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https://www.readbyqxmd.com/read/28328241/perfusion-ct-in-acute-stroke-effectiveness-of-automatically-generated-colour-maps
#1
Maja Ukmar, Ferruccio Degrassi, Roberta Antea Pozzi Mucelli, Francesca Neri, Fabio Pozzi Mucelli, Maria Assunta Cova
OBJECTIVE: To evaluate the accuracy of perfusion CT (pCT) in the definition of the infarcted core and the penumbra, comparing the data obtained from the evaluation of parametric maps [cerebral blood volume (CBV), cerebral blood flow (CBF) and mean transit time (MTT)] with software-generated colour maps. METHODS: A retrospective analysis was performed to identify patients with suspected acute ischaemic strokes and who had undergone unenhanced CT and pCT carried out within 4...
April 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28323516/does-normobaric-hyperoxia-cause-oxidative-stress-in-the-injured-brain-a-microdialysis-study-using-8-iso-pgf2%C3%AE-as-a-biomarker
#2
Marian Vidal-Jorge, Angela Sánchez-Guerrero, Gemma Mur-Bonet, Lidia Castro, Andreea Rădoi, Marilyn Riveiro, Natividad Fernández-Prado, Jacinto Baena, Maria A Poca, Juan Sahuquillo
Significant controversy exists regarding the potential clinical benefit of normobaric hyperoxia therapy (NBO) in patients with traumatic brain injury (TBI). This study consisted of two aims: 1) to assess whether NBO improves brain oxygenation and metabolism and 2) to determine whether this therapy may increase the risk of oxidative stress (OxS), using 8-iso-PGF2α as a biomarker. Thirty-one patients with a median admission Glasgow Coma Scale score of 4 (min: 3, max: 12) were monitored with cerebral microdialysis and brain tissue oxygen sensors and treated with FiO2 of 1...
March 21, 2017: Journal of Neurotrauma
https://www.readbyqxmd.com/read/28320175/mechanical-embolectomy-for-acute-ischemic-stroke-beyond-six-hours-from-symptom-onset-using-mri-based-perfusion-imaging
#3
Ryan A McTaggart, Shadi Yaghi, Daniel C Sacchetti, Richard A Haas, Morgan Hemendinger, Daniel Arcuri, Jeffrey M Rogg, Karen L Furie, Mahesh V Jayaraman
INTRODUCTION: There is very limited data on the use of MRI based perfusion imaging to select patients with acute ischemic stroke and large vessel occlusion (LVO) for intraarterial therapy beyond 6h from onset. Our aim is to report the outcome of patients with acute ischemic stroke and large artery occlusion who presented beyond 6h from onset, had favorable MRI imaging profile, and underwent mechanical embolectomy. METHODS: This is a single institution (Rhode Island Hospital) retrospective study between December 1st, 2015, and July 30th, 2016 that included patients with acute ischemic stroke and proximal LVO with CT ASPECTS of 6 or more and 6-24h from symptom onset who were assessed for mechanical embolectomy using MRI based perfusion imaging...
April 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28320070/dexpramipexole-improves-bioenergetics-and-outcome-in-experimental-stroke
#4
Mirko Muzzi, Elisabetta Gerace, Daniela Buonvicino, Elisabetta Coppi, Francesco Resta, Laura Formentini, Riccardo Zecchi, Laura Tigli, Daniele Guasti, Martina Ferri, Emidio Camaioni, Alessio Masi, Domenico E Pellegrini-Giampietro, Guido Mannaioni, Daniele Bani, Anna M Pugliese, Alberto Chiarugi
BACKGROUND AND PURPOSE: To investigate the effects of dexpramipexole, a drug recently tested in ALS patients able to bind F1Fo ATP synthase and increase mitochondrial ATP production, on experimental ischemic brain injury. EXPERIMENTAL APPROACH: The effects of dexpramipexole on bioenergetics, Ca(2+) fluxes, electrophysiological functions and death were evaluated in primary neural cultures and hippocampal slices exposed to oxygen-glucose deprivation (OGD). The drug's impact on infarct volumes and neurological functions was also evaluated in mice subjected to proximal or distal MCAo...
