Correlation between Retinol Binding Protein 4 and CT Perfusion Imaging and Prognosis in Patients with Acute Ischemic Stroke Based on Cell Imaging Data Analysis.

Objective: In order to explore the correlation between the retinol binding protein 4 (RBP4) and prognosis of patients with acute ischemic stroke (AIS), CT perfusion imaging can be used to scan the brain tissue of patients, which can identify abnormal perfusion areas and ischemic penumbra brain tissue, so as to provide a basis for doctors to formulate a reasonable clinical treatment plan. Methods: 200 patients with first-episode acute ischemic stroke were selected from the Department of Neurology of our hospital, including 128 males and 72 females, aged between 32 and 85 years, with an average age of 45 ± 4.3 years. After admission, the patients were tested for xanthol binding protein 4 in time, the patient's demographic data and the basic clinical data were recorded, the degree of brain injury was evaluated, and the short-term outcome was evaluated after treatment. Results: A total of 200 AIS patients with different degrees of brain injury were included in this study, including 128 males and 78 females, aged between 32 and 85 years, with an average age of 45 ± 4.3 years. Among them, 100 patients used CT perfusion imaging for brain scanning as the observation group, 100 patients used traditional imaging methods as the reference group, and 100 healthy people were included as the blank group. At the same time, the contents of total cholesterol, triacylglycerol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured by using an automatic biochemical analyzer. The patients were evaluated in the early stage of treatment and the effect of prognostic intervention was recorded. Conclusion: The application of CT perfusion imaging in the adjuvant treatment of AIS patients was helpful to identify the abnormal perfusion area and the brain tissue of ischemic penumbra, so as to provide a basis for doctors' follow-up treatment. At the same time, AIS patients with high serum RBP4 level had mild stroke severity, good short-term prognosis, and improved treatment effect, which improved patients' quality of life.

Predicting outcome of advanced head-and-neck cancer by measuring tumor blood perfusion in patients receiving neoadjuvant chemotherapy.

PURPOSE: The purpose of this study was to correlate treatment response with tumor blood perfusion in patient of advanced head-and-neck cancer undergoing neoadjuvant chemotherapy. MATERIALS AND METHODS: A total of 40 patients of advanced head-and-neck cancer, who were planned for neoadjuvant chemotherapy, were included in the study. All patients underwent diagnostic computed tomography (CT) with perfusion study for staging and quantitative measurement of tumor volume as well as perfusion parameters (including tumor blood volume, blood flow, permeability, and time to peak enhancement), at baseline and after completion of neoadjuvant chemotherapy. Total 3 cycles of neoadjuvant chemotherapy with paclitaxel, cisplatin, and 5 fluorouracil were given. Tumor response was evaluated in terms of change in tumor volume and correlated with perfusion parameters. RESULTS: Out of 40 patients, 22 patients had more than 50% reduction in tumor volume, who were grouped as responder and remaining 18 patients had <50% decrease in tumor volume, grouped as nonresponder. Both the groups were similar in terms of age, gender, performance status, stage, nodal status, or addiction. Baseline CT scan shows a significant difference in tumor blood flow (P = 0.048) and marginal difference in time to peak enhancement (P = 0.058) in two groups. However, there is no difference in tumor blood volume (P = 0.32) and permeability surface area (P = 0.07). CONCLUSIONS: Evaluation of tumor blood flow by perfusion CT is helpful in predicting chemotherapy outcome and deciding appropriate treatment modality, but further evaluation with more number of patients is required for validating the predictive role of each perfusion parameters.

Diaschisis revisited: quantitative evaluation of thalamic hypoperfusion in anterior circulation stroke.

