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ABSTRACT: Carotid atherosclerotic disease is one of the major preventable causes of ischaemic strokes. In clinical practice, decision making with regard to carotid endarterectomy or stenting is still primarily based on the extent of luminal stenosis. In most centres worldwide, luminal stenosis is now mainly assessed with non-invasive techniques, such as Doppler ultrasound, magnetic resonance angiography, and CT angiography, either alone or in combination. Although intra-arterial digital subtraction angiography remains the historical gold standard, it has now mostly been replaced by these non-invasive techniques. Moreover, in addition to luminal stenosis, certain morphological features of carotid plaques, such as large lipid cores, intraplaque haemorrhage, or thin or ruptured fibrous caps, are increasingly believed to be associated with heightened risk of stroke. In this Review, we discuss current state-of-the-art non-invasive diagnostic imaging strategies for luminal stenosis and describe the most promising novel imaging techniques, such as high-resolution MRI and CT combined with PET imaging, which can be used to characterise vulnerable carotid-plaque features in vivo.
The Lancet Neurology 07/2009; 8(6):569-80. · 23.46 Impact Factor
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ABSTRACT: The selection of patients for vascular interventions has been solely based on luminal stenosis and symptomatology. However, histological data from both the coronary and carotid vasculature suggest that other plaque features such as inflammation may be more important in predicting future thromboembolic events. Ultrasmall superparamagnetic iron oxide (USPIO) contrast agents have been used for noninvasive MRI assessment of atherosclerotic plaque inflammation in humans. It has reached the stage of development to have been recently used in an interventional drug study to not only assess inflammatory progression but also select patients at high risk. This article reviews the basic science behind the use of USPIO contrast agents in atheroma MR imaging, experimental work in animals, and how this has led to the emergence of this promising targeted imaging platform for assessment of high risk carotid atherosclerosis in humans.
Arteriosclerosis Thrombosis and Vascular Biology 03/2009; 29(7):1001-8. · 6.37 Impact Factor
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ABSTRACT: The mechanical properties of arterial walls have long been recognized to play an essential role in the development and progression of cardiovascular disease (CVD). Early detection of variations in the elastic modulus of arteries would help in monitoring patients at high cardiovascular risk stratifying them according to risk. An in vivo, non-invasive, high resolution MR-phase-contrast based method for the estimation of the time-dependent elastic modulus of healthy arteries was developed, validated in vitro by means of a thin walled silicon rubber tube integrated into an existing MR-compatible flow simulator and used on healthy volunteers. A comparison of the elastic modulus of the silicon tube measured from the MRI-based technique with direct measurements confirmed the method's capability. The repeatability of the method was assessed. Viscoelastic and inertial effects characterizing the dynamic response of arteries in vivo emerged from the comparison of the pressure waveform and the area variation curve over a period. For all the volunteers who took part in the study the elastic modulus was found to be in the range 50–250 kPa, to increase during the rising part of the cycle, and to decrease with decreasing pressure during the downstroke of systole and subsequent diastole.
Engineering in Medicine and Biology Society, 2008. EMBS 2008. 30th Annual International Conference of the IEEE; 09/2008
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ABSTRACT: The mechanical properties of arterial walls have long been recognized to play an essential role in the development and progression of cardiovascular disease (CVD). Early detection of variations in the elastic modulus of arteries would help in monitoring patients at high cardiovascular risk stratifying them according to risk. An in vivo, non-invasive, high resolution MR-phase-contrast based method for the estimation of the time-dependent elastic modulus of healthy arteries was developed, validated in vitro by means of a thin walled silicon rubber tube integrated into an existing MR-compatible flow simulator and used on healthy volunteers. A comparison of the elastic modulus of the silicon tube measured from the MRI-based technique with direct measurements confirmed the method's capability. The repeatability of the method was assessed. Viscoelastic and inertial effects characterizing the dynamic response of arteries in vivo emerged from the comparison of the pressure waveform and the area variation curve over a period. For all the volunteers who took part in the study the elastic modulus was found to be in the range 50-250 kPa, to increase during the rising part of the cycle, and to decrease with decreasing pressure during the downstroke of systole and subsequent diastole.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 02/2008; 2008:5569-72.
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ABSTRACT: Abstract
Background
Stroke is the third most common cause of death in the UK and the largest single cause of severe disability. Each year more than 110,000 people in England suffer from a stroke which costs the National Health Service (NHS) over GBP2.8 billion. Thus, it is imperative that patients at risk be screened for underlying carotid artery atherosclerosis.
Aim
To assess the role of carotid ultrasound in different carotid screening programmes.
Methods
A literature overview was carried out by using PubMed search engine, to identify different carotid screening programmes that had used ultrasound scan as a screening tool.
Results
It appears that the carotid ultrasound is an effective method for screening carotid artery disease in community as it effectively predicts the presence of stenosis with high accuracy. There is a need for primary care to recommend high risk patients for regular screening, to reduce stroke and transient ischemic attack (TIA) related morbidity and mortality.
Conclusion
Screening programmes using carotid ultrasonography contribute to public health awareness and promotion which in long term could potentially benefit in disease prevention and essentially promote better standards of healthcare.
Cardiovascular Ultrasound. 01/2008;