March 20, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28318954/computed-tomography-perfusion-based-decision-making-for-acute-ischemic-stroke-missing-the-mismatch
#5
J A Molad, M Findler, E Auriel
The emerging use of mechanical thrombectomy for acute ischemic stroke treatment focuses on the importance of patient selection. Computed tomography perfusion (CTP) is one of widely used techniques. However, the accuracy and reliability of this modality is in debate among vascular neurologists. We present a case of an 80-year-old man admitted because of acute ischemic stroke. CT angiography demonstrated left proximal M2 occlusion. As CTP demonstrated signs of large ischemic core with no significant penumbra, mechanical thrombectomy was not performed following tPA administration...
March 15, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28316869/forced-arterial-suction-thrombectomy-using-distal-access-catheter-in-acute-ischemic-stroke
#6
Ho-Cheol Lee, Dong-Hun Kang, Yang-Ha Hwang, Yong-Sun Kim, Yong-Won Kim
Historical innovations in mechanical thrombectomy devices and strategies for ischemic stroke have resulted in improved angiographic outcomes and better clinical outcomes. Various devices have been used, but the two most common approaches are aspiration thrombectomy and stent-retrieval thrombectomy. Aspiration thrombectomy has advanced from the traditional Penumbra system to forced arterial suction thrombectomy and a direct aspiration first-pass technique. Newer generation aspiration catheters with flexible distal tips and a larger bore have demonstrated faster and better recanalization relative to older devices...
March 2017: Neurointervention
https://www.readbyqxmd.com/read/28304203/manual-aspiration-thrombectomy-using-a-penumbra-catheter-in-patients-with-acute-migrated-mca-occlusion
#7
Sung Hyun Baik, Hyo Sung Kwak, Seung Bae Hwang, Gyung Ho Chung
Background We retrospectively assessed the efficacy and safety of manual aspiration thrombectomy (MAT) using a Penumbra catheter in patients with acute migrated middle cerebral artery (MCA) occlusion. Methods We conducted a retrospective review of patients who underwent MAT using Penumbra 4 or 5 MAX reperfusion catheters for the treatment of acute MCA occlusion between January 2012 and December 2015. A migrated thrombus was defined as distal migration greater than ≥1 cm on initial cerebral angiography compared with preprocedural angiographic findings...
April 2017: Interventional Neuroradiology
https://www.readbyqxmd.com/read/28300551/role-of-caveolin-1-vascular-endothelial-growth-factor-pathway-in-basic-fibroblast-growth-factor-induced-angiogenesis-and-neurogenesis-after-treadmill-training-following-focal-cerebral-ischemia-in-rats
#8
Qiongyi Pang, Huimei Zhang, Zhenzhen Chen, Yudan Wu, Min Yidian Bai Liu, Yun Zhao, Fengxia Tu, Chan Liu, Xiang Chen
Exercise is known to aid functional recovery following ischemia, though the mechanisms responsible for the beneficial effects of exercise on recovery from ischemic stroke are not fully understood. Basic fibroblast growth factor (bFGF) contributes to angiogenesis and promotes neurologic functional recovery after stroke. The present study aimed to investigate the possible mechanisms whereby treadmill exercise ameliorated impaired angiogenesis and neurogenesis following transient cerebral ischemia in middle cerebral artery occlusion (MCAO) rats...
March 11, 2017: Brain Research
https://www.readbyqxmd.com/read/28297340/dosimetric-properties-of-equivalent-quality-flattening-filter-free-fff-and-flattened-photon-beams-of-versa-hd-linear-accelerator
#9
Mukesh N Meshram, Srimanta Pramanik, C P Ranjith, Saravana K Gopal, Rishabh Dobhal
This study presents the basic dosimetric properties of photon beams of a Versa HD linear accelerator (linac), which is capable of delivering flattening filter-free (FFF) beams with a beam quality equivalent to the corresponding flattened beams based on comprehensive beam data measurement. The analyzed data included the PDDs, profiles, penumbra, out-of-field doses, surface doses, output factors, head and phantom scatter factors, and MLC transmissions for both FFF and flattened beams of 6 MV and 10 MV energy from an Elekta Versa HD linac...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297294/real-time-in-vivo-dosimetry-for-sbrt-prostate-treatment-using-plastic-scintillating-dosimetry-embedded-in-a-rectal-balloon-a-case-study
#10
Justin L Cantley, Chee-Wai Cheng, Fredrick B Jesseph, Tarun K Podder, Valdir C Colussi, Bryan J Traughber, Lee E Ponsky, Rodney J Ellis
A novel FDA approved in vivo dosimetry device system using plastic scintillating detectors placed in an endorectal balloon to provide real-time in vivo dosimetry for prostatic rectal interface was tested for use with stereotactic body radiotherapy (SBRT). The system was used for the first time ever to measure dose during linear accelerator based SBRT. A single patient was treated with a total dose of 36.25 Gy given in 5 fractions. Delivered dose was measured for each treatment with the detectors placed against the anterior rectal wall near the prostate rectal interface...
