George Robert Matcuk MD, Presenter: Nothing to Disclose

Imran Siddiqi, Abstract Co-Author: Nothing to Disclose

Steven Cen PhD, Abstract Co-Author: Nothing to Disclose

Ashley Hagiya, Abstract Co-Author: Nothing to Disclose

Reese Isaacson, Abstract Co-Author: Nothing to Disclose

Russell Brynes, Abstract Co-Author: Nothing to Disclose

The goal of this study is to develop a semi-quantitative measurement of marrow cellularity from routine lumbar spine MRI and show a correlation with standard iliac crest bone marrow biopsy cellularity.

65 patients with lymphoma and available bone marrow biopsies had MR imaging of the lumbar spine retrospectively reviewed, with 27 patients passing exclusion criteria (>6 months between MRI and biopsy; interval treatment; or inadequate history or MRI). Marrow cellularity was calculated from the mean signal intensity measurements from T1 MR images, as follows: cellularity (%) = [(marrow – CSF) / (subcutaneous fat – CSF)] X 100 Measurements for the posterior ilia were taken from the axial T1 image at the L5/S1 level. Measurements for the T11 through S1 vertebral bodies were taken from a mid-sagittal T1 image. These MRI cellularities were compared to the estimated cellularity from the biopsy specimen, assigned to the nearest 10% after consensus review by three hematopathologists. Data normality was inspected using normality test and histogram visualization. Natural log or cubic transformation was used for the data with skewed distribution. Pearson correlation was used to access the correlation, and linear regression was used to form a prediction equation.

The histologic cellularities demonstrated statistically significant correlation with the left ilium MRI calculated cellularity (r=0.59, p=0.001), and high correlation with the right ilium and between sides (r=0.83, p<0.001). Decreases in cellularity were observed with ascending vertebral level from S1 to T11. Marrow cellularity also decreased with age, but less dramatically than the rule of thumb of “100 – age”. The following calculation demonstrated marrow cellularity variation with age: cellularity (%) = 67.6 – (age X 0.36)

Marrow cellularity from MRI shows statistically significant correlation compared to bone marrow biopsy. Significant differences in marrow cellularity between vertebral levels and changes in cellularity with age are also demonstrated.

This simple method of marrow cellularity calculation from routine MRI may be applicable in the setting of osteoporosis, aplastic processes, or other marrow disorders to compare individual patients to age matched normals or to follow a disease and its response to treatment. 

Matcuk, G, Siddiqi, I, Cen, S, Hagiya, A, Isaacson, R, Brynes, R, Marrow Cellularity MRI Calculation and Correlation with Bone Marrow Biopsy.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14008096.html