The quantitative determination of regional cerebral blood flow (rCBF) is important in certain clinical and research applications. The disadvantage of most quantitative methods using H(2)(15)O positron emission tomography (PET) is the need for arterial blood sampling. In this study a new non-invasive method for rCBF quantification was evaluated. The method is based on the washout rate of H(2)(15)O following intravenous injection. All results were obtained with Alpert's method, which yields maps of the washin parameter K(1) (rCBF(K1)) and the washout parameter k(2) (rCBF(k2)). Maps of rCBF(K1) were computed with measured arterial input curves. Maps of rCBF(k2*) were calculated with a standard input curve which was the mean of eight individual input curves. The mean of grey matter rCBF(k2*) (CBF(k2*)) was then compared with the mean of rCBF(K1) (CBF(K1)) in ten healthy volunteer smokers who underwent two PET sessions on day 1 and day 3. Each session consisted of three serial H(2)(15)O scans. Reproducibility was analysed using the rCBF difference scan 3-scan 2 in each session. The perfusion reserve (PR = rCBF(acetazolamide)-rCBF(baseline)) following acetazolamide challenge was calculated with rCBF(k2*) (PR(k2*)) and rCBF(K1) (PR(K1)) in ten patients with cerebrovascular disease. The difference CBF(k2*)-CBF(K1) was 5.90+/-8.12 ml/min/100 ml (mean+/-SD, n=55). The SD of the scan 3-scan 1 difference was 6.1% for rCBF(k2*) and rCBF(K1), demonstrating a high reproducibility. Perfusion reserve values determined with rCBF(K1) and rCBF(k2*) were in high agreement (difference PR(k2*)-PR(K1)=-6.5+/-10.4%, PR expressed in percentage increase from baseline). In conclusion, a new non-invasive method for the quantitative determination of rCBF is presented. The method is in good agreement with Alpert's original method and the reproducibility is high. It does not require arterial blood sampling, yields quantitative voxel-by-voxel maps of rCBF, and is computationally efficient and easy to implement.
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J Transl Med
December 2024
Department of Cardiovascular Medicine, The First Affiliated Hospital of Nanjing Medical University, Guangzhou Road 300, Nanjing, 210029, Jiangsu, China.
Background: Coronary artery disease (CAD) has become a dominant economic and health burden worldwide, and the role of autophagy in CAD requires further clarification. In this study, we comprehensively revealed the association between autophagy flux and CAD from multiple hierarchies. We explored autophagy-associated long noncoding RNA (lncRNA) and the mechanisms underlying oxidative stress-induced human coronary artery endothelial cells (HCAECs) injury.
View Article and Find Full Text PDFHipertens Riesgo Vasc
December 2024
Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Argentina; Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani" CONICET-UNLP, Argentina. Electronic address:
Background: Blood pressure (BP) is linearly related to the incidence of cardiovascular disease from values as low as 115/75mmHg, even at young ages. A particularly concerning issue is the decrease representation of optimal BP among children and youth. The mechanisms by which minimal elevations in BP increase cardiovascular risk are not defined.
View Article and Find Full Text PDFAm J Crit Care
January 2025
Shih-Hua Lin is a professor, Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei.
Background: Hyperkalemia can be detected by point-of-care (POC) blood testing and by artificial intelligence- enabled electrocardiography (ECG). These 2 methods of detecting hyperkalemia have not been compared.
Objective: To determine the accuracy of POC and ECG potassium measurements for hyperkalemia detection in patients with critical illness.
In Vivo
December 2024
Group Brain Vasculature and Perivascular Niche, Division of Experimental and Translational Neuroscience, Krembil Brain Institute, Krembil Research Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada;
Background/aim: Brain arteriovenous malformations (AVMs) are vascular malformations characterized by dysmorphic, aberrant vasculature. During previous surgeries of compact nidus brain AVMs (representing the majority of cases), we have observed a "shiny" plane between nidal and perinidal AVM vessels and the surrounding grey and white matter and hypothesized that preoperative neuroimaging of brain AVMs may show a neuroradiological correlate of these intraoperative observations.
Patients And Methods: We retrospectively reviewed and analyzed multiplanar and multisequence 3-Tesla magnetic resonance (3T MR) imaging in five consecutive brain AVMs with special attention on imaging characteristics of the brain-AVM interface, i.
Bone Joint J
January 2025
Oxford Trauma and Emergency Care, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kadoorie Centre, University of Oxford, Oxford, UK.
Aims: There is compelling evidence for the use of cemented hip hemiarthroplasty for displaced intracapsular hip fractures; however, the risks of cement are well reported and in rare cases may be associated with haemodynamic collapse. It is therefore important to improve our understanding of haemodynamic instability, intraoperative monitoring, and strategies to reduce the risk to patients.
Methods: We measured arterial blood pressure using the LiDCO Continuous Non-invasive Arterial Pressure (CNAP) finger cuff during surgery in patients enrolled in the WHiTE 5 trial randomized to cemented or modern uncemented hip hemiarthroplasty at a single recruiting site.
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