Blood Flow Perfusion Research Articles

Preliminary ultrasonography study of the pancreas in the dromedary camel (Camelus dromedarius)

IntroductionPancreatic lesions in camels can lead to significant economic losses. They are practically undetectable, as clinical signs alone are insufficient for specific diagnosis. Ultrasonography is a valuable diagnostic tool for evaluating the pancreas. However, ultrasonographic reference patterns of the pancreas in the camel are yet to be established. This study aimed to define the ultrasonographic appearance, reference values, location, and acoustic window for evaluating the pancreas in healthy camels.MethodsEight adult and 14 young Moroccan camels were investigated by ultrasonography using a micro-convex probe with SIUI CTS-900 V and Samsung MH70A Doppler ultrasound scanners at 3.5 MHz.ResultsThe body of the pancreas was scanned just below the right kidney, behind the 12th rib; an ultrasonographic pattern of pancreatic parenchyma appeared as a hyperechoic elongated band, including the portal vein, with a Doppler flow response. The average thickness of the body was 3.60 ± 0.24 cm (n = 14) in young camels significantly lower than in adult camels 4.61 ± 0.26 cm (n = 8). The right lobe was scanned on the right side, adjacent to the duodenal ampulla and abomasum, beneath the liver along the 11th, 10th, and 9th intercostal spaces. The ultrasonographic pattern of parenchyma appeared as a hyperechoic triangle compared to the liver, including portal and duodenal-pancreatic veins, showing a Doppler flow response. The corresponding parenchyma thickness within the three intercostal spaces was 3.93 ± 0.33 cm, 4.40 ± 0.20 cm, and 3.46 ± 0.39 cm in the young camels (n = 14), and 4.99 ± 0.46 cm, 5.90 ± 0.27 cm, and 4.11 ± 0.68 cm in the adults (n = 8), respectively. The pancreatic major duct was seen as an anechoic circle with a hyperechoic wall, with a maximum diameter of 1 cm, and the left lobe scanned beneath the cranial extremity of the spleen; its ultrasonographic pattern showed an irregular hypoechoic band with a mean thickness of 2.32 ± 0.32 cm (n = 14) in young camels and 3.08 ± 0.52 cm (n = 8) in the adults, including a small splenic vein.ConclusionUltrasonography combined with Doppler techniques provides valuable information on pancreatic health, blood flow, and tissue perfusion, aiding early detection of pancreatic diseases and, consequently, minimizing economic losses in camel husbandry.

Quantitative evaluation of placental microvascular blood flow and microstructure in fetal growth restriction with IVIM MRI.

Intravoxel incoherent motion (IVIM) MRI uses diffusion-weighted (DW) MRI acquisitions to evaluate the microvascular and cellular environments of tissue. Due to these properties, IVIM has been increasingly utilized to evaluate abnormal placentation. Our primary objective was to compare IVIM parameters in the placenta of patients with fetal growth restriction and appropriate for gestational age controls across gestational ages. Our secondary aim was to quantify IVIM parameters in fetal versus maternal placental aspects to evaluate microvascular and parenchymal differences. With IRB approval, pregnant individuals with a diagnosis of fetal growth restriction (n=24) and controls (n=22) were retrospectively analyzed. DW-MRI data were collected at 1.5 T with nine b-values (range, 0 s/mm2 to 1,000 s/mm2). Data were processed by one non-blinded reader to obtain mean perfusion fraction (f), pseudo-diffusion coefficient (D*), their product fD*, and diffusion coefficient (D) in maternal and fetal aspects of the placenta, defined by bisecting the thickness of the placenta. Repeated measures of two-way ANOVAs were used to compare IVIM parameters in fetal and maternal placental aspects between participant groups. Correlations between IVIM parameters and gestational age were also evaluated in both groups. The average gestational age at MRI was 27±4 weeks for both groups. The percentile estimated fetal weight was 5.4±5.9% for the fetal growth restriction group and 42.8±28.5% for controls (P<0.001). The parameters D* and fD*, related to microvascular blood flow and tissue perfusion, were significantly lower in participants with fetal growth restriction compared to controls (D*, 40.5 vs. 52.4×10-3 mm2/s, P=0.043; fD*, 14.7 vs. 21.0×10-3 mm2/s, P=0.019). No other differences were observed, nor associations between gestational age and IVIM parameters in either group. Our results suggest reduced microvascular flow in placentas of patients with fetal growth restriction compared to controls.

Oxygenation and intestinal perfusion and its association with perturbations of the early life gut microbiota composition of children with congenital heart disease.