PURPOSE: Ipsilateral thalamic diaschisis (ITD) refers to the phenomenon of thalamic hypoperfusion or hypometabolism due to a distant cerebral injury. To further investigate the characteristics and spectrum of ITD, we analyzed quantitative measurements of thalamic hypoperfusion in acute anterior circulation stroke. METHODS: We selected consecutive patients with large-vessel occlusion (LVO) anterior circulation stroke and available CT perfusion (CTP) examination on admission who underwent endovascular thrombectomy. Thalamic perfusion parameters on CTP were tested between ipsi- and contralesional thalamus and ischemic territory. Values were compared with thresholds from CTP analysis software. Associations of thalamic perfusion parameters with acute imaging and clinical data were determined in uni- and multivariate logistic regression analyses. RESULTS: Ninety-nine patients were included. All perfusion parameters indicated significant non-ischemic hypoperfusion of the thalamus, not reaching the levels of ischemia in the middle cerebral artery territory due to LVO (all p < 0.002). Multiple perfusion parameters exhibited significant association with ischemic lesion extent (relative cerebral blood flow [CBF]: ß =  - 0.23, p = 0.022; Δtime to drain: ß = 0.33, p < 0.001; ΔTmax: ß =  - 0.36, p < 0.001) and involvement of the Lentiform Nucleus (Δmean transit time: ß = 0.64, p = 0.04; Δtime to drain: ß = 0.81, p = 0.01; ΔTmax: ß =  - 0.82, p = 0.01). Symptom severity on admission exhibited minor significant association with reduction of thalamic CBF in uncorrected analysis (Odds ratio: 0.05, p = 0.049), but short- and long-term outcomes were unaffected by perfusion status. ITD reached guideline-based software-threshold levels in only one patient. CONCLUSIONS: ITD in acute stroke is a non-binary phenomenon affected by lesion extent and involvement of the lentiform nucleus. We found uncorrected association of ITD with early clinical presentation, but no association with short- or long-term outcome was evident. Relevant misclassification of ITD by guideline-based CTP software was not indicated, which needs further dedicated testing.

Neurovascular and perfusion imaging findings in coronavirus disease 2019: Case report and literature review.

Central nervous system involvement in severe acute respiratory syndrome caused by coronavirus disease 2019 (COVID-19) has increasingly been recognised in the literature, and possible mechanisms of neuroinvasion, neurotropism and neurovirulence have been described. Neurological signs have been described in 84% of COVID-19 intensive care unit patients, and haemostatic abnormalities in such patients may play an important role, with a broad spectrum of neuroimaging findings. This report describes the magnetic resonance imaging neurovascular findings in an acutely ill patient with COVID-19, including perfusion abnormalities depicted in the arterial spin labelling technique.

Computed tomography (CT) imaging evaluation of integrated traditional Chinese medicine cooperative therapy in treating acute cerebral infarction: A randomized controlled trial.

INTRODUCTION: Acute cerebral infarction is a clinically common cerebrovascular disease. Acute cerebral infarction is characterized by sudden onset, dangerous illness, high risk of death, and disability. Computed tomography perfusion imaging can detect abnormal brain tissue perfusion 30 minutes after the onset of cerebral ischemia, providing the earliest and most valuable information for clinical diagnosis and treatment. In recent years, the effect of traditional Chinese medicine on acute cerebral infarction has been remarkable. METHODS/DESIGN: This study plan randomly divided eligible acute cerebral infarction patients into two groups. Patients in the control group will be treated with conventional Western medicine; patients in the intervention group will be treated with traditional Chinese medicine cooperative therapy on the basis of conventional Western medicine. The curative effects will be selected before treatment, 2 weeks after treatment, and 3 months follow-up. The changes in CT imaging evaluation, NIHSS score, and BI index of the two groups of patients will be observed. DISCUSSION: We aim to provide higher evidence-based medical evidence for traditional Chinese medicine treatment of acute cerebral infarction. And clarify the application value of computed tomography perfusion imaging in the diagnosis and efficacy evaluation of acute cerebral infarction. TRIAL REGISTRATION: ClinicalTrials.gov, ChiCTR2000030230, Registered on 03 March 2020.

Changes in Skin Perfusion Pressure After Hyperbaric Oxygen Therapy Following Revascularization in Patients With Critical Limb Ischemia: A Preliminary Study.

