Effect of Calcium Channel Blockers on Vertebral Bone Marrow Perfusion of the Lumbar Spine

PURPOSE: To investigate the effect of calcium channel blockers on blood perfusion of vertebral bone marrow in the lumbar spine. MATERIALS AND METHODS: Sixteen healthy volunteers (eight men and eight women) underwent dynamic contrast material-enhanced magnetic resonance (MR) imaging of the lumbar spine. One hundred twenty minutes after the first MR examination, each subject ingested 10 mg sublingual nifedipine before undergoing a second MR examination 20-25 minutes later. Semiquantitative (peak enhancement ratio and enhancement slope) and quantitative (amplitude and rate constant of the exchange [K _out]) parameters were analyzed with the time-intensity curve. Data obtained before and after administration of nifedipine were compared. The Wilcoxon signed rank test and Spearman rank correlation test were used. RESULTS: Median peak enhancement ratio of vertebral bodies decreased from 0.60 (mean ± SD, 0.68 ± 0.29) to 0.51 (mean, 0.56 ± 0.24) after administration of nifedipine. Median and mean decreases were 0.11 and 0.12 ± 0.15, respectively, and the percentage difference was 17% (P = .005). A P value of less than .05 was considered to indicate a statistically significant difference. Median enhancement slope changed from 0.45 (mean, 0.45 ± 0.13) to 0.41 (mean, 0.40 ± 0.24). Median and mean changes were 0.05 and 0.04 ± 0.23, respectively, and the percentage difference was 9% (P = .334). Median amplitude changed from 0.059 (mean, 0.059 ± 0.028) to 0.045 (mean, 0.048 ± 0.023). Median and mean changes were 0.008 and 0. 011 ± 0.025, respectively, and the percentage difference was 18% (P = .072). Median K_out changed from 0.068 (mean, 0.063 ± 0.018) to 0.067 (mean, 0.066 ± 0.028). Median and mean changes were 0.011 and 0.004 ± 0.028, respectively (P = .404). Nifedipine affected peak enhancement ratio significantly but did not affect enhancement slope, amplitude, or K_out. Data before and after administration of nifedipine showed no differences between men and women. Spearman rank correlation coefficients suggest no significance between the differences in heart rate and blood pressure and the differences in peak enhancement ratio, enhancement slope, amplitude, or K_out. CONCLUSION: After sublingual administration of nifedipine, the peak enhancement ratio of vertebral bone marrow decreased.