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Cerebral Gliomas (cerebral + glioma)
Selected AbstractsPredicting the Histopathological Grade of Cerebral Gliomas Using High b value MR DW Imaging at 3-TeslaJOURNAL OF NEUROIMAGING, Issue 3 2008Juan Alvarez-Linera MD ABSTRACT BACKGROUND Our aim was to prospectively assess whether magnetic resonance (MR) diffusion-weighted (DW) imaging using high b values can predict better than b value of 1,000 s/mm2 the histopathological grade of cerebral gliomas. METHODS Fifty-four patients with histologically verified brain gliomas (35 high-grade and 19 low-grade gliomas) underwent MR DW imaging. Isotropic DW images and apparent diffusion coefficient (ADC) were obtained with b values of 1,000 and 3,000 s/mm2. Each tumor was evaluated as being hyperintense, iso-intense or hypointense to normal, contralateral-hemisphere white matter. RESULTS Most of the patients with high- and low-grade gliomas showed areas of increased signal intensity on their isotropic images, obtained with a b value of 1,000 s/mm2. However, with a b value of 3,000 s/mm2 the areas of increased signal intensity were seen in 97.1% of the high-grade gliomas, while 94.7% of the low-grade gliomas showed no area of increased signal intensity. The mean area under the ROC curve for ADC ratio, obtained with a b value of 3,000 s/mm2, was significantly higher than that obtained with 1,000 s/mm2 (.932 vs. .856, P= .04). CONCLUSION High b value DW MR might be useful as a complementary tool in preoperative assessment of the histopathological grading of cerebral gliomas. [source] Blood oxygenation level-dependent MRI of cerebral gliomas during breath holdingJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2004Yuan-Yu Hsu MD Abstract Purpose To assess the cerebrovascular responses to short breath holding of cerebral gliomas using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Materials and Methods Six patients with a low-grade glioma and one patient with a high-grade glioma were studied using T2*-weighted echo planar imaging (EPI) during repeated periods of 15-second or 20-second breath-holding. Tumor vascularity was evaluated using dynamic susceptibility contrast perfusion MRI. Results Increases in BOLD signal intensity during repeated breath-holding were consistently identified in patients' normal appearing gray matter, comparable with those in healthy adults. Absence of significant BOLD signal enhancement was noted both in low-grade and high-grade gliomas, which is either due to overwhelming hypoxia in a tumor, inadequacy or absence of hypercapnia-induced vasodilatation of tumor vessels, or both. Breath-hold regulated decreases in BOLD signals occurred only in the high-grade glioma, which is most likely due to the hypercapnia-induced steal effect that redistributes blood flow from tumor regions with unresponsive neovasculature to surrounding normal tissue. Conclusion BOLD MRI during short breath holding can disclose differential cerebrovascular response between normal tissue and cerebral glioma. J. Magn. Reson. Imaging 2004;19:160,167. © 2004 Wiley-Liss, Inc. [source] A comparison of Ktrans measurements obtained with conventional and first pass pharmacokinetic models in human gliomasJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2004Hamied A. Haroon MSc Abstract Purpose To compare in a group of patients with cerebral gliomas the estimates of Ktrans between a conventionally established pharmacokinetic model and a recently developed first pass method. Materials and Methods Glioma patients (23) were studied using T1 -weighted dynamic contrast-enhanced magnetic resonance imaging (MRI), and two alternative pharmacokinetic models were used for analysis to derive the volume transfer constant Ktrans. These were a modified version of the established model (yielding KTK) and a recently published method based on first pass leakage profile (FP) of contrast bolus (yielding Kfp). Results We found a strong correlation between intra-tumoral median KTK and Kfp (rho = 0.650, P < 0.01), but the values from the conventional model were consistently and significantly higher (mean of inter-tumoral Kfp and KTK medians were 0.018 minute,1 and 0.284 minute,1, respectively, P < 0.001). The spatial distribution of KTK and Kfp showed poor correlation in the presence of large vascular structures and good correlation elsewhere. Conclusion KTK and Kfp produce similar biologic information within voxels not dominated by vascular tissue. The FP method avoids erroneous overestimation of Ktrans in areas of significant intravascular contrast. Findings are in keeping with the predictions of previous mathematical simulations. J. Magn. Reson. Imaging 2004;19:527,536. © 2004 Wiley-Liss, Inc. [source] Blood oxygenation level-dependent MRI of cerebral gliomas during breath holdingJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2004Yuan-Yu Hsu MD Abstract Purpose To assess the cerebrovascular responses to short breath holding of cerebral gliomas using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI). Materials and Methods Six patients with a low-grade glioma and one patient with a high-grade glioma were studied using T2*-weighted echo planar imaging (EPI) during repeated periods of 15-second or 20-second breath-holding. Tumor vascularity was evaluated using dynamic susceptibility contrast perfusion MRI. Results Increases in BOLD signal intensity during repeated breath-holding were consistently identified in patients' normal appearing gray matter, comparable with those in healthy adults. Absence of significant BOLD signal enhancement was noted both in low-grade and high-grade gliomas, which is either due to overwhelming hypoxia in a tumor, inadequacy or absence of hypercapnia-induced vasodilatation of tumor vessels, or both. Breath-hold regulated decreases in BOLD signals occurred only in the high-grade glioma, which is most likely due to the hypercapnia-induced steal effect that redistributes blood flow from tumor regions with unresponsive neovasculature to surrounding normal tissue. Conclusion BOLD MRI during short breath holding can disclose differential cerebrovascular response between normal tissue and cerebral glioma. J. Magn. Reson. Imaging 2004;19:160,167. © 2004 Wiley-Liss, Inc. [source] Predicting the Histopathological Grade of Cerebral Gliomas Using High b value MR DW Imaging at 3-TeslaJOURNAL OF NEUROIMAGING, Issue 3 2008Juan Alvarez-Linera MD ABSTRACT BACKGROUND Our aim was to prospectively assess whether magnetic resonance (MR) diffusion-weighted (DW) imaging using high b values can predict better than b value of 1,000 s/mm2 the histopathological grade of cerebral gliomas. METHODS Fifty-four patients with histologically verified brain gliomas (35 high-grade and 19 low-grade gliomas) underwent MR DW imaging. Isotropic DW images and apparent diffusion coefficient (ADC) were obtained with b values of 1,000 and 3,000 s/mm2. Each tumor was evaluated as being hyperintense, iso-intense or hypointense to normal, contralateral-hemisphere white matter. RESULTS Most of the patients with high- and low-grade gliomas showed areas of increased signal intensity on their isotropic images, obtained with a b value of 1,000 s/mm2. However, with a b value of 3,000 s/mm2 the areas of increased signal intensity were seen in 97.1% of the high-grade gliomas, while 94.7% of the low-grade gliomas showed no area of increased signal intensity. The mean area under the ROC curve for ADC ratio, obtained with a b value of 3,000 s/mm2, was significantly higher than that obtained with 1,000 s/mm2 (.932 vs. .856, P= .04). CONCLUSION High b value DW MR might be useful as a complementary tool in preoperative assessment of the histopathological grading of cerebral gliomas. [source] | ||||||||||