Department of Cardiology, University of Erlangen-Nürnberg, Ulmenweg 18, 91054 Erlangen, Germany.
J Cardiovasc Comput Tomogr. 2012 Nov-Dec;6(6):422-8. doi: 10.1016/j.jcct.2012.10.008. Epub 2012 Nov 3.
In transcatheter aortic valve implantation (TAVI), optimal selection of fluoroscopic projections that permit orthogonal visualization of the aortic valve plane is important but may be difficult to achieve.
We developed and validated a simple method to predict suitable fluoroscopic projections on the basis of cardiac CT datasets.
In 75 consecutive patients that underwent TAVI, angulations in which a 35-mm thick maximum intensity projection would render all aortic valve calcium into 1 plane were determined by manual interaction with contrast-enhanced dual-source CT datasets. TAVI operators used the predicted angulation for the first aortic angiogram and performed additional aortic angiograms if no satisfactory view of the aortic valve plane was obtained. Predicted angulations were compared with the angulation used for valve implantation. Radiation exposure and contrast use was compared between patients with accurate prediction of fluoroscopic angulations by CT and patients in whom CT failed to predict a suitable view.
The mean difference between the predicted angulation according to CT and the angulation used for implantation was 3 ± 6 degrees. CT predicted a suitable angulation (<5-degree deviation) in 63 of 75 cases (84%). The mean number of aortic angiograms acquired in patients with correct prediction (1.02 ± 0.1) was significantly lower than in patients with incorrect prediction of the implantation angle by CT (3.0 ± 1.7; P < 0.001). Contrast agent required for the entire TAVI procedure was lower in patients with correct prediction (72 ± 36 mL vs 106 ± 39 mL; P = 0.001).
CT permits prediction of suitable angulations for TAVI in most cases.
在经导管主动脉瓣植入术（TAVI）中，选择能够使主动脉瓣平面实现正交可视化的最佳透视投影非常重要，但可能难以实现。
我们开发并验证了一种基于心脏 CT 数据集预测合适透视投影的简单方法。
在连续 75 例行 TAVI 的患者中，通过手动交互增强双源 CT 数据集确定了使 35mm 厚的最大强度投影将所有主动脉瓣钙化为 1 个平面的角度。TAVI 操作者将预测的角度用于第一次主动脉造影，如果未能获得满意的主动脉瓣平面视图，则进行额外的主动脉造影。将预测的角度与用于植入瓣膜的角度进行比较。比较了 CT 准确预测透视角度的患者与 CT 未能预测合适视角的患者之间的辐射暴露和造影剂使用情况。
根据 CT 预测的角度与植入角度之间的平均差异为 3±6 度。CT 在 75 例中的 63 例（84%）预测了合适的角度（<5 度偏差）。在 CT 正确预测植入角度的患者中（1.02±0.1）获得的主动脉造影数量明显低于 CT 错误预测植入角度的患者（3.0±1.7；P<0.001）。CT 正确预测患者整个 TAVI 过程所需的造影剂用量也较低（72±36mL 比 106±39mL；P=0.001）。
CT 可预测大多数情况下 TAVI 的合适角度。
