Pattern Of Blood Flow Distribution Research Articles

Zonal pattern of blood flow distribution in the Pliss lymphosarcoma microcirculatory bed caused by single exposure of high-intensity focused ultrasound

Introduction. Cell damage is not the only important mechanism of high-intensity focused ultrasound (HIFU) for cancer therapy; concomitant microcirculation disorders having alterations patterns not studied enough also have high significance. The aim of the study was to analyze perfusion along the tumor perimeter depending on the HIFU exposure. Materials and methods. We used a stand for HIFU therapy (MTL LLC). Mode: 8.2 kW/cm2 intensity at 0.6 mm focal spot at 1.4 MHz, exposure time: 150, 200, 250 and 500 ms. The object of the study is the vascular bed of Pliss lymphosarcoma. Tumor tissue temperature was monitored by a T-8 thermograph (Russia), blood flow was measured by the BLF21 laser Doppler recorder (USA). Results. After HIFU exposure time from 150–250 ms, perfusion was noted to have decreased to 1.06 perfusion units (pf.u) in the central zone (p<0.01) compared to the control, but by the 30 min perfusion has increased to 1.22 pf.un. No signs of perfusion improvement were found in exposure time of 500 ms. In the peripheral zone, against the background of a decrease in blood flow to 3.6 pf. u. (p < 0.05) by 30 min of the experiment, hyperperfusion was restored to 5.86 pf. u. in all exposure time. In the central zone, a sharp decrease in microcirculation was observed, probably caused by damage of blood vessels; in the periphery of the tumor, perfusion changes had a phasic and reversible pattern. Conclusion. An increase of HIFU exposure correlates with an increase of temperature of Pliss lymphosarcoma tissue near the focus of exposure. Specific perfusion changes are recorded in the central and peripheral zones of the tumor when single exposed to HIFU with different time exposure; the severity of changes depends on ultrasound exposure-time and is characterized by a zonal pattern of blood flow distribution due to the formation of zones of irreversible and reversible damage to microcirculation.

Effects of hysterosalpingo-contrast sonography examination on endometrial receptivity among women with unexplained infertility

Hysterosalpingo-contrast sonography (HyCoSy) is the preferred method for evaluating fallopian tubal patency, and it is associated with improved rates of natural pregnancy among infertile patients. However, the mechanism underlying the improvement in pregnancy rates following HyCoSy remains unclear. This study aimed to investigate the effect of HyCoSy examination on endometrial receptivity as well as pregnancy rates among infertile women. This prospective study included 120 women with unexplained infertility who visited our department between June 2018 and February 2021. These patients were classified into the study group (n = 60) and the control group (n = 60) depending on their willingness to undergo three-dimensional HyCoSy in the present cycle (study group) or 6months later (control group). Endometrial characteristics, including endometrial thickness and pattern as well as the endometrial blood flow distribution pattern, were measured twice by transvaginal Doppler ultrasonography in the preovulatory phase before and after HyCoSy examination. Participants were followed for 6months to observe the outcome of spontaneous conception. Compared with the control group, the study group had a significantly higher cumulative pregnancy rate at 6months after HyCoSy (21.6% [13/60] vs 5.0% [3/60], P = 0.007). More patients in the study group showed improved endometrial blood flow distribution (P = 0.021, χ2 = 7.699), but no differences in endometrial thickness and pattern were observed between the groups (P > 0.05). HyCoSy examination may improve endometrial perfusion and has a therapeutic effect on improving spontaneous pregnancy among women with unexplained infertility.

Ventricular outputs, central blood flow distribution and flow pattern through the aortic isthmus of fetuses with simple transposition of the great arteries.

