Associations of carotid atherosclerosis with cognitive function and brain health: Findings from a UK tri-ethnic cohort study (Southall and Brent Revisited).

Background: Cognitive function has an important role in determining the quality of life of older adults. Cardiovascular disease (CVD) is common in older people and may compromise cognitive performance; however, the extent to which this is related to carotid atherosclerosis is unclear. Aim: We investigated associations between carotid atherosclerosis and cognitive function and neuroimaging markers of brain health in a UK multi-ethnic community-based sample including older people of European, South Asian, and African-Caribbean ethnicity. Methods: Carotid plaques and intima-media thickness (cIMT) were assessed using ultrasound in 985 people (mean age 73.2y, 56 % male). Associations of carotid atherosclerosis with cognitive function (memory, executive function, language and CSI-D, a global measure of cognitive state) and neuroimaging measures (total brain volume, hippocampal volume, white matter (WM) lesion volume and coalescence score) were analysed using regression analyses, with and without adjustment for potential confounders using two models: 1) adjustment for age, sex, and ethnicity; 2) model 1 plus education, physical activity category, body mass index, hypertension, diabetes, total and high density lipoprotein cholesterol, atrial fibrillation, smoking, previous CVD, alcohol consumption, and presence of chronic kidney disease. Results: People with carotid plaque or higher cIMT had lower CSI-D score, poorer memory poorer executive function and higher WM lesion volume and coalescence. Language was poorer in people with plaque but was not correlated with cIMT. Associations with plaque were preserved after full adjustment (model 2) but relationships for cIMT were attenuated. Associations with other plaque characteristics were generally unconvincing after adjustment. Conclusions: This multi-ethnic cohort study provides evidence that presence of carotid plaque, is associated with poorer cognitive function and brain health.

The prevalence of extracranial carotid atherosclerosis detected via ultrasound imaging: A single-centre study in Jeddah, Saudi Arabia.

OBJECTIVES: To assess the prevalence of carotid atherosclerosis in Jeddah, Saudi Arabia. METHODS: Data on patients who underwent carotid ultrasound examinations between 2017-2021 were collected retrospectively from the archive of King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Patient characteristics, blood lipid profiles, and plaque features were extracted from the medical records and ultrasound images. Descriptive data were presented as percentages. RESULTS: In total, 1334 patients were reviewed. Of these, 13.5% had carotid plaques and were included in the analysis. The mean patient age was 69.8±10.4 years, and 76.1% were men. The prevalence of hypertension was 62.7% and the prevalence of diabetes was 50%, and 7.2% of patients were smokers. Regarding blood lipid profiles, 6.5% of patients had high total cholesterol, 15.1% had high triglyceride levels, and 10.7% had high low-density lipoprotein levels. The median (interquartile range) stenosis was 34.4 (17.2) %, while the median plaque length was 5 (6) mm and thickness was 3 (1) mm. The median carotid intima-media thickness was 1 (0.3) mm. Regarding plaque distribution, 62.7% of plaques were in the carotid bulb. Additionally, 28.3% was in the internal carotid artery, 6.1% was in the common carotid artery, and 2.7% was in the external carotid artery. CONCLUSION: The prevalence of carotid atherosclerosis among patients in Jeddah, Saudi Arabia, was low. A high prevalence of hypertension and diabetes (≥50%) was observed among the patients. Multicenter studies involving larger Saudi samples are warranted to explore carotid atherosclerosis risk factors.

Investigating the Correlation between Liver Ultrasound pSWE and Portal Vein Hemodynamics: Preliminary Findings.

