TY - JOUR T1 - MR Evaluation of Chiari I Malformations at 0.15 T JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 203 LP - 208 VL - 6 IS - 2 AU - Efstathios Spinos AU - D. Wayne Laster AU - Dixon M. Moody AU - Marshall R. Ball AU - Richard L. Witcofski AU - David L. Kelly, Jr. Y1 - 1985/03/01 UR - http://www.ajnr.org/content/6/2/203.abstract N2 - Twelve patients with known or presumed Chiari I malformations and two with clinical diagnoses of multiple sclerosis were examined by magnetic resonance (MR) imaging. MR confirmed or established the diagnosis of Chiari I malformation in all 14 cases. The spin-echo technique with a short time to echo (TE = 40 msec) and a short time to recover (TR = 1000 msec) provided optimum imaging of tonsillar position, hydromyelia cavities, and cervicomedullary “kinking.” Long TE (>80 msec) and TR (>2000 msec) increase the signal intensity of cerebrospinal fluid and may obscure the pathology. Sagittal, transaxial, and coronal images provided complementary data; sagittal and coronal views best imaged the abnormal spinal cord and tonsils, but slitlike cavities were best seen on transaxial images. Cervicomedullary kinking was found in 10 (71%) of 14 patients and in 90% of the hydromyelic patients. This high incidence suggests that in other radiologic techniques tonsillar herniation masks the kinking. Symptoms of the Chiari I malformation overlap those of demyelinating diseases and brain tumors. Our early experience suggests MR is the preferred noninvasive procedure for identifying Chiari I malformation. Moreover, the ability to portray the variable cavity morphology of hydromyelia directly offers the potential for improved shunt placement. ER -