Hyperbaric oxygen (HBO) therapy promotes wound healing in patients with ischemic disease; however, HBO-induced changes in skin peripheral circulation have not been evaluated in clinical practice. Here, we investigated these changes in patients with critical limb ischemia (CLI), with a focus on the angiosome of crural blood vessels with blood flow improved by endovascular therapy (EVT). Six patients with CLI and ulcers who were treated with HBO after EVT (7 limbs; 1 patient had ulcers in the bilateral limbs) and 3 healthy subjects (6 limbs) were enrolled. HBO therapy was performed at 2 atm under 100% oxygen for 90 min per session. Skin perfusion pressure (SPP) was measured in the dorsum and sole of the foot 1 hour before (pre-SPP) and after (post-SPP) HBO therapy. ΔSPP was calculated as post-SPP minus pre-SPP. SPP measurement regions were divided into those that did (direct region) and did not (indirect region) correspond to the vascular angiosome in which angiography findings of the crus were improved after EVT; i.e., when the anterior tibial artery was effectively treated with EVT, the dorsum was the direct region and the sole was the indirect region, and vice versa when the posterior tibial artery was treated. In the direct, indirect, and healthy subject groups, the ΔSPPs were 20.5±8.7 (p=0.002), -6.4±10.9, and -15.1±18.1 (p=0.014), respectively; that of the direct group was significantly greater than that of the other groups. These results suggest that short-term improvement of the peripheral circulation by HBO therapy was significant in patients with successful revascularization.

Does the Application of Tecar Therapy Affect Temperature and Perfusion of Skin and Muscle Microcirculation? A Pilot Feasibility Study on Healthy Subjects.

Background: Tecar therapy (TT) is an endogenous thermotherapy used to generate warming up of superficial and deep tissues. TT capability to affect the blood flow is commonly considered to be the primary mechanism to promote tissue healing processes. Despite some preliminary evidence about its clinical efficacy, knowledge on the physiologic responses induced by TT is lacking. Objective: The aim of this quantitative randomized pilot study was to determinate if TT, delivered in two modes (resistive and capacitive), affects the perfusion of the skin microcirculation (PSMC) and intramuscular blood flow (IMBF). Design: A randomized controlled pilot feasibility study. Subjects: Ten healthy volunteers (n = 4 females, n = 6 males; mean age 35.9 ± 10.7 years) from a university population were recruited and completed the study. Intervention: All subjects received three different TT applications (resistive, capacitive, and placebo) for a period of 8 min. Outcome measures: PSMC, IMBF, and the skin temperature (ST) were measured pre- and post-TT application using power Doppler sonography, laser speckle contrast imaging (LSCI), and infrared thermography. Results: Compared with placebo application, statistically significant differences in PSMC resulted after both the resistive (p = 0.0001) and the capacitive (p = 0.0001) TT applications, while only the resistive modality compared with the placebo was capable to induce a significant change of IMBF (p = 0.013) and ST (p = 0.0001). Conclusions: The use of power Doppler sonography and LSCI enabled us to evaluate differences in PSMC and IMBF induced by TT application.

Physiological impact of nanoporous acupuncture needles: Laser Doppler perfusion imaging in healthy volunteers.

BACKGROUND: Recently, porous acupuncture (PA), which is anodized to increase its surface area for higher stimulation intensity, was developed and showed significantly improved therapeutic effects with more comfort as compared with original acupuncture (OA) in vivo. However, the impact of PA on the change of local blood flow as well as its efficacy and acceptability has not yet been confirmed in a clinical trial. In a randomized, controlled crossover clinical trial, we investigated the effects of PA on the change in local blood flow using laser Doppler perfusion imaging and considered the sensation of pain intensity and discomfort severity using a visual analogue scale (VAS) to explore its physiological impact and the possibility of PA in clinical use. METHODS: Twenty-one healthy participants were randomly treated with PA or OA on one side of Zusanli (ST36) and each participant served as his or her own control. Baseline local blood flow and galvanic skin response (GSR) were obtained for 5 min and acupuncture interventions were subsequently performed. Next, local blood flow and GSR were subsequently obtained for 10 min after insertion, 10 min after manipulation, and 5 min after the withdrawal of acupuncture. At the end of the experiment, participants were asked to indicate the sensation of pain intensity at each session of insertion, retention, manipulation, and withdrawal as well as the overall pain intensity and discomfort severity. RESULTS: PA significantly increased the local blood flow as compared with OA and there was no significant difference in GSR between patients treated with PA versus OA in each phase of insertion and manipulation. No significant difference in pain intensity or discomfort severity was found during manipulation, retention, or withdrawal of acupuncture. CONCLUSIONS: These results indicate that PA increases local blood flow, which can be closely related to the observed enhanced performance, without any associated discomfort or pain, suggesting its applicability in clinical practice.

