Blood Flow Characteristics Research Articles

Fibromyalgia in women: association of inflammatory plasma proteins, muscle blood flow, and metabolism with body mass index and pain characteristics.

Obesity is a common comorbidity in fibromyalgia (FM). Both FM and obesity have been connected to low-grade inflammation, although it is possible that previously reported inflammatory alterations in FM primarily may be linked to increased body mass index (BMI). This study aimed to investigate whether the inflammatory plasma protein profile, muscle blood flow, and metabolism and pain characteristics (clinical parameters and patient-reported outcome measurements) differed between female patients with FM with and without obesity. Patients with FM underwent clinical examinations, physical tests, and answered questionnaires. They were dichotomized according to BMI (<30 kg/m2 [n = 14]; ≥30 kg/m2 [n = 13]). Blood samples were collected and analyzed using a panel of 71 inflammatory plasma proteins. There were significant (P < 0.05) differences in blood pressure, pulse, max VO2, pain intensity, physical capacity, and Fibromyalgia Impact Questionnaire between the groups; the obese group had higher blood pressure, pulse, pain intensity, and Fibromyalgia Impact Questionnaire. There were 14 proteins that contributed to the group belonging. The 4 most important proteins for the group discrimination were MIP1β, MCP4, IL1RA, and IL6, which showed higher concentrations in obese patients with FM. Significantly decreased blood flow and increased concentration of pyruvate were detected in obese patients compared with nonobese patients. There was significant correlation between inflammatory proteins and sedentary behavior and health status in obese patients with FM. These findings suggest that metabolism and inflammation interact in female patients with FM with obesity and might cause chronic low-grade inflammation. Screening for obesity and monitoring of BMI changes should be considered in the treatment of patients with FM.

Thermal enhancement and numerical solution of blood nanofluid flow through stenotic artery

The blood flow through stenotic artery is one of the important research area in computational fluid mechanics due to its application in biomedicine. Aim of this research work is to investigate the impact of nanoparticles on the characteristics of human blood flow in a stenosed blood artery. In under consideration problem Newtonian fluid is assumed as human blood. Newtonian fluid flows through large blood vessels (more than 300 μm). The constitutive equations together with the boundary conditions are diminished to non-dimensional form by using boundary layer approximation and similarity transfiguration to attain the solution of velocity and temperature distribution of blood flow through arterial stenosis numerically with the help of Matlab bvp4c. The results for physical quantities at cylindrical surface are calculated and their effects are also presented through tables. The heat transfer rate increases throughout the stenosed artery with the concentration of copper nanoparticle. Velocity curve decreases by increasing the values of flow parameter and nanoparticle volume fraction. Temperature curve increases due to increase in the values of nanoparticle volume fraction and decrease in Prandtl number.

Characteristics of cerebral blood flow in an Eastern sample of multiple sclerosis patients: A potential quantitative imaging marker associated with disease severity.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is rare in China. At present, there are no widespread quantitative imaging markers associated with disease severity in MS. Despite several previous studies reporting cerebral blood flow (CBF) changes in MS, no consensus has been reached. In this study, we enrolled 30 Eastern MS patients to investigate CBF changes in different brain regions using the arterial spin labeling technique and their relationship with disease severity. The average CBF in MS patients were higher than those in health controls in various brain regions except cerebellum. The results indicated that MS patients with strongly increased CBF showed worse disease severity, including higher Expanded Disability Status Scale (EDSS) scores and serum neurofilament light chain (sNfL) values than those with mildly increased CBF in the parietal lobes, temporal lobes, basal ganglia, and damaged white matter (DWM). From another perspective, MS patients with worse disease severity (higher EDSS score and sNfL values, longer disease duration) showed increased CBF in parietal lobes, temporal lobes, basal ganglia, normal-appearing white matter (NAWM), and DWM. Correlation analysis showed that there was a strong association among CBF, EDSS score and sNfL. MS patients with strongly increased CBF in various brain regions had more ratio in relapsing phase than patients with mildly increased CBF. And relapsing patients showed significantly higher CBF in some regions (temporal lobes, left basal ganglia, right NAWM) compared to remitting patients. In addition, MS patients with cognitive impairment had higher CBF than those without cognitive impairment in the right parietal lobe and NAWM. However, there were no significant differences in CBF between MS patients with and without other neurologic dysfunctions (e.g., motor impairment, visual disturbance, sensory dysfunction). These findings expand our understanding of CBF in MS and imply that CBF could be a potential quantitative imaging marker associated with disease severity.

