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Transcranial doppler ultrasound

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https://www.readbyqxmd.com/read/28322988/measurement-reliability-of-atypical-language-lateralisation-assessed-using-functional-transcranial-doppler-ultrasound
#1
Jessica C Hodgson, John M Hudson
It is well established that some individuals present with atypical, non-left hemisphere, cerebral lateralisation for language processing. However previous studies exploring the reliability of functional blood flow responses to detect lateralised activation during speech have focused only on individuals with typical left sided dominance. Here we report test-retest and between-task reliability measures obtained with functional transcranial Doppler ultrasound in 47 participants, including 9 with atypical language presentation...
March 16, 2017: Biological Psychology
https://www.readbyqxmd.com/read/28287758/cerebral-hemodynamics-during-scene-viewing-hemispheric-lateralization-predicts-temporal-gaze-behavior-associated-with-distinct-modes-of-visual-processing
#2
Mark Mills, Mohammed Alwatban, Benjamin Hage, Erin Barney, Edward J Truemper, Gregory R Bashford, Michael D Dodd
Systematic patterns of eye movements during scene perception suggest a functional distinction between 2 viewing modes: an ambient mode (characterized by short fixations and large saccades) thought to reflect dorsal activity involved with spatial analysis, and a focal mode (characterized by long fixations and small saccades) thought to reflect ventral activity involved with object analysis. Little neuroscientific evidence exists supporting this claim. Here, functional transcranial Doppler ultrasound (fTCD) was used to investigate whether these modes show hemispheric specialization...
March 13, 2017: Journal of Experimental Psychology. Human Perception and Performance
https://www.readbyqxmd.com/read/28287282/cerebrovascular-reactivity-in-acute-hyperoxia-in-patients-with-acute-ischaemic-stroke
#3
Ivana Hegeduš, Jakov Milić, Anita Ćosić, Krunoslav Buljan, Ines Drenjančević
AIM: This study aimed to assess the effect of acute hyperoxia on cerebral and systemic heamodynamics and the plasma concentration of prostacyclin and thromboxane in patients with stroke. METHODS: Mean blood flow velocity (MBFV), pulsatility and resistance indices of the middle cerebral artery using transcranial Doppler ultrasound before and during acute hyperoxia (4 L of 100%O2/15' over facial mask) in 92 participants - 25 patients with acute ischaemic stroke (AIS) that occurred within 72 hours and diabetes mellitus (SPDM), 26 AIS patients without DM (SP) and in 41 healthy controls (HS), were measured...
March 13, 2017: Brain Injury: [BI]
https://www.readbyqxmd.com/read/28269120/automated-embolic-signal-detection-using-adaptive-gain-control-and-classification-using-anfis
#4
Praotasna Sombune, Phongphan Phienphanich, Sombat Muengtaweepongsa, Anuchit Ruamthanthong, Charturong Tantibundhit
This work proposes an automated system for real-time high-accuracy detection of cerebral embolic signals (ES) to couple with transcranial Doppler ultrasound (TCD) devices in diagnosing a risk of stroke. The algorithm employs Adaptive Gain Control (AGC) approach to capture suspected ESs in real-time. Then, Adaptive Wavelet Packet Transform (AWPT) and Fast Fourier Transform (FFT) are used to extract from them features most efficiently representing ES, which determined by Sequential Feature Selection technique...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28269071/pre-clinical-investigations-of-multi-path-propagation-in-transcranial-doppler-ultrasound-flow-phantom
#5
Alexander J Weir, Cheng-Xiang Wang, Stuart Parks
There are various practical situations in medical applications when pre-clinical investigations must be performed using a simulation environment or test bench prior to human studies. One example is the analysis of propagation channels in Transcanial Doppler (TCD) ultrasound (US), a signal processing challenge requiring the analysis of data from US waves scattered in three dimensions (3D). When examining the effects of scatterers in such channels, it is common to use a data acquisition test bench and a Doppler flow phantom...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28268789/perspective-imaging-of-flow-in-arterial-model-obtained-with-continuous-wave-doppler-focusing-technique
