Intra coronary thrombus detection by cardiac magnetic resonance (CMR) imaging

Intra coronary thrombus is usually detected by conventional coronary angiography as a negative shadow with haziness. Direct imaging of the carotid thrombus and hemorrhage within the plaque has been done using non contrast enhanced T1 weighted magnetic resonance imaging. This technique takes advantage of the short T1 of methemoglobin present in the acute thrombus and intraplaque hemorrhage. Christian Jansen and associates from the St. Thomas’ Hospital, King’s College London [Jansen CH et al. Detection of intracoronary thrombus by magnetic resonance imaging in patients with acute myocardial infarction. Circulation. 2011;124:416-24], have evaluated the use of non contrast enhanced magnetic resonance for direct thrombus imaging in patients with acute myocardial infarction. Non contrast enhanced magnetic resonance for direct thrombus imaging was done with a T1 weighted, three dimensional, inversion recovery black blood gradient echo sequence. Ten of the eighteen patients imaged were found to have intra coronary thrombus by conventional coronary angiography. Nine of these could be identified by magnetic resonance imaging as well. One thrombus in posterior descending artery was not detected by CMR (sensitivity 91%). Seven of the eight in the control group (without thrombus) were correctly classified by CMR (specificity 88%).