Cardiac magnetic resonance (CMR) can potentially be used to detect thrombi at the same time as being used for pulmonary venous anatomy mapping, say researchers.

Compared with the more invasive gold standard of transesophageal echocardiogram (TEE), CMR was more than 99% accurate for detecting thrombi in the left atrium and the left atrial appendage (LAA), report researchers.

The team tested three CMR sequences in the 261 patients referred for pulmonary vein isolation (PVI): cine-CMR; contrast-enhanced magnetic resonance angiography (MRA); and equilibrium phase delayed enhancement CMR with a long inversion time of 600 ms (long TI DE-CMR).

They found the long TI DE-CMR to be the best sequence. It detected all of the nine thrombi found on TEE (seven in the LAA; two in the left atrium) giving a sensitivity of 100%, although it was unable to definitively exclude thrombus in two cases, giving a specificity and overall accuracy of 99.2%. In addition, the interobserver agreement was highest for this sequence.