Early life gut microbiota is known to shape the immune system and has a crucial role in immune homeostasis. Only little is known about composition and dynamics of the intestinal microbiota in infants with congenital heart disease (CHD) and potential influencing factors. We evaluated the intestinal microbial composition of neonates with CHD (n = 13) compared to healthy controls (HC, n = 30). Fecal samples were analyzed by shotgun metagenomics. Different approaches of statistical modeling were applied to assess the impact of influencing factors on variation in species composition. Unsupervised hierarchical clustering of the microbial composition of neonates with CHD was used to detect associations of distinct clusters with intestinal tissue oxygenation and perfusion parameters, obtained by the "oxygen to see" (O2C) method. Overall, neonates with CHD showed an intestinal core microbiota dominated by the genera Enterococcus (27%) and Staphylococcus (20%). Furthermore, a lower abundance of the genera Bacteroides (8% vs. 14%), Parabacteroides (1% vs. 3%), Bifidobacterium (4% vs. 12%), and Escherichia (8% vs. 23%) was observed in CHD compared to HCs. CHD patients that were born by vaginal delivery showed a lower fraction of the genera Bacteroides (15% vs. 21%) and Bifidobacterium (7% vs. 22%) compared to HCs and in those born by cesarean section, these genera were not found at all. In infants with CHD, we found a significant impact of oxygen saturation (SpO2) on relative abundances of the intestinal core microbiota by multivariate analysis of variance (F[8,2] = 24.9, p = 0.04). Statistical modeling suggested a large proportional shift from a microbiota dominated by the genus Streptococcus (50%) in conditions with low SpO2 towards the genus Enterococcus (61%) in conditions with high SpO2. We identified three distinct compositional microbial clusters, corresponding neonates differed significantly in intestinal blood flow and global gut perfusion. Early life differences in gut microbiota of CHD neonates versus HCs are possibly linked to oxygen levels. Delivery method may affect microbiota stability. However, further studies are needed to assess the effect of potential interventions including probiotics or fecal transplants on early life microbiota perturbations in neonates with CHD.

Noninvasive in vivo assessment of placental insufficiency using pCASL: a prospective case–control study

BackgroundArterial spin labeling is a noninvasive imaging modality that does not use contrast for evaluation of placental perfusion in the placental pathological conditions. Our study enrolled 30 pregnant females with different risk factors for developing IUGR and other 30 females with the same age group having normal pregnancy. The two groups were evaluated by free breathing arterial spin labeling magnetic resonance imaging. Image findings of pseudo-continuous arterial spin labeling were compared to color duplex Doppler ultrasound of umbilical and middle cerebral arteries.AimThe aim of the present study was to evaluate the role of pseudo-continuous arterial spin labeling in measurement of placental perfusion with quantitative analysis of regional placental blood flow.MethodsThis prospective case–control study enrolled 30 pregnant females who had different causes of placental insufficiency, and another healthy group of matched ages, all were evaluated by 2D and color duplex Doppler ultrasound, conventional non-contrast magnetic resonance imaging and MRI perfusion using arterial spin labeling technique. The study was carried out from October 2021 to October 2023.ResultsSignificant relation was found between placental perfusion values and umbilical and middle cerebral artery resistive indices as indicator for placental insufficiency with sensitivity and specificity 77.8%, 80%, respectively, for umbilical artery resistive index and 90%, 83.3%, respectively, for middle cerebral artery resistive index. While the diagnostic value of ASL perfusion was as follows, it had sensitivity = 90%, specificity = 83.3%, PPV = 84.4%, NPV = 89.3% and accuracy = 86.7%.ConclusionsASL-MRI is an excellent noninvasive in vivo MRI technique for evaluation of placental perfusion and quantitative analysis of regional placental blood flow in cases of placental insufficiency. This study supported the value of the new noninvasive MRI techniques in the elaboration of placental pathology.

Axial length to corneal curvature radius ratio is negatively correlated with choroidal blood flow in myopic children.

