PURPOSE: To investigate whether high-resolution images of necrotic regions in tumors can be derived from gadopentetate dimeglumine (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) series. MATERIALS AND METHODS: E-13 human melanoma xenografts were used as preclinical models of human cancer. DCE-MRI was performed at a voxel size of 0.23 x 0.47 x 2.0 mm3 with the use of spoiled gradient recalled sequences. Tumor images of E . F (E is the initial extraction fraction of Gd-DTPA and F is blood perfusion) and lambda (the partition coefficient of Gd-DTPA, which is proportional to extracellular volume fraction) were produced by subjecting DCE-MRI series to Kety analysis, and these images were compared with histological preparations from the imaged slices. RESULTS: Strong correlations were found between fraction of necrotic tissue and fraction of voxels with lambda > lambdaL for lambdaL values of 0.4 to 0.6. Binary lambda images differentiating between lambda values > lambdaL and lambda values < lambdaL were found to mirror necrotic regions well in tumors with large necroses. However, necrotic foci that were small compared with the voxel size were not detectable. CONCLUSION: Clinically relevant images of necrotic tumor regions can be obtained for E-13 melanomas by subjecting Gd-DTPA-based DCE-MRI series to Kety analysis. Copyright 2007 Wiley-Liss, Inc.
PURPOSE: To investigate whether high-resolution images of necrotic regions in tumors can be derived from gadopentetate dimeglumine (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) series. MATERIALS AND METHODS: E-13 humanmelanoma xenografts were used as preclinical models of humancancer. DCE-MRI was performed at a voxel size of 0.23 x 0.47 x 2.0 mm3 with the use of spoiled gradient recalled sequences. Tumor images of E . F (E is the initial extraction fraction of Gd-DTPA and F is blood perfusion) and lambda (the partition coefficient of Gd-DTPA, which is proportional to extracellular volume fraction) were produced by subjecting DCE-MRI series to Kety analysis, and these images were compared with histological preparations from the imaged slices. RESULTS: Strong correlations were found between fraction of necrotic tissue and fraction of voxels with lambda > lambdaL for lambdaL values of 0.4 to 0.6. Binary lambda images differentiating between lambda values > lambdaL and lambda values < lambdaL were found to mirror necrotic regions well in tumors with large necroses. However, necrotic foci that were small compared with the voxel size were not detectable. CONCLUSION: Clinically relevant images of necrotic tumor regions can be obtained for E-13 melanomas by subjecting Gd-DTPA-based DCE-MRI series to Kety analysis. Copyright 2007 Wiley-Liss, Inc.
Authors: James W Baish; Triantafyllos Stylianopoulos; Ryan M Lanning; Walid S Kamoun; Dai Fukumura; Lance L Munn; Rakesh K Jain Journal: Proc Natl Acad Sci U S A Date: 2011-01-11 Impact factor: 11.205