MRI gadolinium enhancement of bone marrow: age-related changes in normals and in diffuse neoplastic infiltration.

OBJECTIVE

To quantify gadolinium-related enhancement in the bone marrow of the spine in normals and in patients with homogeneous diffuse malignant bone marrow infiltration.

DESIGN AND PATIENTS

The patients consisted of two groups: group 1 comprised 94 healthy adults (18-86 years) without bone marrow disease and group 2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n = 20) or breast carcinoma (n = 10). All patients received intravenous gadopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast signal intensity (SI) on T1-weighted spin-echo (SE) images (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI) and the percentage SI increase was calculated. The results were confirmed by bone marrow biopsy (n = 20) and clinical parameters (n = 10). Dynamic contrast-enhanced studies using a spoiled gradient-recalled-echo (GRE) sequence (TR/TE/alpha: 68 ms/6 ms 75 degrees) were performed in 10 controls with normal bone marrow.

RESULTS AND CONCLUSION

Contrast material enhancement in healthy persons can vary greatly (range 3-59%, mean 21%, SD 11%). With increasing age there is a significant decrease in contrast enhancement (Pearson's correlation, P < 0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20-50 vol%) and high-grade (biopsy > 50 vol%) diffuse malignant bone marrow infiltration was significantly higher than in normals (mean 67%, SD 34%, P < 0.001). Low-grade (biopsy < 20 vol%) diffuse malignant bone marrow infiltration can not be assessed by non-enhanced T1-weighted SE images or Gd-DTPA application. In conclusion, contrast material enhancement in healthy persons can vary greatly and is dependent on age, while intermediate-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed with SI measurements.