scholarly journals Determination of oxygen extraction fraction using magnetic resonance imaging in canine models with internal carotid artery occlusion

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Fei-Yan Chang ◽  
Jiang-Xi Xiao ◽  
Sheng Xie ◽  
Lei Yu ◽  
Zhen-Xia Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Internal Carotid ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Oxygen Extraction Fraction ◽  
Resonance Imaging ◽  
Extraction Fraction ◽  
Canine Models

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 < 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 < 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.

MIDTERM CLINICAL AND MAGNETIC RESONANCE IMAGING FOLLOW-UP OF LARGE AND GIANT CAROTID ARTERY ANEURYSMS AFTER THERAPEUTIC CAROTID ARTERY OCCLUSION

Neurosurgery ◽  
2007 ◽  
Vol 60 (6) ◽  
pp. 1025-1031 ◽  
Author(s):  
Anjob N. de Gast ◽  
Marieke E. Sprengers ◽  
Willem Jan van Rooij ◽  
Cristina Lavini ◽  
Menno Sluzewski ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Carotid Artery ◽  
Clinical Symptoms ◽  
Incidental Finding ◽  
Mass Effect ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Resonance Imaging

Abstract OBJECTIVE The purpose of this study was to evaluate aneurysm size and clinical symptoms midterm after therapeutic carotid artery occlusion in 39 patients with large or giant carotid artery aneurysms. METHODS Between January 1996 and August 2004, 39 patients with large or giant carotid artery aneurysms were treated with therapeutic carotid artery occlusion and had clinical and magnetic resonance imaging follow-up of at least 3 months (mean, 35.9 mo; median, 29 mo; range, 3–107 mo; 117 patient-yr). Initial clinical presentation was mass effect caused by the aneurysm in 32 (82%) of the 39 patients. Three patients presented with subarachnoid hemorrhage and one presented with epistaxis; two aneurysms were an incidental finding and one was additional to another ruptured aneurysm. RESULTS There were no early or late complications of therapeutic carotid artery occlusion. All aneurysms seemed to have thrombosed completely after carotid artery occlusion as observed on early and late magnetic resonance imaging and magnetic resonance angiographic follow-up studies. At the time of the most recent magnetic resonance imaging follow-up study, 29 (74%) of the 39 aneurysms involuted totally, two aneurysms decreased to 25% of the original diameter, two aneurysms decreased to 50%, and five aneurysms decreased to 75%. Two aneurysms remained unchanged in size after 49 and 58 months, respectively. At the most recent clinical follow-up evaluation, symptoms of mass effect were cured in 19 (60%), improved in 10 (31%), and remained unchanged in three (9%) of the 32 patients. CONCLUSION Therapeutic carotid artery occlusion was a simple, safe, and effective treatment for large and giant carotid artery aneurysms. Almost all aneurysms involute completely or substantially decrease in size. Alleviation of symptoms of mass effect was achieved in most patients.

scholarly journals Brain Temperature Measured by Magnetic Resonance Spectroscopy to Predict Clinical Outcome in Patients with Infarction

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 490
Author(s):  
Tomohisa Ishida ◽  
Takashi Inoue ◽  
Tomoo Inoue ◽  
Toshiki Endo ◽  
Miki Fujimura ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Mr Spectroscopy ◽  
Internal Carotid ◽  
Brain Temperature ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Clinical Settings ◽  
Brain Swelling

Acute ischemic stroke is characterized by dynamic changes in metabolism and hemodynamics, which can affect brain temperature. We used proton magnetic resonance (MR) spectroscopy under everyday clinical settings to measure brain temperature in seven patients with internal carotid artery occlusion to explore the relationship between lesion temperature and clinical course. Regions of interest were selected in the infarct area and the corresponding contralateral region. Single-voxel MR spectroscopy was performed using the following parameters: 2000-ms repetition time, 144-ms echo time, and 128 excitations. Brain temperature was calculated from the chemical shift between water and N-acetyl aspartate, choline-containing compounds, or creatine phosphate. Within 48 h of onset, compared with the contralateral region temperature, brain temperature in the ischemic lesion was lower in five patients and higher in two patients. Severe brain swelling occurred subsequently in three of the five patients with lower lesion temperatures, but in neither of the two patients with higher lesion temperatures. The use of proton MR spectroscopy to measure brain temperature in patients with internal carotid artery occlusion may predict brain swelling and subsequent motor deficits, allowing for more effective early surgical intervention. Moreover, our methodology allows for MR spectroscopy to be used in everyday clinical settings.

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.

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