АНГИОПУЛЬМОНОГРАФИЯ С НИТРОГЛИЦЕРИНОВЫМ ТЕСТОМ В ДИАГНОСТИКЕ ОСТРЫХ ИНФЕКЦИОННЫХ ДЕСТРУКЦИЙ ЛЕГКИХ

Objective. To present the possibilities of angiopulmonography with a nitroglycerin test in the differential diagnosis of acute pneumonia with acute abscess and gangrene of the lung.Material and methods. А pulmonary angiogram with a nitroglycerin test was performed in 51 patients with suppurative inflammations of the lungs and pleura in cases where it was difficult to interpret computed tomography data.Results. Acute gangrenous lung abscess was diagnosed in 27 (53%) patients (absence of the parenchymal phase of contrast, including after administration of nitrospray, of which in 4 cases it was due to thrombosis of the segmental branches of the pulmonary artery). In 14 (27%) cases there was lung gangrene (absence of the parenchymal phase of contrast, including after administration of nitrospray, of which 5 were associated with thrombosis of the segmental branches of the pulmonary artery). With preserved main blood flow along all branches of the pulmonary artery and a pronounced parenchymal phase or its restoration after a nitroglycerin test, a conclusion was made about the functional nature and reversibility of the identified microcirculation disorders, the absence of necrotic changes in the pulmonary parenchyma and the presence of acute pneumonia in the patient - 4 (8%) cases. In case of deformation of the pulmonary artery branches with preservation of blood flow through them and the parenchymal phase, a conclusion was made about compression of the pulmonary parenchyma by pleural effusion, on the basis of which pleural empyema was suspected in 6 (12%) patients.Conclusion. The developed method for the differential diagnosis of acute pneumonia with acute abscess and gangrene of the lung by means of angiopulmonography with a nitroglycerin test makes it possible to supplement and improve the early and differential diagnosis of purulent-inflammatory diseases of the lungs in difficult clinical situations. Nitroglycerin preparations improve microcirculation in the inflammation of the pulmonary parenchyma.

Modern History of Surgical Management of Lung Abscess: From Harold Neuhof to Current Concepts

The mechanism underlying the plateau or relative decrease in cerebral blood flow (CBF) during maximal incremental dynamic exercise remains unclear. We hypothesized that cerebral perfusion is limited during high-intensity dynamic exercise due to a redistribution of carotid artery blood flow. To identify the distribution of blood flow among the arteries supplying the head and brain, we evaluated common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and vertebral artery (VA) blood flow during dynamic exercise using Doppler ultrasound. Ten subjects performed graded cycling exercise in a semi-supine position at 40, 60 and 80% of peak oxygen uptake (VO2 peak) for 5 min at each workload. The ICA blood flow increased by 23.0 ± 4.6% (mean ± SE) from rest to exercise at 60% (VO2 peak). However, at 80% (VO2 peak), ICA blood flow returned towards near resting levels (9.6 ± 4.7% vs. rest). In contrast, ECA, CCA and VA blood flow increased proportionally with workload. The change in ICA blood flow during graded exercise was correlated with end-tidal partial pressure of CO2 (r = 0.72). The change in ICA blood flow from 60% (VO2 peak) to 80% (VO2 peak) was negatively correlated with the change in ECA blood flow (r = −0.77). Moreover, there was a significant correlation between forehead cutaneous vascular conductance and ECA blood flow during exercise (r = 0.79). These results suggest that during high-intensity dynamic exercise the plateau or decrease in ICA blood flow is partly due to a large increase in ECA blood flow, which is selectively increased to prioritize thermoregulation.

The objective of this study was to use non-invasive laser Doppler flowmeter to measure changes in blood flow in peripheral vessels in the legs before and after stress induced by leg elevation stress test and investigate correlations with the ankle-brachial pressure index (ABI). Subjects included 28 patients over 20 years of age (mean, 73 years) who reported chiefly of leg symptoms such as intermittent claudication, numbness, chills, or cramps had been examined at the study institution, and agreed to participate in the study. The ABI of both legs was measured, and patients were divided into two groups: low ABI (ABI ≤0.9) and normal ABI (ABI ≥0.9). Blood flow in the big toe was measured using a box-type laser Doppler flowmeter before, during, and after leg-elevation stress. Amplitude of the recorded waveform and changes in blood flow were compared. Average ABI was 1.09 ± 0.10 in the normal ABI group (33 legs) and 0.68 ± 0.17 in the low ABI group (21 legs). Amplitude before and during stress was significantly smaller in the low ABI group than in the normal ABI group (p <0.01), and there was a significant correlation with ABI before and during stresses (r = 0.4606, r = 0.5048, respectively; p <0.05). Change in blood flow during stress was significantly lower in the low ABI group than in the normal ABI group (p <0.05). There was a significant correlation between change in blood flow during stress and ABI in both groups (r = 0.5073; p <0.05). There was also a significant correlation between change in blood flow and change in amplitude in both groups (r = 0.5477; p <0.05). RESULTS of this study show, that comparing amplitude and change in blood flow before and after leg extension and elevation stress, there was a correlation between change in blood flow and amplitude, and ABI during stress. A box-type laser Doppler flowmeter may provide a means of screening for peripheral arterial disease.