#6
Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo
Flowing emboli in the circulatory system cause fatal diseases such as stroke or pulmonary embolism. Conventional transcranial Doppler ultrasound for detection of emboli requires precise positioning by experienced examiner. In the present study, an easier emboli detection device by visualizing perspective view of blood vessel is proposed. The perspective image was obtained with continuous wave (CW) Doppler ultrasound from 2-dimensional array probe. CW Doppler signal from each element was focused by novel beam forming algorithm to obtain en face images at arbitrary depth to form perspective image...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28261153/non-invasive-respiratory-impedance-enhances-cerebral-perfusion-in-healthy-adults
#7
Christopher G Favilla, Ashwin B Parthasarathy, John A Detre, Arjun G Yodh, Michael T Mullen, Scott E Kasner, Kimberly Gannon, Steven R Messé
Optimization of cerebral blood flow (CBF) is the cornerstone of clinical management in a number of neurologic diseases, most notably ischemic stroke. Intrathoracic pressure influences cardiac output and has the potential to impact CBF. Here, we aim to quantify cerebral hemodynamic changes in response to increased respiratory impedance (RI) using a non-invasive respiratory device. We measured cerebral perfusion under varying levels of RI (6 cm H2O, 9 cm H2O, and 12 cm H2O) in 20 healthy volunteers. Simultaneous measurements of microvascular CBF and middle cerebral artery mean flow velocity (MFV), respectively, were performed with optical diffuse correlation spectroscopy and transcranial Doppler ultrasound...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28243101/efficacy-and-safety-of-ginkgo-biloba-standardized-extract-in-the-treatment-of-vascular-cognitive-impairment-a-randomized-double-blind-placebo-controlled-clinical-trial
#8
Vida Demarin, Vanja Bašić Kes, Zlatko Trkanjec, Mislav Budišić, Marija Bošnjak Pašić, Petra Črnac, Hrvoje Budinčević
OBJECTIVES: The aim of this randomized, double-blind, placebo-controlled trial was to determine the efficacy and safety of Ginkgo biloba extract in patients diagnosed with vascular cognitive impairment (VCI). METHODS: A total of 90 patients (aged 67.1±8.0 years; 59 women) were randomly allocated (1:1:1) to receive G. biloba 120 mg, G. biloba 60 mg, or placebo during a 6-month period. Assessment was made for efficacy indicators, including neuropsychological tests scores (Sandoz Clinical Assessment Geriatric Scale, Folstein Mini-Mental State Examination, Mattis Dementia Rating Scale, and Clinical Global Impression) and transcranial Doppler ultrasound findings...
2017: Neuropsychiatric Disease and Treatment
https://www.readbyqxmd.com/read/28241122/numerical-investigation-of-vasospasm-detection-by-extracranial-blood-velocity-ratios
#9
Jaiyoung Ryu, Nerissa Ko, Xiao Hu, Shawn C Shadden
BACKGROUND: Early diagnosis of vasospasm following subarachnoid hemorrhage can prevent cerebral ischemia and improve neurological outcomes. This study numerically evaluates the relevance of extracranial blood velocity indices to detect vasospasm. METHODS: A numerical model of cerebral blood flow was used to evaluate the hemodynamics associated with anterior and posterior vasospasm under normal and impaired cerebral autoregulation conditions. Extracranial blood velocities at the carotid and vertebral arteries and their ratios between ipsilateral and contralateral, anterior and posterior, and downstream and upstream arteries were monitored during vasospasm progression...
February 28, 2017: Cerebrovascular Diseases
https://www.readbyqxmd.com/read/28240783/applications-of-transcranial-color-coded-sonography-in-the-emergency-department
#10
REVIEW
Pablo Blanco, Michael Blaivas
Transcranial color-coded Doppler sonography is a noninvasive bedside ultrasound application that combines both imaging of parenchymal structures and Doppler assessment of intracranial vessels. It may aid in rapid diagnoses and treatment decision making of patients with intracranial emergencies in point-of-care settings. This pictorial essay illustrates the technical aspects and emergency department applications of transcranial color-coded Doppler sonography, and provides some rationale for implementation of this technique into the emergency department practice...
