Normal bone marrow signal of the clivus

Dr Derek Smith and A.Prof Frank Gaillard et al.

Bone marrow signal of the clivus changes predictably with age and is well assessed with midline T1 non-fat-saturated, non-contrast images. As is seen in the rest of the body the proportion of yellow (fatty) marrow increases with age. Knowledge of these changes allows diagnosis of the abnormal clivus

Kimura et al 1 divided the appearance into three grades, by comparing the clivus to the pons and subcutaneous fat. High signal was similar to subcutaneous fat, whereas low was iso- to slightly hypointense to the pons. It should be pointed out that the figures obtained in the study by Kimura et al, have not been exactly replicated in other studies 2,3, and that the grading proposed is by no means widely used in clinical practice. Nonetheless, it serves as a useful guide when examining MRI of the brain, and relating bone marrow signal to age. 

Classification

  • grade 1: predominantly low signal (>50% of clivus)
  • grade 2: mixed signal (low signal 20-50% of clivus)
  • grade 3: predominantly high signal (>80% of clivus)

The signal will vary according to the age of patients 1:

  • patients in their 20s
    • grade 1: 33% of patients
    • grade 2: 33%
    • grade 3: 34%
  • patients in their 50s
    • grade 1: 0%
    • grade 2: 40%
    • grade 3: 60%
  • patients in their 80s
    • grade 1: 0%
    • grade 2: 0%
    • grade 3: 100%

Most importantly, a finding of low signal in elderly patients warrants comment and review of additional imaging and clinical information. 

See also

Share article

Article information

rID: 6519
Synonyms or Alternate Spellings:

Support Radiopaedia and see fewer ads

Cases and figures

  • Case 1: grade 1
    Drag here to reorder.
  • Case 2: grade 2
    Drag here to reorder.
  • Case 3: grade 3
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.