Clinical significance of asymmetric venous vasculature on minimum-intensity projection in patients with moyamoya disease.

This study analyzed the clinical significance and characteristics of asymmetric venous blood flow in patients with Moyamoya disease (MMD) using minimum intensity projection (minIP) susceptibility-weighted imaging. The minIP views of 30 patients diagnosed with MMD were retrospectively analyzed using clinical features, brain magnetic resonance angiography, electroencephalography, and brain single-photon emission computed tomography (SPECT). Simultaneously, differences between patients with acute cerebral infarction and non-MMD causes were analyzed. Twelve (40.0%) of the 30 patients had asymmetrical venous flow, which is usually seen in patients with acute cerebral infarction (P = .146). They also had significantly higher Suzuki stages than symmetric patients (P = .014), with five (41.7%) and three (25.0%) of them in stages 4 and 5, respectively. When the Suzuki stages of both hemispheres were different, more veins were found in the stenotic hemisphere (88.9%). Brain SPECT showed more severe hypoperfusion on the side with prominent vascularity in the minIP view (100.0%). Additionally, asymmetric blood flow was observed in 66.7% of the patients with cerebral infarction caused by MMD, whereas only 11.1% of the children with cerebral infarction caused by non-MMD had asymmetry (P = .005). Patients with MMD showed asymmetric hypointensity of the cortical veins with a minIP appearance. The venous structure showed greater signal loss on SWI and was more prominent in the hemisphere where stenosis was advanced or infarction occurred in other examinations. Cerebral infarction in patients with MMD tended to occur with asymmetrically prominent venous patterns with damaged areas in minIP images, which had distinct characteristics from those of patients without MMD.

Evaluation of cardiac involvement in patients with clinical post-COVID-19 syndrome

Abstract Introduction The underlying pathophysiology of Post-COVID-19 syndrome remains unknown, but increased cardiometabolic demand and state of mitochondrial dysfunction have emerged as candidate mechanisms. Cardiovascular magnetic resonance (CMR) provides insight into pathophysiological mechanisms underlying cardiovascular disease and 31-phosphorus magnetic resonance spectroscopy (31P-MRS) allows non-invasive assessment of the myocardial energetic state. Purpose We sought to assess whether Post-COVID-19 syndrome is associated with abnormalities of myocardial structure, function, perfusion and tissue characteristics or energetic derangement. Methods Prospective case-control study. A total of 20 patients with a clinical diagnosis of Post-COVID-19 syndrome (seropositive) and no prior underlying cardiovascular disease (CVD) and ten matching controls underwent 31P-MRS and CMR at 3T at a single time point. (Figure 1) All patients had been symptomatic with acute COVID-19, but none required hospital admission. Results Between the Post-COVID-19 syndrome patients and matched contemporary controls there were no differences in myocardial energetics (phosphocreatine to ATP ratio), in cardiac structure (biventricular volumes, left ventricular mass), function (biventricular ejection fractions, global longitudinal strain), tissue characterization (T1 and extracellular volume [ECV] fraction mapping, late gadolinium enhancement) or perfusion (myocardial rest and stress blood flow, myocardial perfusion reserve). One patient with Post-COVID-19 syndrome showed subepicardial hyperenhancement on the late gadolinium enhancement imaging compatible with prior myocarditis, but no accompanying abnormality in cardiac size, function, perfusion, ECV, T1, T2 mapping or energetics. This patient was excluded from statistical analyses. (Table 1) Conclusion In this study, the overwhelming majority of patients with a clinical Post-COVID-19 syndrome with no prior CVD did not exhibit any abnormalities in myocardial energetics, structure, function, blood flow or tissue characteristics. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Welcome Trust Clinical Career Development Fellowship (221690/Z/20/Z);NIHR-UKRI COVID-19 Rapid Response Rolling Call (COV0254)ESC Training Grant