INTRODUCTION: Portal vein size and hemodynamics can be altered in patients with portal hypertension. Elastography for liver stiffness has been proposed as a potential predictor of portal hypertension. However, the relationship between liver stiffness measured using point shear wave elastography (pSWE) and portal vein diameter and Doppler parameters remains unclear. Therefore, this observational study aimed to investigate the correlation between liver ultrasound pSWE and portal vein hemodynamics in healthy participants. METHODS: Twenty-five healthy men with no underlying medical conditions and who were not on regular medications were enrolled in the study. Liver stiffness, portal vein diameter, and Doppler parameters were measured using ultrasound EPIQ Elite with a curved-array transducer (C5-1 MHz) equipped with pSWE and Doppler imaging. Real-time pSWE measurements were taken from the liver. Portal vein diameter and Doppler parameters were measured in a longitudinal view of the extra-hepatic segment. Spearman correlation was used to assess the association between liver pSWE and portal vein diameter as well as Doppler parameters, with a significance level set at < 0.05. RESULTS: There was no significant correlation between liver stiffness and portal vein diameter (p = 0.67) or Doppler parameters, including peak systolic velocity (p = 0.89), end-diastolic velocity (p = 0.65), and resistive index (p = 0.86). CONCLUSION: Our findings suggest no direct correlation between liver stiffness measured using pSWE and portal vein hemodynamics in healthy adults. Further studies are warranted to investigate the relationship between liver pSWE and the hemodynamics of portal veins in patients with liver diseases.

Gender and cytoarchitecture differences: Functional connectivity of the hippocampal sub-regions.

Introduction: The hippocampus plays a significant role in learning, memory encoding, and spatial navigation. Typically, the hippocampus is investigated as a whole region of interest. However, recent work has developed fully detailed atlases based on cytoarchitecture properties of brain regions, and the hippocampus has been sub-divided into seven sub-areas that have structural differences in terms of distinct numbers of cells, neurons, and other structural and chemical properties. Moreover, gender differences are of increasing concern in neuroscience research. Several neuroscience studies have found structural and functional variations between the brain regions of females and males, and the hippocampus is one of these regions. Aim: The aim of this study to explore whether the cytoarchitecturally distinct sub-regions of the hippocampus have varying patterns of functional connectivity with different networks of the brain and how these functional connections differ in terms of gender differences. Method: This study investigated 200 healthy participants using seed-based resting-state functional magnetic resonance imaging (rsfMRI). The primary aim of this study was to explore the resting connectivity and gender distinctions associated with specific sub-regions of the hippocampus and their relationship with major functional brain networks. Results: The findings revealed that the majority of the seven hippocampal sub-regions displayed functional connections with key brain networks, and distinct patterns of functional connectivity were observed between the hippocampal sub-regions and various functional networks within the brain. Notably, the default and visual networks exhibited the most consistent functional connections. Additionally, gender-based analysis highlighted evident functional resemblances and disparities, particularly concerning the anterior section of the hippocampus. Conclusion: This study highlighted the functional connectivity patterns and involvement of the hippocampal sub-regions in major brain functional networks, indicating that the hippocampus should be investigated as a region of multiple distinct functions and should always be examined as sub-regions of interest. The results also revealed clear gender differences in functional connectivity.

B-mode ultrasound characteristics of carotid plaques in symptomatic and asymptomatic patients with low-grade stenosis.

