Pilot study on evaluation of any correlation between MR perfusion (Ktrans) and diffusion (apparent diffusion coefficient) parameters in brain tumors at 3 Tesla

PURPOSE To assess any correlation of volume transfer constant (Ktrans) with apparent diffusion coefficient (ADC) in different brain tumor types at 3 T magnetic resonance (MR) imaging. MATERIALS AND METHODS Thirteen patients with brain tumors (8 men, 5 women; mean age 54.6±17.7 years) were enrolled in this retrospective study. All patients underwent dynamic contrast-enhanced T1-weighted MR perfusion and diffusion-weighted imaging using a 3 T scanner. Ktrans was estimated by specially designed software. For each tumor, regions of interest (ROIs) were manually selected on corresponding Ktrans and ADC maps. Pearson correlation coefficients were obtained for maximum, mean and minimum values of Ktrans and ADC of all ROIs. Based on clinicopathologic results, the final diagnoses of patients were glioblastoma multiforme (3), low-grade to anaplastic gliomas (4), meningiomas (3) and metastatic tumors (3). RESULTS Ktrans(max) values were significantly inversely correlated with ADC(min) values (r=-0.536, P<0.001) and ADC(mean) values (r=-0.465, P<0.001). Ktrans(mean) and Ktrans(min) values were significantly inversely correlated with ADC(mean) (r=-0.228, P=0.038) and ADC(max) values (r=-0.355, P=0.001), respectively. CONCLUSION We found that irrespective of brain tumor type, there is an inverse correlation between ADC and Ktrans. Our findings highlight an intricate relationship between vascular permeability and the tumor microenvironment, probably modulating and/or interacting with changes such as increased cellularity, ischemic insult and varying extracellular matrix composition.