Ashok J. Kumar

4L Anne Hayman
3Vinodh A Kumar
2Jingfei Ma
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Patients with recurrent malignant glioma treated with bevacizumab, a monoclonal antibody to vascular endothelial growth factor (VEGF), alone or in combination with irinotecan have had impressive reductions in MRI contrast enhancement and vasogenic edema. Responses to this regimen, as defined by a decrease in contrast enhancement, have led to significant(More)
OBJECTIVE This paper describes the methods used to create annotated deformable anatomic templates (DATs) and display them in a patient's axial 2-dimensional and reformatted volume brain images. METHODS A senior neuroradiologist annotated and manually segmented 1185 color-coded structures on axial magnetic resonance images of a normal template brain using(More)
PURPOSE To develop a phased-array coil-compatible, fast three-point Dixon (TPD) technique, and compare its performance in T2-weighted spine imaging with that of the standard chemical shift selective (CHESS) fat suppression technique. MATERIALS AND METHODS We acquired T2-weighted spine images of 27 patients using essentially identical scanning parameters(More)
In order to satisfy the Carr-Purcell-Meiboom-Gill (CPMG) condition, echo shift as dictated in fast-spin-echo (FSE)-based Dixon imaging was previously achieved by applying a time shift to the readout gradient and the data acquisition window. Accordingly, interecho spacing is increased, which entails increased image blurring and, in multislice imaging, a(More)
Magnetic resonance (MR) venography and computed tomographic (CT) venography are suited for displaying the convexity veins that drain the medial and lateral surfaces of the brain hemispheres. However, such is not the case for the bridging veins of the skull base. Technical factors prevent contrast material-enhanced MR or CT images obtained in standard axial,(More)
Individual analysis of functional Magnetic Resonance Imaging (fMRI) scans requires user-adjustment of the statistical threshold in order to maximize true functional activity and eliminate false positives. In this study, we propose a novel technique that uses radiomic texture analysis (TA) features associated with heterogeneity to predict areas of true(More)
Leptomeningeal metastasis of melanoma is a devastating complication with a grave prognosis, and there are no known effective standard treatments. Although selective BRAF inhibitors have demonstrated a significant clinical activity in patients with metastatic melanoma harboring a BRAF mutation, the clinical benefit of BRAF inhibitor-based therapy in(More)
The posterior frontal lobe of the brain houses Brodmann area 4, which is the primary motor cortex, and Brodmann area 6, which consists of the supplementary motor area on the medial portion of the hemisphere and the premotor cortex on the lateral portion. In this area, safe resection is dependent on accurate localization of the motor cortex and the central(More)
A novel manifold learning approach is presented to efficiently identify low-dimensional structures embedded in high-dimensional MRI data sets. These low-dimensional structures, known as manifolds, are used in this study for predicting brain tumor progression. The data sets consist of a series of high-dimensional MRI scans for four patients with tumor and(More)
Diffusion tensor imaging (DTI) data has traditionally been displayed as a grayscale functional anisotropy map (GSFM) or color coded orientation map (CCOM). These methods use black and white or color with intensity values to map the complex multidimensional DTI data to a two-dimensional image. Alternative visualization techniques, such as V max maps utilize(More)