Investigative Magnetic Resonance Imaging

Korean Society of Magnetic Resonance in Medicine (대한자기공명의과학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Number of Measurement Points on Accuracy of Muscle T2 Calculations

  • Tawara, Noriyuki (Department of Radiological Sciences, Faculty of Health Sciences, Japan Health Care College) ;
  • Nishiyama, Atsushi (Department of Radiological Sciences, Faculty of Health Sciences, Japan Health Care College)
  • Received : 2016.08.31
  • Accepted : 2016.11.29
  • Published : 2016.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Purpose: The purpose of this study was to investigate the effect of the number of measurement points on the calculation of transverse relaxation time (T2) with a focus on muscle T2. Materials and Methods: This study assumed that muscle T2 was comprised of a single component. Two phantom types were measured, 1 each for long ("phantom") and short T2 ("polyvinyl alcohol gel"). Right calf muscle T2 measurements were conducted in 9 healthy male volunteers using multiple-spin-echo magnetic resonance imaging. For phantoms and muscle (medial gastrocnemius), 5 regions of interests were selected. All region of interest values were expressed as the mean ${\pm}$ standard deviation. The T2 effective signal-ratio characteristics were used as an index to evaluate the magnetic resonance image quality for the calculation of T2 from T2-weighted images. The T2 accuracy was evaluated to determine the T2 reproducibility and the goodness-of-fit from the probability Q. Results: For the phantom and polyvinyl alcohol gel, the standard deviation of the magnetic resonance image signal at each echo time was narrow and mono-exponential, which caused large variations in the muscle T2 decay curves. The T2 effective signal-ratio change varied with T2, with the greatest decreases apparent for a short T2. There were no significant differences in T2 reproducibility when > 3 measurement points were used. There were no significant differences in goodness-of-fit when > 6 measurement points were used. Although the measurement point evaluations were stable when > 3 measurement points were used, calculation of T2 using 4 measurement points had the highest accuracy according to the goodness-of-fit. Even if the number of measurement points was increased, there was little improvement in the probability Q. Conclusion: Four measurement points gave excellent reproducibility and goodness-of-fit when muscle T2 was considered mono-exponential.