Left atrial vorticity is independently associated with embolic brain infarcts and represents a promising imaging biomarker of cardioembolism in sinus rhythm and atrial fibrillation

Abstract Background Atrial fibrillation (AF) is associated with embolic stroke, but risk scores such as CHA2DS2-VASc perform only modestly (C statistics 0.6–0.7). Meanwhile, up to 25% of embolic strokes in patients without AF have no identifiable cause, and occult left atrial (LA) thromboembolism may be a relevant mechanism in such cases. Purpose We hypothesised that imaging of left atrial blood flow could improve embolic risk prediction in patients with and without AF. We used 4D flow magnetic resonance imaging (MRI) to identify a biomarker that is: (a) independently associated with embolic brain infarction by brain MRI, (b) able to stratify blood flow characteristics both during AF and in sinus rhythm (SR), and (c) reproducible. Methods We recruited 3 patient cohorts to respectively address each aim. Firstly, to assess the association between LA flow parameters and embolic brain infarcts, we recruited cohort A, consisting of 134 patients (41% female; age 70±9 years) with a history of ischaemic stroke (N=44) or no history of stroke but with CHA2DS2VASc score ≥1 (N=90). Next, the sensitivity of 4D flow parameters to rhythm change was assessed in cohort B: 37 patients with persistent AF studied before and after cardioversion, whose results were compared with those of 23 healthy controls in SR [CHA2DS2-VASc = 0.0 (0.0–0.0)]. Finally, scan-rescan coefficients of variation (CV) and interval-scan CV at 30 days were determined in Cohort C (86 subjects; 64 in SR, 22 in AF). Brain MRI was used to identify large non-cortical or cortical brain infarcts (LNCCI) – i.e. infarcts likely to be embolic in origin. Results At least one LNCCI was present in 39 of 134 patients in cohort A. Lower LA vorticity was significantly associated with higher risk of prevalent LNCCIs (Figure 1), after adjustment for AF, age, and CHA2DS2VASc score [OR=2.10 (95% CI 1.12–3.92) per SD, P=0.02]. This association remained significant after further adjustment for other cardiac parameters (all P&amp;lt;0.05, Figure 1). By contrast, there was no significant association between peak velocity and LNCCIs (P=0.21). LA vorticity was sensitive to rhythm change, improving significantly in patients in cohort B in SR at ≥4 weeks after cardioversion (CV) of persistent AF (Figure 2A, paired P&amp;lt;0.001 vs pre-CV), but remained impaired compared to healthy controls (Figure 2B, P&amp;lt;0.01). Finally, reproducibility studies in cohort C showed that LA vorticity had a same-day scan-rescan CV of 7% without significant differences between SR and AF subjects (P&amp;gt;0.05), and also showed no significant temporal variability on interval scanning (P&amp;gt;0.05). Conclusions LA vorticity is reproducible, sensitive to changes in heart rhythm, and independently associated with embolic brain infarcts, suggesting a promising imaging biomarker of cardioembolism in SR and AF. LA blood flow imaging could improve stroke prediction and the personalisation of decisions about anticoagulation, regardless of heart rhythm. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Oxford BRC, BHF

Aneurysm geometric features effect on the hemodynamic characteristics of blood flow in coronary artery: CFD simulation on CT angiography-based model.

The main purpose of the present numerical study is to evaluate the influences of aneurysm geometric features on the hemodynamic conditions within the left coronary arteries (LCA). Simulations have been conducted in two major parts: Section (I)encompassing three different cases(case 1, case 2, and case 3), in which three various sizes of the bifurcation region ([Formula: see text], [Formula: see text], and [Formula: see text]) were considered for each case, and Section (II)also consists of three distinct cases (case 4, case 5, and case 6) which two different positions (P1 and P2; proximal and distal to the main bifurcation, respectively) were taken into account for a fusiform aneurysm located on their left circumflex branch. Prediction and assessment of the correlation between morphological characteristics of an aneurysm with atherosclerosisandthrombosis were performed using quantitative and qualitative results including streamline and velocity contours, wall shear stress, oscillatory shear index, and relative residence time.Depending on the various cases, the time-averaged wall shear stress (TAWSS) of the bifurcation region for models of [Formula: see text] was nearly 18-24% fewer than [Formula: see text], and around 74-81% fewer than intact models. Moreover, the smaller size of the LCA dilation results in less flow recirculation and, accordingly, the lower risk of blood clotting. Additionally, the TAWSS of the aneurysm in the P1 model of case 4 was found 16.4% lower than in P2; however, the values for P1 models of case 5 and case 6 were higher than in P2 by close to 16.3% and 12.5%, respectively. Furthermore, it was concluded that the intricate geometry of LCAs, especially pre-aneurysm curvatures, have remarkable effects on the hemodynamics within the aneurysms. Even though a limited number of cases were used in this study, due to the scarcity of similar works, the outcomes of this computational evaluation can positively contribute to clinical decision-making in the assessment of coronary aneurysms.

