Dynamic contrast-enhanced (DCE) derived transfer coefficient (ktrans) is a surrogate marker of matrix metalloproteinase 9 (MMP-9) expression in brain tuberculomas.

Purpose To correlate dynamic contrast-enhanced (DCE) MRI derived perfusion indices with immunohistochemically obtained vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in a cellular fraction of brain tuberculomas (BT). Materials and Methods Thirteen BT patients underwent DCE MRI. Perfusion indices (cerebral blood volume [CBV], transfer coefficient [k^trans] and leakage [v_e]) maps were generated for the quantitative analysis. The CBV was corrected for the leaky blood-brain barrier (BBB). The relative CBV (rCBV), k^trans, and v_e were calculated by placing 10 regions of interest (ROIs) showing the highest values in the lesion. The percentage area of VEGF and percentage area of MMP-9 and microvessel density (MVD) were quantified from 10 fields per lesion with maximal expression of the excised BT. Pearson correlation analysis between physiological indices and quantitative VEGF, MMP-9, and MVD was performed for each ROI. Results The average value of rCBV, k^trans, v_e, VEGF, MMP-9, and MVD were 3.53 ± 0.37, 2.04 ± 0.40 min⁻¹, 0.71 ± 0.09, 12.51 ± 2.56, 18.09 ± 2.06, 10.87 ± 1.99, respectively. The k^trans ( r = 0.918, P < 0.001) and v_e ( r = 0.899, P < 0.001) showed significant correlation with MMP-9, while rCBV correlated significantly with MVD ( r = 0.962, P < 0.001) and VEGF ( r = 0.868, P < 0.001). Conclusion We conclude that the expression of MMP-9, a marker of BBB disruption and disease activity in BT correlates with DCE-derived k^trans and thus has the potential to be used as its surrogate marker. J. Magn. Reson. Imaging 2008;28:588-597. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]