Tag Archives: coronary imaging

Introduction As a way of moving on from our previous articles, I have devised a summary table (table 1) looking at what can or cannot be provided by the existing techniques and what may be provided by the newer techniques that will be discussed briefly in this article. Table 1. Comparative features of plaque imaging tools Future plaque imaging techniques Raman spectroscopy Figure 1. Co-registration of intravascular ultrasound (IVUS) images (A) with Raman spectroscopy data (B) Raman spectroscopy is an established analytical technique that is widely utilised throughout the world. Over the last decade, a Raman spectroscopy catheter system has be

Background: carotid/vascular MRI Figure 1. 3T magnetic resonance imaging (MRI) of atherosclerotic plaque in a right common carotid artery. The vessel wall is lined with complicated, lipid-rich plaque, which has a necrotic core (solid arrow). A thin fibrous cap can be seen in the bottom-left of the image (dashed arrow) Magnetic resonance arteriography (MRA) has for many years been used as a non-invasive means of producing an arterial lumenogram, an image of flow down the arterial lumen, from which the presence of significant stenosis could often be detected, if needed, by comparison to the comparatively normal flow in the contralateral vessel.

Development of cardiac computed tomography The concept of ‘computerised transverse axial scanning’ was first demonstrated by Godfrey Hounsfield nearly 30 years ago.1 Initial computed tomography (CT) scanners required up to 300 seconds for the acquisition of a single image. With such poor temporal resolution they were only suitable for imaging static structures such as the brain.2 The coronary arteries move throughout the cardiac cycle, although their velocity decreases in diastole.3 This underlies the concept of ‘gating’ the scan with the electrocardiogram (ECG), so that data are acquired preferentially during diastole.4 The advent o

Introduction Table 1. Image characteristics of optical coherence tomography (OCT) Optical coherence tomography (OCT) uses near-infrared electromagnetic radiation, and cross-sectional images are generated by measuring the echo time delay and intensity of light that is reflected or back-scattered from internal structures in the tissue.1,2 Current OCT images are obtained at the peak wavelength in the 1,280–1,350 nm band that enables a 10–15 µm tissue axial resolution, 94 µm lateral resolution at 3 mm, and maximal scan diameter of 6–8 mm (about 10 times resolution as compared with intravascular ultrasound [IVUS]). There are two main tech

Background Figure 1. Positive remodelling: arterial expansion to protect luminal size Coronary luminal narrowing is prevented by a vascular mechanism known as positive remodelling. This is an outwards expansion of the blood vessel to accommodate the build up of plaque within the artery (figure 1). This phenomenon appears within diseased segments of coronary arteries and the build up of these plaques is dependent on multiple, well-known factors from genetics and lifestyle through to coronary anatomy and flow patterns. The complex pathobiology that creates these plaques and leads to plaque structure weakening is beyond the scope of this review.