State of the art: utility of multi-energy CT in the evaluation of pulmonary vasculature.

Multi-energy computed tomography (MECT) refers to acquisition of CT data at multiple energy levels (typically two levels) using different technologies such as dual-source, dual-layer and rapid tube voltage switching. In addition to conventional/routine diagnostic images, MECT provides additional image sets including iodine maps, virtual non-contrast images, and virtual monoenergetic images. These image sets provide tissue/material characterization beyond what is possible with conventional CT. MECT provides invaluable additional information in the evaluation of pulmonary vasculature, primarily by the assessment of pulmonary perfusion. This functional information provided by the MECT is complementary to the morphological information from a conventional CT angiography. In this article, we review the technique and applications of MECT in the evaluation of pulmonary vasculature.

Change in Perfusion Angiography During Transcatheter Arterial Chemoembolization for Hepatocellular Carcinoma Predicts Short-Term Outcomes.

OBJECTIVE. The purpose of this study is to quantitatively assess perfusion reductions occurring in hepatocellular carcinoma (HCC) during transcatheter arterial chemoembolization (TACE) using 2D perfusion angiography and to evaluate the relationships between various 2D perfusion angiography parameter changes and short-term tumor response. SUBJECTS AND METHODS. This prospective study included 172 patients (144 men and 28 women; mean [± SD] age, 65.4 ± 10.2 years) who underwent TACE for HCC between November 2015 and November 2017. Two-dimensional perfusion angiography was performed before and after TACE. Pre- and postprocedural CT images were also reviewed. Index lesions were defined as all discrete lesions 1.5 cm or larger. The tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors. Periprocedural 2D perfusion angiography parameters, including the arrival time, time to peak, wash-in rate, width, AUC, and mean transit time, were compared using the Wilcoxon signed rank test. Correlations between 2D perfusion angiography parameter changes and objective tumor response were evaluated using multivariate logistic regression analysis. RESULTS. A total of 187 lesions meeting the inclusion criteria were identified in 172 patients. All analyzed 2D perfusion angiography parameters were significantly different after versus before TACE (p < 0.001). A significant relationship between periprocedural change in AUC and short-term tumor response was found (odds ratio, 1.535; 95% CI, 1.314-1.793; p < 0.001). CONCLUSION. Two-dimensional perfusion angiography could objectively quantify perfusion reductions and predict short-term tumor response to TACE in patients with HCC.

Modified Rat Hepatocellular Carcinoma Models Overexpressing Vascular Endothelial Growth Factor.

