keyword
MENU ▼
Read by QxMD icon Read
search

Flow-volume

keyword
https://www.readbyqxmd.com/read/28937857/evaluation-of-retinal-blood-flow-before-and-after-panretinal-photocoagulation-using-pattern-scan-laser-for-diabetic-retinopathy
#1
Yoshihisa Yamada, Kiyoshi Suzuma, Naoko Onizuka, Masafumi Uematsu, Yasser Helmy Mohamed, Takashi Kitaoka
PURPOSE: Laser speckle flowgraphy (LSFG) can measure blood flow in the ocular fundus. We analyzed the relationship between retinal blood flow and panretinal photocoagulation (PRP) in diabetic retinopathy. METHODS: This retrospective observational study examined the eyes of 35 patients with proliferative diabetic retinopathy (PDR) or non-PDR (NPDR). PRP was performed using a pattern scan laser. Using LSFG, blood flow was evaluated as the mean blur rate (MBR) or the relative flow volume (RFV)...
September 22, 2017: Current Eye Research
https://www.readbyqxmd.com/read/28898284/optic-nerve-head-and-retinal-blood-flow-regulation-during-isometric-exercise-as-assessed-with-laser-speckle-flowgraphy
#2
Katarzyna J Witkowska, Ahmed M Bata, Giacomo Calzetti, Nikolaus Luft, Klemens Fondi, Piotr A Wozniak, Doreen Schmidl, Matthias Bolz, Alina Popa-Cherecheanu, René M Werkmeister, Gerhard Garhöfer, Leopold Schmetterer
The aim of the present study was to investigate regulation of blood flow (BF) in the optic nerve head (ONH) and a peripapillary region (PPR) during an isometric exercise-induced increase in ocular perfusion pressure (OPP) using laser speckle flowgraphy (LSFG) in healthy subjects. For this purpose, a total of 27 subjects was included in this study. Mean blur rate in tissue (MT) was measured in the ONH and in a PPR as well as relative flow volume (RFV) in retinal arteries (ART) and veins (VEIN) using LSFG. All participants performed isometric exercise for 6 minutes during which MT and mean arterial pressure were measured every minute...
2017: PloS One
https://www.readbyqxmd.com/read/28863175/the-modeling-of-attraction-characteristics-regarding-passenger-flow-in-urban-rail-transit-network-based-on-field-theory
#3
Man Li, Yanhui Wang, Limin Jia
Aimed at the complicated problems of attraction characteristics regarding passenger flow in urban rail transit network, the concept of the gravity field of passenger flow is proposed in this paper. We establish the computation methods of field strength and potential energy to reveal the potential attraction relationship among stations from the perspective of the collection and distribution of passenger flow and the topology of network. As for the computation methods of field strength, an optimum path concept is proposed to define betweenness centrality parameter...
2017: PloS One
https://www.readbyqxmd.com/read/28856715/feasibility-of-quantitative-regional-ventilation-and-perfusion-mapping-with-phase-resolved-functional-lung-preful-mri-in-healthy-volunteers-and-copd-cteph-and-cf-patients
#4
Andreas Voskrebenzev, Marcel Gutberlet, Filip Klimeš, Till F Kaireit, Christian Schönfeld, Alexander Rotärmel, Frank Wacker, Jens Vogel-Claussen
PURPOSE: In this feasibility study, a phase-resolved functional lung imaging postprocessing method for extraction of dynamic perfusion and ventilation parameters using a conventional 1H lung MRI Fourier decomposition acquisition is introduced. METHODS: Time series of coronal gradient-echo MR images with a temporal resolution of 288 to 324 ms of two healthy volunteers, one patient with chronic thromboembolic hypertension, one patient with cystic fibrosis, and one patient with chronic obstructive pulmonary disease were acquired at 1...
August 30, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28835050/-implantation-of-the-irradiation-stent-system-intoportal-vein-studies-on-normal-beagles
#5
T K Li, G Y Zhu, W M Li, J Lu, C Wang, T F Pan, Y Wang, J H Guo
Objective: To assess the feasibility and safety of the irradiation stent system in portal vein on normal beagles. Methods: A portal vein irradiation stent system was composed of an Iodine-125 seeds-carrier and a conventional stent.Twenty beagle dogs were randomly assigned to receive treatment with a conventional stent (5 beagle dogs) or an irradiation stent system (15 beagle dogs in three groups received 11.1, 22.2, 33.3 MBq radioactivity, n=5 in each dose group). Follow-up methods included blood biochemical test, color Doppler sonographyand CT scan at 0, 15, 30, 60, and 120 days after implantation of irradiation stent system...