What is the central question of this study? Recently, the heterogeneity of the cerebral arterial circulation has been argued. Orthostatic tolerance may be associated with an orthostatic stress-induced change in blood flow in vertebral arteries rather than in internal carotid arteries, because vertebral arteries supply blood to the medulla oblongata, which is the location of important cardiac, vasomotor and respiratory control centres. What is the main finding and its importance? The effect of graded orthostatic stress on vertebral artery blood flow is different from that on internal carotid artery blood flow. This response allows for the possibility that orthostatic tolerance may be associated with haemodynamic changes in posterior rather than anterior cerebral blood flow. Recently, the heterogeneity of the cerebral arterial circulation has been argued, but the characteristics of vertebral artery (VA) and internal carotid artery (ICA) blood flow during graded orthostatic stress remain unknown. We hypothesized that the change in blood flow in VA is not similar to that in ICA blood flow during graded orthostatic stress. We measured blood flows in both ICA and VA during graded lower body negative pressure (LBNP; -20, -35and -50mmHg) by using two colour-coded ultrasound systems. The effect of graded orthostatic stress on the VA blood flow was different from that on the ICA blood flow (LBNP×artery, P=0.006). The change in ICA blood flow was associated with the level of LBNP (r = 0.287, P=0.029), and a reduction in ICA blood flow from pre-LBNP was observed during -50mmHg LBNP (from 411±35 to 311±40mlmin(-1) , P=0.044) without symptoms of presyncope. In contrast, VA blood flow was unchanged during graded LBNP compared with the baseline (P=0.597) relative to the reduction in ICA blood flow and thus there was no relationship between VA blood flow and the level of LBNP (r=0.167, P=0.219). These findings suggest that the change in ICA blood flow is due to the level of LBNP during graded orthostatic stress, but the change in VA blood flow is different from that in ICA blood flow across the different levels of LBNP. These findings provide the possibility that posterior cerebral blood flow decreases only during severe orthostatic stress and is therefore more likely to be linked with orthostatic tolerance.

Flow in hemodialysis grafts after angioplasty: Do radiologic criteria predict success?

ObjectivesTo compare blood flow (BF) changes of teeth subjected to orthodontic forces during curve of Spee (COS) leveling using different archwires (AW).Material and methodsThirty subjects with COS > 5 mm were randomly assigned (1:1:1) into three groups based on the AW used: group 1: 0.017 × 0.025-inch stainless-steel (SS)AW, group 2: 0.019 × 0.025-inch SSAW, and group 3: 0.021 × 0.025-inch β-titanium (TMA)AW. In the 3 groups, a 5 mm-depth reverse COS was placed in the AWs. A laser Doppler flowmeter was used to measure BF at different time intervals (T0–T4).ResultsIn the 3 AWs group, BF of all measured teeth was reduced 20 min after force application. Afterwards, the BF values started to increase until the baseline values were almost restored within 1 week. Differences in BF changes between the extrusion and intrusion subgroups were observed within groups 1 and 3 during the first 20 min of force application (P < 0.05). Similar BF changes were recorded using the 3 different AWs. BF changes were associated with tooth type and the amount of COS depth change.ConclusionsDuring CoS leveling, similar BF changes were recorded using the 3 different AWs. Tooth type and the amount of COS depth change were associated with BF changes within the first 20 min of force application. Greater BF reduction was found in premolars compared to incisors during the first 20 min of AW placement.Clinical relevanceIt is important to select a type of applied forces that minimally affect the BF. Intrusive forces appeared to have lower negative effects on the BF of teeth during COS leveling.Trial registrationClinicalTrial.gov (# NCT04549948).

Validity of Doppler measurements of superior mesenteric artery blood flow velocity: Comparison with blood flow measured by microsphere technique

To clarify various conditions in the transplanted kidney, invasive biopsy must be performed in most cases. In this study, we measured blood flow in the transplanted kidney by color Doppler tomography to examine the usefulness of measuring renal blood flow in clarifying various conditions. Blood flow in the transplanted kidney was measured using peak flow velocity (PFV) and an index of resistance, the pulsatility index (PI), as parameters. In acute cellular rejection, there were no changes in blood flow in the segmental arteries, while there was a significant decrease in the blood flow in the interlobar artery. In acute vascular rejection, it was difficult to measure blood flow in the interlobar artery. The values of parameters were low even in the segmental arteries, suggesting markedly decreased blood flow. In chronic rejection, the values of the parameters were low in proportion to transplanted kidney function. In addition, parameters were examined with respect to vascular stenosis, fibrous stroma and edema in the histopathology of the transplanted kidney. As a result, vascular stenosis and fibrous stroma affected the segmental and interlobar arteries, severely reducing blood flow. It was also shown that interstitial edema reduced blood flow in the interlobar artery. Color Doppler tomography may facilitate diagnosis of certain conditions in the transplanted kidney biopsy.

