159 research outputs found
Supplemental_Material - Cerebrospinal Fluid in Posterior Reversible Encephalopathy Syndrome: Implications of Elevated Protein and Pleocytosis
No full textSupplemental_Material for Cerebrospinal Fluid in Posterior Reversible Encephalopathy Syndrome: Implications of Elevated Protein and Pleocytosis by Colin A. Ellis, Andrew C. McClelland, Suyash Mohan, Emory Kuo, Scott E. Kasner, Cen Zhang, Pouya Khankhanian, and Ramani Balu in The Neurohospitalist</p
Abstract CT068: Tumor treating fields in patients with glioblastomas: Evaluation of treatment response using advanced mr imaging techniques
No full textAbstract
Introduction: Tumor treating fields (TTFields) is a new modality for the treatment of patients with newly diagnosed and recurrent glioblastomas (GBMs). TTFields system delivers low intensity, intermediate frequency alternating electric field directly to brain causing neoplastic cell death with minimal effect on the normal dividing cells. The purpose of present investigator sponsored trial was to evaluate the effects of TTFields in GBM patients using diffusion tensor imaging (DTI), perfusion weighted imaging (PWI) and 3D-echoplanar spectroscopic imaging (EPSI).
Methods: Two patients with newly diagnosed GBM and six patients with recurrent GBMs previously treated with standard of care maximal safe resection and chemo-radiation therapy received TTFields. Patients underwent baseline (prior to TTFields) and two follow-up (one and two months post initiation of TTFields) MR imaging on a 3T MR system. DTI data were acquired using 30 directions with a single-shot spin-echo EPI sequence. After motion and eddy current correction of raw DTI data, parametric maps [mean diffusivity (MD), fractional anisotropy (FA)] were generated using in-house developed algorithm. For PWI, T2* weighted gradient-echo EPI sequence was acquired with a temporal resolution of 2.1s. Leakage corrected cerebral blood volume (CBV) maps were constructed. 3D-EPSI was acquired using a spin-echo based sequence. EPSI data were processed using metabolic imaging and data analysis system (MIDAS) package. DTI (MD, FA), EPSI [choline (Cho)/creatine(Cr)], CBV maps and FLAIR images were co-registered to post-contrast T1-weighted images and a semi-automated algorithm was used to segment the contrast-enhancing region of neoplasms. Median values of MD, FA, relative CBV (rCBV) and Cho/Cr were computed at each time point. The 90th percentile rCBV (rCBVmax) values were also measured. Percent changes of each parameter between baseline and follow-up time points were evaluated.
Results and Discussion: In general, there was an increasing trend in MD (~3%) and steadily decline trend in FA (~8%) at the 2 month follow-up relative to baseline. Additionally, from baseline to post- TTFields, reductions in Cho/Cr and rCBVmax were also observed from most of the patients. Clinically, all these patients were stable at 2 month follow-up. The inhibited cellular growth may account for large increase in MD and decrease in FA and Cho/Cr as observed in the current study. Reducing trends in rCBVmax at the follow-up may indicate anti- angiogenetic effects of TTFields and tissue perfusion within the tumor bed after the therapy. Conclusion: Our preliminary data suggest that advanced MR imaging may be useful in evaluating treatment response to TTFields in patients with GBMs. Inclusion of more patients is warranted to validate our findings.
Acknowledgement: Support of NovoTTF-100A system (Novocure Ltd., Haifa, Israel) is gratefully acknowledged.
Citation Format: SANJEEV CHAWLA, Sumei Wang, Gaurav Verma, Aaron Skolnik, Lauren Karpf, Lisa Desiderio, Steven Brem, Katherine Peters, Harish Poptani, Suyash Mohan. Tumor treating fields in patients with glioblastomas: Evaluation of treatment response using advanced mr imaging techniques [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT068. doi:10.1158/1538-7445.AM2017-CT068</jats:p
Hybridised Mimetic Discretisation and Variational Multiscale Theory for Advection-Dominated Problems: M.Sc. Thesis
No full textStructure-preserving or mimetic discretisations are a class of advanced discretisation techniques derived by employing concepts from differential geometry. Such techniques can attain specific conservation properties at the discrete level such as conservation of mass, kinetic energy, etc when applied to conservation laws. However, like traditional techniques, they are not entirely robust in specific multiscale cases such as under-resolved simulations which are often encountered in industrial applications. This ties into the concept of Large Eddy Simulations (LES) of which an enticing approach is the Variational Multiscale (VMS) method. Both Mimetic methods and VMS approaches have been extensively studied independently, however, their combination offers the potential of achieving a favorable robust solver capable of handling complicated industrial problems. Moreover, the extension of the Hybridised variant of the Mimetic methods towards advection-dominated problems is an interesting avenue yet to be explored. Therefore, this thesis focuses on the extension of the Hybridised Mimetic method and its combination with the VMS theory. The said combination is tested on simple linear equations, namely the advection-diffusion equation in both steady and unsteady cases. Additionally, the Hybridised Mimetic method is studied in more complex test cases such as the Burgers' equation and the incompressible Euler/Navier-Stokes equations.Aerospace Engineerin
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Diverse Applications of Artificial Intelligence in Neuroradiology.
No full textRecent advances in artificial intelligence (AI) and deep learning (DL) hold promise to augment neuroimaging diagnosis for patients with brain tumors and stroke. Here, the authors review the diverse landscape of emerging neuroimaging applications of AI, including workflow optimization, lesion segmentation, and precision education. Given the many modalities used in diagnosing neurologic diseases, AI may be deployed to integrate across modalities (MR imaging, computed tomography, PET, electroencephalography, clinical and laboratory findings), facilitate crosstalk among specialists, and potentially improve diagnosis in patients with trauma, multiple sclerosis, epilepsy, and neurodegeneration. Together, there are myriad applications of AI for neuroradiology
Diagnostic value of 3D contrast-enhanced magnetic resonance angiography in Takayasu’s arteritis—a comparative study with digital subtraction angiography
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