Tag Archives: non-invasive imaging

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