Pattern of breast cancer blood flow and metabolism, assessed using dual-acquisition 18FDG PET: Correlation with tumor phenotypic features and pathological response to neoadjuvant chemotherapy

Increasing evidence suggests that local blood flow should be monitored during microdialysis (MD) as the recovery of analytes is affected by local blood flow. At present ethanol clearance is the standard technique for this purpose, but it is not functional at very low perfusion velocities. Here, we introduce a technique for MD whereby local tissue blood flow is recorded by the use of urea clearance (changes inflow/outflow concentration), in conjunction with measurements of tissue metabolism (glucose, lactate and puruvate). MD probes were inserted into the gracilis muscle of 15 rats and perfused with a medium containing urea (20 mmol l(-1)). Changes in muscle blood flow were made by addition of noradrenaline (5 microg ml(-1)) to the perfusion medium at two perfusion velocities (0.6 and 0.4 microl min(-1)). The clearance of urea from the perfusion medium was then calculated and examined in relation to the dose of noradrenaline and to the coexisting changes in extracellular metabolites. The results showed reproducible and dose-dependent changes in blood flow that were induced by noradrenaline. These were characterized by dose-dependent changes in the urea clearance as well as blood-flow-specific changes in the MD metabolic markers (reduction in glucose and increase in lactate). The sensitivity for blood flow changes as assessed by urea clearance (MD) was increased at 0.4 compared with the 0.6 microl min(-1) perfusion speed. The results indicate that inclusion of urea to the perfusion medium may be used to monitor changes in skeletal muscle blood flow at low perfusion velocities and in parallel assess metabolic variables with a high recovery (>90%).

Quantitation of myocardial perfusion by contrast echocardiography: Analysis of contrast gray level appearance variables and intracyclic variability

Changes in Lower-Leg Blood Flow During Warm-, Cold-, and Contrast-Water Therapy

Intraoperative methods to assess skeletal muscle blood flow or muscle-flap perfusion during vascular reconstructive surgery are limited. At present, techniques enable only anatomic identification of the degree of patency of large vessels. We report here the first use of ultrasonography to assess dynamic changes in skeletal muscle perfusion. Baseline blood flow in the adductor muscle group of the hindlimbs of seven dogs was measured with an electromagnetic flow probe and with contrast ultrasound using the contrast agent Albunex. Blood flow was manipulated in each dog pharmacologically with random administration of intraarterial injections of Neo-Synephrine and papaverine. After each change in blood flow detected by electromagnetic flow probe, flow also was assessed qualitatively by four independent observers who graded video-recorded contrast enhancement in the muscle group on a 0 to 4 scale. Videodensitometry also was used to generate time versus intensity curves in the adductor muscle region of interest. Peak pixel intensity was determined during each flow condition. A total of 21 flow measurements were made with each assessment scheme (electromagnetic flow probe, video enhancement, videodensitometry) for each condition (7 control, 7 papaverine, 7 Neo-Synephrine). Changes in blood flow assessed by video enhancement scores and changes in peak pixel intensity correlated with changes measured by electromagnetic flow probe (r = 0.84 and 0.66, respectively). We conclude that contrast ultrasound may be used to detect changes in skeletal muscle perfusion intraoperatively. Measures of muscle perfused by visual inspection of contrast enhancement and videodensitometric data were in agreement with direct measurements of changes in skeletal muscle blood flow.

Purpose: Ascertain effects of mammographic compression on microvascular blood flow and thus understand potential confounding factors due to compression on contrast agent distribution. Method and Materials: An X‐ray mammogram simulator was constructed to hold optical fibers for diffuse correlation spectroscopy measurements of blood flow and diffuse optical spectroscopy measurements of hemoglobin concentration and oxygenation. 15 healthy subjects were recruited for experiments consisting of 3 serial compression‐release cycles. Results: Small (∼15% or ∼1cm) changes in plate separation resulted in dramatic changes in blood volume (∼47%) and flow (∼65%) in measurements of 15 subjects. However, there was significant inter‐ and intra‐ subject variation in response within the population. Conclusion: The distribution of contrast agents injected during mammographic compression will be affected by the average and inhomogeneous changes in blood flow measured in this study. This study is currently being expanded and instrumentation improved to identify the cause of inter‐subject variation in blood flow changes.