Carotid plaque features assessed using B-mode ultrasound can be useful for the prediction of cerebrovascular symptoms. Therefore, the aim of this retrospective study was to determine the ability of ultrasound B-mode imaging to differentiate between carotid plaques causing less than 50% stenosis in symptomatic and asymptomatic patients. A dataset of 1,593 patients with carotid disease who underwent carotid ultrasound between 2016 and 2021 was evaluated retrospectively between January and April of 2022. A total of 107 carotid plaques from 35 symptomatic and 52 asymptomatic patients causing low-grade stenosis on B-mode images were included in the analysis. Chi-square, independent t-test and Mann-Whitney U test were used to compare the variables. There was a significant association between hypertension and the presence of cerebrovascular symptoms (p = 0.01). Predominantly hypoechoic and hyperechoic carotid plaque were significantly associated with the presence and absence of cerebrovascular symptoms, respectively (predominantly hypoechoic: p = 0.01; predominantly hyperechoic: p = 0.02). Surface irregularity was significantly associated with the presence of cerebrovascular symptoms (p = 0.02). There is was a significant difference in the carotid plaque length and area between the symptomatic and asymptomatic patients (plaque length: symptomatic median 9 mm, interquartile range [IQR] 6 mm; asymptomatic median 6 mm, IQR 4.5 mm, p = 0.01; plaque area: symptomatic median 24 mm, IQR 30 mm; asymptomatic median 14 mm, IQR 17 mm, p = 0.01); however, this difference was not significant for plaque thickness (p = 0.55), or common carotid artery intima-media thickness (p = 0.7). Our findings indicate that hypertension patients with predominantly hypoechoic carotid plaques and plaques with an irregular surface are associated with the presence of cerebrovascular symptoms. In addition, the carotid plaques in symptomatic patients were longer and larger compared to asymptomatic patients.

Reliability of tomographic 3D ultrasound in measuring internal carotid artery plaque volume.

BACKGROUND: Tomographic 3D ultrasound (t3DUS) is a promise imaging technique for quantifying carotid plaque through measuring the degree of stenosis and plaque volume. Carotid plaque volume (CPV) could add benefit in predicting the potential risk of stroke. PURPOSE: To assess the reproducibility and accuracy of t3DUS for measuring CPV within the internal carotid artery in patients undergoing carotid endarterectomy. MATERIAL AND METHODS: t3DUS was used to obtain CPV in vivo from 25 symptomatic patients prior to surgery. Ex vivo CPV from the carotid endarterectomy specimen was then measured using a validated saline displacement method as a reference standard. CPV for each patient was measured twice using both methods (total n = 50 per technique). Intraclass correlation coefficient (ICC) and Bland-Altman plot were used to establish bias and limit of agreement between CPV measurements. RESULTS: There was an excellent agreement between t3DUS and reference test with respect to measuring CPV with an ICC value of 0.98 (95% confidence interval = 0.97-0.99, P < 0.001). Bias in measurements was 0.02 ± 0.11 cm3 (95% limit of agreement = -0.19 to 0.25). Intra-observer agreement of t3DUS CPV measurements was excellent with an ICC value of 0.95 (95% confidence interval = 0.92-0.97, P < 0.001). Bias in measurements was 0.004 ± 0.07 cm3 (95% limit of agreement = -0.14 to 0.15). CONCLUSION: t3DUS is a reproducible imaging method and showed excellent agreement with the reference standard with respect to measuring CPV. These findings suggest that t3DUS has the potential to be a valuable non-invasive tool for assessing carotid plaque burden and predicting the risk of stroke.

B-mode Ultrasound Characteristics of Thyroid Nodules With High-Benign Probability and Nodules With Risk of Malignancy.

INTRODUCTION: Thyroid nodules are commonly found on clinical examination or diagnostic imaging of the neck. Malignant thyroid nodules are increasing worldwide, making thyroid cancer one of the most common endocrine malignancies worldwide. The aim of this study was to determine B-mode ultrasound characteristics of benign thyroid nodules and nodules with risk of malignancy.  Material and methods: This retrospective study was conducted on subjects (n=99) who underwent thyroid ultrasound. Data were retrieved from the Thyroid Digital Image Database of Universidad Nacional de Colombia, a published open-access dataset, in which B-mode ultrasound images were interpreted by expert radiologists providing a complete diagnostic description of thyroid lesions using the Thyroid Imaging Reporting and Data System. RESULTS: Sponge-like appearance (Pearson Chi-Square 4.6, p=0.02), cystic (Pearson Chi-Square 27.3, p<0.001), isoechoic (Pearson Chi-Square 26, p<0.001), and well-defined (Pearson Chi-Square 13.7, p<0.001) thyroid nodules were more likely to be observed in benign nodules (risk of malignancy <5%). On the other hand, predominately solid (Pearson Chi-Square 5.9, p=0.01), microcalcifications (Pearson Chi-Square 50.7, p<0.001), hypoechoic (Pearson Chi-Square 27.7, p<0.001), irregular shape (Pearson Chi-Square 6.6, p=0.01), and ill-defined (Pearson Chi-Square 8.8, p=0.003) thyroid nodules were more likely to be observed in nodules with risk of malignancy (>5%). CONCLUSION: Ultrasound characteristics could be used to determine thyroid nodules with risk of malignancy and avoid over-diagnosing nodules with benign features. Further research evaluating the use of multiparametric ultrasound to distinguish between benign thyroid nodules and thyroid nodules with risk of malignancy is required.