Our objective was to determine the impact of simple transposition of the great arteries (TGA) on fetal left ventricular (LV) and right ventricular (RV) performances and central circulatory dynamics including the aortic isthmus. Ventricular stroke volumes were calculated as the product of the cross-sectional area of the corresponding semi-lunar valve and the flow velocity integral through these valves. Volume flow in ductus arteriosus (QDA ) was evaluated using the same technique. Flow through the lungs (QLUNGS ) was calculated by subtracting net QDA from flow in main pulmonary artery [net QDA = QDA minus retrograde ductus arteriosus (DA) diastolic flow]. Relative performance of each ventricle expressed as percentage of combined cardiac output was also indirectly assessed by the aortic isthmus systolic index (ISI) (nadir of incisura/peak systolic of the Doppler waveforms in the isthmus); the relation between ISI and QLUNGS was investigated. Fifty-one fetuses with TGA were compared with 74 normal controls matched for gestational age. TGA fetuses had higher QLV at T2 (58.6 ± 9.4% vs. 43.4 ± 5.0%, p < 0.001) and T3 (53.7 ± 8.9% vs. 43.9 ± 5.7%, p < 0.001). QLUNGS was higher in fetuses with TGA, in the second (50.4 ± 16.3% vs. 39.0 ± 16.8%, p = 0.007) and third trimesters of gestation (52.8 ± 22.0% vs. 37.1 ± 16.3%, p = 0.005). No difference was found between ISI values from normal and TGA groups. A significant inverse correlation was observed between ISI and QLUNGS (r = -0.55, p = 0.006). Central distribution of combined cardiac output of fetuses with simple TGA is characterized by a greater QLUNGS leading to a dominant LV. In prenatal TGA, changes in QLUNGS could be monitored by measuring ISI. The clinical importance of this last observation deserves further investigations.

Heterogeneous ageing of skeletal muscle microvascular function.

The distribution of blood flow to skeletal muscle during exercise is altered with advancing age. Changes in arteriolar function that are muscle specific underlie age-induced changes in blood flow distribution. With advancing age, functional adaptations that occur in resistance arterioles from oxidative muscles differ from those that occur in glycolytic muscles. Age-related adaptations of morphology, as well as changes in both endothelial and vascular smooth muscle signalling, differ in muscle of diverse fibre type. Age-induced endothelial dysfunction has been reported in most skeletal muscle arterioles; however, unique alterations in signalling contribute to the dysfunction in arterioles from oxidative muscles as compared with those from glycolytic muscles. In resistance arterioles from oxidative muscle, loss of nitric oxide signalling contributes significantly to endothelial dysfunction, whereas in resistance arterioles from glycolytic muscle, alterations in both nitric oxide and prostanoid signalling underlie endothelial dysfunction. Similarly, adaptations of the vascular smooth muscle that occur with advancing age are heterogeneous between arterioles from oxidative and glycolytic muscles. In both oxidative and glycolytic muscle, late-life exercise training reverses age-related microvascular dysfunction, and exercise training appears to be particularly effective in reversing endothelial dysfunction. Patterns of microvascular ageing that develop among muscles of diverse fibre type and function may be attributable to changing patterns of physical activity with ageing. Importantly, aerobic exercise training, initiated even at an advanced age, restores muscle blood flow distribution patterns and vascular function in old animals to those seen in their young counterparts.

Logistic Regression Analysis of Contrast-Enhanced Ultrasound and Conventional Ultrasound Characteristics of Sub-centimeter Thyroid Nodules

The purpose of the study described here was to determine specific characteristics of thyroid microcarcinoma (TMC) and explore the value of contrast-enhanced ultrasound (CEUS) combined with conventional ultrasound (US) in the diagnosis of TMC. Characteristics of 63 patients with TMC and 39 with benign sub-centimeter thyroid nodules were retrospectively analyzed. Multivariate logistic regression analysis was performed to determine independent risk factors. Four variables were included in the logistic regression models: age, shape, blood flow distribution and enhancement pattern. The area under the receiver operating characteristic curve was 0.919. With 0.113 selected as the cutoff value, sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 90.5%, 82.1%, 89.1%, 84.2% and 87.3%, respectively. Independent risk factors for TMC determined with the combination of CEUS and conventional US were age, shape, blood flow distribution and enhancement pattern. Age was negatively correlated with malignancy, whereas shape, blood flow distribution and enhancement pattern were positively correlated. The logistic regression model involving CEUS and conventional US was found to be effective in the diagnosis of sub-centimeter thyroid nodules.