Influence of the Anatomical Structure on the Hemodynamics of Iliac Vein Stenosis.

Few reports study the effects of the anatomical structure of the iliac vein on hemodynamics and the methods to reduce and delay in-stent thrombosis. The anatomical structure of iliac vein stenosis was used to establish vascular models with different stenosis rates, taper angle, and left branch tilt angle in the work. The influence of anatomical structure on hemodynamics was revealed through theoretical research and in vitro experimental verification. A real iliac vein model was built based on computed tomography angiography (CTA) images, and hemorheological parameters including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI) and relative residence time (RRT) were analyzed by computational fluid dynamics (CFD). The results showed that iliac vein stenosis could significantly increase the wall shear stress (WSS) of the blood vessels at the stenosis site and outside the intersection area, which was easy to produce eddy currents in the distal blood vessels. With the increased taper angle, the proportion of low-wall shear stress areas and the risk of thrombosis increased. A small tilt angle could aggravate the influence of narrow blood vessels on the blood flow characteristics and vascular wall. The numerical simulation results were consistent with the theoretical research results, and the experimental study verified the correctness of the simulation. The work is helpful to further understand the hemodynamic characteristics of the iliac vein, providing a scientific reference for clinical treatment and diagnosis.

The vaginal and uterine blood flow changes during the ovsynch program and its impact on the pregnancy rates in Holstein dairy cows

AimOvSynch is a hormonal protocol for synchronization of estrus and use of artificial insemination (AI) at an optimal time without adverse effects on the ovaries or uterus. This study investigated the use of noninvasive color Doppler ultrasound to assess changes in uterine and vaginal blood flow during the Ovsynch program for synchronization of estrus and its relation to the pregnancy rates in Holstein cows.Materials and methodsThe experimental cows received an intramuscular dose of 10 μg of a GnRH analogue (G1), followed 7 days later with an intramuscular injection of synthetic prostaglandin F2α (P: PGF2α) analogue (500 μg cloprostenol sodium), and given a 10 μg, injection of the GnRH analogue (G2) i.m. 48 h after the PGF2α treatment, and the cows were bred 14-16 h after. Uterine and vaginal perfusion were investigated by performing transrectal Doppler ultrasonography of both the uterine and vaginal arteries in Holstein cows at different time points during the Ovsynch program to determine: peak systolic velocity (PSV), time-averaged maximum velocity (TAMV), the volume of blood flow (BFV), pulsatility index (PI), resistance index (RI), resistance impedance (S/D) and diameters of uterine (UA) and vaginal (VA) arteries. Steroid hormones were also assayed. Transrectal ultrasonography (TUS) was performed at 32 and 60 days to confirm the pregnancy per artificial insemination (P/AI).ResultsThe uterine PSV, TAMV, and PV were greater at the time of the cloprostenol sodium and second GnRH injections (p<0.05) than at the time of the first GnRH injection. The vaginal PSV, PV were greater at the time of the cloprostenol sodium than at the time of the first and second GnRH injections (p<0.05). The receiver operating characteristic curve (ROC curve) indicated a high correlation between the uterine and vaginal blood flow and the rate of the pregnancy (p<0.05). The area under the ROC curve was 0.920 and 0.87 (p<0.05) for vaginal and uterine arteries respectively at time of G2. The serum levels of progesterone, estrogen and cortisol were correlated with the P/AI (p<0.05). The P/AI significantly decreased from 43.9 % at 32 d to 35.37 % at 60 d.ConclusionThese results indicate that noninvasive Doppler ultrasonography is a valid method to evaluate changes in the characteristics of uterine and vaginal blood flow in cows during the Ovsynch protocol. Furthermore, vaginal and uterine blood flow are two determinant factors for the higher conception rates in Holstein dairy cows.