Tomographic 3D ultrasound for grading stenosis of superficial femoral artery.

INTRODUCTION: Treatment decision of lower extremity peripheral arterial disease (PAD) is governed by the severity of stenosis. Tomographic 3D ultrasound (t3DUS) is a reliable imaging technique for measuring vessel stenosis. In this study we attempted to provide a precise measurement of superficial femoral artery (SFA) stenosis using t3DUS in patients with PAD. METHODS: t3DUS was used to measure maximum stenosis percentage in SFA from 50 patients with lower extremity PAD. The maximum stenosed segment in SFA was defined using Duplex 2DUS aliasing was noted. The peak systolic velocity (PSV) was measured at the maximum stenotic site and proximal to aliasing for calculating the velocity ratio. The association between blood flow velocity ratio and the degree of stenosis measured using Duplex 2DUS and t3DUS, respectively, was assessed using Spearman rank correlation. RESULTS: There was a strong positive correlation between velocity ratio and degree of stenosis in SFA measured using t3DUS (correlation value (r) = 0.99, p < 0.001). The correlation between Stenosis percentage and velocity ratio in SFA are as followed: <50:<2; 50-54:2-2.4; 55-59:2.5-2.9; 60-64:3-3.4; 65-69:3.5-3.9; 70-74:4-4.4; 75-79:4.5-4.9; >80:>5.t3DUS can be used to provide precise measurement of the severity of SFA stenosis in patients with lower extremities arterial disease. The established criteria for grading SFA stenosis in this study can be applied to the current practice alongside Duplex 2DUS as it showed a strong positive correlation with velocity ratio. Further studies investigating the sensitivity and specificity of t3DUS in the assessment of stenosis in lower limbs arteries are required.

Is 3D ultrasound reliable for the evaluation of carotid disease? A systematic review and meta-analysis.

AIM: Studies assessing the use of 3D ultrasound (3DUS) for the evaluation of carotid disease reported varying views among observers about its reliability vis-à-vis 2DUS or angiography; ratings provided ranged from poor to excellent. Thisstudy aims to systematically review and analyze the reliability of 3DUS for the evaluation of carotid disease. MATERIALS AND METHODS: The PubMed database was searched for studies that evaluated carotid disease (i.e. plaque measurements and characteristics and degree of stenosis) using 3DUS. RESULTS: Sixteen studies comprising a total of 918 stenosed carotids were reviewed and meta-analyzed. Data on intra- and inter-observer reproducibility and inter-method agreement (i.e. 3DUS vs 2D and 3DUS vs angiography) were analyzed. Overall analysis showed excellent intra- and inter-observer reproducibility (intraobserver: correlation coefficient r=0.88, 95% confidence intervals (CI) 0.84-0.92; intra-observer: r=0.91, 95% CI 0.87-0.95). The analysis also showed excellent agreement between 3DUS and 2DUS (r=0.89, 95% CI 0.83-0.95) and between 3DUS and angiography (r=0.73, 95% CI 0.44-0.1). CONCLUSION: 3DUS has excellent intra- and inter-observer reproducibility and excellent agreement with 2DUS and angiography for the evaluation of carotid disease. Further studies assessing the reliability ofcarotid plaque characteristics using 3DUS in symptomatic and asymptomatic patients are required.

