Noninvasive imaging modalities to visualize atherosclerotic plaques

Abstract

Atherosclerotic cardiovascular disease is becoming a major cause of death in the world due to global epidemic of diabetes and obesity. For the prevention of atherosclerotic cardiovascular disease, it is necessary to detect high-risk atherosclerotic plaques prior to events. Recent technological advances enable to visualize atherosclerotic plaques noninvasively. This ability of noninvasive imaging helps to refine cardiovascular risk assessment in various individuals, select optimal therapeutic strategy and evaluate the efficacy of medical therapies. In this review, we discuss the role of the currently available imaging modalities including computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography. Advantages and disadvantages of each noninvasive imaging modality will be also summarized.

Keywords: Noninvasive imaging; atherosclerotic plaque; computed tomography (CT); magnetic resonance imaging (MRI); positron emission tomography.

Figure 1

CAC evaluation. (A) Normal coronary artery without any calcification; (B) mild calcification in the left main trunk and the left anterior descending artery; (C) severe calcification involving the left main trunk, the left anterior descending and the left circumflex coronary arteries. CAC, coronary artery calcification.

Figure 2

Visualization of coronary arteries by 64-slice MDCT. (A) Volume rendering technique demonstrates stenosis of right coronary artery; (B) left coronary artery does not have any significant stenosis; (C,D) maximum-intensity projection of the same arteries also visualizes severe stenosis within the right coronary artery, whereas there is no coronary artery stenosis in the left descending artery; (E,F) corresponding images by invasive coronary angiography. MDCT, multi-detector-row computed tomography. Reprinted from (26), with permission from Elsevier.

Figure 3

Assessment of plaque characteristics by MDCT. (A) Mild stenosis (white box) is observed in the proximal left descending artery; (B) this segment shows positive remodeling (yellow dot line); (C) cross-sectional image in the segment with positive remodeling; (D) substantial plaque burden is observed. White line, lumen area; white dashed line, vessel wall area. MDCT, multi-detector-row computed tomography.

Figure 4

Contrast-enhanced cardiac MRI of coronary artery. (A) Invasive coronary angiography shows the presence of mild stenosis in the right coronary artery; (B) MRA visualizes the right coronary artery; (C,D) contrast-enhanced cardiac MRI revealed diffuse contrast enhancement (white arrow) in the right coronary artery. MRI, magnetic resonance imaging; MRA, magnetic resonance angiography. Reprinted from (69), with permission from Elsevier.

Figure 5

HIP Measurement on MRI. (A) MDCT identified tight stenosis with positive remodeling in the proximal left descending artery (arrow); (B) a “hyperintense spot” (dashed arrow) was observed at the corresponding segment on CMR; (C) invasive coronary angiography showed severe coronary stenosis in the proximal left descending artery (arrow head); (D) on IVUS imaging, positive remodeling and ultrasound attenuation (arrowheads) were observed. IVUS, intravascular ultrasound; HIP, hyperintense plaque; MDCT, multi-detector-row computed tomography. Reprinted from (70), with permission from Elsevier.

Figure 6

¹⁸F-FDG (fluorodeoxyglucose) PET imaging of coronary artery. (A) Increased uptake was observed in the left main trunk of patients with ACS (dashed arrow); (B) in a patient with stable CAD, the amount of uptake in the left main trunk was smaller compared to ACS case. ACS, acute coronary syndrome; CAD, coronary artery disease; FDG, fluorodeoxyglucose; PET, positron emission tomography. Reprinted from (85), with permission from Elsevier.

Figure 7

¹⁸F-NaF (sodium fluoride) PET imaging. Focal ¹⁸F-NaF uptake is observed in the proximal LAD overlying existing coronary calcium. NaF, sodium fluoride; PET, positron emission tomography. Reprinted from (88), with permission from Elsevier.