PURPOSE: To compare tumor vascularity in 4 types of rat hepatocellular carcinoma (HCC) models: N1S1, vascular endothelial growth factor (VEGF)-transfected N1S1 (VEGF-N1S1), McA-RH7777, and VEGF-transfected McA-RH7777 (VEGF-McA-RH777) tumors. MATERIALS AND METHODS: The N1S1 and McA-RH7777 cell lines were transfected with expression vectors containing cDNA for rat VEGF. Eighty-eight male Sprague-Dawley rats (weight range, 400-450 g) were randomly divided into 4 groups (ie, 22 rats per model), and 4 types of tumor models were created by using the N1S1, VEGF-N1S1, McA-RH7777, and VEGF-McA-RH777 cell lines. Tumor vascularity was evaluated by perfusion computed tomography (CT), enzyme-linked immunosorbent assay of VEGF, CD34 staining, angiography, and Lipiodol transarterial embolization. Intergroup discrepancies were evaluated by Kruskal-Wallis test. RESULTS: Arterial perfusion (P < .001), portal perfusion (P = .015), total perfusion (P < .001), tumor VEGF level (P = .002), and microvessel density (MVD; P = .007) were significantly different among groups. VEGF-McA-RH7777 tumors showed the greatest arterial perfusion (46.7 mL/min/100 mL ± 15.5), total perfusion (60.7 mL/min/100 mL ± 21.8), tumor VEGF level (3,376.7 pg/mL ± 145.8), and MVD (34.5‰ ± 7.5). Whereas most tumors in the N1S1, VEGF-N1S1, and McA-RH7777 groups showed hypovascular staining on angiography and minimal Lipiodol uptake after embolization, 5 of 6 VEGF-McA-RH7777 tumors (83.3%) presented hypervascular tumor staining and moderate to compact Lipiodol uptake. CONCLUSIONS: McA-RH7777 tumors were more hypervascular than N1S1 tumors, and tumor vascularity was enhanced further by VEGF transfection. Therefore, the VEGF-McA-RH7777 tumor is recommended to mimic hypervascular human HCC in rats.

The Value of Exercise Rehabilitation Program Accompanied by Experiential Music for Recovery of Cognitive and Motor Skills in Stroke Patients.

BACKGROUND: The aim of this study was to systematically assess the effects of exercise rehabilitation program accompanied by experiential music for clinical recovery. METHODS: This was a prospective randomized study with 65 stroke survivor patients. All cases underwent a neuropsychological assessment first as a prescreening test, during the admission at the Rehabilitation center (baseline), and 6 months poststroke. All patients received standard treatment for stroke in terms of medical care and rehabilitation. Additionally, all patients were separated into 2 Groups: a music Group (daily listening to experiential/traditional music), and a control Group (CG) with no experiential/traditional music therapy (standard care only). Computed tomography perfusion and full neurological examination including GCS were assessment. As Recovery was defined the improvement of cognitive and motor skills of the limb in the affected site, with an increase of muscle strength at least by 1/5 and with emotional progress. RESULTS: Statistically significant differences were found between the Group CG and the rest of the patients in respect of Lesion size (P = .001) and CBF in affected area (P = .001). Μultivariate analysis revealed that only Group and Lesion size were independent predictors for Recovery (odd ratio [OR][95%confidence interval]) .11(.001-.133) and .798(.668-.954) respectively. CONCLUSION: The findings of this study suggest that the music-based exercise program has a positive effect on mood profile in stroke patients and Recovery rate is higher when exercise rehabilitation program was accompanied by an enriched sound environment with experiential music.

Microvascular endothelial dysfunction during cardiopulmonary bypass in surgery for correction of cyanotic and acyanotic congenital heart disease.

OBJECTIVE: To evaluate endothelium-dependent microvascular reactivity during cardiopulmonary bypass (CPB) in surgery for the correction of cyanotic and acyanotic congenital heart disease (CHD) in children and infants using laser Doppler perfusion monitoring (LDPM). METHODS: This cross-sectional observational study included one hundred consecutive acyanotic (AC, n = 61) and cyanotic (C, n = 39) pediatric patients scheduled for cardiac surgery for correction of CHD. The endothelium-dependent microvascular vasodilation of the skin of the forehead was evaluated using a single-point LDPM coupled with local thermal hyperemia (LTH). RESULTS: LTH induced significant increases in microvascular conductance both in AC and C patients after the induction of anesthesia, during CPB and after weaning from CPB. Nevertheless, the vasodilation induced by LTH was significantly blunted during CPB when compared with values obtained after the induction of anesthesia both in AC and C patients. Microvascular endothelial reactivity nearly normalized after the discontinuation of CPB. CONCLUSION: The evaluation of systemic microvascular reactivity on the forehead skin of infants and children using LDPM appears to be a valuable tool for optimizing microvascular perfusion during CPB in pediatric cardiac surgery.

Time-resolved hypothalamic open flow micro-perfusion reveals normal leptin transport across the blood-brain barrier in leptin resistant mice.