The pathophysiologic mechanisms underlying early-onset myopia remain unclear; in this study, we investigate the pathogenesis by examining the interrelationships between axial length to corneal curvature radius ratio ( ) and choroidal blood flow. This cross-sectional study included 202 eyes from myopic children, categorized into 141 eyes with mild myopia, 47 eyes with moderate myopia, and 14 eyes with high myopia. Optical coherence tomography angiography (OCTA) was used to measure choroidal blood flow perfusion within a 6mm × 6mm area of the macular region, divided into nine subareas based on ETDRS partitioning: macular fovea, nasal side 1, superior 1, temporal side 1, inferior 1, nasal side 2, superior 2, temporal side 2, and inferior 2. Data on corneal curvature and ocular axial length were collected to calculate the , with equivalent spherical lens power, gender, and age gathered for group comparisons, and the correlation between AL/CR and choroidal blood flow perfusion volume was analyzed. was significantly negatively correlated with choroidal blood flow perfusion ( ). Linear regression and mediation analyses indicated that for each unit increase in choroidal blood perfusion volume in nasal region 1, decreased by an average of 0.421 units. This relationship is mediated by several factors, with axial length serving as a key mediator. correlates with choroidal blood flow perfusion, indicating a link between refractive biological parameters and ocular blood circulation. Myopia is an ischemic eye condition that warrants attention to fundus microcirculation changes in myopic children.

BMSCs-derived small extracellular vesicles antagonize cerebral endothelial Caveolin-1 driven autophagic degradation of tight-junction proteins to protect blood-brain barrier post-stroke.

Bone marrow mesenchymal stem cells (BMSCs) -derived extracellular vesicles (EVs), especially small EVs (sEVs), were vastly reported to enable multiple restorative effects on ischemic stroke, yet the protective mechanism of blood-brain barrier (BBB) has not been fully illustrated. In the present study, we investigated the therapeutic effects and mechanism of BMSCs-derived sEVs on BBB injury after ischemic stroke. In-vivo, administering sEVs to transient middle cerebral artery occlusion (tMCAo) mice mitigated the brain infarct volume, BBB permeability and neural apoptosis, and improved the cerebral blood flow perfusion and neurological function. Simultaneously, cerebral vascular endothelial overexpressed Caveolin-1 (Cav-1) together with its strong co-localization with autophagosome protein LC3B were suppressed, and ZO-1 and Occludin expressions were enhanced, whose results were consistent with those of oxygen-glucose-deprivation/reperfusion (OGD/R)-insulted brain endothelial cells (BECs) in vitro. Furthermore, by employing Cav-1 siRNA and pcDNA3.1 transfection, Co-immunoprecipitation, cycloheximide assay, and molecular docking, it proved that brain endothelial Cav-1 was an essential upstream of autophagy activation, contributing to tight-junction proteins delegation via the autophagy-lysosomal pathway. Altogether, our study demonstrates the novel mechanism of Cav-1-dependent tight-junction proteins autophagic disruption on BBB integrity after ischemic stroke, and BMSC-sEVs treatment can reverse such hazard cascades.

History of contrast enhanced ultrasound (CEUS).

The 50th year of the European Federation of Societies in Ultrasound in Medicine and Biology (EFSUMB) has been celebrated 2022 publishing articles on the history of US. Contrast enhanced ultrasound (CEUS) allows to visualize blood flow and tissue perfusion. CEUS has proven to be safe without risk of nephrotoxicity. The availability of a contrast agent (tracer) for ultrasound imaging allows for the first time a dynamic assessment of tissue perfusion (blood flow and wash-in/wash-out pattern) which is an essential part for the detection and characterisation of pathological tissue and abnormal organ function. It was an outstanding achievement of academic centers in close cooperation with EFSUMB to investigate and validate the clinical potential of this new technology for the diagnosis and monitoring of various diseases and to develop clinical guidelines based on an in-depth assessment of the existing scientific publications. An important part of the implementation of CEUS in clinical practice was the development of contrast-specific imaging modes on the ultrasound scanners (in close cooperation with the machine manufacturers), the optimization of the machine setups for contrast imaging and the education provided to clinical users in form of workshops, webinars, textbooks and scientific congresses.

Therapeutic Efficacy of Tirofiban Combined With Thrombus Aspiration and Stent Thrombectomy in the Treatment of Large Vessel Occlusion Ischemic Stroke.

This research aimed to ascertain the effects of tirofiban combined with thrombus aspiration and stent thrombectomy on large vessel occlusion ischemic stroke (LVO-IS). Sixty patients with acute ischemic stroke (AIS) caused by LVO were randomized into the control group and the intervention group (n=30). Patients in the control group received thrombus aspiration combined with stent thrombectomy, while those in the intervention group were treated with tirofiban combined with thrombus aspiration and stent thrombectomy. General data, perioperative-related indicators, cerebral blood flow perfusion, coagulation function indicators, and neurological function indicators were collected, and the prognosis was observed after 3-month treatment. A comparison of symptomatic cerebral hemorrhage rate and hospital mortality rate between the 2 groups displayed no significant difference (P>0.05). The rate of revascularization in the intervention group (90.00%) was higher versus the control group (66.67%). After treatment, the mean blood flow and cerebral blood volume of the intervention group were higher and the time to peak cerebral blood flow was less versus the control group. The prothrombin time, activated partial thromboplastin time, and prothrombinogen time of the intervention group were higher, and fibrinogen was lower versus the control group. A lower National Institutes of Health Stroke Scale score was observed in the intervention group versus the control group. Tirofiban combined with thrombus aspiration and stent thrombectomy has good efficacy in LVO-IS patients.

