Magnetic Resonance Imaging in Neurologic Diseases

ABSTRACT

Magrjetic resonance (MR) imagings with 0.15 Tesla resistive magnet developed by Korea Advanced Institute of 5cience were performed in 27 patients with various neurologic diseases and compared with X-ray computed tomography (CT). The purpose óf the paper is to evaluate the image quality, the diagnostic value and limitation, and the optimal pulse sequence of MR imagings with a resistive magnet. The MR images were obtained by using a variety of pulse sequence with spin echo technique includïng saturation recovery, T2-weighted spin echo, and/or inversion recovery with various pulse repetition(TR) and echo delay (TE) times. The M R imaging demonstrated the capability of detecting the lesions shown on CT in all cases and also detected an additional finding in one case (multiple sclerosis) which was not seen on CT. The MR imaging appeared to be more useful than CT in the evaluation of syringomyelia of spinal cord and white matter disease, while it failed to demonstrate small calcific lesion or inflammatory nodule (less than 1 cm) shown on CT and has shown somewhat poor contrast resolution in the case of meningioma. The spatial resolution of saturation recovery images was similar or superior to CT, whereas the contrast resolution of saturation recovery was inferior to CT. While the saturation recovery images have shown false negative findings in 5 patients (19%), the inversion recovery and T2-weighted spin echo have shown consistently positive findings. The inversion recovery and T2-weighted spin echo images demonstrated better contrast discrimination between normal and pathologic conditions than the saturation recovery images, but somewhat poorer spatial resolution. Authors suggest that the MR images of both the saturation recovery with 300/30 and T2-weighted spin echo with 1000/90 be used as a routine procedure and additional iversion recovery of 1300/300/30 sequence as a option if white matter disease is suspected.