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Dynamic Susceptibility Contrast (dynamic + susceptibility_contrast)
Selected AbstractsImproved dynamic susceptibility contrast (DSC)-MR perfusion estimates by motion correctionJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2007Robert K. Kosior BSc Abstract Purpose To investigate the effect of patient motion on quantitative cerebral blood flow (CBF) maps in ischemic stroke patients and to evaluate the efficacy of a motion-correction scheme. Materials and Methods Perfusion data from 25 ischemic stroke patients were selected for analysis. Two motion profiles were applied to a digital anthropomorphic brain phantom to estimate accuracy. CBF images were generated for motion-corrupted and motion-corrected data. To correct for motion, rigid-body registration was performed. The realignment parameters and mean CBF in regions of interest were recorded. Results All patient data with motion exhibited visibly reduced intervolume misalignment after motion correction. Improved flow delineation between different tissues and a more clearly defined ischemic lesion (IL) were achieved in the motion-corrected CBF. A significant difference occurred in the IL (P < 0.05) for patients with severe motion with an average difference between corrupted and corrected data of 4.8 mL/minute/100 g. The phantom data supported the patient results with better CBF accuracy after motion correction and high registration accuracy (<1 mm translational and <1° rotational error). Conclusion Motion degrades flow differentiation between adjacent tissues in CBF maps and can cause ischemic severity to be underestimated. A registration motion correction scheme improves dynamic susceptibility contrast (DSC)-MR perfusion estimates. J. Magn. Reson. Imaging 2007;26:1167,1172. © 2007 Wiley-Liss, Inc. [source] Method for improving the accuracy of quantitative cerebral perfusion imaging,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2005Ken E. Sakaie PhD Abstract Purpose To improve the accuracy of dynamic susceptibility contrast (DSC) measurements of cerebral blood flow (CBF) and volume (CBV). Materials and Methods In eight volunteers, steady-state CBV (CBVSS) was measured using TrueFISP readout of inversion recovery (IR) before and after injection of a bolus of contrast. A standard DSC (STD) perfusion measurement was performed by echo-planar imaging (EPI) during passage of the bolus and subsequently used to calculate the CBF (CBFDSC) and CBV (CBVDSC). The ratio of CBVSS to CBVDSC was used to calibrate measurements of CBV and CBF on a subject-by-subject basis. Results Agreement of values of CBV (1.77 ± 0.27 mL/100 g in white matter (WM), 3.65 ± 1.04 mL/100 g in gray matter (GM)), and CBF (23.6 ± 2.4 mL/(100 g min) in WM, 57.3 ± 18.2 mL/(100 g min) in GM) with published gold-standard values shows improvement after calibration. An F-test comparison of the coefficients of variation of the CBV and CBF showed a significant reduction, with calibration, of the variability of CBV in WM (P< 0.001) and GM (P < 0.03), and of CBF in WM (P < 0.0001). Conclusion The addition of a CBVSS measurement to an STD measurement of cerebral perfusion improves the accuracy of CBV and CBF measurements. The method may prove useful for assessing patients suffering from acute stroke. J. Magn. Reson. Imaging 2005;21:512,519. © 2005 Wiley-Liss, Inc. [source] Susceptibility Contrast and Arterial Spin Labeled Perfusion MRI in Cerebrovascular DiseaseJOURNAL OF NEUROIMAGING, Issue 1 2003Ronald L. Wolf MD ABSTRACT Purpose. To directly compare dynamic susceptibility contrast (DSC) and continuous arterial spin labeled (CASL) magnetic resonance (MR) perfusion techniques in patients with known cerebrovascular disease, with the goals of identifying possible pitfalls in interpretation and determining potential for a complementary role in this setting. Methods. DSC and CASL MR perfusion studies were performed and compared in 11 patients with acute and/or chronic cerebrovascular disease. Using an automated segmentation technique, Pearson correlation coefficients were generated for CASL perfusion measurements compared to DSC perfusion maps (time-to-peak [TTP], relative cerebral blood volume [rCBV], cerebral blood flow [rCBF], and mean transit time [MTT]) by hemisphere and vascular territory. Results. TTP maps obtained using DSC perfusion MR correlated best both subjectively and objectively with CASL perfusion MRmeasurements when all patients studied were considered. If patients with a major transit delay were excluded, DSC rCBF correlated best with CASL CBF measurements. Conclusion. There may be a complementary role for CASL and DSC perfusion MR methods in cerebrovascular disease, especially in the setting of a marked transit delay. [source] | ||||||||||