Assessment of Uterine Receptivity by the Subendometrial-Endometrial Blood Flow Distribution Pattern in Frozenthawed Embryo Transfer Cycles

ABSTRACTObjectiveTo investigate the correlation of blood flow detected by 2-Dimensional Power Doppler (2D-PD) sonography in the subendometrial-endometrial unit with the pregnancy outcome in frozen-thawed embryo transfer (FET) cycles.Study designProspective non-randomized observational study.Materials and methodsA total of 127 patients undergoing their first FET cycle were recruited and prepared using hormone replacement therapy. All patients were evaluated for subendometrial-endometrial blood flow by 2D-PD once the endometrium was ≥7 mm thick. Progesterone supplement was added and transfer of 2 to 3 cleavage stage good quality embryos was done after 3 days.ResultsThe difference in the BMI, FSH, LH and endometrial thickness of women in the three zones was not statistically significant (p &gt; 0.05). However, women with blood flow in zone 1 were of older age as compared to women in zone 3 with a statistically significant difference (p = 0.0001). In the present study, the overall pregnancy rate was 35.43% (45/127). Women having blood flow in zone 3 or 4 showed a rising trend of pregnancy rate as compared to those in zone 1 and 2 although it was not statistically significant (p = 0.15). But, clinical pregnancy and implantation rates were significantly higher in women with zone 3 or 4 penetration compared with zone 1 or 2 penetration (p = 0.03 and 0.01, respectively).ConclusionThe subendometrial-endometrial vascularity has a useful predictive value for pregnancy outcome in FET cycles. However, larger studies are needed to reach definite conclusion.How to cite this articleSardana D. Assessment of Uterine Receptivity by the Subendometrial-Endometrial Blood Flow Distribution Pattern in Frozen-Thawed Embryo Transfer Cycles. Int J Infertil Fetal Med 2015;6(1):35-39.

Evaluation of the hemodynamics in straight 6-mm and tapered 6- to 8-mm grafts as upper arm hemodialysis vascular access.

The present study is intended to investigate and compare the hemodynamics in two different sizes of hemodialysis arteriovenous grafts for upper arm hemodialysis vascular access: 8-mm tapered to 6-mm at the arterial side and straight 6mm. A computational simulation approach is presented for this study, which is validated against the available experimental and numerical pressure measurements in the literature. The imposed boundary conditions at the arterial inlet and venous outlet boundaries of the models are physiological velocity and pressure waveforms, respectively. Blood flow fields and distribution patterns of the hemodynamic indices including wall shear stress (WSS) as one of the major hemodynamic parameters of the cardiovascular system and spatial wall shear stress gradient (SWSSG) as an indicator of disturbed flow patterns and hence susceptible sites of lesion developments are analyzed and compared between the two grafts. The tapered 6- to 8-mm graft seemingly is associated with less disturbed flow patterns within the venous anastomosis (VA) and the vein downstream while benefiting from higher blood flow rates within. Also, it shows a definitive advantage in terms of WSS and SWSSG distribution patterns around the VA and throughout the vein downstream with significantly lower values, which reduce the risk of thrombosis formation and stenotic lesion developments. The only disadvantage encountered in using 6- to 8-mm tapered graft is higher values of hemodynamic parameters at the arterial junction attributable to its significantly higher mean blood flow rate within. The results clearly indicate that the tapered 6- to 8-mm graft entirely outperforms straight 6-mm graft hemodynamically as an upper arm hemodialysis vascular access graft and confirms clinical data in the literature, which suggests advantageous use of tapered 6- to 8-mm grafts in the creation of upper arm brachioaxillary hemodialysis vascular access grafts in selected groups of patients with expectably higher patency rates and lower complications.

A Study of low-dose Aspirin on endometrial and subendometrial blood flows in ovulation induction

Objective To investigate Low-dose Aspirin Effects on Endometrial and subendometrial blood flows in ovulation induction.Metbods A prospective study on the women(254cycles)who received ovulation induction in our hospital were randomly allocated into two groups:A group (Aspirin group,136 cycles)with Low dose aspirin (50 mg/d) and clomiphene citrate(100 mg/d on cycle days 5 to 9)in ovulation induction; B group (CC group,118 cycles) only with clomiphene citrate(100 mg/d on cycle days 5 to 9).Transvaginal color Doppler ultrasound examination was performed to determine the blood flow distribution patterns,pulsatility index (PI),resistance index(RI),systolic/diastolic ratio(S/D) of endometrial and subendometrial blood flows on the day of HCG injection.Results Grades of visible blood flow of the endometrial detected by Transvaginal color Doppler ultrasound was significantly different between the two groups(P＜0.01).Aspirin group had lower PI,RT,and S/D of endometrial and subendometrial blood flows than those in the B group (P＜0.01).Conclusion Low dose aspirin therapy in ovulation induction combined with CC can promotes endometrial and subendometrial blood flows. Key words: Aspirin; Ovulation induction; Endometrial and subendometrial blood flows