Contrast-enhanced ultrasound for the evaluation of symptomatic and asymptomatic carotid plaques: A systematic review and meta-analysis.

BACKGROUND: Contrast-enhanced ultrasound (CEUS) is a promising imaging modality for the assessment of plaque vulnerability. We aimed to systematically review and meta-analyze the ability of CEUS parameters to differentiate between symptomatic and asymptomatic carotid plaques and to assess its reproducibility. METHODS: PubMed, EMBASE, and Cochrane Library databases were searched for studies that potentially evaluated carotid plaques using CEUS. From the initial 2870 searches, 11 relevant publications comprising a total of 821 carotid plaques were reviewed. Data on CEUS parameters including quantitative and semi-quantitative parameters were extracted and analyzed. RESULTS: The overall analysis showed significantly higher CEUS parameters in symptomatic carotid plaques compared to asymptomatic carotid plaques (standardised mean difference (SMD) .95, 95% confidence interval (CI) .56-1.27, p < .01). Intra and inter-observer reproducibility of quantitative CEUS parameters were excellent (intra-observer, r = .95, 95% CI .87-1; inter-observer, r = .93, 95% CI .80-.1). Semi-quantitative CEUS parameters showed good intra-observer reliability and moderate inter-observer reliability (intra-observer, r = .77, 95% CI .64-.89; inter-observer, r = .75, 95% CI .61-.89). Heterogeneity among studies compared CEUS parameters in symptomatic and asymptomatic plaques and studies assessed inter-observer reproducibility, and significant biases in studies assessing CEUS reproducibility were present. CONCLUSION: CEUS is a useful vascular imaging method to differentiate between symptomatic and asymptomatic carotid plaques with moderate to excellent reproducibility. Quantitative CEUS analysis appeared to be more sensitive and reliable in assessing carotid plaques than semi-quantitative parameters. Further longitudinal prospective trials evaluating carotid plaque in asymptomatic population using CEUS to determine plaque characteristics that can become symptomatic are required.

Reliability and Accuracy of Tomographic 3-D Ultrasound for Grading Vessel Stenosis: A Phantom Study.

The aim of this phantom study was to assess the accuracy of 3-D tomographic ultrasound (t3DUS) for grading stenosis, using the manufacturer's measurements as the gold standard. The percentage of maximum stenosis was obtained using 2-D ultrasound (2DUS) and t3DUS imaging techniques on a peripheral vascular phantom, including channels with 50%, 75% and 90% stenosis. The inter-observer reproducibility of t3DUS for grading stenosis was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Mean and mean differences were used to evaluate the accuracy of 2DUS and t3DUS in measuring maximum stenosis in all channels. Inter-operator agreement was excellent, with an ICC value of 0.99 (95% confidence interval: 0.994-0.998, p < 0.001). Bias in measurements was -0.59 ± 2.01% (95% limits of agreement: 4.54, 3.36). The mean difference (MD) between maximum stenosis measurements and reference values for all channels was lower in t3DUS than in 2DUS (t3DUS MD: +1.01%, diameter reduction 2DUS MD: -6.10%; area reduction 2DUS MD: +8.20%). Tomographic 3DUS is a reproducible and accurate imaging method for grading stenosis. The current B-mode 2DUS stenosis grading criteria used in vascular assessment may be underestimating or overestimating the percentage stenosis. Further phantom and human studies investigating the reliability of t3DUS for grading stenosis and other metrics including plaque volume are required.

Is carotid artery atherosclerosis associated with poor cognitive function assessed using the Mini-Mental State Examination? A systematic review and meta-analysis.

