Magnetic resonance imaging estimates of muscle volume and inter-muscular fat in the thigh in sarcopenia population: correlation with physical performances
Yu Xin Yang1, Mei Sian Chong1, Laura Tay1, Suzanne Yew1, Audrey Yeo1, and Cher Heng Tan2

1Institute of Geriatrics and Active Ageing, Tan Tock Seng Hospital, Singapore, Singapore, 2Department of Diagnostic Radiology, Tan Tock Seng Hospital, Singapore, Singapore

Synopsis

This study presented using MRI to quantify muscle and fat volumes in thigh for sarcopenic and sarcopenic obese (SO) populations. The correlation between different thigh components and patients’ physical performances was also assessed. Results show that MRI is a promising tool for early detection of sarcopenia and SO. This may translate to use in clinical trials and in clinical practice. MRI measurement of inter-muscular fat volume is a valuable component in thigh to monitor patients’ physical performances.

Introduction

Muscle and fat volume is particularly relevant to management of sarcopenia and sarcopenic obese (SO) patients. Emerging evidence suggests that inter-muscular fat (IMF) accumulation is associated with reduced muscle quality and increased risk of physical limitation. However, the impact and mechanism of IMF in sarcopenia or sarcopenic obesity (SO) are still unclear. Magnetic resonance imaging (MRI) is a promising imaging modality to quantify muscle and fat volume including IMF, given its ionizing radiation-free nature and excellent soft tissue contrast. This study aims at (i) using MRI to quantify muscle and fat volumes in thigh for sarcopenic and SO populations, and to (ii) assess the correlation between different thigh components and patients’ physical performances.

Methods and Materials

190 healthy community dwelling older adults (age 50-99) were recruited and categorized into four subgroups based on Asian established criteria [1]: normal, obese, sarcopenia, and SO. Dixon GRE sequences were acquired and muscles, subcutaneous fat (SF), and inter-muscular fat (IMF) were automatically segmented in both thighs using an in-house machine learning based segmentation method. Volumes of muscles and fat were calculated for the middle third of each patients’ thigh. Chair stand, gait speed based on the time to walk 3 m, knee extension strength, and the Short Physical Performance Battery (SPPB) was used to measure physical performance.

Results

Figure 1 shows sample segmented images of muscle, SF, and IMF in thigh. All thigh component volumes correlated significantly with clinical diagnosis of normal, obesity, sarcopenia, and SO (Table 1). Spearman correlation coefficients (CCs) between thigh component volumes and physical performances are listed in Table 2. IMF showed significant correlation with all physical performance measurements (p<0.05).

Conclusion

MRI is a promising tool for early detection of sarcopenia and SO. This may translate to use in clinical trials and in clinical practice. MRI measurement of IMF volume is a valuable component in thigh to monitor patients’ physical performances. In future work, changes of thigh components will be monitored in the longitudinal study.

Acknowledgements

This study was funded by Lee Foundation Grant 2013 (GERILABS - Longitudinal Assessment of Biomarkers for characterisation of early Sarcopenia and predicting frailty and functional decline in community-dwelling Asian older adults Study).

References

[1] Chen, Liang-Kung, Li-Kuo Liu, Jean Woo, Prasert Assantachai, Tung-Wai Auyeung, Kamaruzzaman Shahrul Bahyah, Ming-Yueh Chou et al. "Sarcopenia in Asia: consensus report of the Asian Working Group for Sarcopenia." Journal of the American Medical Directors Association 15, no. 2 (2014): 95-101.

[2] Guralnik, Jack M., Eleanor M. Simonsick, Luigi Ferrucci, Robert J. Glynn, Lisa F. Berkman, Dan G. Blazer, Paul A. Scherr, and Robert B. Wallace. "A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission." Journal of gerontology 49, no. 2 (1994): M85-M94.

Figures

Fig. 1 Representative sample segmented images. Structures in yellow: bone resion, blue: muscle, red: IMF, green: SF.

Table 1. ANOVA test results of thigh component volumes and patients’ sarcopenia status. All component volumes were adjusted by patients’ height square (cm3/m2).

Table 2. Spearman correlating of thigh components volume with SPPB, chair stand, knee extension, and gait speed (p value in parentheses). Significant results with p < 0.05 are marked in red.



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)
4524