Ceria-containing uncoated and coated hydroxyapatite-based galantamine nanocomposites for formidable treatment of Alzheimer's disease in ovariectomized albino-rat model.

A large variety of severe medical conditions involve alterations in microvascular circulation. Hence, measurements or simulation of circulation and perfusion has considerable clinical value and can be used for diagnostics, evaluation of treatment efficacy, and for surgical planning. However, the accuracy of traditional tracer kinetic one-compartment models is limited due to scale dependency. As a remedy, we propose a scale invariant mathematical framework for simulating whole brain perfusion. The suggested framework is based on a segmentation of anatomical geometry down to imaging voxel resolution. Large vessels in the arterial and venous network are identified from time-of-flight (ToF) and quantitative susceptibility mapping (QSM). Macro-scale flow in the large-vessel-network is accurately modelled using the Hagen-Poiseuille equation, whereas capillary flow is treated as two-compartment porous media flow. Macro-scale flow is coupled with micro-scale flow by a spatially distributing support function in the terminal endings. Perfusion is defined as the transition of fluid from the arterial to the venous compartment. We demonstrate a whole brain simulation of tracer propagation on a realistic geometric model of the human brain, where the model comprises distinct areas of grey and white matter, as well as large vessels in the arterial and venous vascular network. Our proposed framework is an accurate and viable alternative to traditional compartment models, with high relevance for simulation of brain perfusion and also for restoration of field parameters in clinical brain perfusion applications.

A new framework for assessing subject-specific whole brain circulation and perfusion using MRI-based measurements and a multi-scale continuous flow model.

Hypoxia plays an important role for the prognosis and therapy response of cancer. Thus, hypoxia imaging would be a valuable tool for pre-therapeutic assessment of tumor malignancy. However, there is no standard validated technique for clinical application available yet. Therefore, we performed a study in 12 patients with high-grade glioma, where we directly compared the two currently most promising techniques, namely the MR-based relative oxygen extraction fraction (MR-rOEF) and the PET hypoxia marker H-1-(3-[(18) F]-fluoro-2-hydroxypropyl)-2-nitroimidazole ([(18) F]-FMISO). MR-rOEF was determined from separate measurements of T2 , T2 * and relative cerebral blood volume (rCBV) employing a multi-parametric approach for quantification of the blood-oxygenation-level-dependent (BOLD) effect. With respect to [(18) F]-FMISO-PET, besides the commonly used late uptake between 120 and 130 min ([(18) F]-FMISO120-130 min ), we also analyzed the hypoxia specific uptake rate [(18) F]-FMISO-k3 , as obtained by pharmacokinetic modeling of dynamic uptake data. Since pharmacokinetic modeling of partially acquired dynamic [(18) F]-FMISO data was sensitive to a low signal-to-noise-ratio, analysis was restricted to high-uptake tumor regions. Individual spatial analyses of deoxygenation and hypoxia-related parameter maps revealed that high MR-rOEF values clustered in (edematous) peritumoral tissue, while areas with high [(18) F]-FMISO120-130 min concentrated in and around active tumor with disrupted blood-brain barrier, i.e. contrast enhancement in T1 -weighted MRI. Volume-of-interest-based correlations between MR-rOEF and [(18) F]-FMISO120-130 min as well as [(18) F]-FMISO-k3 , and voxel-wise analyses in individual patients, yielded limited correlations, supporting the notion that [(18) F]-FMISO uptake, even after 2 h, might still be influenced by perfusion while [(18) F]-FMISO-k3 was severely hampered by noise. According to these results, vascular deoxygenation, as measured by MR-rOEF, and severe tissue hypoxia, as measured by [(18) F]-FMISO, show a poor spatial correspondence. Overall, the two methods appear to rather provide complementary than redundant information about high-grade glioma biology.

Characterizing hypoxia in human glioma: A simultaneous multimodal MRI and PET study.

Objectives: This study aimed to examine the correlation between carotid artery intima-media thickness (IMT) and luminal diameter (LD) with body mass index (BMI) and other cardiovascular risk factors. Methods: This observational cross-sectional study took place between June 2013 and March 2014 in the Radiology Department of Rizgary Teaching Hospital in Erbil, Iraq. Non-randomly selected subjects ≥20 years old (n = 140) were divided into BMI groups and evaluated for the following cardiovascular risk factors: gender, age, hypertension (HTN), diabetes (DM), smoking, alcohol consumption, blood pressure, serum total cholesterol and triglyceride (TG) levels. IMT and LD of the extracranial carotid arteries were measured by B-mode ultrasonography. Results: The mean IMT was 0.8 ± 0.3 mm, ranging from a total mean of 0.7 mm in the normal BMI group to 1.0 mm in the extremely obese group. A significant correlation was found between IMT and BMI ( P = 0.04), but not between BMI and LD ( P = 0.3). No significant difference in mean IMT or LD was seen between genders. Significant correlations were found between IMT and age, HTN, DM, high serum cholesterol and TG levels ( P <0.001). An increase of one BMI unit caused a 0.009 mm increase in IMT and an increase of one year in age caused a 0.011 mm increase in IMT. Conclusion: Age, obesity, HTN, DM, high serum cholesterol and TG levels were found to have an impact on carotid IMT, which is a strong marker for the early development of atherosclerosis. Keywords: Carotid Intima-Media Thickness; Ultrasonography; Atherosclerosis; Body Mass Index; Risk Factors; Iraq.

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Correlation between Carotid Artery Intima-Media Thickness and Luminal Diameter with Body Mass Index and Other Cardiovascular Risk Factors in Adults

The favourable effects of community-based, mixed-intensity aerobic interval training on arterial stiffness and structure

UNLABELLED Assessment of carotid artery lumen diameter and intima-media thickness is becoming as a surrogate marker of early evaluation of cardiovascular disease. Present study aims to describe the normal carotid dimensions in healthy adults of both sexes. A total of 123 healthy volunteers including 65 men and 58 women, aged 21 to 60 years (mean +/- SD; 35.66 +/- 8.84 years) were studied. Ultrasound study of both carotid arteries were performed with a 7.5 MHz linear array transducer. Common carotid artery lumen diameter ranged from 4.3 mm to 7.7 mm. Difference was not noted between left and right common carotid artery lumen diameter (5.78 +/- 0.57 mm and 5.86 +/- 0.66 mm), and internal and external carotid artery lumen diameter as well. Both left and right common carotid artery, internal and external carotid artery lumen diameter tended to be larger (p < 0.05) in men than women. Common carotid artery intima-media thickness ranged from 0.4 mm to 0.8 mm. Difference was not noted between left and right common carotid intima-media thickness when separately analyzed among men, women and the entire population. Difference was also not noted in comparison between men and women. CONCLUSION Common carotid artery and internal and external carotid artery lumen diameter tends to be larger in men than women among young adults. There is no difference between left and right carotid artery lumen diameter. Common carotid artery intima-media thickness is similar in comparison between left and right and both sexes.

Ghanshyam Gurung

Papers

Assessment of carotid artery dimensions by ultrasound in non-smoker healthy adults of both sexes.