August 15, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/28803685/quantification-of-pulmonary-regurgitation-by-vector-flow-mapping-in-congenital-heart-patients-after-repair-of-right-ventricular-outflow-obstruction-a-preliminary-study
#6
Ashley Hoi-Man To, Vivian Wing-Yi Li, Ming-Yen Ng, Yiu-Fai Cheung
BACKGROUND: Vector flow mapping (VFM) enables direct visualization of flow pattern and estimation of flow volume. The aim of this study was to determine its accuracy in the quantification of pulmonary regurgitation (PR) in congenital heart patients after repair of right ventricular (RV) outflow obstruction. METHODS: This study comprised two parts: (1) validation of VFM in the quantification of PR in patients with repaired tetralogy of Fallot by cardiac magnetic resonance and (2) clinical application of VFM to determine PR in patients after biventricular repair of pulmonary atresia and stenosis with intact ventricular septum...
August 10, 2017: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/28777399/postoperative-day-1-access-blood-flow-and-resistive-index-can-predict-patency-in-distal-forearm-arteriovenous-fistula
#7
Sadanori Shintaku, Hideki Kawanishi, Misaki Moriishi, Rika Ago, Masataka Banshodani, Shinji Hashimoto, Shinichiro Tsuchiya
INTRODUCTION: Early access failure is an important complication of autogenous arteriovenous fistulas (AVFs). We prospectively monitored patients who underwent AVF creation using ultrasonography. METHODS: Color flow imaging was used to assess access blood flow in patients undergoing creation of a new AVF in the distal forearm preoperatively and at 1 day and 1 week postoperatively. We measured the flow volume (FV) and resistive index (RI) of the brachial artery, and the internal diameter of the brachial artery and outflow vein...
August 2, 2017: Journal of Vascular Access
https://www.readbyqxmd.com/read/28760582/improved-outcomes-with-proximal-radial-cephalic-arteriovenous-fistulas-compared-with-brachial-cephalic-arteriovenous-fistulas
#8
Dean J Arnaoutakis, Elise P Deroo, Patrick McGlynn, Maxwell D Coll, Michael Belkin, Dirk M Hentschel, C Keith Ozaki
BACKGROUND: Brachial-cephalic arteriovenous fistulas (BCFs) are associated with high-flow volumes, leading to potential risks such as arm swelling, steal syndrome, pseudoaneurysm (due to a pressurized access), and cephalic arch stenosis. We hypothesized that a proximal radial-cephalic fistula (prRCF) configuration mitigates these risks because a lower flow state is created. Furthermore, we also hypothesized that despite these lower flows, patencies (primary, primary assisted, secondary) are sustained...
July 28, 2017: Journal of Vascular Surgery
https://www.readbyqxmd.com/read/28754075/oval-housing-for-the-st-jude-medical-bileaflet-mechanical-heart-valve
#9
Hadi Mohammadi, Guy Fradet
The St. Jude Medical bileaflet mechanical heart valve was approved by the Food and Drug Administration in late 1970s. The basic idea for the design of the valve is simply two semicircular flat plates pivoting on hinges. The overall performance of St. Jude Medical valves such as blood flow being central, the leaflets opening completely, and the pressure drop across the valve being trivial is satisfactory. St. Jude Medical valves provide an improved hemodynamics compared to the other mechanical heart valve models; however, their non-physiological hemodynamics which may lead to red blood cells lysis and thrombogenicity still remains a major issue...
July 1, 2017: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
https://www.readbyqxmd.com/read/28740164/raised-volume-forced-expiratory-flow-volume-curve-in-healthy-taiwanese-infants
#10
Shen-Hao Lai, Sui-Ling Liao, Tsung-Chieh Yao, Ming-Han Tsai, Man-Chin Hua, Chih-Yung Chiu, Kuo-Wei Yeh, Jing-Long Huang
The raised-volume rapid thoracoabdominal compression (RVRTC) manoeuvre has been applied to obtain full forced expiratory flow-volume curves in infants. No reference data are available for Asian populations. This study was conducted to establish predictive reference equations for Taiwanese infants. Full-term infants without any chronic disease or major anomaly were enrolled from this cohort study. Full forced expiratory flow-volume curves were acquired using RVRTC manoeuvres through Jaeger's system. Tidal breath analysis, passive respiratory mechanics, and tidal forced expiratory flow-volume curves were performed and collected at the same measurement...