Keywords

References

  1. Fleckenstein JL, Canby RC, Parkey RW, Peshock RM. Acute effects of exercise on MR imaging of skeletal muscle in normal volunteers. AJR Am J Roentgenol 1988;151:231-237 https://doi.org/10.2214/ajr.151.2.231
  2. Fleckenstein JL, Watumull D, McIntire DD, Bertocci LA, Chason DP, Peshock RM. Muscle proton T2 relaxation times and work during repetitive maximal voluntary exercise. J Appl Physiol (1985) 1993;74:2855-2859 https://doi.org/10.1152/jappl.1993.74.6.2855
  3. Saab G, Thompson RT, Marsh GD. Effects of exercise on muscle transverse relaxation determined by MR imaging and in vivo relaxometry. J Appl Physiol (1985) 2000;88:226-233 https://doi.org/10.1152/jappl.2000.88.1.226
  4. Morvan D, Leroy-Willig A. Simultaneous measurements of diffusion and transverse relaxation in exercising skeletal muscle. Magn Reson Imaging 1995;13:943-948 https://doi.org/10.1016/0730-725X(95)02006-F
  5. Price TB, McCauley TR, Duleba AJ, Wilkens KL, Gore JC. Changes in magnetic resonance transverse relaxation times of two muscles following standardized exercise. Med Sci Sports Exerc 1995;27:1421-1429
  6. Price TB, Gore JC. Effect of muscle glycogen content on exercise-induced changes in muscle T2 times. J Appl Physiol (1985) 1998;84:1178-1184 https://doi.org/10.1152/jappl.1998.84.4.1178
  7. Ababneh ZQ, Ababneh R, Maier SE, et al. On the correlation between T(2) and tissue diffusion coefficients in exercised muscle: quantitative measurements at 3T within the tibialis anterior. MAGMA 2008;21:273-278 https://doi.org/10.1007/s10334-008-0120-8
  8. Nygren AT, Kaijser L. Water exchange induced by unilateral exercise in active and inactive skeletal muscles. J Appl Physiol (1985) 2002;93:1716-1722 https://doi.org/10.1152/japplphysiol.01117.2001
  9. Nygren AT. Shortened T2 after exercise in ischemic skeletal muscle. J Magn Reson Imaging 2006;23:177-182 https://doi.org/10.1002/jmri.20481
  10. Ploutz-Snyder LL, Convertino VA, Dudley GA. Resistance exercise-induced fluid shifts: change in active muscle size and plasma volume. Am J Physiol 1995;269:R536-543
  11. Ploutz-Snyder LL, Nyren S, Cooper TG, Potchen EJ, Meyer RA. Different effects of exercise and edema on T2 relaxation in skeletal muscle. Magn Reson Med 1997;37:676-682 https://doi.org/10.1002/mrm.1910370509
  12. Cannon DT, Howe FA, Whipp BJ, et al. Muscle metabolism and activation heterogeneity by combined 31P chemical shift and T2 imaging, and pulmonary O2 uptake during incremental knee-extensor exercise. J Appl Physiol (1985) 2013;115:839-849 https://doi.org/10.1152/japplphysiol.00510.2013
  13. Akima H, Takahashi H, Kuno SY, Katsuta S. Coactivation pattern in human quadriceps during isokinetic kneeextension by muscle functional MRI. Eur J Appl Physiol 2004;91:7-14 https://doi.org/10.1007/s00421-003-0942-z
  14. Akima H, Kinugasa R, Kuno S. Recruitment of the thigh muscles during sprint cycling by muscle functional magnetic resonance imaging. Int J Sports Med 2005;26:245-252 https://doi.org/10.1055/s-2004-821000
  15. Kinugasa R, Kawakami Y, Fukunaga T. Quantitative assessment of skeletal muscle activation using muscle functional MRI. Magn Reson Imaging 2006;24:639-644 https://doi.org/10.1016/j.mri.2006.01.002
  16. Kubota J, Ono T, Araki M, et al. Relationship between the MRI and EMG measurements. Int J Sports Med 2009;30:533-537 https://doi.org/10.1055/s-0029-1202352
  17. Tawara N, Nitta O, Kuruma H, et al. Functional T(2) mapping of the trunkal muscle. Magn Reson Med Sci 2009;8:81-83 https://doi.org/10.2463/mrms.8.81
  18. Spiess AN, Neumeyer N. An evaluation of R2 as an inadequate measure for nonlinear models in pharmacological and biochemical research: a Monte Carlo approach. BMC Pharmacol 2010;10:6
  19. Gambarota G, Cairns BE, Berde CB, Mulkern RV. Osmotic effects on the T2 relaxation decay of in vivo muscle. Magn Reson Med 2001;46:592-599 https://doi.org/10.1002/mrm.1232
  20. Tawara N, Itoh A. Effects of MR image noise on estimation of short T2 values from T2-weighted image series. Magn Reson Med Sci 2007;6:187-197 https://doi.org/10.2463/mrms.6.187
  21. Press WH, Teukolsky SA, Vetterling WT, Flannery BP. Numerical recipes in C (2nd ed.): the art of scientific computing. NY, USA: Cambridge University Press New York, 1996:629-661.
  22. Kjaer L, Thomsen C, Henriksen O, Ring P, Stubgaard M, Pedersen EJ. Evaluation of relaxation time measurements by magnetic resonance imaging. A phantom study. Acta Radiol 1987;28:345-351 https://doi.org/10.1177/028418518702800323
  23. Saab G, Thompson RT, Marsh GD. Multicomponent T2 relaxation of in vivo skeletal muscle. Magn Reson Med 1999;42:150-157 https://doi.org/10.1002/(SICI)1522-2594(199907)42:1<150::AID-MRM20>3.0.CO;2-5
  24. Hazlewood CF, Nichols BL, Chamberlain NF. Evidence for the existence of a minimum of two phases of ordered water in skeletal muscle. Nature 1969;222:747-750 https://doi.org/10.1038/222747a0
  25. Hazlewood CF, Chang DC, Nichols BL, Woessner DE. Nuclear magnetic resonance transverse relaxation times of water protons in skeletal muscle. Biophys J 1974;14:583-606 https://doi.org/10.1016/S0006-3495(74)85937-0