Lower neurovascular coupling response despite higher cerebral blood flow at rest in apolipoprotein ɛ4 positive adults.

Cerebral blood flow at rest declines with age. However, age-related changes in functional measures of cerebrovascular health including cerebrovascular reactivity and neurovascular coupling are not well understood. Additionally, the effect of apolipoprotein E (APOE) ε4, a strong genetic risk factor for Alzheimer's disease, on cerebral blood flow and cerebrovascular function remains unclear. APOEε4 positive (APOEε4+; n = 37, age = 63±4y) and APOEε4 negative (APOEε4-; n = 50, age = 63±4y) cognitively unimpaired adults participated in this study. Macrovascular cerebral blood flow and microvascular cerebral perfusion were measured using 4D flow MRI and pseudo-continuous arterial spin labeling MRI, respectively. Cerebrovascular reactivity and neurovascular coupling were assessed by measuring middle cerebral artery blood velocity in response to hypercapnia and the n-back test, respectively. Neurovascular coupling was lower in APOEε4+ compared with APOEε4- adults (P<0.05), despite higher cerebral blood flow and cerebrovascular reactivity to hypercapnia. Alterations in neurovascular coupling may occur early, prior to changes in cognition, in aging APOEε4 carriers.

Dual-Wavelength Confocal Laser Speckle Contrast Imaging Using a Deep Learning Approach

This study developed a novel dual-wavelength confocal laser speckle imaging platform. The system includes both visible and near-infrared lasers and two imaging modes: confocal and wide-field laser speckle contrast imaging. The experimental results confirm that the proposed system can be used to measure not only blood flow but also blood oxygen saturation. Additionally, we proposed a blood flow perfusion imaging method called BlingNet (a blood flow imaging CNN) based on the laser speckle contrast imaging technique and deep learning approach. Compared to the traditional nonlinear fitting method, this method has superior accuracy and robustness with higher imaging speed, making real-time blood flow imaging possible.

Quantum machine learning enhanced laser speckle analysis for precise speed prediction

Laser speckle contrast imaging (LSCI) is an optical technique used to assess blood flow perfusion by modeling changes in speckle intensity, but it is generally limited to qualitative analysis due to difficulties in absolute quantification. Three-dimensional convolutional neural networks (3D CNNs) enhance the quantitative performance of LSCI by excelling at extracting spatiotemporal features from speckle data. However, excessive downsampling techniques can lead to significant information loss. To address this, we propose a hybrid quantum–classical 3D CNN framework that leverages variational quantum algorithms (VQAs) to enhance the performance of classical models. The proposed framework employs variational quantum circuits (VQCs) to replace the 3D global pooling layer, enabling the model to utilize the complete 3D information extracted by the convolutional layers for feature integration, thereby enhancing velocity prediction performance. We perform cross-validation on experimental LSCI speckle data and demonstrate the superiority of the hybrid models over their classical counterparts in terms of prediction accuracy and learning stability. Furthermore, we evaluate the models on an unseen test set and observe that the hybrid models outperform the classical models with up to 14.8% improvement in mean squared error (MSE) and up to 26.1% improvement in mean absolute percentage error (MAPE) evaluation metrics. Finally, our qualitative analysis shows that the hybrid models offer substantial improvements over classical models in predicting blood flow at both low and high velocities. These results indicate that the hybrid models possess more powerful learning and generalization capabilities.