Evaluated of Testicular Tumors using Doppler Sonography

This study aimed to determine the gray scale and color Doppler sonographic features of the most common and some of the least common scrotal lesions. Between October 2012 to May 2013, 100 patients the age range of new born to 85 years old the mean 30.95, with scrotal symptoms, who underwent scrotal ultrasonography (US), were retrospectively reviewed. The clinical presentation, outcome, and US results were analyzed. The presentation symptoms including scrotal pain, painless scrotal mass or swelling, and trauma. Sonographic features that were reviewed included the size and echogenicity of the tumors, presence of cystic areas or calcifications,and distribution pattern of detectable blood flow on color or power Doppler

Predictive value of sonographic features in preoperative evaluation of malignant thyroid nodules

To retrospectively evaluate the diagnostic accuracy of ultrasonographic (US) features for the pre-operative differentiation of benign and malignant thyroid nodules by using pathological diagnosis as the reference standard. A total of 1501 patients with 2123 thyroid nodules (1864 malignant, 259 benign) diagnosed intra-operatively and undergoing pre-operative ultrasonography at our hospital were recruited. The following characteristics of US images were evaluated: nodule size, shape, margin, echotexture, echogenicity, presence and type of calcification, blood flow inside or around nodules and the presence of ipsilateral cervical lymphadenectasis. (1) The risk of malignancy was higher in a solitary nodule than in a non-solitary nodule [16.7% (109/653) vs 10.2% (150/1470), P=0.000]. The mean diameter of benign nodules was larger than that of malignant nodules [(2.4±1.4) vs (2.1±1.9) cm, P=0.009]. (2) Microcalcification, irregular shape, ill-defined border, solid and hypoechogenicity were more common in malignant nodules. Irregular shape had the highest sensitivity and positive predictive value while microcalcification had the highest diagnostic accuracy. (3) Nodules with a rich blood flow inside tended to have a higher risk of malignancy. The distribution pattern of blood flow around the nodules was not associated with the differentiation of benign and malignant thyroid nodules. Nodules with the presence of ipsilateral cervical lymphadenectasis had a higher risk of malignancy than those without lymphadenectasis [28.3% (80/283) vs 9.6% (92/963), P<0.01]. (4) If microcalcification, irregular shape, ill-defined border, solid, hypoechogenicity and the presence of ipsilateral cervical lymphadenectasis were treated as the characteristics of malignancy, a higher frequency of these characteristics was correlated with a higher risk of malignancy. Despite a lack of specific US imaging characteristics in malignant thyroid nodules, microcalcification and irregular shape appear closely correlated with malignancy. A combined use of conventional US characteristics may improve the accuracy of differential diagnosis.

Computational Analysis of Oxygen Transport in the Retinal Arterial Network

Purpose: The retina has a high oxygen consumption, making it particularly vulnerable to vascular insults, impairing oxygen and nutrient supply. The aim of this study was to develop a detailed computational model for quantitative analysis of blood flow and oxygen transport in physiologically realistic retinal arterial networks. Such a model will allow us to examine the effect of topological changes in retinal vasculature on hemodynamics and oxygen distribution in the retinal circulation.Materials and Methods: The Navier-Stokes equations for blood flow and the convection-diffusion equation for oxygen transfer were solved numerically to obtain detailed blood flow and oxygen distribution patterns in a retinal arterial tree. The geometrical outlines of the central retinal artery and its major branches were extracted from retinal images acquired from a healthy young adult by a Zeiss FF450+ fundus camera. The reconstructed subject-specific retinal arterial network geometry was combined with a structured tree model for the distal peripheral vessels. The non-Newtonian rheological properties of blood were incorporated by using an empirical viscosity model to account for the Fahraeus-Lindqvist effect.Results: The model predicted pressure drops in the range of 11–14.6 mmHg between the inlet and outlets of the reconstructed network and non-uniform oxygen tension, which varied with the vessel diameter and distance from the optic disc. The mean oxygen saturation in retinal arteries was 93.1% for vessels larger than 50 μm in diameter and 82.2% for smaller arterioles.Conclusions: Our numerical results are in good agreement with in vivo measurements reported in the literature, demonstrating the potential of our model for prediction of oxygen distribution and intravascular oxygen tension profiles in the retinal arterial network. This paves the way for investigating the effects of parameter variation, simulating cases not available from experimental studies.