February 27, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28229841/-neuroimaging-and-blood-biomarkers-in-functional-prognosis-after-stroke
#11
REVIEW
João Paulo Branco, Joana Santos Costa, João Sargento-Freitas, Sandra Oliveira, Bruno Mendes, Jorge Laíns, João Pinheiro
INTRODUCTION: Stroke remains one of the leading causes of morbidity and mortality around the world and it is associated with an important long-term functional disability. Some neuroimaging resources and certain peripheral blood or cerebrospinal fluid proteins can give important information about etiology, therapeutic approach, follow-up and functional prognosis in acute ischemic stroke patients. However, among the scientific community, there is currently more interest in the stroke vital prognosis over the functional prognosis...
November 2016: Acta Médica Portuguesa
https://www.readbyqxmd.com/read/28227349/automated-embolic-signal-detection-using-adaptive-gain-control-and-classification-using-anfis
#12
Praotasna Sombune, Phongphan Phienphanich, Sombat Muengtaweepongsa, Anuchit Ruamthanthong, Charturong Tantibundhit, Praotasna Sombune, Phongphan Phienphanich, Sombat Muengtaweepongsa, Anuchit Ruamthanthong, Charturong Tantibundhit, Praotasna Sombune, Charturong Tantibundhit, Phongphan Phienphanich, Sombat Muengtaweepongsa, Anuchit Ruamthanthong
This work proposes an automated system for real-time high-accuracy detection of cerebral embolic signals (ES) to couple with transcranial Doppler ultrasound (TCD) devices in diagnosing a risk of stroke. The algorithm employs Adaptive Gain Control (AGC) approach to capture suspected ESs in real-time. Then, Adaptive Wavelet Packet Transform (AWPT) and Fast Fourier Transform (FFT) are used to extract from them features most efficiently representing ES, which determined by Sequential Feature Selection technique...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227290/pre-clinical-investigations-of-multi-path-propagation-in-transcranial-doppler-ultrasound-flow-phantom
#13
Alexander J Weir, Cheng-Xiang Wang, Stuart Parks, Alexander J Weir, Cheng-Xiang Wang, Stuart Parks, Alexander J Weir, Stuart Parks, Cheng-Xiang Wang
There are various practical situations in medical applications when pre-clinical investigations must be performed using a simulation environment or test bench prior to human studies. One example is the analysis of propagation channels in Transcanial Doppler (TCD) ultrasound (US), a signal processing challenge requiring the analysis of data from US waves scattered in three dimensions (3D). When examining the effects of scatterers in such channels, it is common to use a data acquisition test bench and a Doppler flow phantom...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226983/perspective-imaging-of-flow-in-arterial-model-obtained-with-continuous-wave-doppler-focusing-technique
#14
Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo, Ryo Nagaoka, Katsuhiro Sasaki, Seiichi Zama, Masaaki Nagone, Hiroshi Nagai, Yasuhito Takeuchi, Yoshifumi Saijo, Yoshifumi Saijo, Hiroshi Nagai, Katsuhiro Sasaki, Masaaki Nagone, Seiichi Zama, Ryo Nagaoka, Yasuhito Takeuchi
Flowing emboli in the circulatory system cause fatal diseases such as stroke or pulmonary embolism. Conventional transcranial Doppler ultrasound for detection of emboli requires precise positioning by experienced examiner. In the present study, an easier emboli detection device by visualizing perspective view of blood vessel is proposed. The perspective image was obtained with continuous wave (CW) Doppler ultrasound from 2-dimensional array probe. CW Doppler signal from each element was focused by novel beam forming algorithm to obtain en face images at arbitrary depth to form perspective image...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28218603/frequency-and-clinical-course-of-cerebral-embolism-in-patients-undergoing-transcatheter-left-atrial-appendage-closure
#15
Nicolas Majunke, Franziska Eplinius, Matthias Gutberlet, Sven Moebius-Winkler, Ingo Daehnert, Matthias Grothoff, Stephan Schürer, Norman Mangner, Philipp Lurz, Sandra Erbs, Katharina Kirsch, Gerhard Schuler, Marcus Sandri
AIMS: To assess silent and clinically apparent cerebral embolic events in patients undergoing transcatheter left atrial appendage closure. METHODS AND RESULTS: In this prospective single-center study 28 patients underwent percutaneous closure of the left atrial appendage. In all patients a diffusion-weighted magnetic resonance imaging (DWI-MRI) study was performed before, the day after the procedure and during routine follow-up after 45 days. All patients underwent neurological assessment at the time of DWI-MRI...