Simvastatin ameliorates adverse pregnancy by inhibiting glycolysis-related NETs in obstetrical antiphospholipid syndrome

AimsSome patients with Obstetric Antiphospholipid Syndrome (OAPS) still experience miscarriage and placental dysfunction after routine treatment, which is related to an abnormal increase in neutrophil extracellular traps (NETs). The labeling of statins has been revised to remove the contraindication for use during pregnancy. Our aim is to investigate the effect of Simvastatin on pregnancy outcomes in OAPS and its correlation mechanisms with NETs. Main methodsThe effect of Simvastatin on pregnancy outcomes was observed. The effect of simvastatin on the function and apoptosis of neutrophils has evaluated. The effect of Simvastatin to NETs and the changes in oxidative stress levels were observed. Different groups of NETs were extracted to intervene the HTR8-Svneo.RNA-seq analysis of the mechanism of which Simvastatin reduces NETs. Seahorse experiment detected the effect of Simvastatin on neutrophil glycolysis levels. Fluorescence co-localization and flow cytometry and Co-IP were used to verify relevant mechanisms. Key findingsIn the OAPS mice, Simvastatin can reduce embryo absorption rate, reshape placental blood flow perfusion. Simultaneously reducing the production of NETs both in vivo and vitro, remolding oxidative stress. Simvastatin can improve neutrophil dysfunction caused by aPL-IgG. The reduction of NETs improved HTR8-Svneo's dysfunction. The intervention of Simvastatin on neutrophils under the stimulation of aPL-IgG showed a signature in glycolytic. The key rate limiting enzyme PKM2 in glycolysis interacts with Cit-H2b and PI3K/AKT signaling pathway. SignificanceOur study providing basic theoretical support for the treatment of OAPS with Simvastatin.

Do as Sonographers Think: Contrast-Enhanced Ultrasound for Thyroid Nodules Diagnosis via Microvascular Infiltrative Awareness.

Dynamic contrast-enhanced ultrasound (CEUS) imaging can reflect the microvascular distribution and blood flow perfusion, thereby holding clinical significance in distinguishing between malignant and benign thyroid nodules. Notably, CEUS offers a meticulous visualization of the microvascular distribution surrounding the nodule, leading to an apparent increase in tumor size compared to gray-scale ultrasound (US). In the dual-image obtained, the lesion size enlarged from gray-scale US to CEUS, as the microvascular appeared to be continuously infiltrating the surrounding tissue. Although the infiltrative dilatation of microvasculature remains ambiguous, sonographers believe it may promote the diagnosis of thyroid nodules. We propose a deep learning model designed to emulate the diagnostic reasoning process employed by sonographers. This model integrates the observation of microvascular infiltration on dynamic CEUS, leveraging the additional insights provided by gray-scale US for enhanced diagnostic support. Specifically, temporal projection attention is implemented on time dimension of dynamic CEUS to represent the microvascular perfusion. Additionally, we employ a group of confidence maps with flexible Sigmoid Alpha Functions to aware and describe the infiltrative dilatation process. Moreover, a self-adaptive integration mechanism is introduced to dynamically integrate the assisted gray-scale US and the confidence maps of CEUS for individual patients, ensuring a trustworthy diagnosis of thyroid nodules. In this retrospective study, we collected a thyroid nodule dataset of 282 CEUS videos. The method achieves a superior diagnostic accuracy and sensitivity of 89.52% and 94.75%, respectively. These results suggest that imitating the diagnostic thinking of sonographers, encompassing dynamic microvascular perfusion and infiltrative expansion, proves beneficial for CEUS-based thyroid nodule diagnosis.

Low-dose aspirin improves blood perfusion of obstetric anticardiolipin syndrome in China.

This study evaluates the endometrial receptivity of obstetric anticardiolipin syndrome (OAPS) patients using various ultrasound indicators and the efficacy of low-dose aspirin (LDA) treatment. This retrospective study recruited patients from Shanghai Ren Ji Hospital, China from January 2022 to December 2023. Doppler parameters of the endometrium and uterine artery blood flow were recorded to assess the endometrial receptivity of OAPS patients compared with normal pregnant women and an other immune diseases group. The receiver operating characteristic curve was used to predict the risk of OAPS patients. Doppler parameters of OAPS patients were conducted repeatedly after a 2-month period of treatment with LDA. Compared with normal pregnant women, the OAPS group showed remarkably increased endometrial perfusion resistance (PI, RI, S/D) and uterine artery perfusion resistance (RI and S/D) (P < 0.001) and had good predictive values (area under the curve = 0.806, 0.976, 0.942, 0.902, and 0.901, respectively). The endometrial thickness of the OAPS group was much thinner than that of the normal group (P < 0.001). Uterine blood flow impedance PI showed no difference in both groups (P = 0.68). In comparison to other autoimmune diseases, the OAPS group also showed an increasing trend in the resistance of endometrium and uterine artery blood flow. After LDA treatment, there was an obvious improvement in the endometrial blood flow perfusion in the OAPS group (P < 0.01). Compared with the normal group and other autoimmune diseases, the resistance of endometrial and uterine artery blood flow in the OAPS group was increased significantly. The Doppler index showed the predictive value of OAPS, and it was confirmed that LDA could enhance blood perfusion among OAPS women.