OBJECTIVE: The inability of leptin to suppress food intake in diet-induced obesity, sometimes referred to as leptin resistance, is associated with several distinct pathological hallmarks. One prevailing theory is that impaired transport of leptin across the blood-brain barrier (BBB) represents a molecular mechanism that triggers this phenomenon. Recent evidence, however, has challenged this notion, suggesting that leptin BBB transport is acquired during leptin resistance. METHODS: To resolve this debate, we utilized a novel cerebral Open Flow Microperfusion (cOFM) method to examine leptin BBB transport in male C57BL/6J mice, fed a chow diet or high fat diet (HFD) for 20 days. RESULTS: Basal plasma leptin levels were 3.8-fold higher in HFD-fed mice (p < 0.05). Leptin administration (2.5 mg/kg) elicited similar pharmacokinetic profiles of circulating leptin. However, while leptin reduced food intake by 20% over 22 h in chow-fed mice, it did not affect food intake in HFD-fed mice. In spite of this striking functional difference, hypothalamic leptin levels, as measured by cOFM, did not differ between chow-fed mice and HFD-fed mice following leptin administration. CONCLUSIONS: These data suggest that leptin transport across the BBB is not impaired in non-obese leptin resistant mice and thus unlikely to play a direct role in the progression of pharmacological leptin resistance.

Thalamic Diaschisis in Acute Ischemic Stroke: Occurrence, Perfusion Characteristics, and Impact on Outcome.

BACKGROUND AND PURPOSE: Ipsilateral thalamic diaschisis (ITD) describes the reduction of thalamic function, metabolism, and perfusion resulting from a distant lesion of the ipsilateral hemisphere. Our aim was to evaluate the perfusion characteristics and clinical impact of ITD in acute middle cerebral artery stroke, which does not directly affect the thalamus. METHODS: One hundred twenty-four patients with middle cerebral artery infarction were selected from a prospectively acquired cohort of 1644 patients who underwent multiparametric computed tomography (CT), including CT perfusion for suspected stroke. Two blinded readers evaluated the occurrence of ITD, defined as ipsilateral thalamic hypoperfusion present on ≥2 CT perfusion maps. Perfusion alterations were defined according to the Alberta Stroke Program Early CT Score regions. Final infarction volume and subacute complications were assessed on follow-up imaging. Clinical outcome was quantified using the modified Rankin Scale. Multivariable linear and ordinal logistic regression analysis were applied to identify independent associations. RESULTS: ITD was present in 25/124 subjects (20.2%, ITD+). In ITD+ subjects, perfusion of the caudate nucleus, internal capsule, and lentiform nucleus was more frequently affected than in ITD- patients (each with P<0.001). In the ITD+ group, larger cerebral blood flow (P=0.002) and cerebral blood volume (P<0.001) deficit volumes, as well as smaller cerebral blood flow-cerebral blood volume mismatch (P=0.021) were observed. There was no independent association of ITD with final infarction volume or clinical outcome at discharge in treatment subgroups (each with P>0.05). ITD had no influence on the development of subacute stroke complications. CONCLUSIONS: ITD in the form of thalamic hypoperfusion is a frequent CT perfusion finding in the acute phase in middle cerebral artery stroke patients with marked involvement of subcortical areas. ITD does not result in thalamic infarction and had no independent impact on patient outcome. Notably, ITD was misclassified as part of the ischemic core by automated software, which might affect patient selection in CT perfusion-based trials.

Prognostic value of perfusion CT in hepatocellular carcinoma treatment with sorafenib: comparison with mRECIST in longitudinal follow-up.