Numerical simulation of the fractional Maxwell fluid flow in locally narrow artery

Research on hemorheology and blood flow behavior in non-uniform vessels is of extreme significance for diagnosis and treatment of many cardiovascular diseases. The aim of this study is to reveal the hemodynamics in stenotic vessels, and provide a reference for formulating a clinical operation plan. A set of rheological data of human blood at 37° is utilized in the paper to construct the fractional Maxwell constitutive equation of blood. Consequently, the continuity and momentum equations of a fractional Maxwell fluid passing through a stenosis artery in a two-dimensional cylindrical coordinate system are established. With the help of the vorticity and stream function, the finite difference method combined with the fractional order derivative L1 algorithm is applied to acquire the numerical solutions of the velocity, wall shear stress and intravascular pressure gradient, and the validity of the algorithm is verified. Furthermore, the effects of the stenosis degree, stenosis shoulder length, various Reynolds numbers and fractional parameter α on the blood flow characteristics in stenosis are analyzed.

Pseudocontinuous Arterial Spin Labeling: Clinical Applications and Usefulness in Head and Neck Entities.

Simple SummaryConventional imaging methods, such as ultrasonography, computed tomography, and magnetic resonance imaging may be inadequate to accurately diagnose lesions of the head and neck because they vary widely. Recently, the arterial spin labeling technique, especially pseudocontinuous arterial spin labeling (pCASL) with the three-dimensional (3D) readout method, has been dramatically developed to improve diagnostic performance for lesion differentiation, which can show prominent blood flow characteristics. Here, we demonstrate the clinical usefulness of 3D pCASL for diagnosing various entities, including inflammatory lesions, hypervascular lesions, and neoplasms in the head and neck, for evaluating squamous cell carcinoma (SCC) treatment responses, and for predicting SCC prognosis.As functional magnetic resonance imaging, arterial spin labeling (ASL) techniques have been developed to provide quantitative tissue blood flow measurements, which can improve the performance of lesion diagnosis. ASL does not require contrast agents, thus, it can be applied to a variety of patients regardless of renal impairments and contrast agent allergic reactions. The clinical implementation of head and neck lesions is limited, although, in recent years, ASL has been increasingly utilized in brain lesions. Here, we review the development of the ASL techniques, including pseudocontinuous ASL (pCASL). We compare readout methods between three-dimensional (3D) turbo spin-echo and 2D echo planar pCASL for the clinical applications of pCASL to head and neck lesions. We demonstrate the clinical usefulness of 3D pCASL for diagnosing various entities, including inflammatory lesions, hypervascular lesions, and neoplasms; for evaluating squamous cell carcinoma (SCC) treatment responses, and for predicting SCC prognosis.

The characteristics of arterial spin labeling cerebral blood flow in patients with subjective cognitive decline: The Chinese imaging, biomarkers, and lifestyle study.

ObjectiveWe aimed to characterize the potential risk factors and cerebral perfusion of patients with subjective cognitive decline (SCD).MethodsThis prospective study enrolled consecutive patients from the Chinese Imaging, Biomarkers, and Lifestyle (CIBL) Cohort of Alzheimer’s disease between February 2021 and March 2022. Patients who met the SCD diagnostic criteria were categorized into the SCD group, while those without cognitive complaints or any concerns were assigned to the healthy control (HC) group. The demographic and clinical characteristics and cerebral blood flow (CBF) from pseudo-continuous arterial spin labeling (pCASL) in standard cognitive regions were compared between these two groups. A multivariate analysis was performed to identify independent factors associated with SCD.ResultsThe frequency of family history of dementia in the SCD group was higher compared with the HC group (p = 0.016). The CBF of left hippocampus (p = 0.023), left parahippocampal gyrus (p = 0.004), left precuneus (p = 0.029), left middle temporal gyrus (p = 0.022), right parahippocampal gyrus (p = 0.018), and right precuneus (p = 0.024) in the SCD group were significantly increased than those in the HC group. The multivariate logistic regression analyses demonstrated that the family history of dementia [OR = 4.284 (1.096–16.747), p = 0.036] and the CBF of left parahippocampal gyrus [OR = 1.361 (1.006–1.840), p = 0.045] were independently associated with SCD.ConclusionThis study demonstrated that the family history of dementia and the higher CBF within the left parahippocampal gyrus were independent risk factors associated with patients with SCD, which could help in the early identification of the SCD and in intervening during this optimal period.

