Magnetic resonance imaging of lesions of the posterior fossa and upper cervical cord in childhood.

Magnetic resonance imaging (MRI) promises to be an effective, noninvasive means of visualizing intracranial pathology. It should be especially useful in the evaluation of posterior fossa and cervical spinal cord disease of childhood; computed tomographic (CT) evaluation is frequently suboptimal in this region. MRI results are reported for 46 consecutively seen children with posterior fossa and/or cervical spinal cord disease (28 had brain malignancies; seven had congenital anomalies; three had cerebrovascular accidents). MRI was performed primarily by the partial saturation on a .12 Tesla resistive proton unit. All patients underwent concurrent CT evaluation. MRI demonstrated abnormalities in 96% of scans in patients with structural CNS disease (48 of 50). CNS malignancies were visualized in 100% (28 of 28) of children studied. MRI was especially useful in demonstrating the full extent of infiltrating gliomas and the anatomic location of other mass lesions. MRI frequently demonstrated disease to be more extensive than seen on CT. MRI was more sensitive than CT in documenting response to treatment and disease relapse in patients with infiltrating tumors. Cystic regions within tumors were poorly seen on MRI. Congenital anomalies were demonstrated in all patients evaluated and were better delineated using MRI than CT. MRI is sensitive in the evaluation of posterior fossa and cervical spinal cord disease of childhood and it has obvious advantages over CT; however, its specificity in such evaluations has yet to be proven.