Human respiratory muscle blood flow measured by near-infrared spectroscopy and indocyanine green

Measurement of respiratory muscle blood flow (RMBF) in humans has important implications for understanding patterns of blood flow distribution during exercise in healthy individuals and those with chronic disease. Previous studies examining RMBF in humans have required invasive methods on anesthetized subjects. To assess RMBF in awake subjects, we applied an indicator-dilution method using near-infrared spectroscopy (NIRS) and the light-absorbing tracer indocyanine green dye (ICG). NIRS optodes were placed on the left seventh intercostal space at the apposition of the costal diaphragm and on an inactive control muscle (vastus lateralis). The primary respiratory muscles within view of the NIRS optodes include the internal and external intercostals. Intravenous bolus injection of ICG allowed for cardiac output (by the conventional dye-dilution method with arterial sampling), RMBF, and vastus lateralis blood flow to be quantified simultaneously. Esophageal and gastric pressures were also measured to calculate the work of breathing and transdiaphragmatic pressure. Measurements were obtained in five conscious humans during both resting breathing and three separate 5-min bouts of constant isocapnic hyperpnea at 27.1 +/- 3.2, 56.0 +/- 6.1, and 75.9 +/- 5.7% of maximum minute ventilation as determined on a previous maximal exercise test. RMBF progressively increased (9.9 +/- 0.6, 14.8 +/- 2.7, 29.9 +/- 5.8, and 50.1 +/- 12.5 ml 100 ml(-1) min(-1), respectively) with increasing levels of ventilation while blood flow to the inactive control muscle remained constant (10.4 +/- 1.4, 8.7 +/- 0.7, 12.9 +/- 1.7, and 12.2 +/- 1.8 ml 100 ml(-1) min(-1), respectively). As ventilation rose, RMBF was closely and significantly correlated with 1) cardiac output (r = 0.994, P = 0.006), 2) the work of breathing (r = 0.995, P = 0.005), and 3) transdiaphragmatic pressure (r = 0.998, P = 0.002). These data suggest that the NIRS-ICG technique provides a feasible and sensitive index of RMBF at different levels of ventilation in humans.

Optimal timing of ultrasonographic and Doppler evaluation of uterine receptivity to implantation

In IVF programmes, transvaginal ultrasonography is used as a non-invasive method to evaluate uterine receptivity. The aim of this study was to determine when to perform this investigation in order to optimize prediction of the likelihood of pregnancy. Over 9 months, 124 patients undergoing IVF or intracytoplasmic sperm injection were studied. The ultrasonographic evaluation included endometrial thickness, endometrial pattern, uterine artery pulsatility index, protodiastolic notch, end-diastolic blood flow, and endometrial–subendometrial blood flow distribution pattern. All patients underwent ultrasonographic investigation on the days of human chorionic gonadotrophin (HCG) administration, oocyte retrieval, and embryo transfer. Statistical analysis was done using recursive-partitioning analysis. The pregnancy and implantation rates per transfer were 33 and 19.8% respectively. In terms of single parameters, women with an end-diastolic blood flow, an endometrial–subendometrial blood flow and a multilayered endometrium were more likely to be pregnant than women without one or more of these signs. The most effective combination for evaluation of uterine receptivity was end-diastolic blood flow, endometrial pattern and endometrial thickness. Sensitivity and specificity of this combination were around 81%, positive predictive value was 68.2%, and negative predictive value 89.7%. The best sensitivity and specificity were obtained on the day of HCG administration: respectively 81.1 and 81.3%.

Assessment of endometrial receptivity by Color Doppler and ultrasound imaging

Color Doppler sonography is a new method used to investigate changes during the menstrual cycle in infertile women. The objective of this study was to investigate the correlation of uterine and endomterial-subendomterial blood flow in infertile women using ultrasound and color Doppler sonography. A prospective clinical study included 65 infertile women divided into three groups. Transvaginal ultrasound examination was performed on days XI, XIV and XX All results were statistically analyzed. We investigated the correlation between cycles, pregnancy outcome and distribution of endomterial-subendomterial blood flow, as well as uterine arterial blood flow. Endomterial-subendometerial blood flow distribution pattern assessed by transvaginal color Doppler, as well as good flow in uterine vessels, are necessery for good pregnancy rates. Thin endomterium, undetectable subendomterial blood flow and higher uterine arterial resistance, were associated with low pregnancy rate and poor outcome.