OBJECTIVES: To determine associations between carotid atherosclerosis assessed by ultrasound and the Mini-Mental State Examination (MMSE), a measure of global cognitive function. DESIGN: Systematic review and meta-analysis. METHODS: MEDLINE and EMBASE databases were searched up to 1 May 2020 to identify studies assessed the associations between asymptomatic carotid atherosclerosis and the MMSE. Studies reporting OR for associations between carotid plaque or intima-media thickness (cIMT) and dichotomised MMSE were meta-analysed. Publication bias of included studies was assessed. RESULTS: A total of 31 of 378 reviewed articles met the inclusion criteria; together they included 27 738 participants (age 35-95 years). Fifteen studies reported some evidence of a positive association between measures of atherosclerosis and poorer cognitive performance in either cross-sectional or longitudinal studies. The remaining 16 studies found no evidence of an association. Seven cross-sectional studies provided data suitable for meta-analysis. Meta-analysis of three studies that assessed carotid plaque (n=3549) showed an association between the presence of plaque and impaired MMSE with pooled estimate for the OR (95% CI) being 2.72 (0.85 to 4.59). An association between cIMT and impaired MMSE was reported in six studies (n=4443) with a pooled estimate for the OR (95% CI) being 1.13 (1.04 to 1.22). Heterogeneity across studies was moderate to small (carotid plaque with MMSE, I2=40.9%; cIMT with MMSE, I2=4.9%). There was evidence of publication bias for carotid plaque studies (p=0.02), but not cIMT studies (p=0.2). CONCLUSIONS: There is some, limited cross-sectional evidence indicating an association between cIMT and poorer global cognitive function assessed with MMSE. Estimates of the association between plaques and poor cognition are too imprecise to draw firm conclusions and evidence from studies of longitudinal associations between carotid atherosclerosis and MMSE is limited. PROSPERO REGISTRATION NUMBER: CRD42021240077.

Evaluation of ultrasound point shear wave elastography reliability in an elasticity phantom.

PURPOSE: To date, limited studies have specifically addressed the reliability of ultrasound point shear-wave elastography (pSWE). Therefore, the aim of the present study was to assess the reproducibility of ultrasound pSWE within and between operators using two ultrasound scanners. METHODS: iU22 and EPIQ7 ultrasound scanners were used to assess the reliability of pSWE measurements of four inclusions [L I (8 kPa), L II (14 kPa), L III (48 kPa), and L IV (80 kPa)] at a depth of 3.5 cm in an elasticity phantom using a curvilinear 5-1 MHz transducer. The intraoperator, inter-operator, and inter-scanner reproducibility of pSWE was assessed using intraclass correlation coefficients (ICCs). Bland-Altman plots were used to establish bias and limits of agreement (LoA) between measurements. The accuracy of pSWE from manufacturer values was determined using the one-sample t-test. RESULTS: Intra-operator agreement was excellent, with an ICC >0.90. The bias in measurements for operator A was -0.36±3.13 kPa (LoA, -6.47 to 5.75), and for operator B it was 1.97±6.29 kPa (LoA, -10.25 to 14.21). Inter-operator agreement was excellent, with an ICC of 0.95. The bias in measurements between operators was -0.42±5.00 kPa (LoA, -10.24 to 9.38). The inter-scanner agreement between EPIQ7 and iU22 was excellent, with an ICC of 0.96. The bias in measurements between scanners was 1.74±4.44 kPa (LoA, -6.95 to 10.45). There was significant overestimation for L I (17.75%) and L II (31.14%) and underestimation for L III (-15.28%) and L VI (-98.00%) relative to the manufacturer-reported values. CONCLUSION: Phantom ultrasound pSWE was reproducible within and between operators, and between Philips ultrasound scanners; further studies using different ultrasound systems and transducers are required.

Association Between Lung Ultrasound Patterns and Pneumonia.

