MATLAB PROJECT
Semiautomatic
Estimation of Device Size for Left Atrial Appendage Occlusion in 3-D TEE Images
Abstract:
Left atrial appendage (LAA) occlusion is used to reduce the risk of
thromboembolism in patients with nonvalvular atrial fibrillation by obstructing
the LAA through a percutaneously delivered device. Nonetheless, correct device
sizing is complex, requiring the manual estimation of different measurements in
preprocedural/periprocedural images, which is tedious and time-consuming and
with high interobserver and intraobserver variability. In this paper, a
semiautomatic solution to estimate the required relevant clinical measurements
is described. This solution starts with the 3-D segmentation of the LAA in 3-D
transesophageal echocardiographic images, using a constant blind-ended model
initialized through a manually defined spline. Then, the segmented LAA surface
is aligned with a set of templates, i.e., 3-D surfaces plus relevant
measurement planes (manually defined by one observer), transferring the latter
to the unknown situation. Specifically, the alignment is performed in three
consecutive steps, namely: 1) rigid alignment using the LAA clipping plane
position; 2) orientation compensation using the circumflex artery location; and
3) anatomical refinement through a weighted iterative closest point algorithm.
The novel solution was evaluated in a clinical database with 20 volumetric TEE
images. Two experiments were set up to assess: 1) the sensitivity of the
model's parameters and 2) the accuracy of the proposed solution for the
estimation of the clinical measurements. Measurement levels manually identified
by two observers were used as ground truth. The proposed solution obtained
results comparable to the interobserver variability, presenting narrower limits
of agreement for all measurements. Moreover, this solution proved to be fast,
taking nearly 40 s (manual analysis took 3 min) to estimate the relevant
measurements while being robust to the variation of the model's parameters.
Overall, the proposed solution showed its potential for fast and robust
estimation of ...
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