Computational fluid dynamics investigation on aortic hemodynamics in double aortic arch before and after ligation surgery

Double aortic arch (DAA) malformation is one of the reasons for symptomatic vascular rings, the hemodynamics of which is still poorly understood. This study aims to investigate the blood flow characteristics in patient-specific double aortic arches using computational fluid dynamics (CFD). Seven cases of infantile patients with DAA were collected and their computed tomography images were used to reconstruct 3D computational models. A modified Carreau model was used to consider the non-Newtonian effect of blood and a three-element Windkessel model taking the effect of the age of patients into account was applied to reproduce physiological pressure waveforms. Numerical results show that blood flow distribution and energy loss of DAA depends on relative sizes of the two aortic arches and their angles with the ascending aorta. Ligation of either aortic arch increases the energy loss of blood in the DAA, leading to the increase in cardiac workload. Generally, the rising rate of energy loss before and after the surgery is almost linear with the area ratio between the aortic arch without ligation and the ascending aorta.

Hypoxic Training Ameliorates Skeletal Muscle Microcirculation Vascular Function in a Sirt3-Dependent Manner.

Hypoxic training improves the microcirculation function of human skeletal muscle, but its mechanism is still unclear. Silent information regulator 2 homolog 3 (Sirt3) can improve mitochondrial function and oxidative status. We aimed to examine the role of Sirt3 in the process of hypoxic training, which affects skeletal muscle microcirculation. C57BL/6 mice were assigned to control (C), hypoxic training (HT), Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP), and 3-TYP + hypoxic training (3-TYP + HT) groups (n = 6/group). Sirt3 inhibition was induced by intraperitoneal injection of Sirt3 inhibitor 3-TYP. After 6 weeks of intervention, microcirculatory capillary formation and vasomotor capacity were evaluated using immunofluorescence, Western blot, biochemical tests, and transmission electron microscopy (TEM). Laser Doppler flowmetry was used to evaluate skeletal muscle microcirculation blood flow characteristics. Six weeks of hypoxic training enhanced skeletal muscle microcirculation function and increased microcirculatory vasodilation capacity and capillary formation. After the pharmacological inhibition of Sirt3, the reserve capacity of skeletal muscle microcirculation was reduced to varying degrees. After the inhibition of Sirt3, mice completed the same hypoxic training, and we failed to observe the microcirculation function adaptation like that observed in hypoxic training alone. The microcirculation vasodilation and the capillaries number did not improve. Hypoxic training improved skeletal muscle microcirculation vasodilation capacity and increased skeletal muscle microcirculation capillary density. Sirt3 is involved in the adaptation of skeletal muscle microcirculation induced by hypoxic training.

EFFECTS OF HEAD DOWN TILT TRAINING ON CAROTID BLOOD FLOW, PSYCHOLOGICAL STRESS AND ANXIETY SENSITIVITY IN THE ELDERLY

EFFECTS OF HEAD DOWN TILT TRAINING ON CAROTID BLOOD FLOW, PSYCHOLOGICAL STRESS AND ANXIETY SENSITIVITY IN THE ELDERLY

Evaluation of blood flow in superficial arteries of face by Doppler ultrasound in young adults