ABSTRACT: Pneumonia is a common respiratory infection that affects the lungs. Lung ultrasound (LUS) is a portable, cost-effective imaging method, which is free of ionizing radiation and has been shown to be useful for evaluating pneumonia. The aim of this retrospective analytical study was to determine the association between lung ultrasound patterns and pneumonia. For the purpose of performing the required analysis, LUS patterns including consolidations, pleural line irregularities, A lines and B lines from 90 subjects (44 patients with confirmed pneumonia and 46 controls) were retrieved from a published open-access data set, which was reviewed and approved by medical experts. A χ 2 test was used for the comparison of categorical variables to determine the association between each LUS pattern and the presence of pneumonia. There is a significant association between LUS consolidation and the presence of pneumonia ( P < 0.0001). Lung ultrasound A lines are significantly associated with the absence of pneumonia ( P < 0.0001), whereas there are no associations between B lines or pleural line irregularities with pneumonia. Lung ultrasound consolidation is found to be associated with the presence of pneumonia. A lines are associated with healthy lungs, and there is no association of B lines and pleural irregularities with the presence of pneumonia. Further studies investigating LUS patterns with clinical information and symptoms of patients with pneumonia are required.

Diagnosis of parotid gland tumours with Contrast-Enhanced Ultrasound: a systematic review and meta-analysis.

AIM: Contrast-enhanced ultrasound (CEUS) appears to be a promising application for the diagnosis of parotid gland tumours. We aimed to systematically review and meta-analyse the ability of CEUS in distinguishing benign from malignant parotid gland tumours. MATERIAL AND METHODS: PubMed was searched for relevant studies. Data on area under time intensity curve (AUC) in arbitrary unit (AU), and mean transit time (MTT) in seconds (sec) were analysed using the Cochrane Review Manager Software. RESULTS: Nine studies met the eligibility criteria comprising a total number of 498 parotid gland tumours (benign, number (n)=423; malignant, n=75). Descriptive evaluation of parotid gland tumours following CEUS administration showed overlap characteristics in benign and malignancies. Two publications assessed AUC and MTT in 72 and 60 parotid gland tumours, respectively. AUC was significantly lower in benign compared to malignant tumours following contrast administration (AUC, mean difference (MD) -266.77 AU, 95% confidence intervals (CI) -433.22, -100.33, p=0.002). No significant different in MTT between benign and malignant tumours (p=0.12). Heterogeneity was statistically significant in AUC (p=0.04) and MTT (p<0.00001). CONCLUSION: Descriptive evaluation of parotid gland tumours showed overlap CEUS characteristics. Perfusion related CEUS parameters analysis is promising in differentiating benign parotid tumours from malignancies.

The effects of acute and sustained cannabidiol dosing for seven days on the haemodynamics in healthy men: A randomised controlled trial.

BACKGROUND: In vivo studies show that cannabidiol (CBD) acutely reduces blood pressure (BP) in men. The aim of this study was to assess the effects of repeated CBD dosing on haemodynamics. METHODS: Twenty-six healthy males were given CBD (600 mg) or placebo orally for seven days in a randomised, placebo-controlled, double-blind, parallel study (n = 13/group). Cardiovascular parameters were assessed at rest and in response to isometric exercise after acute and repeated dosing using Finometer®, Vicorder® and Duplex ultrasound. RESULTS: Compared to placebo, CBD significantly reduced resting mean arterial pressure (P = .04, two-way ANOVA, mean difference (MD) -2 mmHg, 95% CI -3.6 to -0.3) after acute dosing, but not after repeated dosing. In response to stress, volunteers who had taken CBD had lower systolic BP after acute (P = .001, two-way ANOVA, MD -6 mmHg, 95% CI -10 to -1) and repeated (P = .02, two-way ANOVA, MD -5.7 mmHg, 95% CI -10 to -1) dosing. Seven days of CBD increased internal carotid artery diameter (MD +0.55 mm, P = .01). Within the CBD group, repeated dosing reduced arterial stiffness by day 7 (pulse wave velocity; MD -0.44 m/s, P = .05) and improved endothelial function (flow mediation dilatation, MD +3.5%, P = .02, n = 6 per group), compared to day 1. CONCLUSION: CBD reduces BP at rest after a single dose but the effect is lost after seven days of treatment (tolerance); however, BP reduction during stress persists. The reduction in arterial stiffness and improvements in endothelial function after repeated CBD dosing are findings that warrant further investigation in populations with vascular diseases.

