Interpretation of optical coherence tomography images

The interpretation of the optical coherence tomography (OCT) image provided by Dennis Wong and colleagues1Wong DTL Soh SY Nerlekar N Meredith IT Malaiapan Y Identification of concomitant ruptured plaque and intracoronary thrombus by optical coherence tomography.Lancet. 2014; 383: e11Summary Full Text Full Text PDF PubMed Scopus (9) Google Scholar suggests a plaque rupture with superimposed thombus in one of the lesions. However, by following the luminal contour around vessel circumference, one can appreciate a trilaminar structure of the vessel wall (11–3 o'clock), where the intima is seen as a bright, homogeneous, thin layer, followed by a thin signal-poor media overlying the adventitia. Between 4 and 11 o'clock, the intima is thickened showing a homogeneous, bright signal suggestive of a fibrous plaque. Notably, the luminal contour of the intima is intact along the circumference. The discontinuation at 7 o'clock represents the communication between the lumen and a side branch rather than a plaque rupture. The crescent-shaped bright structure in the lumen exhibits a whirly appearance, and could be mistaken for a thrombus,2Kume T Akasaka T Kawamoto T et al.Assessment of coronary arterial thrombus by optical coherence tomography.Am J Cardiol. 2006; 97: 1713-1717Summary Full Text Full Text PDF PubMed Scopus (407) Google Scholar as suggested by the authors. However, in this case it suggests insufficient blood removal during image acquisition. The red blood cells scatter the light, causing insufficient visualisation of the underlying structures. Accordingly, the low signal intensity of the underlying tissue (7–2 o'clock) is due to shadowing from erythrocytes rather than lipid accumulation. Taken together, the published OCT image is of suboptimum quality and shows a fibrous plaque with intact luminal contour. This example shows that interpretation of OCT images needs to be approached with caution, and the most important differential diagnoses, including artifacts,3Radu MD Räber L Serruys PW Artefacts with intracoronary optical coherence tomography.in: Radu MD Räber L Garcia-Garcia HM Serruys PW The Clinical Atlas of Intravascular Optical Coherence Tomography. Europa Edition, Toulouse2012Google Scholar should be kept in mind. We declare no competing interests. Identification of concomitant ruptured plaque and intracoronary thrombus by optical coherence tomographyA 74-year-old man was admitted with a non-ST segment elevation myocardial infarction with no localising electrocardiogram changes. Coronary angiography showed a severe eccentric stenosis with possible overlying thrombus in a moderate caliber first diagonal artery, and severe stenosis in proximal left anterior descending artery. Optical coherence tomography (OCT) was done to assess whether the stenosis in the first diagonal artery was the culprit stenosis. A ruptured thin cap fibrous atheroma with overlying thrombus was identified in the first diagonal artery, showing an actively developing acute coronary syndrome (figure). Full-Text PDF Interpretation of optical coherence tomography images – Authors' replyWe would like to express our gratitude for the feedback that we received following our Clinical Picture1 on a potential ruptured plaque and intracoronary thrombus. We acknowledge the concerns raised about our initial interpretation of the optical coherence tomography (OCT) images. Image interpretation remains the Achilles' heel of interventional cardiology with invasive intracoronary imaging, but must also always be done in the context of the clinical scenario. Full-Text PDF