Vulnerable Plaque Imaging—Current Techniques

Abstract

Tremendous progress has been made over the past 30 years in the management of plaque rupture and acute coronary thrombosis. With the advent of new interventional cardiac techniques and concomitant advances in medical therapy, there has been a steady decline in cardiovascular mortality. Acute coronary syndromes, especially ST elevation myocardial infarction, still occur frequently and are associated with significant morbidity and mortality. As these events typically occur in lesions without severe pre-existing stenosis, interest has increased in identifying these "vulnerable plaques" and ultimately preventing myocardial infarction. Recently, several new invasive and non-invasive modalities have been developed to identify and better characterize vulnerable plaque. This review will cover the pathobiology of vulnerable plaque, current invasive and non-invasive imaging techniques, tissue characterization, and future applications of this exciting technology.

In vivo measurement of plaque neovascularisation and thermal heterogeneity in intermediate lesions of human carotid arteries

“…During the last decades there is growing interest on imaging modalities aimed to reveal these biological activities of atherosclerotic lesions 3 4 23 24. Despite the high sensitivity of these methods, several limitations, including radioactive probes, partial volume effect and poor spatial resolution, have not yet permitted the wide application in humans.…”

“…A potential positive feedback loop between plaque neovascularisation and inflammatory activation has emerged 3. Several non-invasive methods have been developed for the identification of neovascularisation and plaque inflammation 4. Contrast-enhanced carotid ultrasound (CEUS) is a non-invasive imaging modality that provides direct visualisation of plaque neovascularisation, using contrast microspheres as intravascular tracers 5–7.…”

Optical coherence elastography: current status and future applications

“…The main components of atherosclerotic plaque include a large extracellular necrotic core with a thin fibrous cap infiltrated by macrophages, all of which have varying biomechanical properties. 28,29 Rupture of the cap induces the formation of a thrombus, which may obstruct the coronary artery, causing an acute heart attack and frequently results in patient death. 30,31 Detailed characterization of the arterial wall biomechanics may provide complementary information to quantify lesion stability.…”

An introduction to molecular imaging in radiation oncology: A report by the AAPM Working Group on Molecular Imaging in Radiation Oncology (WGMIR)

“…99 SPECT imaging of inflammatory properties of vulnerable atherosclerotic plaque is an active area of research, in order to preemptively identify high-risk coronary cases and individualize patient treatment. 100 In the near future, innovative applications of SPECT imaging may include radioactive labeling and noninvasive in vivo tracking of stem cell trafficking and tissue homing in the interest of targeted cardiovascular stem cell therapies for myocardial infarction and therapeutic angiogenesis. 101,102 SPECT has an increasing role in oncology due to a number of novel radiopharmaceuticals that are designed for specific tumors.…”