July 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28731594/duplex-doppler-sonographic-assessment-of-the-superior-mesenteric-artery-in-patients-with-mesenteric-panniculitis
#11
Berat Acu, Mehmet Emrah Güven, Mehmet Ali Kaptan, Çiğdem Öztunalı, Erkan Gökçe, Murat Beyhan, Taylan Kara
OBJECTIVES: We aimed to determine how the hemodynamic parameters of the superior mesenteric artery are affected in mesenteric panniculitis. METHODS: Twenty-one patients with a diagnosis of mesenteric panniculitis on computed tomography were evaluated with duplex Doppler sonography. The control group consisted 20 asymptomatic volunteers. The peak systolic velocity, end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), blood flow volume, and body mass index were measured in the group of patients with mesenteric panniculitis, and the findings were compared with those of the control group...
July 21, 2017: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
https://www.readbyqxmd.com/read/28717121/impact-of-doppler-ultrasound-on-diagnosis-and-therapy-control-of-lienalis-steal-syndrome-after-liver-transplantation
#12
Eva M Teegen, Timm Denecke, Rosa B Schmuck, Robert Öllinger, Dominik Geisel, Johann Pratschke, Sascha S Chopra
BACKGROUND Lienalis steal syndrome is a rare complication after orthotopic liver transplantation leading to severe complications. Routine duplex sonography allows early and safe detection of lienalis steal syndrome and secondarily helps to monitor the outcome by evaluating the hemodynamics. MATERIAL AND METHODS This analysis included eight patients who after orthotopic liver transplantation needed splenic artery embolization due to lienalis steal syndrome. Lienalis steal syndrome was assumed in case of elevated transaminases, bilirubinemia or persistent ascites, and the absence of further pathologies...
July 18, 2017: Annals of Transplantation: Quarterly of the Polish Transplantation Society
https://www.readbyqxmd.com/read/28708210/particle-image-velocimetry-tests-on-pediatric-45-cc-and-30-cc-ventricle-assist-devices-effects-of-heart-rate-on-vad-operation
#13
Dariusz Witkowski, Damian Obidowski, Piotr Reorowicz, Daniel Jodko, Krzysztof Jozwik
BACKGROUND: This study investigated flow analysis inside pediatric ventricle assist devices (VADs) designed and manufactured at the Foundation for Cardiac Surgery Development (FRK), Zabrze, Poland. The main goal of the experiment was to define the minimal heart rate admissible in clinical practice. METHODS: The flow was directed by mechanical, single-disc valves developed at the Lodz University of Technology, Institute of Turbomachinery in Lodz, Poland. VAD operation conditions under different heart rates were analyzed...
July 8, 2017: International Journal of Artificial Organs
https://www.readbyqxmd.com/read/28704516/ultrasound-diagnosis-of-transverse-sinus-hypoplasia-using-flow-profiles-of-the-internal-jugular-vein
#14
A-Ching Chao, Ke Han, Feng-Chi Chang, Hung-Yi Hsu, Chih-Ping Chung, Wen-Yung Sheng, Lung Chan, Jiang Wu, Han-Hwa Hu
Accurate diagnosis of subtypes of transverse sinus (TS) hypoplasia requires more expensive methods like magnetic resonance (MR) imaging. We hypothesized ultrasound findings of the internal jugular vein (IJV) can be surrogate indicators for diagnosis of TS hypoplasia. MR images were reviewed in 131 subjects to evaluate TS diameter and the location and degree of venous flow stenosis and obstruction. Ultrasound parameters including the cross-sectional lumen area (CSA), time-average-mean velocity (TAMV), and flow volume (FV) at each IJV segment were also evaluated...
2017: PloS One
https://www.readbyqxmd.com/read/28678314/lung-characteristics-in-elderly-males-and-females-patients-with-copd-differences-and-optimal-use-of-dry-powder-inhalers-dpis
#15
C Terzano, F Oriolo
OBJECTIVE: We have measured peak inspiratory flow (PIF), inspiratory capacity (IC), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) and other functional parameters in COPD patients to investigate which PIF's patients generate with maximal effort, through three different resistances, representing Diskus, Nexthaler and Turbuhaler. PATIENTS AND METHODS: Forty patients with COPD were enrolled in this study. All patients were examined: pulmonary function tests, including flow/volume spirometry and N2-wash out, were conducted...
