Skeletal muscular relaxation time from postmortem MR imaging of adult humans

Abstract Purpose To measure T1, and T2 values of the skeletal muscle by postmortem magnetic resonance (PMMR) imaging in adult humans at 1.5 T, and to compare them with those of living human subjects. Materials and Methods We performed skeletal muscular PMMR imaging on 45 deceased adults (31 men, 14 women; mean age, 55.6 years). We measured T1 and T2 values of the right and left erector spinae muscles. The PMMR imaging data were compared with those from the corresponding sites in 13 healthy subjects. The association among rectal temperature, age and sex in T1 and T2 values was assessed by multiple regression analysis. Results By skeletal muscular PMMR imaging (clinical MR imaging), the average T1 values were: right:745 ± 107 ms (820 ± 108 ms); left:930 ± 133 ms (1022 ± 116 ms), and the average T2 values were: right:62± 9 ms (43± 5 ms); left:59 ± 7 ms (42 ± 5 ms). The left-right T1 difference was due to B1 inhomogeneity. Compared with clinical skeletal muscular MR imaging, PMMR imaging demonstrated significantly shorter T1 values and longer T2 values. On PMMR imaging, T1 values were significantly influenced by rectal temperature, whereas T2 values were significantly influenced by age and sex, but not by rectal temperature. Conclusion In the skeletal muscle, PMMR imaging shows shorter T1 values and longer T2 values than clinical MR imaging. T1 values decrease with lower rectal temperature and T2 values increase with female and elder age.