scholarly journals Crossed Cerebellar Diaschisis: Insights into Oxygen Challenge MRI

2012 ◽  
Vol 32 (12) ◽  
pp. 2114-2117 ◽  
Author(s):  
Krishna A Dani ◽  
Celestine Santosh ◽  
David Brennan ◽  
Donald M Hadley ◽  
Keith W Muir
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cerebral Blood Volume ◽  
Oxygen Extraction Fraction ◽  
Resonance Imaging ◽  
Crossed Cerebellar Diaschisis ◽  
Relative Contribution ◽  
Extraction Fraction ◽  
Signal Change ◽  
Cerebellar Diaschisis ◽  
Weighted Magnetic Resonance Imaging

Hyperoxia during T2∗-weighted magnetic resonance imaging (oxygen challenge imaging (OCI)) causes T2∗-weighted signal change that is dependent on cerebral blood volume (CBV) and oxygen extraction fraction (OEF). Crossed cerebellar diaschisis (CCD), where CBV is reduced but OEF is maintained, may be used to understand the relative contributions of OEF and CBV to OCI results. In subjects with large hemispheric strokes, OCI showed reduced signal change in the contralesional cerebellum ( P = 0.027, n = 12). This was associated with reduced CBV in contralesional cerebellum ( P = 0.039, n = 9). CCD may be a useful model to determine the relative contribution of CBV to signal change measured by OCI.

scholarly journals The Application of Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Therapy of Acute Cerebral Infarction

2006 ◽  
Vol 2006 ◽  
pp. 1-11 ◽  
Author(s):  
Ying Han ◽  
Enzhong Li ◽  
Jie Tian ◽  
Jian Chen ◽  
Huifang Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Diffusion Coefficient ◽  
Magnetic Resonance ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Resonance Imaging ◽  
Stroke Patients ◽  
Apparent Diffusion ◽  
Weighted Magnetic Resonance Imaging ◽  
Adc Map

Diffusion- and perfusion-weighted magnetic resonance imaging (DWI and PWI) was applied for stroke diagnose in 120 acute (<48h) ischemic stroke patients. At hyperacute (<6h) stage, it is difficult to find out the infarction zone in conventional T1 or T2 image, but it is easy in DWI, apparent diffusion coefficient (ADC) map; when at 3–6-hour stage it is also easy in PWI, cerebral blood flow (CBF) map, cerebral blood volume (CBV) map, and mean transit time (MTT) map; at acute (6–48 h) stage, DWI or PWI is more sensitive than conventional T1 or T2 image too. Combining DWI with ADC, acute and chronic infarction can be distinguished. Besides, penumbra which should be developed in meaning was used as an indication or to evaluate the therapeutic efficacy. There were two cases (<1.5h) that broke the model of penumbra because abnormity was found in DWI but not that in PWI, finally they recovered without any sequela.

scholarly journals Application of Cluster Analysis of Time Evolution for Magnetic Resonance Imaging -Derived Oxygen Extraction Fraction Mapping: A Promising Strategy for the Genetic Profile Prediction and Grading of Glioma

2021 ◽  
Vol 15 ◽  
Author(s):  
Nanxi Shen ◽  
Shun Zhang ◽  
Junghun Cho ◽  
Shihui Li ◽  
Ju Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cluster Analysis ◽  
Magnetic Resonance ◽  
Roc Analysis ◽  
Oxygen Metabolism ◽  
Oxygen Extraction Fraction ◽  
Idh Mutation ◽  
Resonance Imaging ◽  
Dce Mri ◽  
Extraction Fraction

Background: The intratumoral heterogeneity of oxygen metabolism and angiogenesis are core hallmarks of glioma, unveiling that genetic aberrations associated with magnetic resonance imaging (MRI) phenotypes may aid in the diagnosis and treatment of glioma.Objective: To explore the predictability of MRI-based oxygen extraction fraction (OEF) mapping using cluster analysis of time evolution (CAT) for genetic profiling and glioma grading.Methods: Ninety-one patients with histopathologically confirmed glioma were examined with CAT for quantitative susceptibility mapping and quantitative blood oxygen level–dependent magnitude-based OEF mapping and dynamic contrast-enhanced (DCE) MRI. Imaging biomarkers, including oxygen metabolism (OEF) and angiogenesis [volume transfer constant, cerebral blood volume (CBV), and cerebral blood flow], were investigated to predict IDH mutation, O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation status, receptor tyrosine kinase (RTK) subgroup, and differentiation of glioblastoma (GBM) vs. lower-grade glioma (LGG). The corresponding DNA sequencing was also obtained. Results were compared with DCE-MRI using receiver operating characteristic (ROC) analysis.Results: IDH1-mutated LGGs exhibited significantly lower OEF and hypoperfusion than IDH wild-type tumors (all p &lt; 0.01). OEF and perfusion metrics showed a tendency toward higher values in MGMT unmethylated GBM, but only OEF retained significance (p = 0.01). Relative prevalence of RTK alterations was associated with increased OEF (p = 0.003) and perfusion values (p &lt; 0.05). ROC analysis suggested OEF achieved best performance for IDH mutation detection [area under the curve (AUC) = 0.828]. None of the investigated parameters enabled prediction of MGMT status except OEF with a moderate AUC of 0.784. Predictive value for RTK subgroup was acceptable by using OEF (AUC = 0.764) and CBV (AUC = 0.754). OEF and perfusion metrics demonstrated excellent performance in glioma grading. Moreover, mutational landscape revealed hypoxia or angiogenesis-relevant gene signatures were associated with specific imaging phenotypes.Conclusion: CAT for MRI-based OEF mapping is a promising technology for oxygen measurement and along with perfusion MRI can predict genetic profiles and tumor grade in a non-invasive and clinically relevant manner.Clinical Impact: Physiological imaging provides an in vivo portrait of genetic alterations in glioma and offers a potential strategy for non-invasively selecting patients for individualized therapies.