June 2017: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/28668430/pixel-wise-derivation-of-pulmonary-regurgitation-index-could-influence-clinical-decision-a-phase-contrast-mr-imaging-study-on-patients-with-repaired-tetralogy-of-fallot
#16
Pei-Hsin Wu, Hsiao-Wen Chung, Ming-Ting Wu, Cheng-Wen Ko
PURPOSE: Regurgitant fraction (RF) measured from 2D phase-contrast MRI has been used as a standard to quantitate the degree of pulmonary regurgitation and serves as a determinant indicator of prognosis for tetralogy of Fallot after surgical repair. This study demonstrated the potential underestimate of RF using the conventional definition and its impact on clinical decision when backward flow occurred during systolic periods. METHODS: Quantitative flow parameters, including forward flow volume (FFV), backward flow volume (BFV), and RF were estimated by two approaches: One derived from conventional ROI-averaged curve (bulk quantity) and the other in a pixel-wise manner to spatially reflect inhomogeneous flow profile (pixel-wise quantity)...
August 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28656716/the-effects-of-chronic-smoking-on-total-cerebral-blood-volume-measured-by-carotid-and-vertebral-artery-doppler-ultrasonography
#17
Melike E Kalfaoglu, Mustafa Hızal, Aysu Kiyan, Kamil Gurel
PURPOSE: To evaluate the effects of chronic cigarette smoking on total cerebral blood flow in healthy adults by Doppler ultrasonography (US). METHODS: We evaluated 50 smoker (median age 29) and 50 nonsmoker (median age 28) healthy, 20- to 40-year-old subjects without any cardiovascular and cerebrovascular disease. Peak systolic maximal blood flow velocity (PSV), end-diastolic maximal blood flow velocity (EDV), time-averaged mean blood flow velocity (TAMV), resistance index (RI), and pulsatility index (PI) were measured in the left and right carotid and vertebral arteries, and total cerebral blood flow volume was calculated...
June 27, 2017: Journal of Clinical Ultrasound: JCU
https://www.readbyqxmd.com/read/28640394/in-scan-and-scan-rescan-assessment-of-lv-in-and-outflow-volumes-by-4d-flow-mri-versus-2d-planimetry
#18
Vivian P Kamphuis, Roel L F van der Palen, Patrick J H de Koning, Mohammed S M Elbaz, Rob J van der Geest, Albert de Roos, Arno A W Roest, Jos J M Westenberg
PURPOSE: To evaluate the in-scan and scan-rescan consistency of left ventricular (LV) in- and outflow assessment from 1) 2D planimetry; 2) 4D flow magnetic resonance imaging (MRI) with retrospective valve tracking, and 3) 4D flow MRI with particle tracing. MATERIALS AND METHODS: Ten healthy volunteers (age 27 ± 3 years) underwent multislice cine short-axis planimetry and whole-heart 4D flow MRI on a 3T MRI scanner twice with repositioning between the scans...
June 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28591188/a-constrained-multinomial-probit-route-choice-model-in-the-metro-network-formulation-estimation-and-application
#19
Yongsheng Zhang, Enjian Yao, Heng Wei, Kangning Zheng
Considering that metro network expansion brings us with more alternative routes, it is attractive to integrate the impacts of routes set and the interdependency among alternative routes on route choice probability into route choice modeling. Therefore, the formulation, estimation and application of a constrained multinomial probit (CMNP) route choice model in the metro network are carried out in this paper. The utility function is formulated as three components: the compensatory component is a function of influencing factors; the non-compensatory component measures the impacts of routes set on utility; following a multivariate normal distribution, the covariance of error component is structured into three parts, representing the correlation among routes, the transfer variance of route, and the unobserved variance respectively...
2017: PloS One
https://www.readbyqxmd.com/read/28587731/prediction-of-clinical-outcome-using-blood-flow-volume-in-the-superior-mesenteric-artery-in-patients-with-pseudomyxoma-peritonei-treated-by-cytoreductive-surgery
#20
A Dohan, M Barral, C Eveno, R Lo Dico, R Kaci, A Pasteur-Rousseau, P Soyer, M Pocard, P Bonnin
BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare carcinomatosis limited to the peritoneal cavity, mainly supplied by the superior mesenteric artery (SMA). The only curative treatment is cytoreductive surgery (CRS) associated with hyperthermic intraperitoneal chemotherapy. This study aimed to evaluate the ability of blood flow volume (BFV) recorded in the SMA using Doppler ultrasonography pre-operatively to predict the extent and resectability of the disease and post-operatively to assess clinical outcome...
May 25, 2017: European Journal of Surgical Oncology
keyword
keyword
52148
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"