Effect of Body Warming on Regional Blood Flow Distribution in Conscious Hypoxic One-Month-Old Rabbits

Background: Previous experiments have shown that warming hypoxic infants reduces total peripheral vascular resistance. This suggests that the usual vasoconstriction of less essential vascular beds during hypoxia may be reduced and that the normal redistribution of blood flow to more vital organs may be compromised. Objective:Evaluate the effect of body warming during hypoxia on the distribution of blood flow. Methods: The fluorescent microsphere technique was used to compare regional blood flow in 1-month-old rabbits during systemic hypoxia (10% inspired O₂) with (n = 9) and without (n = 10) body warming. Blood flow was measured in brain, stomach, small intestine, hindlimb muscle, skin, and kidneys. Arterial blood pressure, whole-body O₂ consumption, arterial blood O₂ saturation and blood gases were also measured. Measurements and Main Results: In hypoxia all animals decreased body temperature (–2°C). With hypoxia blood flow increased to brain and hindlimb muscle; decreased to stomach, small intestine, and kidneys, and was unchanged in skin. The increase in brain-blood flow maintained O₂ delivery at normoxic levels. Rewarming to the normoxic body temperature significantly changed blood flow in hypoxia. Brain blood flow increased by 102 ± 30% (mean ± SEM) thereby increasing O₂ delivery by 50 ± 23% above normoxic values. Blood flow also increased to skin, stomach, and small intestine. However, O₂ delivery to these tissues remained below normoxic levels. Conclusions: Warming during hypoxia may impose an additional cardiovascular demand. The changes in the pattern of blood flow distribution with mild warming during hypoxia support the hypothesis that warming represents a significant heat stress.

Leydig cell tumors of the testis: gray scale and color Doppler sonographic appearance.

To determine the gray scale and color Doppler sonographic features of Leydig cell tumors of the testis in a series of patients. We retrospectively analyzed the sonographic appearance of 10 proven Leydig cell tumors in 9 patients aged 26 to 47 years. Sonographic features that were reviewed included the size and echogenicity of the tumors, presence of cystic areas or calcifications, and distribution pattern of detectable blood flow on color or power Doppler imaging. The tumors ranged from 0.4 to 3.0 cm in diameter, but most were less than 1.0 cm in diameter. In 1 testis, 2 discrete Leydig cell tumors were found. Nine (90%) of the 10 tumors were homogeneously hypoechoic. Only 1 tumor was isoechoic with the testis. None of the tumors contained calcifications. Of 8 tumors with color Doppler imaging, 7 (88%) showed a characteristic pattern of increased peripheral blood flow, which was either circumferential or punctate. Only 1 tumor was found with internal hypervascularity. Peripheral hypervascularity in a hypoechoic testicular tumor that has little or no internal color Doppler flow should suggest the possibility of a Leydig cell tumor, and consideration should be given to testicle-sparing surgery.

Usefulness of percutaneous intracardiac administration of colored microspheres in measuring blood flow distribution to the brain in 7-day-old rats.

By using colored microsphere (CMS) technique in newborn rats, we explored the relationship between injection sites and blood flow distribution patterns in open-chest and in closed-chest models, with hopes that percutaneous left ventricle injection can be applicable to measure relative blood flow distribution to the brain. Seven-day-old Wistar rats were used. In open-chest models (n = 30), we exposed the heart and injected CMS (15 microm diameter, 125000 spheres in 0.05 mL) to left and right ventricles, respectively. In closed-chest models (n = 12), we percutaneously punctured the left ventricle to administer microspheres to see the difference in blood flow distribution between the right and left side of organs. Microsphere counts were compared between the left and right side of each organ by unpaired t-test (mean +/- SD). Open-chest showed that right ventricle injection resulted in exclusive entrapment in the lungs, while left ventricle injection resulted in systemic distribution. According to this, one of 12 injections in the closed-chest was judged as right ventricle injection. The other 11 showed insignificant differences between the right and left side in the cortex, lung, and kidney. Right ventricle injection is differentiated from left ventricle injection and microsphere counts are the same between right and left side of the organs, suggesting that percutaneous microsphere injection is applicable for relative blood flow distribution in 7-day-old rat models.

