Thrombus Detection in the Left Atrial Appendage Using Contrast-Enhanced MRI: A Pilot Study

Abstract

The image quality was good for both 2D perfusion (grade 4 +/- 1) and 3D turbo fast low-angle shot (FLASH) (grade 4 +/- 1, n.s.). Compared with TEE, 2D perfusion, 3D turboFLASH, and the combination of both techniques yielded sensitivities of 47/35/44%, specificities of 50/67/67%, positive predictive values of 73/75/80%, and negative predictive values of 25/27/29%, respectively. The size of the thrombus was overestimated by 2D perfusion (66%) and by 3D turboFLASH (25%) and agreement for location and shape of thrombus was 50% and 75% for 2D perfusion and 75% and 50% for 3D turboFLASH, respectively. The TEE thrombus size was significantly larger in patients with true-positive diagnoses by 2D perfusion (148%) and by 3D turboFLASH (151%) when compared with patients with false-negative diagnoses (p < 0.05 for both). No such difference was found for image quality, time delay between TEE and MRI examination, and location and shape of thrombi. Contrast-enhanced MRI lacks diagnostic accuracy for the detection of thrombi in the left atrial appendage. Future technical improvements are essential to establish this technique as a noninvasive alternative to TEE.

Can Contrast-Enhanced Multi-Detector Computed Tomography Replace Transesophageal Echocardiography for the Detection of Thrombogenic Milieu and Thrombi in the Left Atrial Appendage: A Prospective Study with 124 Patients

“…Other MRI examination techniques evaluated for the detection of LAA thrombi are black blood sequences, which, however, are susceptible to slow flow artifacts, and contrast-enhanced 2 D and 3 D perfusion sequences. The sensitivity and specificity are between 47 % and 50 % for these sequences [29,30]. Up to date, there are only a few studies regarding the use of MRI for the detection of LA/LAA thrombi.…”

Association Between Left Atrial Appendage Morphology Evaluated by Trans-Esophageal Echocardiography and Ischemic Cerebral Stroke in Patients With Atrial Fibrillation

“…3,4) As the LAA represents one of the major sources of cardiac thrombus formation responsible for stroke in patients with AF, 5,6) the imaging of the different structures and lobes is of utmost importance to diagnose the presence of thrombus, especially in patients with non-valvular AF. 7,8) Multidetector computed tomography 9) and contrast-enhanced magnetic resonance imaging 10) are able to image the LAA; however, it was concluded that magnetic resonance imaging lacks diagnostic accuracy for the detection of LAA thrombi. 10) Transesophageal echocardiography (TEE) is the gold standard to detect LAA thrombus, 11) but false positive results still occur.…”

“…7,8) Multidetector computed tomography 9) and contrast-enhanced magnetic resonance imaging 10) are able to image the LAA; however, it was concluded that magnetic resonance imaging lacks diagnostic accuracy for the detection of LAA thrombi. 10) Transesophageal echocardiography (TEE) is the gold standard to detect LAA thrombus, 11) but false positive results still occur. 12) In this study, we evaluated the LAA structure and functions by TEE in patients with non-valvular AF (both chronic and paroxysmal types) to study the possible association between the different LAA morphologies and functional changes with the patients' history of ischemic cerebral stroke.…”

First experiences with contrast-enhanced first-pass MR perfusion imaging in patients with primary, benign cardiac masses and tumour-like lesions

“…Also, the ability to differentiate thrombus from myxoma has to be validated in patients with chronic thrombus, which could also enhance due to neo-organisation with capillaries. We did not enrol patients with thrombus in the left atrial appendage because this kind of tumour-like lesions is a special entity that has been reported previously [9]. Cardiac paraganglioma are rare, but usually located in the left atrium, and therefore a potential differential diagnosis to atrial myxoma and atrial thrombus.…”