November 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297286/the-dose-penumbra-of-a-custom-made-shield-used-in-hemibody-skin-electron-irradiation
#11
Charlotte I Rivers, Ismail AlDahlawi, Iris Z Wang, Anurag K Singh, Matthew B Podgorsak
We report our technique for hemibody skin electron irradiation with a custom-made plywood shield. The technique is similar to our clinical total skin electron irradiation (TSEI), performed with a six-pair dual field (Stanford technique) at an extended source-to-skin distance (SSD) of 377 cm, with the addition of a plywood shield placed at 50 cm from the patient. The shield is made of three layers of standard 5/8" thick plywood (total thickness of 4.75 cm) that are clamped securely on an adjustable-height stand...
November 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28296303/development-of-a-monte-carlo-model-for-treatment-planning-dose-verification-of-the-leksell-gamma-knife-perfexion-radiosurgery-system
#12
Jiankui Yuan, Simon S Lo, Yiran Zheng, Jason W Sohn, Andrew E Sloan, Rodney Ellis, Mitchell Machtay, Barry Wessels
Detailed Monte Carlo (MC) modeling of the Leksell Gamma Knife (GK) Perfexion (PFX) collimator system is the only accurate ab initio approach appearing in the literature. As a different approach, in this work, we present a MC model based on film measurement. By adjusting the model parameters and fine-tuning the derived fluence map for each individual source to match the manufacturer's ring output factors, we created a reasonable virtual source model for MC simulations to verify treatment planning dose for the GK PFX radiosurgery system...
July 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28294350/high-resolution-fiber-optic-dosimeters-for-microbeam-radiation-therapy
#13
James Archer, Enbang Li, Marco Petasecca, Michael Lerch, Anatoly Rosenfeld, Martin Carolan
PURPOSE: A high resolution, water equivalent, optical and passive x-ray dosimeter has been constructed using plastic scintillator and optical fiber. This dosimeter has a peak edge-on spatial resolution of 100 μm in one dimension, with a 10 μm resolution dosimeter under investigation. The dosimeter design has a potential application in synchrotron x-ray microbeam radiation therapy where a high resolution is vital for accurate dose measurements and quality assurance. METHODS: BC-400 plastic scintillator, of thickness 100 μm, was optically coupled to an optical fiber with core diameter 1 mm...
March 14, 2017: Medical Physics
https://www.readbyqxmd.com/read/28291930/development-and-performance-evaluation-of-a-high-speed-multileaf-collimator
#14
Xiang Zhang, Peiqing Ye, Hui Zhang
Multileaf collimator (MLC) tracking represents a promising technique for motion management in radiotherapy. However, the conflict between limited leaf speed/acceleration and the demand for tracking fast target motion is now a prominent issue. Conventional MLCs typically have a maximum leaf speed of 3-4 cm/s and a maximum leaf acceleration of 50-70 cm/s(2), which are inadequate to track fast target motion. To cope with this problem, we have recently developed a high-speed multileaf collimator (HS-MLC) prototype, which employs linear motors instead of rotary motors to drive leaves...
