Contrast-enhanced CMR in patients after percutaneous closure of the left atrial appendage: A pilot study

<p>Abstract</p> <p>Background</p> <p>To 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.</p> <p>Methods</p> <p>7 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.</p> <p>Results</p> <p>All 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.</p> <p>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).</p> <p>Conclusion</p> <p>This 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.</p

Dependence of magnetic properties of (Fe50Co50)(78)Si7B15 amorphous wire on the diameter

The dependence of the magnetic properties of amorphous wire on the diameter have been investigated. The anisotropy constant, hence the internal stress, of the wire increases with the wire diameter. The size of the pinned reverse domain at the wire end increases with the wire diameter. Domain observation shows that irrespective of the change in the wire diameter, the domain structure basically consists of chevron domain layer sandwiched between the surface maze domain and the inner core domain

Aortic atherosclerosis as an embolic source

Stroke is the third leading cause of death in several industrial countries and cardiogenic embolism accounts for 15\u201330 % of ischaemic strokes [1\u20135]. The diagnosis of a cardioembolic source of stroke is frequently uncertain and relies on the identification of a potential cardiac source of embolism in the absence of significant autochthonous cerebrovascular occlusive disease. In this regard, echocardiography (either transthoracic \u2013 TTE or Transoesophageal \u2013 TEE) serves as a cornerstone in the evaluation and diagnosis of these patients [6, 7]