Assessment of uterine receptivity by the endometrial-subendometrial blood flow distribution pattern in women undergoing in vitro fertilization-embryo transfer

Objective: To investigate the correlation of blood flow detected by color Doppler sonography in the endometrial-subendometrial unit with pregnancy outcome of IVF-ET treatments. Design: Prospective clinical study. Setting: University setting. Patient(s): Six hundred twenty-three patients selected prospectively on the day of ET. Intervention(s): Transvaginal ultrasound examination was performed before ET. Main Outcome Measure(s): Association between pregnancy outcome and distribution of endometrial-subendometrial blood flow (primary outcome measure) and between pregnancy rate and endometrial measurements as well as uterine arterial blood flow (secondary outcome measures). Result(s): The overall pregnancy rate was 28.4% (177/623) per ET. The pregnancy and implantation rates of patients with the presence of both endometrial and subendometrial flow were 47.8% (64/134) and 24.2% (94/388); for patients with subendometrial flow only, 29.7% (102/343) and 15.8% (153/967); and for patients with no detectable endometrial-subendometrial flow, 7.5% (11/146) and 3.5% (13/376), respectively. The presence of both endometrial and subendometrial blood flow is indicative of good endometrial receptivity, whereas the absence of both represents a poor uterine environment. Nondetectable endometrial-subendometrial flow was associated with women who were older, had a thinner endometrium, and had higher uterine arterial resistance compared with those women who had detectable flow. Conclusion(s): Endometrial-subendometrial blood flow distribution pattern assessed by transvaginal color Doppler before ET is correlated with the implantation and pregnancy rate of IVF treatment.

Distribuição do fluxo sangüíneo pulmonar na bronquiolite viral aguda

To assess lung perfusion patterns in inpatients with acute viral bronchiolitis using quantitative 99mTc-MAA scintigraphy so as to establish an association with clinical and radiological findings. A comparative, prospective case series study with a focus on diagnosis was carried out in a population of patients with acute viral bronchiolitis admitted to Hospital de Clínicas de Porto Alegre. Inclusion criteria were age between 1 and 24 months and first sudden-onset wheezing episode, suggesting bronchiolitis. The patients in the study were submitted to clinical, radiological and 99mTc-MAA lung perfusion evaluation during the first 24 hours of admission. Statistical analysis employed t test, taking into consideration a significance level of 0.05. The regional distribution of lung blood flow in the 38 patients studied was more pronounced in the upper section of the left lung in relation to the right lung (P<0.001). The distribution gradients of blood flow between the upper and middle and upper and lower sections were higher in the left lung (P<0.001). The distribution gradients of blood flow between the middle and lower sections were higher in the right lung, but without significance. The distribution gradient of the pulmonary flow in the anteroposterior axis was >1.0 in the upper and middle sections of both lungs. In the lower section it was >1.0 only in the right lung (P<0.007). There was no association between lung blood flow distribution patterns and clinical or radiological findings. There was no evidence of an association between lung blood flow distribution and ventilation-perfusion ratio in hospitalized infants with acute viral bronchiolitis; only a tendency to redirect lung blood flow towards upper lung sections was observed.

Effects of free and liposome-encapsulated hemoglobin on choroidal vascular plexus blood flow, using the rabbit eye as a model system.

This study investigated the vasoconstrictive effects of both stroma-free and liposome-encapsulated cross-linked hemoglobin (Hb) on vascular plexus hemodynamics, using the choroid of the rabbit eye as a model system. Sequential subtraction of high-speed ICG fluorescence angiogram images facilitated visualization of the time-varying patterns of blood flow distribution in the choriocapillaris during the cardiac cycle. Differences between baseline and post-hemoglobin injection blood flow distributions were analyzed. Likewise, differences in the time-varying patterns of flow distribution between the particulate and liquid phases of blood during a cardiac cycle were investigated, since this may bear on differences in vasoactivity induced by circulating stroma-free vs. encapsulated Hb. Cross-linked Hb induced a transient, but marked, localized reduction in choriocapillaris blood flow. This effect was significantly attenuated when liposome encapsulated cross-linked hemoglobin was administered. Plexus blood flow distribution was different for particulate and liquid ICG. Differences in particulate and liquid ICG flow patterns suggest that one contribution to the different plexus blood flow patterns observed in the encapsulated and free Hb experiments may be due to differences in liquid and particle-bound Hb distribution within the plexus. The observed choriocapillaris blood flow reductions may be attributable to an aggregate endothelial cell contractility induced by presence of extra-cellular Hb in the choriocapillaris plexus.