scholarly journals Relation between Relative Cerebral Blood Flow, Relative Cerebral Blood Volume, and Mean Transit Time in Patients with Acute Ischemic Stroke Determined by Perfusion-Weighted MRI

2003 ◽  
Vol 23 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Oliver C. Singer ◽  
Richard du Mesnil de Rochemont ◽  
Christian Foerch ◽  
Astrid Stengel ◽  
Heiner Lanfermann ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Resonance Imaging ◽  
Unaffected Side ◽  
Weighted Magnetic Resonance Imaging

The relation between relative cerebral blood flow (relCBF), relative cerebral blood volume (relCBV), and mean transit time (MTT) changes was examined in 20 patients with acute cerebral ischemia (<6 h) using perfusion-weighted magnetic resonance imaging. Regions of interest (ROI) were selected on MTT maps covering the entire MTT abnormal cortical area. These ROIs were transferred to the relCBF and relCBV maps to analyze the relation between relCBF, relCBV, and MTT on a voxel-by-voxel basis. On the unaffected side, a tight coupling of relCBF and relCBV was found with little variation of MTT. In hypoperfused cortex, relCBV was increased at all investigated relCBF categories, and there was greater relCBV variability than on the unaffected side. Only a severe decrease of relCBF, to less than 0.3, in comparison with the unaffected side was associated with a reduction of relCBV less than 1.0. In contrast to the unaffected side, a power law function (relCBV = 2.283 × relCBF0.549) resulted in a better fit than using a linear function for the correlation of relCBF and relCBV. MTT ratios increased steadily with decreasing CBF values. In conclusion, there is a clear relation between different perfusion-weighted magnetic resonance imaging parameters in acute ischemia, reflecting both the degree of hemodynamic failure as well as compensatory mechanisms including vasodilation.

scholarly journals Apolipoprotein E Polymorphism and Acute Ischemic Stroke: A Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging Study

2002 ◽  
Vol 22 (11) ◽  
pp. 1336-1342 ◽  
Author(s):  
Yawu Liu ◽  
Mikko P. Laakso ◽  
Jari O. Karonen ◽  
Ritva L. Vanninen ◽  
Juho Nuutinen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Apolipoprotein E ◽  
Cerebral Blood Volume ◽  
Infarct Volume ◽  
Clinical Status ◽  
Imaging Study ◽  
Resonance Imaging ◽  
Apoe Polymorphism ◽  
Weighted Magnetic Resonance Imaging

Diffusion- and perfusion-weighted magnetic resonance imaging (MRI) was used to study the putative effects of apolipoprotein E (ApoE) polymorphism in stroke. Thirty-one patients with acute stroke, comparative for age and gender were scanned, nine of whom were ApoE allele ***ε4 carriers. Initially, less than 24 hours from the onset of stroke, the ε4 carriers had significantly smaller volumes of hypoperfusion on relative cerebral blood volume map ( P = 0.001), and smaller infarct volumes ( P = 0.008) compared with the noncarriers. By day 8, this difference in the infarct volumes had disappeared, suggesting relatively enhanced infarct growth. On average, the total infarct volume increased 145% of the initial infarct volume in the ε4 carriers, and 84% in the noncarriers. There were strong correlations between the imaging findings and clinical status initially and with the outcome 3 months after the stroke in the ε4 noncarriers, but, with a single exception at acute phase, a lack thereof in the ε4 carriers. These patterns were virtually similar in a subgroup of patients with middle cerebral artery stroke. These data support the hypothesis of increased general vulnerability of the brain in the e4 carriers. Thus, the effects of ApoE polymorphism should be accounted for when interpreting diffusion- and perfusion-weighted MRI studies, particularly if predicting lesion growth.

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