Diagnosis of Atherosclerosis by Imaging

https://doi.org/10.1016/j.amjmed.2008.10.014Get rights and content

Abstract

New and experimental imaging techniques are being developed that will permit better visualization and compositional characterization of atheromatous plaques. This review provides discussion of techniques that are currently used in clinical practice, as well as techniques that are investigational only, including coronary angiography, intravascular ultrasound, computed tomography, magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography. Types of atheromatous plaque are reviewed, and the value of examining vascular calcification in risk assessment is discussed. Experimental use of these imaging techniques in animal models and in clinical studies will enhance our understanding of the development of plaque and will determine whether these techniques would be useful and practical for predicting disease course. Early detection and identification of the type of plaque that is present may generate novel opportunities for primary prevention through changes in lifestyle or even through drug therapy, especially in patients at high cardiovascular risk.

Section snippets

Coronary Angiography

Coronary angiography (Figure 1) was the first modality to become available for in vivo assessment of the coronary arteries. This procedure consists of injection of an iodinated contrast agent through a catheter placed at the ostium of the coronaries. The contrast agent is visible through x-ray fluoroscopic examination of the heart. Coronary angiography depicts “only” a luminogram of the vessel (the vessel space occupied by blood); the actual extent of atherosclerotic plaque volume in the wall

Carotid Plaque

B-mode ultrasound has been established as the imaging modality of choice for visualizing IMT. Abnormal thickening of carotid IMT is considered and has been validated as a marker of generalized atherosclerotic disease.16 In fact, it correlates linearly with the number of atherosclerotic risk factors.17 Arterial wall thickness can also be measured and the structure and composition of atheromatous plaques analyzed with the use of MRI and transthoracic or transesophageal ultrasound, among other

Functional and molecular imaging through noninvasive methods: Future modalities

New techniques based on molecular imaging that are currently under development may make it possible for the clinician to visualize inflammatory and other activities of atheromatous plaque. Such techniques would greatly enhance our ability to understand and assess mechanisms of the atherosclerotic disease process and monitor the efficacy of treatment. Several techniques with sufficient spatial resolution have been developed to facilitate molecular imaging; these include MRI with targeted

Current trials to test the broad clinical usefulness of vascular imaging

The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled (between July 2000 and August 2002) a total of 6,814 men and women aged 45 to 84 years of diverse ethnic origin who were free of clinically apparent cardiovascular disease.69 Baseline data obtained included measurements of the following: coronary calcium by CT; ventricular mass and function by MRI; and flow-mediated brachial artery endothelial vasodilation, carotid IMT, and peripheral vascular disease assessed by means of ankle-brachial

Summary

Atherosclerosis plaque imaging represents a new paradigm in cardiovascular medicine. At a research level, plaque imaging is a powerful tool for evaluating the mechanisms and efficacy of novel drug therapies. At a clinical level, plaque imaging may help clinicians to identify patients at risk who may benefit from secondary prevention strategies. The specific roles of different imaging modalities must be clearly defined. Significant evidence supports the role of the calcium score scan as a

Pearls for clinical guidance

  • Common characteristics of atherosclerotic plaques may be determined noninvasively.

  • Carotid ultrasound provides a measurement of IMT, which has been related to cardiovascular events and risk factors.

  • MRI can reveal total plaque burden across different vascular beds. Resolution most often is limited to large-caliber vessels.

  • CT can be used to determine coronary plaque burden and type. In contrast to MRI and ultrasound, this technique requires ionizing radiation.

  • Molecular imaging with MRI and/or PET

Author disclosures

The authors who contributed to this article have disclosed the following industry relationships:

  • Borja Ibañez, MD, has no financial arrangement or affiliation with a corporate organization or a manufacturer of a product discussed in this article.

  • Juan J. Badimon, PhD, has served as an advisory board participant (honorarium) for AstraZeneca Pharmaceuticals LP, Lilly-Sankyo, Pfizer Inc, and sanofi aventis.

  • Mario J. Garcia, MD, is a consultant for Philips Medical Systems and BG Medicine and has

Acknowledgments

We thank Michael Theisen, Dolores Matthews, and Marsha Hall from Scientific Connexions, Newtown, Pennsylvania, who provided editorial assistance funded by AstraZeneca Pharmaceuticals LP.

References (70)

  • B. Ibanez et al.

    Novel imaging techniques for quantifying overall atherosclerotic burden [in Spanish]

    Rev Esp Cardiol

    (2007)
  • B. Ibanez et al.

