes. The correlation of RF-EI with the IntraMAT of the RF and the whole QF and muscle strength was also comparable among the scanning locations for both sexes.Conclusion: The results of this study suggest that ultrasound measurements at the distal thigh can predict MV, IntraMAT, and muscle strength of the QF to the same degree as those at the mid-thigh.Keywords: ultrasound scanning, rectus femoris, thigh, muscle strength, MRI