The impact of AAOCA anatomical characteristics in coronary blood supply

Abstract Background Impact of AAOCA in coronary blood flow and myocardial perfusion is an unknown field although it is well-accepted that the anomaly is one of the leading causes of sudden death during effort. The risk factors for AAOCA are the anatomical characteristics of the abnormal vessel, such as the presence of intramural (IM) segment, the ostium shape, and the take-off angle. Purpose We aim to evaluate the impact of AAOCA anatomical risk profile in the blood flow using the thermodilution technique, an accurate and reproducible method used to investigate coronary physiology. Methods This is a single-centre prospective study that included AAOCA subjects who underwent invasive thermodilution functional coronary assessment. We divided patients into two groups according to the anatomical risk profile: a) ischemic risk (IR): concomitant presence of IM segment, take-off angle&amp;lt;45°, and slit-like/oval shape ostium, or a IM length&amp;gt;10 mm; b) no-ischemic risk (no-IR): absence of IM segment, take-off angle&amp;gt;45°, round ostium. We obtained coronary functional measures using the thermodilution method. We measured the absolute flow, and coronary resistance at rest and maximal hyperemia. Data were reported as median and IQR and we used Wilcoxon signed-rank test for paired data in the rest vs. hyperaemia comparison. Results We included 28 AAOCA pts (22 male, 6 female, median age: 48.6 (IQR: 18.9) ) that were 20 anomalies of the right coronary and 8 of the left. Symptomatic subjects (n=16) presented with angina (n=12), syncope (n=1), presyncope (n=1), fatigue (n=1), and dyspnea associated with arrhythmia (n=1). The IR group (26 pts; R-AAOCA=24, L-AAOCA=2) has an IM segment with a median length of 10 mm (IQR: 5.5), a median take-off angle of 28° and the ostium was slit-like (n=16), oval (n=10), and round (n=1). The no-IR group consisted of 9 (R-AAOCA=3, L-AAOCA=6), median take-off angle of 69° and the ostium was oval (n=1), and round (n=8). The absolute flow and coronary resistance at rest of the IR group did not have significant differences compared to no-IR. Hyperemia determines an increment of coronary flow in both groups although the IR had a 2.9 fold increase and the no-IR as 3.5 fold increase compared to rest. In particular, the absolute flow of the IR group was significantly lower compared to the no-IR group (185 vs. 330 mL/min, p=0.012) and there was a greater coronary resistance (419 vs. 268 mmHg/(mL/min), p=0.027), as shown in Fig. 1. Conclusions Anatomical risk factors of AAOCA, such as IM take-off angle and ostium morphology, have a negative impact on the coronary blood supply that is reduced when compared to AAOCA without such anatomical features. Such impact can be revealed also at rest using the thermodilution method that induces maximal coronary vasodilatation that is the natural coronary response to physical effort. Further studies are needed to validate benefit of functional assessment in AAOCA risk stratification.

Serial quantitative stress perfusion cardiac magnetic resonance in patients undergoing coronary artery bypass grafting; prediction of symptomatic benefit

Abstract Background Serial multiparametric cardiovascular magnetic resonance (CMR) in patients undergoing coronary artery bypass grafting (CABG) may provide mechanistic insight into dynamic and persistent abnormalities of the myocardium in patients with stable coronary artery disease (CAD). Objectives To assess for dynamic CMR markers of myocardial hypoperfusion and cardiac remodelling in patients undergoing CABG. Methods Patients with CAD awaiting elective CABG were recruited into an observational cohort study. Baseline evaluation included bloods, Seattle Angina Questionnaire-7, and adenosine stress perfusion CMR. Automated fully quantitative stress and rest myocardial blood flow was calculated, alongside assessment of the visual ischaemic burden. Native and post-contrast septal T1 indices were also measured. Repeat evaluation at 6-12 months post CABG was performed. Results Of 43 patients who underwent serial evaluation with CMR (mean age 62.1±9.3, median LVEF 68% [IQR: 62-73%]), there was improvement in the median visual ischaemic burden (18% [IQR: 11-21] vs 42% [IQR: 27-51], P&amp;lt;0.001), mean global stress myocardial blood flow (1.5±0.5 ml/min/g vs 1.3±0.5 ml/min/g, P=0.002) and median global myocardial perfusion reserve (2.4 [IQR: 1.7-2.8] vs 1.7 [IQR: 1.4-2.2], P=0.002) following CABG. Greater improvement in the SAQ-7 summary score was associated with a larger visual ischaemic burden at baseline (ρ=0.44, P=0.004) and a greater decrease in the visual ischaemic burden following CABG (ρ=-0.38, P=0.02). Quantitative MBF metrics did not associate with baseline or change in SAQ-7 summary score. Mean LV extracellular matrix volume decreased following CABG (16.6±3.6ml/m2 vs 18.2±4.6ml/m2, P=0.009). Conclusion Multiparametric CMR identifies dynamic changes in markers of myocardial perfusion and interstitial fibrosis in patients following CABG. Visual assessment of inducible myocardial hypoperfusion may identify patients who will derive the most symptomatic benefit from CABG. The results, however, suggest an important degree of residual inducible ischaemia and an unclear clinical role for CMR-derived MBF calculations.Serial CMR perfusion dataAssociation of SAQ with perfusion

