Bone marrow burden score

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The bone marrow burden score, also known as BMB-score, is a semi-quantitative MRI scoring system for assessing the extent of bone marrow involvement in Gaucher disease . It was presented as an alternative for the quantitative Dixon quantitative chemical shift imaging (QCSI or fat fraction measurement) which is not available on every machine.

Scoring system

The BMB-score is scored on sagittal T1 and T2 images of the lumbar spine and coronal T1 and T2 images of the femurs. A higher total BMB-score indicates more severe bone marrow involvement.

Lumbar spine
MRI signal intensity
  • T1: vertebral bodies relative to nondiseased intervertebral discs
    • 0 = slightly hyperintense
    • 1 = isointense
    • 2 = slightly hypointense
    • 3 = hypointense
  • T2: vertebral bodies relative to presacral fat 
    • 2 = hyperintense
    • 1 = slightly hyperintense
    • 0 = isointense
    • 1 = slightly hypointense
    • 2 = hypointense
Infiltration pattern
  • 1 = patchy
  • 2 = diffuse
  • 1 = absence of fat in basivertebral vein region
Femora
MRI signal intensity
  • T1: femur relative to subcutaneous fat
    • 0 = slightly hyperintense or isointense
    • 1 = slightly hypointense
    • 2 = hypointense
  • T2: femur relative to subcutaneous fat
    • 2 = hyperintense
    • 1 = slightly hyperintense
    • 0 = isointense
    • 1 = slightly hypointense
    • 2 = hypointense
    • 3 = mixed type
Sites of involvement
  • 1 = diaphysis
  • 2 = proximal epiphysis/apophysis
  • 3 = distal epiphysis

Related pathology