TY - JOUR T1 - Signal Intensity of the Motor Cortex on Phase-Weighted Imaging at 3T JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1171 LP - 1175 DO - 10.3174/ajnr.A1002 VL - 29 IS - 6 AU - S. Kakeda AU - Y. Korogi AU - K. Kamada AU - N. Ohnari AU - J. Moriya AU - T. Sato AU - M. Kitajima AU - H. Hasnine AU - N. Hirata Y1 - 2008/06/01 UR - http://www.ajnr.org/content/29/6/1171.abstract N2 - BACKGROUND AND PURPOSE: It is known that the motor cortex shows hypointensity on T2-weighted images in older patients. The goal of this study was to assess the signal intensity of the motor cortices on the phase-weighted imaging performed with a Windows-based software program that we developed ourselves.MATERIALS AND METHODS: All studies were performed at 3T MR imaging. First, the TE for the phase-weighted image was optimized; the best contrast between the motor and other cortices was obtained with a TE of 40 ms. The study population consisted of 45 healthy subjects (23 females, 22 males; mean age, 32.1 years). The signal intensity of the motor cortices was divided into 3 grades by 2 neuroradiologists in comparison with that of the superior frontal cortex (SFC): In grade I, the motor cortex was isointense to the SFC; in grade II, the motor cortex was slightly hypointense to the SFC; and in grade III, the motor cortex was markedly hypointense to the SFC.RESULTS: The motor cortex was classified as either grade II or III in all subjects older than 20 years of age on the phase-weighted images. Even at 10–19 years of age, the grade II or III appearance was found in 14 (88%) of 16 motor cortices (8 subjects) on the phase-weighted images.CONCLUSION: In adolescents, the motor cortex is hypointense to other cerebral cortices on phase-weighted MR imaging, which probably reflects differences in the concentration of nonheme iron and/or in the tissue architecture. ER -