3-D Imaging for Aortic Plaque Assessment

3-D transesophageal echocardiography aids in assessment of embolic stroke due to aortic atherosclerotic plaque: A case series

Atherosclerosis is the most common cause of heart disease and stroke. Plaque thickness ≥4 mm in the ascending aorta or aortic arch is strongly correlated with cerebral embolic events and ischemic stroke. However, despite imaging workup, the cause of embolic stroke remains unidentified in many patients. Transesophageal echocardiography (TEE) is the preferred echocardiographic method for the evaluation of cardiac source of emboli. 2D TEE imaging evaluates aortic root and aortic arch in a single plane or two planes with biplane imaging. However, 2D TEE often fails to detect mobile or complex components in the ascending aorta and aortic arch plaques. The routine availability of 3D TEE in current ultrasound systems may significantly improve the assessment of aortic plaques as a potential embolic source. In this case series, we present four consecutive patients with stroke who underwent TEE by a single cardiologist for possible cardioembolic source. Some of these patients may have been labelled as "cryptogenic stroke" or "embolic stroke of undetermined source" (ESUS) due to the presence of insignificant or nonmobile ascending aortic or aortic arch plaques on 2D TEE imaging. In our four consecutive patients with ESUS who underwent TEE by a single operator, 3D TEE showed complex aortic arch plaques with ulceration with mobile components and established these plaques as the likely source of embolic stroke.

Reconstruction of the descending thoracic aorta by multiview compounding of 3-D transesophageal echocardiographic aortic data sets for improved examination and quantification of atheroma burden

A robust and efficient approach to reconstruction of the descending thoracic aorta from contiguous 3-D transesophageal echocardiographic (TEE) images is proposed. An ad hoc image acquisition protocol was designed to acquire ordered and partially overlapped 3-D TEE data sets, followed by dedicated image processing to align and fuse all acquired data sets. Alignment strategy implemented pairwise rigid registration guided by a priori knowledge, and it was validated using artificially misaligned images. Image fusion was finally performed to enable visualization and analysis of extended field-of-view of the acquired aorta. The application of different fusion techniques was also investigated. The method was applied to a population of 17 consecutive patients. Qualitative and quantitative results supported the feasibility and accuracy of the proposed approach. In a clinical scenario, its application could allow the quantitative assessment of aortic plaque burden in the descending thoracic aorta from 3-D TEE images.

Transoesophageal echocardiography of aortic atherosclerosis: the additive value of three-dimensional over two-dimensional imaging

AIMS

Complex aortic atherosclerotic plaques (AAPs) carry a significant risk of embolism. Currently, two-dimensional (2D) transoesophageal echocardiography (TOE) is the principal diagnostic tool of AAPs. However, we hypothesized that the data obtained from three-dimensional (3D) imaging may improve AAPs' spatial assessment.

METHODS AND RESULTS

The study included 67 patients (aged 70 ± 15 years, 35 men), who had routine TEE studies. The thoracic aorta was studied from arch to distal descending aorta, using the x-plane mode (simultaneous short- and long-axis views). If focal intimal thickening (suggestive of AAP) was detected, the 3D zoom algorithm was exercised on the specific site with further post-processing on a Q-lab workstation to measure its thickness in the X, Y, and Z dimensions. The AAP contour was defined qualitatively as regular or irregular in each mode. A total of 100 AAPs were investigated. The AAP thickness estimation was significantly greater in the 3D mode than in the 2D mode (0.51 ± 0.33 vs. 0.28 ± 0.20 cm, P < 0.001). The rate of complex AAPs (defined by AAP thickness of ≥4 mm) was two-fold higher with 3D imaging than with 2D imaging (27% with 2D imaging alone vs. 53% with the addition of 3D imaging). The rate of irregular AAPs increased from 29 to 65% when assessed with 3D imaging compared with 2D imaging.

CONCLUSION

This study has shown a significant difference in the estimation of AAPs between 2D and 3D TEE. The significant shift to a more complex AAPs profile may suggest that 3D imaging is preferable for the assessment of aortic atherosclerosis burden.

Intra–aortic Filtration in Cardiac Surgery

Cardiac surgery is associated with a significant risk of adverse outcomes, particularly neurologic and renal. Embolic events are the primary source of these deleterious consequences. Intraaortic filtration is the only current technology shown to effectively capture particulates released during cardiac procedures and decrease morbidity and mortality. Although most surgical candidates may potentially benefit from intraaortic filtration, some patients are more likely to experience improved outcomes. Based on the evidence reported in the literature and the extensive experience of the authors, the following opinion details the authors’ rationale and recommendations for patient selection for intraaortic filtration during cardiac surgery.