Deep learning detection of subclinical cardiovascular dysfunction in type 2 diabetes through retinal photography

Abstract Background Type 2 diabetes (T2D) is associated with excess atherosclerotic coronary disease and heart failure risk, with several cardiac abnormalities described in asymptomatic patients. Routine digital retinal photography performed for screening of diabetic retinopathy (DR) has the potential to identify patients with underlying cardiovascular disease (CVD). We aimed to determine whether features extracted from digital retinal photographs could detect subclinical cardiovascular dysfunction in asymptomatic people with T2D. Methods We prospectively enrolled adults with T2D and no history or symptoms of CVD to undergo extensive phenotyping with multiparametric stress perfusion cardiac MRI and CT coronary artery calcium scoring. Digital retinal photographs acquired for routine diabetic eye screening and performed within one year of cardiac evaluation were interrogated for retinopathy grading and using four deep learning (DL) models (Xception, Inception, EfficientNet, and MobileNet) to capture complex patterns within the retinal vasculature. Each subject had four retinal photographs (two of each eye) for DL analysis. Cardiac image analysis was performed blinded to participant details and independent of retinal images. Subjects with and without DR were compared. Participants were divided into training (80%) and validation datasets (20%) prior to DL analysis. DL models employed to predict from retinal images: presence or absence of coronary artery calcium on non-contrast CT, myocardial perfusion reserve &amp;lt;2.5, left ventricular (LV) global longitudinal strain &amp;lt;16%, absolute stress and rest myocardial blood flood (mL/g/min) used as continuous variables. AUC was used to assess the ability of DL models to discriminate between those without and without subclinical CVD. Results An initial 254 subjects (comprising 1,016 retinal photographs) were included in the analysis: 212 (83%) with no DR, 42 (17%) with grade 1 (mild background) DR. Key cardiac imaging parameters in subjects with and without DR are displayed in Table 1. The groups were well matched for age, sex, body mass index and blood pressure. Overall, those with grade 1 DR had higher atheroma burden, evidence of increased LV filling pressures (E/e’) and poorer systolic function, but no differences in stress and rest myocardial blood flow or myocardial perfusion reserve. However, all four DL models failed to achieve sufficient discrimination of any of the evaluated cardiac imaging parameters, with the majority achieving AUC scores below 50% for all cardiac parameters. Conclusion Asymptomatic adults with grade 1 DR exhibit more subclinical atherosclerosis and cardiovascular dysfunction than those without DR. However, DL transfer models could not discriminate between subjects with and without cardiovascular disease. Further work is needed to better define whether retinal screening may be used to identify those people with T2D most at risk of underlying cardiovascular disease.Subjects demographics

Orbital decompression improves visual function and macular blood perfusion status in patients with thyroid-related eye disease.