January 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28286764/phase-i-and-phase-ii-therapies-for-acute-ischemic-stroke-an-update-on-currently-studied-drugs-in-clinical-research
#15
REVIEW
Cesar Reis, Onat Akyol, Wing Mann Ho, Camila Araujo, Lei Huang, Richard Applegate Ii, John H Zhang
Acute ischemic stroke is a devastating cause of death and disability, consequences of which depend on the time from ischemia onset to treatment, the affected brain region, and its size. The main targets of ischemic stroke therapy aim to restore tissue perfusion in the ischemic penumbra in order to decrease the total infarct area by maintaining blood flow. Advances in research of pathological process and pathways during acute ischemia have resulted in improvement of new treatment strategies apart from restoring perfusion...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28283192/supine-craniospinal-irradiation-in-pediatric-patients-by-proton-pencil-beam-scanning
#16
Paolo Farace, Nicola Bizzocchi, Roberto Righetto, Francesco Fellin, Francesco Fracchiolla, Stefano Lorentini, Lamberto Widesott, Carlo Algranati, Barbara Rombi, Sabina Vennarini, Maurizio Amichetti, Marco Schwarz
BACKGROUND AND PURPOSE: Proton therapy is the emerging treatment modality for craniospinal irradiation (CSI) in pediatric patients. Herein, special methods adopted for CSI at proton Therapy Center of Trento by pencil beam scanning (PBS) are comprehensively described. MATERIALS AND METHODS: Twelve pediatric patients were treated by proton PBS using two/three isocenters. Special methods refer to: (i) patient positioning in supine position on immobilization devices crossed by the beams; (ii) planning field-junctions via the ancillary-beam technique; (iii) achieving lens-sparing by three-beams whole-brain-irradiation; (iv) applying a movable-snout and beam-splitting technique to reduce the lateral penumbra...
March 7, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28278060/sodomy-s-penumbra
#17
Joseph J Fischel
This article advocates a sodomitical approach to sodomy. Its approach is framed alongside and against three historical glosses on sodomy law: first, that sodomy law instantiates homophobia; second, that sodomy law targets sexual violence against boys; third, that sodomy law reaches assaultive sex against women that did not register as assaultive enough to qualify as "rape" by sexist juries. The first story of sodomy law is mostly wrong. The other two glosses pivot on protection: protection of boys or protection of girls and women...
February 10, 2017: Journal of Homosexuality
https://www.readbyqxmd.com/read/28277465/understanding-the-neurophysiology-and-quantification-of-brain-perfusion
#18
Elizabeth Tong, Leo Sugrue, Max Wintermark
Newer neuroimaging technology has moved beyond pure anatomical imaging and ventured into functional and physiological imaging. Perfusion magnetic resonance imaging (PWI), which depicts hemodynamic conditions of the brain at the microvascular level, has an increasingly important role in clinical central nervous system applications. This review provides an overview of the established role of PWI in brain tumor and cerebrovascular imaging, as well as some emerging applications in neuroimaging. PWI allows better characterization of brain tumors, grading, and monitoring...
March 8, 2017: Topics in Magnetic Resonance Imaging: TMRI
https://www.readbyqxmd.com/read/28277288/ct-imaging-selection-in-acute-stroke
#19
Laurie Bouchez, Roman Sztajzel, Maria Isabel Vargas, Paolo Machi, Zsolt Kulcsar, Pierre-Alexandre Poletti, Vitor Mendes Pereira, Karl-Olof Lövblad
Acute stroke has become an increasingly treatable cause of acute neurological deficits. Indeed, over the last two decades, the introduction of first thrombolysis, and now thrombectomy has improved patient outcomes and extended the therapeutic window. Computed tomography has been established as the most simple and readily available technique for the diagnosis and management of patients with acute stroke. Indeed, CT allows easy confirmation or exclusion of acute hemorrhage on the one hand, and on the other hand the early signs are quite reliable in the detection of ischemia...
October 26, 2016: European Journal of Radiology
https://www.readbyqxmd.com/read/28275555/endovascular-stroke-treatment-now-and-then-procedural-and-clinical-effectiveness-and-safety-of-different-mechanical-thrombectomy-techniques-over-time
#20
Niels von Gadow, Omid Nikoubashman, Jessica Freiherr, Frank Block, Arno Reich, Gunther Fesl, Martin Wiesmann
BACKGROUND: The most essential development in endovascular stroke treatment (EST) was the shift from intra-arterial thrombolysis to endovascular thrombectomy with dedicated thrombectomy devices, most notably the introduction of stent-retrievers. We evaluated procedural and clinical effectiveness and safety of different EST techniques over time. METHODS: We retrospectively analyzed EST cases that were treated by the same interventionalist before (n=36) and after (n=50) stent-retrievers were established as the treatment device of first choice...
February 2017: Quantitative Imaging in Medicine and Surgery
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