    Plaque progression and regression in atherothrombosis

    J Thromb Haemost

    (2007)
  • B. Ibanez et al.

    Rapid change in plaque size, composition and molecular footprint following recombinant ApoA-IMilano (ETC-216) administration: magnetic resonance imaging study in an experimental model of atherosclerosis

    J Am Coll Cardiol

    (2008)
  • A. Schmermund et al.

    Age and gender distribution of coronary artery calcium measured by four-slice computed tomography in 2,030 persons with no symptoms of coronary artery disease

    Am J Cardiol

    (2002)
  • H.S. Hecht et al.

    Coronary artery calcium scanning: clinical paradigms for cardiac risk assessment and treatment

    Am Heart J

    (2006)
  • P.G. O'Malley et al.

    Cost-effectiveness of using electron beam computed tomography to identify patients at risk for clinical coronary artery disease

    Am Heart J

    (2004)
  • D.G. Vince et al.

    Comparison of texture analysis methods for the characterization of coronary plaques in intravascular ultrasound images

    Comput Med Imaging Graph

    (2000)
  • A.J. Taylor et al.

    Coronary calcium independently predicts incident premature coronary heart disease over measured cardiovascular risk factors: mean three-year outcomes in the Prospective Army Coronary Calcium (PACC) project

    J Am Coll Cardiol

    (2005)
  • J. Hausleiter et al.

    Prevalence of noncalcified coronary plaques by 64-slice computed tomography in patients with an intermediate risk for significant coronary artery disease

    J Am Coll Cardiol

    (2006)
  • H. Kostamaa et al.

    Calcified plaque cross-sectional area in human arteries: correlation between intravascular ultrasound and undecalcified histology

    Am Heart J

    (1999)
  • P.M. Carrascosa et al.

    Characterization of coronary atherosclerotic plaques by multidetector computed tomography

    Am J Cardiol

    (2006)
  • N. Tahara et al.

    Simvastatin attenuates plaque inflammation: evaluation by fluorodeoxyglucose positron emission tomography

    J Am Coll Cardiol

    (2006)
  • G. Helft et al.

    Progression and regression of atherosclerotic lesions: monitoring with serial noninvasive magnetic resonance imaging

    Circulation

    (2002)
  • B. Ibanez et al.

    Tako-tsubo transient left ventricular apical ballooning: is intravascular ultrasound the key to resolve the enigma?

    Heart

    (2005)
  • J.C. Tardif et al.

    Effects of reconstituted high-density lipoprotein infusions on coronary atherosclerosis: a randomized controlled trial

    JAMA

    (2007)
  • S.E. Nissen et al.

    Effect of very high-intensity statin therapy on regression of coronary atherosclerosis: the ASTEROID trial

    JAMA

    (2006)
  • A. Nair et al.

    Coronary plaque classification with intravascular ultrasound radiofrequency data analysis

    Circulation

    (2002)
  • M.P. Moore et al.

    Characterization of coronary atherosclerotic morphology by spectral analysis of radiofrequency signal: in vitro intravascular ultrasound study with histological and radiological validation

    Heart

    (1998)
  • S. Achenbach et al.

    Detection of calcified and noncalcified coronary atherosclerotic plaque by contrast-enhanced, submillimeter multidetector spiral computed tomography: a segment-based comparison with intravascular ultrasound

    Circulation

    (2004)
  • S. Achenbach et al.

    Noninvasive coronary angiography by magnetic resonance imaging, electron-beam computed tomography, and multislice computed tomography

    Am J Cardiol

    (2001)
  • B. Ibanez et al.

    Early metoprolol administration before coronary reperfusion results in increased myocardial salvage: analysis of ischemic myocardium at risk using cardiac magnetic resonance

    Circulation

    (2007)
  • J.H. Rudd et al.

    Imaging atherosclerotic plaque inflammation with [18F]-fluorodeoxyglucose positron emission tomography

    Circulation

    (2002)
  • E. de Groot et al.

    Measurement of arterial wall thickness as a surrogate marker for atherosclerosis

    Circulation

    (2004)
  • D. Baldassarre et al.

    Carotid artery intima-media thickness measured by ultrasonography in normal clinical practice correlates well with atherosclerosis risk factors

    Stroke

    (2000)
  • S.E. Nissen et al.

    Intravascular ultrasound: novel pathophysiological insights and current clinical applications

    Circulation

    (2001)
  • Cited by (0)

    Statement of author disclosure: Please see the Author Disclosures section at the end of this article.

    To access a slide kit for this article, please click here.

    View full text