Title

Validation of an MRI analysis for thigh muscle and fat composition changes in strength training

Document Type

Article

Publication details

Bezerra, P, Zhou, S, Davie, AJ, Fuller, H & Hooper, A 2006, 'Validation of an MRI analysis for thigh muscle and fat composition changes in strength training', Journal of Science and Medicine in Sport, vol. 9, suppl. 1, p. 42.

Journal of Science and Medicine in Sport home page available at http://www.elsevier.com/wps/product/cws_home/707423

Publisher's version of article available at http://dx.doi.org/10.1016/j.jsams.2006.12.099

Peer Reviewed

Peer-Reviewed

Abstract

This pilot study aimed to validate an MRI analysis for thigh muscle and fat composition changes following strength training. Fifteen healthy men were randomly assigned into a control (CG), voluntary isometric knee extension (VG) or electromyostimualtion superimposed voluntary training (EG) group. Subjects trained the right leg three sessions per week for 6 weeks. MRI images of both thighs were obtained using a 1.5-T system, and analysed using ImageJ software. The cross-sectional areas of the thigh (CSA-T), fat (CSA-F) and muscle (CSA-M) tissues in MRI images, and circumferences and skinfolds, were measured at middle-point of the thigh, and at 5 cm above and 5 cm below this point. Analyses of 30 images in different formats (8- and 16-bit) were replicated to examine the reproducibility. Results showed high levels of reproducibility within either the 8- or 16-bit images (ICC 0.96–0.99). However, significant differences existed between the measurements of the two formats of images. From the results of all subjects, both CSA-T and CSA-M (in 8-bit images) showed a high correlation with the circumference (Pearson correlation r = 0.99 and r = 0.82, p < 0.01), while CSA-F was well correlated with the skinfold (r = 0.90, p < 0.01). Comparing the pre and post training measurements, variations in CSA-M of the trained limb of VG, EG and CG were +5%, +6% and +0.4%, and that of the untrained limb were +3%, +4% and +0.3%; and that in CSA-F of the trained limb were −1%, −19% and −10%, and that of the untrained limb were +0.6%, −14% and −7%, respectively, although these variations were not statistically significant.