Molecular Imaging in Cardiovascular Diseases

Abstract

Cardiovascular diseases remain the leading cause of morbidity and mortality in industrialized and developing countries. In clinical practice, the in-vivo identification of atherosclerotic lesions, which can lead to complications such as heart attack or stroke, remains difficult. Imaging techniques provide the reference standard for the detection of clinically significant atherosclerotic changes in the coronary and carotid arteries. The assessment of the luminal narrowing is feasible, while the differentiation of stable and potentially unstable or vulnerable atherosclerotic plaques is currently not possible using non-invasive imaging. With high spatial resolution and high soft tissue contrast, magnetic resonance imaging (MRI) is a suitable method for the evaluation of the thin arterial wall. In clinical practice, native MRI of the vessel wall already allows the differentiation and characterization of components of atherosclerotic plaques in the carotid arteries and the aorta. Additional diagnostic information can be gained by the use of non-specific MRI contrast agents. With the development of targeted molecular probes, that highlight specific molecules or cells, pathological processes can be visualized at a molecular level with high spatial resolution. In this review article, the development of pathophysiological changes leading to the development of the arterial wall are introduced and discussed. Additionally, principles of contrast enhanced imaging with non-specific contrast agents and molecular probes will be discussed and latest developments in the field of molecular imaging of the vascular wall will be introduced.

Key Points:

• Molecular magnetic resonance imaging has great potential to improve the in vivo characterization of atherosclerotic plaques.

• Based on the molecular information is feasible to enable a better differentiation of stable and unstable (vulnerable) atherosclerotic plaques.

Citation Format:

• Botnar RM, Ebersberger H, Noerenberg D et al. Molecular imaging in cardiovascular diseases. Fortschr Röntgenstr 2015; 187: 92 – 101

Zusammenfassung

Kardiovaskuläre Erkrankungen sind nach wie vor die häufigste Ursache für Morbidität und Mortalität in den westlichen Industrieländern, aber auch in Entwicklungsländern. Im klinischen Alltag bleibt die In-vivo-Identifizierung von arteriosklerotischen Läsionen, die zu Komplikationen wie Herzinfarkten oder Schlaganfällen führen können, weiterhin schwierig. Bildgebende Verfahren sind gegenwärtig der Referenzstandard für die Detektion klinisch relevanter arteriosklerotischer Veränderungen der Koronararterien und der Karotiden. Dabei bleibt die Beurteilung auf die bildmorphologische Lumeneinengung beschränkt, während eine Differenzierung von stabilen und potenziell instabilen oder vulnerablen arteriosklerotischen Plaques aktuell im Rahmen der nichtinvasiven Bildgebung nicht möglich ist. Mit hoher räumlicher Auflösung und hohem Weichteilkontrast ist die Magnetresonanztomografie (MRT) eine gut geeignete Methode zur Darstellung und Beurteilung der dünnen Arterienwand. In der klinischen Praxis erlaubt die native MRT der Gefäßwand bereits eine Differenzierung sowie Charakterisierung von Komponenten arteriosklerotischer Plaques der Karotiden und der Aorta. Ein Zugewinn an diagnostischer Information kann durch den Einsatz zugelassener unspezifischer MRT-Kontrastmittel erreicht werden. Mit der Entwicklung von zielgerichteten molekularen Sonden, die bestimmte Moleküle oder Zellen markieren, lassen sich pathologische Prozesse auf molekularer Ebene mit hoher räumlicher Auflösung darstellen. In diesem Übersichtsartikel werden zunächst die zur Entwicklung der Arteriosklerose führenden pathophysiologischen Veränderungen der arteriellen Gefäßwand erläutert. Es folgt eine Darstellung der Wirkweise sowie der Eigenschaften unspezifischer Kontrastmittel sowie molekularer Sonden für die MRT-Bildgebung. Zusätzlich werden die neuesten Entwicklungen auf dem Gebiet der molekularen Bildgebung der Gefäßwand erörtert.

Key words

MR-imaging - arteriosclerosis - gadolinium

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