Imaging quality of small aperture orthogonal phased-array coil in MRI: a creatural experiment

Abstract

Objective To compare the rat head MRI image quality of small aperture orthogonal phased-array creatural experimental coil and the C3 surface coil.Methods Ten male SD rats underwent both coils for head MRI.The signal intensities and background noise values of the cerebral cortex,cerebellum, brain stem, muscle and aqueous humor in eye were measured, and signal to noise ratio (SNR)was calculated.Image quality scores were obtained from 2 radiologists, t test was performed for statistical differences.Results SNR values over the cerebral cortex, cerebellum, brain stem, muscle and aqueous humor in eye were obtained from the images of all protocols.Statistically significant differences of the two coils were achieved in the cerebral cortex in the transverse T1WI (SNR sense-body=41.3±23.5; SNR C3=10.3±0.5; t=-3.21), sagittal T2WI (SNR sense-body=63.8±16.6; SNR C3=37.9±4.4; (=-4.00) and coronal T2WI (SNR sense-body=91.6±23.8, SNR C3=38.5±11.8; t=-5.69)(P＜0.01), so were in cerebellum, brain stem and aqueous humor in eye.Statistical differences of muscular tissue were observed merely in the transverse axial TiWI (SNR sense-body=39.9±21.1; SNR C3=8.3±1.7; t=-3.64) and the coronal T2WI (SNR sense-body=23.5±9.8; SNR C3=1 1.9±4.1; t=-3.10)(P＜0.01).Coronal T2WI score achieved the top in the small aperture orthogonal phased array coil, and the image qualities of diffusion-weighted imaging(DWI)in both two coils were low.Conclusion In head MRI of rats, the SNR value and head image quality of small aperture orthogonal phased-array coil is superior to that of the frequently used C3 surface coil. Key words: Magnetic resonance imaging; Small aperture orthogonal phased-array coil; Surface coils; Rat; Image quality