Acknowledgement: Knowledge of vascular hemodynamics of a particular region is essential to draw a fine line between normal and a pathological state. Face is highly vascular and little is known about normal blood flow characteristics of its superficial arteries. Thus there is a need to assess the normal blood flow characteristics of the face and to establish a normative database. This may later be helpful in planning of aesthetic procedures, face reconstruction following trauma or during surgery and in follow up examination of many skin diseases.To evaluate the blood flow of superficial arteries of face by Doppler ultrasound in young adults. Methods: A cross sectional descriptive study was conducted at University of Lahore Teaching Hospital and University Ultrasound Clinic Green Town, Lahore. Data was collected according to inclusion criteria. Sample size of 311 patients were included in this research comprising 112 (36%) females and 199(63.9%) were males. Data entry and analysis was done by using SPSS version-23. Results: Analysis of data showed that out of 311 patients 112 (36%) females and 199(63.9%) were males, According to the result analysis of the total number of 311 patients, facial artery had a mean diameter of 1.4 mm ( 0.14cm) and diameter of temporal artery at tragus was calculated 1.5mm ( 0.15cm) with SD 0.2. Facial and temporal artery average PSV among individuals was 26.8 ± 5.3 and 35.2 ± 11.9 respectively. Average RI value of facial artery was 0.81± 0.05 mm and for temporal was 1.0 ± 0.8 mm . Conclusion: The facial and temporal artery can be assessed on Doppler ultrasound for velocity and resistance parameters. No significant difference was seen in the parameters between males and females.

Heterogeneous Maturation of Arterio-Venous Fistulas and Loop-Shaped Venous Interposition Grafts: A Histological and 3D Flow Simulation Comparison.

Vascular graft maturation is associated with blood flow characteristics, such as velocity, pressure, vorticity, and wall shear stress (WSS). Many studies examined these factors separately. We aimed to examine the remodeling of arterio-venous fistulas (AVFs) and loop-shaped venous interposition grafts, together with 3D flow simulation. Thirty male Wistar rats were randomly and equally divided into sham-operated, AVF, and loop-shaped venous graft (Loop) groups, using the femoral and superficial inferior epigastric vessels for anastomoses. Five weeks after surgery, the vessels were removed for histological evaluation, or plastic castings were made and scanned for 3D flow simulation. Remodeling of AVF and looped grafts was complete in 5 weeks. Histology showed heterogeneous morphology depending on the distribution of intraluminal pressure and WSS. In the Loop group, an asymmetrical WSS distribution coincided with the intima hyperplasia spots. The tunica media was enlarged only when both pressure and WSS were high. The 3D flow simulation correlated with the histological findings, identifying “hotspots” for intimal hyperplasia formation, suggesting a predictive value. These observations can be useful for microvascular research and for quality control in microsurgical training.

Differential diagnosis of gallbladder polypoid lesions by micro-flow imaging

To explore the value of micro-flow imaging (MFI) in evaluating blood flow characteristics and differential diagnosis of gallbladder polypoid lesions. We retrospectively analyzed the clinical data and ultrasound images of 73 patients with gallbladder polypoid lesions, including 24 patients with pathologically confirmed neoplastic polyps (n=24) and 49 with non-neoplastic polyps (n=49). All the patients underwent conventional ultrasound, MFI and contrast enhanced ultrasound (CEUS) before cholecystectomy. The blood flow characteristics of the lesions in color Doppler flow imaging (CDFI) and MFI were compared, and the consistency of the findings by these two modalities with those of CEUS were evaluated by weighted Kappa consistency test. The diagnostic performance of MFI for gallbladder polypoid lesions was assessed. There were significant differences between MFI and CDFI in the evaluation of blood flow characteristics of gallbladder polypoid lesions (χ2=37.684, P < 0.001). MFI showed better performance than CDFI in displaying the blood flow characteristics of the polyps. The consistency in the findings was 0.118 between CDFI and CEUS and 0.816 between MFI and CEUS. The sensitivity, specificity and accuracy of MFI in distinguishing neoplastic polyps from non-neoplastic polyps were 75.00%, 93.88% and 87.67%, respectively. MFI has a good consistency with CEUS in displaying the blood flow characteristics of gallbladder polypoid lesions and can accurately distinguish neoplastic polyps from non-neoplastic polyps, thus providing new ultrasound diagnostic evidence to support clinical decisions on optimal treatments of gallbladder polypoid lesions.

Characteristics of Right Ventricular Blood Flow in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Analysis With 4-Dimensional Flow Cardiovascular Magnetic Resonance Imaging.

