Assessment of normal clivus related to age with magnetic resonance imaging.

The signal intensity pattern cf normal clivus bone marrow related to age was studied on T1-weighted sagittal plain magnetic resonance images. Bone marrow in the clivus had a uniformly low signal intensity (grade 1) in 100% of the patients at 0-5 years and 96% of patients in the first decade (0-9 years). In the second decade there was a sharp decrease in the number of patients (43%) showing grade 1 clivus. Patients having mixed clivus signal intensity (grade 2) were mostly seen in the second decade (28.5%). Uniform high signal intensity (grade 3) was not observed under the age of 10. Grade 3 clivus pattern increased with age from the second decade, while grades 1 and 2 clivus bone marrow showed a marked decrease.