Background Targeted therapies are of increasing clinical importance and classic radiologic therapy response-criteria often fail to detect early therapeutic response or failure. For hepatocellular carcinoma (HCC), this is of major importance as therapeutic options are limited. Purpose To investigate the impact of sorafenib-treatment on intralesional perfusion using perfusion computed tomography (PCT) in HCC and to correlate the observed changes with mRECIST and the course of serum alpha-fetoprotein (AFP) for identification of their prognostic value. Material and Methods PCT was performed before and after two months of sorafenib treatment in 28 consecutive HCC patients and AFP levels were registered. Changes in tumor perfusion parameters blood flow (BF), blood volume (BV), mean transit time (MTT), volume transfer constant (Ktrans), arterial liver perfusion (ALP), and hepatic perfusion index (HPI) were registered in one target lesion. mRECIST measurements were performed at baseline and after two and four months during sorafenib treatment. Results According to mRECIST, after two months of treatment, all patients showed stable disease (SD), whereas after four months, 13 patients (46%) showed SD and 15 patients (54%) showed progressive disease (PD). A significant decrease was found in perfusion parameters BF, BV, Ktrans, ALP, and HPI in patients with SD as well as a significant increase in MTT ( P < 0.05) after two months compared to baseline, while patients with PD showed a significant increase in HPI, BF, and BV. There were no correlations between AFP and mRECIST or perfusion parameters. Conclusion Decreased intralesional BF and HPI after two months of sorafenib treatment predicts disease stabilization after four months, whereas AFP dynamics were of limited value.

Acute black tea consumption improves cutaneous vascular function in healthy middle-aged humans.

BACKGROUND & AIMS: Dietary flavonoids, such as those present in black tea, are associated with reduced risk of cardiovascular disease (CVD), possibly through improving nitric oxide (NO) mediated vascular function. The aim of this study was to examine the effect of acute black tea ingestion on cutaneous microvascular function. METHODS: Twenty healthy participants (58 ± 5 y, 9 men) attended two experimental trials (tea, placebo), 7-days apart in a randomised, controlled, double-blind, cross-over design. Participants ingested a single dose of 200 ml black tea or placebo, followed by assessment of forearm cutaneous perfusion using laser-Doppler flowmetry (LDF) using three distinct heating protocols, enabling us to distinguish between axon- and endothelium-dependent vasodilation: 1. rapid 42°C, 2. rapid 39°C and 3. gradual 42°C. On the contralateral arm, full-field laser perfusion imaging (FLPI) was used to assess forearm perfusion during gradual 42°C. Data were presented as cutaneous vascular conductance (CVC; flux/mean arterial pressure, MAP) and CVC expressed as a percentage of maximal CVC (%CVCmax). RESULTS: Rapid local heating to 39°C or 42°C demonstrated no effect of tea for flux, CVC or %CVCmax (all P > 0.05). Gradual local heating to 42 °C, however, produced a higher skin blood flow following black tea ingestion for absolute CVC (P = 0.04) when measured by LDF, and higher absolute flux (P < 0.001) and CVC (P < 0.001) measured with FLPI. No effect of tea was found for %CVCmax when assessed by either LDF or FLPI. CONCLUSIONS: Acute tea ingestion enhanced cutaneous vascular responses to gradual local heating to 42 °C in healthy, middle-aged participants, possibly through a mechanism related to activation of endothelium-derived chemical mediators, such as NO. These improvements may contribute to the cardiovascular health benefits of regular tea ingestion.

In Patients with Severe Peripheral Arterial Disease, Revascularization-Induced Improvement in Lower Extremity Ischemia Can Be Detected by Laser Speckle Contrast Imaging of the Fluctuation in Blood Perfusion after Local Heating.

