Browsing by Subject "Astrocytoma"
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Item Executive Functioning In Child Survivors of Pediatric Cerebellar Astrocytomas(2008-05-13) Perez, Rogelio; Stavinoha, Peter L.Twenty children who underwent surgery for CPA and were between the ages of eight and 16 years participated in the study. Each child was administered a multidimensional neuropsychological battery of EF, which consisted of the Delis-Kaplan Executive Function System, Wisconsin Card Sorting Test, and the subtests comprising the Working Memory Index from the Wechsler Intelligence Scale for Children - Fourth Edition. Parents and teachers completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Behavior Assessment System for Children - Second Edition (BASC-2). No significant differences were found between the CPA group's performance on the clinical measures and the normative test means. Teacher ratings on the BRIEF showed that the CPA group exhibited significantly more difficulties with working memory, whereas parent ratings showed significantly more difficulties with inhibition, mental flexibility, emotional control, initiation of activities, working memory, planning/organization, and monitoring behavior. In terms of emotional and behavioral functioning on the BASC-2, parents rated the CPA group as exhibiting significantly more difficulties with depression, withdrawal, and overall behavioral problems. Parent ratings on the BASC-2 also showed significantly more problems in several areas of adaptive functioning. This study did not replicate the findings of previous studies on EF in pediatric CPA samples. Although EF impairments were not evident, the CPA sample exhibited subtle and mild EF and behavioral/emotional difficulties.Item Magnetic Resonance Spectroscopy Imaging of 2-Hydroxyglutarate in Brain Tumors at 3T and 7T In Vivo(2018-05-30) An, Zhongxu; Sherry, A. Dean; Choi, Changho; Malloy, Craig R.; Pinho, Marco Da Cunha; Ren, JiminThe identification of 2-hydroxyglutarate (2HG) by 1H magnetic resonance spectroscopy (MRS) in patients with isocitrate dehydrogenase mutant gliomas is a significant breakthrough in neuro-oncology imaging. 2HG is the first imaging biomarker that is specific to a genetic mutation in gliomas, making the diagnosis of IDH mutant gliomas possible without biopsy. 2HG also has a significant predictive value with respect to the stage and survival in gliomas because IDH mutation carries a favorable prognosis. Gliomas are highly heterogeneous and infiltrative in malignant transformation and recur beyond the borders of the initial tumor mass. Therefore, a high-resolution 3D imaging platform to measure 2HG rapidly has an outstanding strength for monitoring IDH-mutant tumors. The present work aims to develop new techniques that provide meaningful estimation of 2HG and other metabolites in gliomas in vivo. As the first topic, novel triple refocusing MRS was developed at 3T for improving the 2HG signal sensitivity and specificity compared to prior methods. The optimized triple refocusing sequence conferred excellent discrimination of the 2HG 2.25-ppm signal from the adjacent resonances and consequently improved the precision of 2HG estimation substantially. Another accomplishment was development of fast high-resolution imaging of 2HG in patients at 3T and 7T. A new echo-planar spectroscopic imaging (EPSI) readout was designed incorporating dual-readout alternated gradients (DRAG-EPSI). At 7T, DRAG-EPSI was utilized for increasing the spectral width for fully covering the spectral region of interest, which is not possible with conventional EPSI. DRAG-EPSI was used for 2D imaging of 2HG in 5 patients at 7T. At 3T, at which the spectral width of conventional EPSI is sufficiently large for covering the spectral region of interest, DRAG-EPSI was utilized for reducing the readout gradient strengths, thereby improving the imaging performance and patient compliance. DRAG-EPSI induced frequency drifts smaller by 5.5-fold and acoustic noise lower by 25 dB compared with conventional EPSI. In a 19-min scan, DRAG-EPSI produced, for the first time, 3D imaging of 2HG with precision at a resolution of 10×10×10 mm3 at 3T. Data from 4 patients indicated that DRAG-EPSI may provide reliable 3D high-resolution imaging of 2HG at 3T in vivo.Item [Southwestern News](2003-07-28) O'Brien, Stephen; Siem, Staishy Bostick