2021 Volume 41 Issue 2 Pages 42-46
Sarcopenia, a condition characterized bedridden skeletal muscle atrophy, is frequently encountered in today's aging society, in which healthy living needs to be improved.
Skeletal muscle cells are composed of slow and fast twitch muscle fibers, and it is known that fast twitch fibers change to slow twitch ones with age. However, there is no way to capture the changes in which fast twitch slows down in clinical research.
Slow twitch muscle fibers are known to have larger cells than fast twitch ones; however, in recent years, a muscle cell visualization method using these differences in muscle cell size has been reported using qsi. In this study, we captured age-related muscular atrophy with q-space imaging and explored the possibility of a quantitative evaluation by observing its transition.
This study was approved by the Keio University School of Medicine's Ethics Committee. It included a total of 24 people (16 men and 8 women, with a mean age 56.1±14.7 years) who gave their informed consent. We used a 3T MRI (Siemens) machine to obtain horizontal magnetic resonance images at a certain level (L3/4).
T2WI and DWI were imaged in the b-value range of 0 to 4000 (mm2/s). The muscle cross-sectional area was measured from the obtained T2WI, and q-space analysis was performed using DWI to calculate HWHM, KT, and ZP. In addition, the ADC values were measured using DWI. Pearson's product-moment correlation coefficients between these image parameters and age were calculated.
The qsi metrics showed a superior correlation. This shows that the amount of displacement of water molecules changes in the elderly, and the possibility qsi analysis is useful for the diagnosis of quantitative sarcopenia.
It is necessary to measure the rate of transition of muscle fibers such as slow and fast twitch fibers, and histological changes such as those that occur in fibers due to sarcopenia, and to validate it by combining clinical, histological, and MRI findings in the future.
