Clivus chordoma.

Chordomas are slow growing, locally invasive tumors that most commonly present as midline masses in the sacrococcygeal or clival regions. The case presented in this paper demonstrates the typical MRI appearance of a clival chordoma in a patient presenting with classic symptoms of cranial nerve compression and headache. While the exact signal characteristics of these lesions seen on MRI may vary with pathologic subtypes, MRI has proven essential in the diagnosis, surgical planning and post-treatment evaluation of patients with these lesions.

Rocky Mountain spotted fever encephalitis: MR findings.

We describe a case of Rocky Mountain spotted fever encephalitis and present the associated findings of an MR examination of the brain, which showed increased signal intensity in the distribution of perivascular spaces. Resolution of the MR abnormalities coincided with clinical improvement.