Orbital decompression surgery is a treatment option for Thyroid-associated Ophthalmopathy (TAO). However, its effects on visual function and macular perfusion status remain unclear. This study examined how orbital decompression surgery affects visual acuity and macular blood flow in TAO patients and the variation between these two factors. This study involved cross-sectional and longitudinal analyses of 54 TAO patients, who were categorized into a normal vision group (n = 40) and an impaired vision group (n = 14) based on the presence of visual impairment before surgery (LogMAR BCVA >0.097). Among the participants, 20 underwent orbital decompression surgery (normal vision group: n = 13, impaired vision group: n = 7). BCVA and IOP were assessed at baseline in patients with TAO, and macular retinal blood perfusion indices were measured using OCTA. One month post-operatively, changes in these indices were compared between the two groups, and the correlation between visual acuity and macular perfusion indices was analyzed. The LogMar BCVA in the visual impairment group was significantly worse than that in the normal vision group (p < 0.001), while the W-MVD was significantly lower (p = 0.01). In the visual impairment group, post-operative LogMar BCVA improved significantly (p = 0.038), and W-MVD increased significantly (p = 0.008) compared to baseline. However, there were no significant changes in LogMar BCVA, S-MVD, D-MVD, or W-MVD in the normal vision group from preoperative to postoperative assessments. A strong negative correlation was found between the changes in W-MVD and changes in LogMar BCVA in the eyes of the visual impairment group treated with orbital decompression (Pearson correlation coefficient, R = -0.812, p = 0.05). This study found that TAO patients with visual impairment had lower macular blood flow perfusion than those with normal vision. Endoscopic orbital decompression surgery was found to improve both the best-corrected visual acuity and macular blood flow perfusion in TAO patients with visual impairment, and the improvement in visual acuity was correlated with the improvement in macular blood flow perfusion.

Unraveling the thrombin–Alzheimer’s connection: Oral anticoagulants as potential neuroprotective therapeutics

In Alzheimer&amp;rsquo;s disease (AD), toxic amyloids formed by amyloid-&amp;beta; (A&amp;beta;) proteins and tau are implicated in the development of inflammatory, vascular, and neurodegenerative brain disorders. Thrombin has also been recognized as a proteopathic factor involved in A&amp;beta;-induced neurovascular dysfunction. Vascular A&amp;beta; activates the contact system in the blood, stimulating the production of inflammatory bradykinin and procoagulant thrombin. Thrombin, in turn, triggers inflammation, platelet activation, and the formation of fibrinolysis-resistant, A&amp;beta;-containing fibrin clots, leading to A&amp;szlig;-type cerebral amyloid angiopathy and associated neuropathology. Targeting thrombin with oral anticoagulants can normalize proinflammatory and prothrombotic states, counteracting the neurovascular consequences of AD. Pre-clinical studies have shown that such interventions preserve vascular and blood&amp;ndash;brain barrier integrity, improve cerebral blood flow and brain perfusion, and reduce parenchymal accumulations of toxic A&amp;beta;, tau, fibrin(ogen), and thrombin. These effects mitigate neuroinflammatory and neurodegenerative processes, ultimately preserving cognitive functions for a longer period. Recent observational clinical studies in patients with atrial fibrillation (AF) demonstrated that treatment with direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs) reduced the risk of dementia by up to 48% compared to non-users. The anti-dementia effects were most prominent in elderly patients but were also observed in individuals with low AF risk or newly diagnosed AF. In addition, DOACs reduced the risk of intracranial hemorrhage by approximately 50% compared to VKAs. The current review highlights the potential neuroprotective role of DOACs in AD. By preventing excessive thrombin generation caused by A&amp;beta; pathology, DOACs could protect vascular and neuronal functions, thereby slowing cognitive decline. DOACs, such as dabigatran, apixaban, and rivaroxaban, warrant further clinical investigation for their potential repurposing as disease-modifying therapeutics in AD.

Enhanced Diagnostic Imaging: Arrival-Time Parametric Imaging in Contrast-Enhanced Ultrasound for Multi-Organ Assessment.

Contrast-enhanced ultrasonography (CEUS) is a novel technology in ultrasound medicine that has gained widespread application in clinical practice. While CEUS offers various quantitative and qualitative parameters, it is limited by factors such as the single-color transient coverage of the contrast agent and its dependence on the operator, rendering it less suitable for detecting blood in organ lesions. Additionally, fluid dynamic perfusion remains unsatisfactory. Recently, arrival-time parametric imaging (At-PI) has emerged as a promising alternative; this technology not only uses color overlay to statically represent the dynamic perfusion of blood flow within lesions but also enhances visualization, minimizes operator variability, and provides insights into the vascular patterns of both benign and malignant lesions. At-PI has demonstrated numerous advantages and has been successfully applied to the liver, adrenal gland, breast, lymph nodes, prostate, and gastrointestinal tract, yielding encouraging preliminary results. This review synthesizes existing research findings, highlights significant parameters, examines the current global research landscape regarding this technology, and outlines the research directions pursued by scholars in the field. Furthermore, we offer a critical analysis and discussion of the limitations of these findings. The ultimate aim is to elucidate the role of At-PI in clinical diagnosis and treatment.