Normal spinal bone marrow in adults: dynamic gadolinium-enhanced MR imaging.

PURPOSE: To determine the patterns of dynamic enhancement of normal spinal bone marrow in adults at gadolinium-enhanced magnetic resonance (MR) imaging and the changes that occur with aging. MATERIALS AND METHODS: Dynamic contrast material-enhanced MR imaging of the thoracolumbar spine was performed in 71 patients. The maximum percentage of enhancement (Emax), enhancement slope, and enhancement washout were determined from bone marrow enhancement time curves (ETCs). The bone marrow signal intensity on T1-weighted spin-echo MR images was qualitatively classified into three grade categories. Quantitative ETC values were correlated with patient age and bone marrow fat content grade. Statistical analysis included mean t test comparison, analysis of variance, and regression analysis of the correlations between age and quantitative MR parameters. RESULTS: Emax, slope, and washout varied widely among the patients. Emax values were obtained within 1 minute after contrast material injection and ranged from 0% to 430%. Emax values were significantly higher in patients younger than 40 years than in those aged 40 years or older (P <.001). These values decreased with increasing age in a logarithmic relationship (r = 0.71). Emax values decreased as fat content increased, but some overlap among the fat content grades was noted. Analysis of variance revealed that Emax was significantly related to age (younger than 40 years vs 40 years or older) (P <.001) and fat content grade (P <.001) but not significantly related to sex. CONCLUSION: Dynamic contrast-enhanced MR imaging patterns of normal spinal bone marrow are dependent mainly on patient age and fat content.

Bone marrow with diffuse tumor infiltration in patients with lymphoproliferative diseases: dynamic gadolinium-enhanced MR imaging.

PURPOSE: To evaluate gadolinium enhancement of bone marrow in patients with lymphoproliferative diseases and diffuse bone marrow involvement. MATERIALS AND METHODS: Dynamic contrast material-enhanced magnetic resonance (MR) imaging of the thoracolumbar spine was performed in 42 patients with histologically proved diffuse bone marrow involvement and newly diagnosed myeloma (n = 31), non-Hodgkin lymphoma (n = 8), or Hodgkin disease (n = 3). The maximum percentage of enhancement (Emax), enhancement slope, and enhancement washout were determined from enhancement time curves (ETCs). A three-grade system for scoring bone marrow involvement was based on the percentage of neoplastic cells in bone marrow samples. Quantitative ETC values for the 42 patients were compared with ETC values for healthy subjects and with grades of bone marrow involvement by using mean t test comparisons. Receiver operating characteristic (ROC) analysis was conducted by comparing Emax values between patients with and those without bone marrow involvement. Baseline and follow-up MR imaging findings were compared in nine patients. RESULTS: Significant differences in Emax (P <.001), slope (P <.001), and washout (P =.005) were found between subjects with normal bone marrow and patients with diffuse bone marrow involvement. ROC analysis results showed Emax values to have a diagnostic accuracy of 99%. Emax, slope, and washout values increased with increasing bone marrow involvement grade. The mean Emax increased from 339% to 737%. Contrast enhancement decreased after treatment in all six patients who responded to treatment but not in two of three patients who did not respond to treatment. CONCLUSION: Dynamic contrast-enhanced MR images can demonstrate increased bone marrow enhancement in patients with lymphoproliferative diseases and marrow involvement.