BackgroundBlood flow is closely related to function, but currently, the relationship of right ventricular (RV) blood flow components with RV function and hemodynamics in patients with chronic thromboembolic pulmonary hypertension (CTEPH) remains unclear. Our objective is to qualify RV function with 4-dimensional flow cardiovascular magnetic resonance (4D-Flow CMR) imaging and to investigate the correlation between RV flow and hemodynamics in patients with CTEPH.MethodsRetrospective enrollment included 67 patients with CTEPH (mean age 47.8±14.2 years, 47 men) who underwent CMR and right heart catheterization (RHC) within 2 days. RHC was used to evaluate hemodynamics. RV flow components including the percentages of direct flow (PDF), retained inflow (PRI), delayed ejection flow (PDEF), and residual volume (PRVo) were quantified on 4D-Flow sequence. RV functional metrics were determined with the CINE balanced steady-state free precession sequence. The sum of PDF and PDEF was compared with RV eject fraction (RVEF). The correlation among RV flow components, RV functional metrics and hemodynamics was analyzed with spearman correlation analysis.ResultsThe median (interquartile range) of RVEF, PDF, PDEF, PRI, and PRVo, respectively was 35.5% (18.2, 45.6%), 18% (8.4, 21.4%), 15.1% (13.5, 19.0%), 15.9% (13.8, 20.8%), and 50.6% (35.6, 60.4%). The sum of PDF and PDEF is 35.1% (24.8, 46.6%), which was similar to RVEF (z = 0.58, p = 0.561). PDF negatively correlated with right ventricular end-systolic volume index (RVESVI), right ventricular myocardial mass index (RVMI) and right ventricular global longitudinal strain (r = −0.61, −0.65, −0.64, p < 0.001). PRVo positively correlated with RVESVI and RVMI (r = 0.50, 0.58, p < 0.001). PDF negatively correlated with pulmonary vascular resistance (PVR) (r = −0.72, p < 0.001) while it positively correlated with cardiac output (CO) and cardiac index (CI) (r = 0.64 & 0.52, p < 0.001). PRVo positively correlated with mean pulmonary pressure and PVR (r = 0.57&0.54, p < 0.001). Total five patients died in the perioperative period. RVEF in the deceased patients was similar to survivors (z = −1.163, p = 0.092). In comparison with the survivors, RVPDF in the deceased patients significantly reduced (z = −2.158, p = 0.029) while RVPDEF, RVPRI, and RVPRVo in deceased patients were similar to survivors.Conclusion4D-Flow CMR can provide simultaneous quantification of RV function and hemodynamics in the assessment of CTEPH without breath-holding. The reduced PDF and increased PRVo were the main characteristics of RV flow in CTEPH.

Flow of two immiscible non-Newtonian fluids in an elastic tube

PurposeThis paper aims to investigate the flow of two-layered non-Newtonian fluids with different viscosities in an axisymmetric elastic tube.Design/methodology/approachA mathematical model was considered for this study to describe the flow characteristics of two-layered non- Newtonian Jeffrey fluids in an elastic tube. Because Jeffrey fluid model is a better model for the description of physiological fluid motion. Further, this model is a significant generalization of Newtonian fluid model. Analytical expressions for flux, stream functions, velocities and interface velocity have been derived in terms of elastic parameters, inlet, outlet and external pressures. The effects of various pertinent parameters on the flow behavior have been studied.FindingsThe volumetric flow rate was calculated by different models of Mazumdar (1992) and Rubinow and Keller (1972); from this it was found that the flux of Jeffrey fluid is more in the case of Rubinow and Keller model than Mazumdar. A comparative study is made between single-fluid and two-fluid models of Jeffrey fluid flows and it was observed that more flux and higher velocities were observed in the case of two-fluid model rather than single-fluid model. Furthermore, when both the Jeffrey parameter tends to zero and ratios of viscosities and radii are unity, the results in this study agree with those of Rubinow and Keller (1972).Originality/valueTo describe the fluid flow in an elastic tube with two-layered systems, the models and solutions developed here are very important. These results will be highly suitable in analyzing the rheological characteristics of blood flow in a small blood vessel because of their elastic nature.