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Your search keyword '"Samantha Guiry"' showing total 2 results
Start Over Author "Samantha Guiry" Publisher nature publishing group uk
2 results on '"Samantha Guiry"'

1. Quantification of tumor microenvironment acidity in glioblastoma using principal component analysis of dynamic susceptibility contrast enhanced MR imaging

Author

Benjamin M. Ellingson, Ali Nabavizadeh, Stephen J Bagley, Donald M. O'Rourke, Elizabeth Mamourian, Jeffrey B. Ware, Hannah Anderson, Catalina Raymond, Samantha Guiry, Christos Davatzikos, Anahita Fathi Kazerooni, Hamed Akbari, Steven Brem, Chiharu Sako, Jingwen Yao, and Arati Desai

Subjects
Male, Data Interpretation, Image Processing, 030218 nuclear medicine & medical imaging, Mice, 0302 clinical medicine, Nuclear magnetic resonance, Computer-Assisted, Image Processing, Computer-Assisted, Tumor Microenvironment, Contrast (vision), media_common, Cancer, Principal Component Analysis, Multidisciplinary, Chemistry, Statistical, Hydrogen-Ion Concentration, Middle Aged, Magnetic Resonance Imaging, Regression, Data Interpretation, Statistical, Principal component analysis, Biomedical Imaging, Medicine, Female, Dynamic susceptibility, media_common.quotation_subject, Science, Article, 03 medical and health sciences, Rare Diseases, Clinical Research, medicine, Animals, Humans, Magnetization transfer, Aged, Neoplasm Staging, Tumor microenvironment, Animal, Neurosciences, medicine.disease, Hyperintensity, Brain Disorders, Brain Cancer, CNS cancer, Disease Models, Animal, Disease Models, Cancer imaging, Neoplasm Grading, Glioblastoma, 030217 neurology & neurosurgery
Abstract

Glioblastoma (GBM) has high metabolic demands, which can lead to acidification of the tumor microenvironment. We hypothesize that a machine learning model built on temporal principal component analysis (PCA) of dynamic susceptibility contrast-enhanced (DSC) perfusion MRI can be used to estimate tumor acidity in GBM, as estimated by pH-sensitive amine chemical exchange saturation transfer echo-planar imaging (CEST-EPI). We analyzed 78 MRI scans in 32 treatment naïve and post-treatment GBM patients. All patients were imaged with DSC-MRI, and pH-weighting that was quantified from CEST-EPI estimation of the magnetization transfer ratio asymmetry (MTRasym) at 3 ppm. Enhancing tumor (ET), non-enhancing core (NC), and peritumoral T2 hyperintensity (namely, edema, ED) were used to extract principal components (PCs) and to build support vector machines regression (SVR) models to predict MTRasym values using PCs. Our predicted map correlated with MTRasym values with Spearman’s r equal to 0.66, 0.47, 0.67, 0.71, in NC, ET, ED, and overall, respectively (p

Published
2021

2. Arterial Spin Labeling and Dynamic Susceptibility Contrast-enhanced MR Imaging for evaluation of arteriovenous shunting and tumor hypoxia in glioblastoma

Author

Samantha Guiry, Donald M. O'Rourke, Hamed Akbari, S. Ali Nabavizadeh, Steven Brem, Jeffrey B. Ware, Timothy Prior, Christos Davatzikos, Whitney Sarchiapone, Scott Levy, Ronald L. Wolf, Arati Desai, John A. Detre, MacLean Nasrallah, and Stephen J Bagley

Subjects
0301 basic medicine, Male, medicine.medical_specialty, lcsh:Medicine, Contrast Media, Article, 03 medical and health sciences, 0302 clinical medicine, Text mining, Internal medicine, medicine, Humans, Arteriovenous shunting, Prospective Studies, lcsh:Science, Aged, Multidisciplinary, Tumor hypoxia, business.industry, Brain Neoplasms, lcsh:R, Hypoxia (medical), Middle Aged, medicine.disease, Magnetic Resonance Imaging, Cell Hypoxia, Shunting, CNS cancer, 030104 developmental biology, Arterial spin labeling, Cardiology, lcsh:Q, Cancer imaging, Female, Spin Labels, medicine.symptom, business, Glioblastoma, Perfusion, 030217 neurology & neurosurgery
Abstract

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults and carries a dismal prognosis. Significant challenges in the care of patients with GBM include marked vascular heterogeneity and arteriovenous (AV) shunting, which results in tumor hypoxia and inadequate delivery of systemic treatments to reach tumor cells. In this study, we investigated the utility of different MR perfusion techniques to detect and quantify arteriovenous (AV) shunting and tumor hypoxia in patients with GBM. Macrovascular shunting was present in 33% of subjects, with the degree of shunting ranging from (37–60%) using arterial spin labeling perfusion. Among the dynamic susceptibility contrast-enhanced perfusion curve features, there were a strong negative correlation between hypoxia score, DSC perfusion curve recovery slope (r = −0.72, P = 0.018) and angle (r = −0.73, P = 0.015). The results of this study support the possibility of using arterial spin labeling and pattern analysis of dynamic susceptibility contrast-enhanced MR Imaging for evaluation of arteriovenous shunting and tumor hypoxia in glioblastoma.

Published
2019

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