February 21, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28215461/the-use-of-ultrasound-for-postoperative-monitoring-of-cerebral-bypass-grafts-a-technical-report
#16
Ryan P Morton, Isaac Joshua Abecassis, Anne E Moore, Cory M Kelly, Michael R Levitt, Louis J Kim, Laligam N Sekhar
Duplex ultrasound and transcranial Doppler are valuable tools for post-operative monitoring of extracranial-intracranial cerebral bypass grafts. Here we describe our technique for the evaluation of both high-flow and low-flow cerebral bypass grafts over a nine year period. 186 bypass grafts were studied daily during the inpatient period between Jan 2005 and Dec 2014 after surgery for various cerebrovascular pathologies. There was a technical success rate of 97%. Duplex ultrasonographic flow measurements had excellent interobserver reliability with an intraclass correlation coefficient (ICC) of 0...
February 16, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/28215270/decreased-cerebral-vasomotor-reactivity-in-patients-with-obstructive-sleep-apnea-syndrome
#17
Oguzhan Oz, Serdar Tasdemir, Hakan Akgun, Murat Erdem, Adem Balikci, Ahmet Cetiz, Mehmet Yucel, Umit Hidir Ulas, Seref Demirkaya, Yasar Kutukcu, Fuat Özgen
OBJECTIVE: In obstructive sleep apnea syndrome (OSAS), any of the activated neural, vascular, hemodynamic, metabolic, inflammatory, and thrombotic mechanisms may be related to increased cerebrovascular disease and risk of death; however, the possible pathophysiological process between obstructive sleep apnea syndrome and stroke has not been clearly explained. We hypothesize that alterations in vasomotor reactivity in patients may be responsible for their altered cerebral blood flow, and may contribute to the increased risk of ischemic stroke...
February 2017: Sleep Medicine
https://www.readbyqxmd.com/read/28204998/discrimination-between-emboli-and-artifacts-for-outpatient-transcranial-doppler-ultrasound-data
#18
Blaise Kévin Guépié, Bruno Sciolla, Fabien Millioz, Marilys Almar, Philippe Delachartre
This paper addresses the detection of emboli in transcranial Doppler ultrasound data acquired from an original portable device. The challenge is the removal of several artifacts (motion and voice) intrinsically related to long-duration (up to 1 h 40 mn per patient) outpatient signals monitoring from this device, as well as high intensities due to the stochastic nature of blood flow. This paper proposes an adapted removal procedure. This firstly consists of reducing the background noise and detecting the blood flow in the time-frequency domain using a likelihood method for contour detection...
February 15, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28199523/detection-and-differentiation-of-cerebral-microemboli-in-patients-undergoing-major-orthopaedic-surgery-using-transcranial-doppler-ultrasound
#19
C Kietaibl, A Engel, I Horvat Menih, M Huepfl, G Erdoes, B Kubista, R Ullrich, R Windhager, K Markstaller, K U Klein
No abstract text is available yet for this article.
February 10, 2017: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/28188214/transcranial-doppler-determined-change-in-posterior-cerebral-artery-blood-flow-velocity-does-not-reflect-vertebral-artery-blood-flow-during-exercise
#20
Takuro Washio, Hiroyuki Sasaki, Shigehiko Ogoh
We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow, in healthy subjects, during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior blood flow, were continuously measured during an exercise trial, using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level...
February 10, 2017: American Journal of Physiology. Heart and Circulatory Physiology
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