A Systematic Review and Meta-Analysis of the In Vivo Haemodynamic Effects of Δ8-Tetrahydrocannabinol.

∆8-Tetrahydrocannabinol (THC) has complex effects on the cardiovascular system. We aimed to systematically review studies of THC and haemodynamic alterations. PubMed, Medline, and EMBASE were searched for relevant studies. Changes in blood pressure (BP), heart rate (HR), and blood flow (BF) were analysed using the Cochrane Review Manager Software. Thirty-one studies met the eligibility criteria. Fourteen publications assessed BP (number, n = 541), 22 HR (n = 567), and 3 BF (n = 45). Acute THC dosing reduced BP and HR in anaesthetised animals (BP, mean difference (MD) -19.7 mmHg, p < 0.00001; HR, MD -53.49 bpm, p < 0.00001), conscious animals (BP, MD -12.3 mmHg, p = 0.0007; HR, MD -30.05 bpm, p < 0.00001), and animal models of stress or hypertension (BP, MD -61.37 mmHg, p = 0.03) and increased cerebral BF in murine stroke models (MD 32.35%, p < 0.00001). Chronic dosing increased BF in large arteries in anaesthetised animals (MD 21.95 mL/min, p = 0.05) and reduced BP in models of stress or hypertension (MD -22.09 mmHg, p < 0.00001). In humans, acute administration increased HR (MD 8.16 bpm, p < 0.00001). THC acts differently according to species and experimental conditions, causing bradycardia, hypotension and increased BF in animals; and causing increased HR in humans. Data is limited, and further studies assessing THC-induced haemodynamic changes in humans should be considered.

A Systematic Review and Meta-Analysis of the Haemodynamic Effects of Cannabidiol.

Despite cannabidiol (CBD) having numerous cardiovascular effects in vitro, its haemodynamic effects in vivo are unclear. Nonetheless, the clinical use of CBD (Epidiolex) is becoming more widespread. The aim of this systematic review was to establish whether CBD is associated with changes in haemodynamics in vivo. Twenty-five studies that assessed the haemodynamic effects of CBD (from PubMed, Medline and EMBASE) were systematically reviewed and meta-analyzed. Data on blood pressure (BP), heart rate (HR), and blood flow (BF) were extracted and analyzed using random effects models. Twenty-two publications assessed BP and HR among 6 species (BP n = 344 and HR n = 395), and 5 publications assessed BF in 3 species (n = 56) after acute dosing of CBD. Chronic dosing was assessed in 4 publications in 3 species (total subjects BP, n = 6; HR, n = 27; BF, n = 3). Acute CBD dosing had no effect on BP or HR under control conditions. Similarly, chronic dosing with CBD had no effect on HR. In models of stress, acute CBD administration significantly reduced the increase in BP and HR induced by stress (BP, mean difference (MD) -3.54, 95% CI -5.19, -1.9, p < 0.0001; HR, MD -16.23, 95% CI -26.44, -6.02, p = 0.002). In mouse models of stroke, CBD significantly increased cerebral blood flow (CBF, standardized mean difference (SMD) 1.62, 95% CI 0.41, 2.83, p = 0.009). Heterogeneity among the studies was present, there was no publication bias except in HR of control and stressful conditions after acute CBD dosing, and median study quality was 5 out of 9 (ranging from 1 to 8). From the limited data available, we conclude that acute and chronic administration of CBD had no effect on BP or HR under control conditions, but reduces BP and HR in stressful conditions, and increases cerebral blood flow (CBF) in mouse models of stroke. Further studies are required to fully understand the potential haemodynamic effects of CBD in humans under normal and pathological conditions.