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 1. 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