BACKGROUND: We previously reported the utility of the perfusion value (PV) fluctuation slope for detecting severe ischemia in the lower limb. Our approach was based on a thermal load test mimicking the well-known physiological reaction termed "cold-induced vasodilation," which is known to occur as a 3-phase phenomenon. The slope parameter quantifies the decrease in PVs accompanying the relative cooling (third phase) following the transient increase in blood flow (second phase) induced by the applied thermal load. This phenomenon of "relative" cold-induced vasodilation (rCIVD) can be monitored using laser speckle contrast imaging (LSCI) after applying the thermal load (LTL test). Here, we aimed to determine whether the slope parameter obtained via the LTL test also reflects the improvement in hemodynamics after revascularization. METHODS: The study enrolled 16 patients (18 limbs), who underwent revascularization for peripheral arterial disease (PAD). The measurements were performed at 2 sites in each limb (in total, 34 sites; 2 sites in one patient were excluded because of significant movement during the measurement). For each site, we recorded the slope describing the behavior of PVs (decrease or plateau) in the third phase of rCIVD, following the initial, heating-induced increase in perfusion (second phase of rCIVD). The plateau group (group P), which included patients with an abnormal rCIVD, and the decrease group (group D), which included patients with a normal rCIVD, were defined based on perfusion slope values of <0.20 and ≥ 0.20 perfusion units/min, respectively. We also quantified the transient increase in perfusion (from baseline to peak) as a descriptor of perfusion behavior during the second phase of rCIVD. RESULTS: In group P, the change in median values (25-75%) of the slope, transcutaneous oxygen tension, and ankle-brachial index (ABI) from before to after operation was (-0.02 [-0.04 to 0.02]; 4 [1-11]; and 0.08 [0-0.27]) to (0.39 [0.32-0.59]; 46 [37-54]; and 0.81 [0.72-0.90]). Conversely, in group D, the change in the median values of the slope, transcutaneous oxygen tension, and ABI between before and after operation was (0.38 [0.32-0.49]; 40.5 [35-45]; and0.58 [0.57-0.65]) to (0.44 [0.30-0.64]; 52 [43-56]; and 0.92 [0.81-0.99]). Sites exhibiting perfusion pattern of group D in the third phase of rCIVD showed no significant change in slope after revascularization (P = 0.21), whereas the slope in group P increased significantly after revascularization, becoming similar to the postoperative slopes in group D (P = 0.81). The amount of transient increase in perfusion, which quantified the behavior in the second phase of rCIVD, showed a similar behavior. Preoperatively, all patients in group P had rest pain and/or ulcer of the foot, whereas only few patients in group D had such symptoms. CONCLUSIONS: Normal rCIVD response in the LTL test indicates less-than-severe ischemia, while abnormal rCIVD response measured via the LTL test indicates severe ischemic symptoms, such as critical limb ischemia. Notably, patients with an abnormal rCIVD response can develop a normal rCIVD response following revascularization, thereby reflecting an improvement in blood flow. The LTL test assessing rCIVD response can be useful for detecting severe limb ischemia, such as critical limb ischemia (CLI), and determining the departure from severe limb ischemia by revascularization.

Arterial Spin-Labeling Perfusion MR Imaging Demonstrates Regional CBF Decrease in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND AND PURPOSE: Regional cerebral blood flow has previously been studied in patients with idiopathic normal pressure hydrocephalus with imaging methods that require an intravenous contrast agent or expose the patient to ionizing radiation. The purpose of this study was to assess regional CBF in patients with idiopathic normal pressure hydrocephalus compared with healthy controls using the noninvasive quantitative arterial spin-labeling MR imaging technique. A secondary aim was to compare the correlation between symptom severity and CBF. MATERIALS AND METHODS: Differences in regional cerebral perfusion between patients with idiopathic normal pressure hydrocephalus and healthy controls were investigated with pseudocontinuous arterial spin-labeling perfusion MR imaging. Twenty-one consecutive patients with idiopathic normal pressure hydrocephalus and 21 age- and sex-matched randomly selected healthy controls from the population registry were prospectively included. The controls did not differ from patients with respect to selected vascular risk factors. Twelve different anatomic ROIs were manually drawn on coregistered FLAIR images. The Holm-Bonferroni correction was applied to statistical analyses. RESULTS: In patients with idiopathic normal pressure hydrocephalus, perfusion was reduced in the periventricular white matter (P < .001), lentiform nucleus (P < .001), and thalamus (P < .001) compared with controls. Cognitive function in patients correlated with CBF in the periventricular white matter (r = 0.60, P < .01), cerebellum (r = 0.63, P < .01), and pons (r = 0.71, P < .001). CONCLUSIONS: Using pseudocontinuous arterial spin-labeling, we could confirm findings of a reduced perfusion in the periventricular white matter, basal ganglia, and thalamus in patients with idiopathic normal pressure hydrocephalus previously observed with other imaging techniques.