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BackgroundTo evaluate the feasibility and value of first-pass contrast-enhanced dynamic and post-contrast 3D CMR in patients after transcatheter occlusion of left atrial appendage (LAA) to identify incorrect placement and persistent leaks.Methods7 patients with different occluder systems (n = 4 PLAATO; n = 2 Watchman; n = 1 ACP) underwent 2 contrast-enhanced (Gd-DOTA) CMR sequences (2D TrueFISP first-pass perfusion and 3D-TurboFLASH) to assess localization, artifact size and potential leaks of the devices. Perfusion CMR was analyzed visually and semi-quantitatively to identify potential leaks.ResultsAll occluders were positioned within the LAA. The ACP occluder presented the most extensive artifact size. Visual assessment revealed a residual perfusion of the LAA apex in 4 cases using first-pass perfusion and 3D-TurboFLASH indicating a suboptimal LAA occlusion.By assessing signal-to-time-curves the cases with a visually detected leak showed a 9-fold higher signal-peak in the LAA apex (567 ± 120% increase from baseline signal) than those without a leak (61 ± 22%; p < 0.03). In contrast, the signal increase in LAA proximal to the occluder showed no difference (leak 481 ± 201% vs. no leak 478 ± 125%; p = 0.48).ConclusionThis CMR pilot study provides valuable non-invasive information in patients after transcatheter occlusion of the LAA to identify correct placement and potential leaks. We recommend incorporating CMR in future clinical studies to evaluate new device types.

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The aim of this study was to evaluate the diagnostic value of contrast-enhanced first-pass perfusion MRI in patients with suspected cardiac masses and tumour-like lesions. Twenty patients underwent contrast-enhanced first-pass saturation-recovery steady-state-free-precession perfusion MRI in addition to clinical MRI. Eleven diagnostic parameters were analysed blinded in consensus by three observers: localisation (paracardiac/mural/intracavitary), malignancy (benign/malignant) and first-pass enhancement pattern (homogeneous/heterogeneous as well as non-perfused/hypoperfused/iso-perfused/ hyperperfused). The results were compared to combined references comprising histology, cytology, medical and surgical reports, echocardiography, chest X-ray, coronary angiography and regular MRI. Also, we analysed if additional first-pass perfusion confirmed, changed or reduced the number of differential diagnoses compared to clinical MRI. All cardiac masses or tumour-like lesions were correctly localised and scored as benign lesions. For homogeneous perfused lesions the sensitivity, specificity, positive and negative predictive value was 94/100/100/67%, 100/94/67/100% for heterogeneous perfused lesions, 92/100/100/88% for non-perfused, 100/94/75/100 for hypoperfused, 100/100/100/100% for hyperperfused and for isoperfused lesions. In 17/2/1 cases perfusion MRI confirmed, reduced or increased the number of potential differentials. First-pass perfusion MRI provides valuable information in patients with benign cardiac masses or tumour-like lesions. Further experience is needed to underline these preliminary observations.