van Bemmel Cornelis M, Wink Onno, Verdonck Bert, Viergever Max A, Niessen Wiro J
Image Sciences Institute, University Medical Center, Room E.01.334, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
IEEE Trans Med Imaging. 2003 May;22(5):645-52. doi: 10.1109/TMI.2003.812262.
Blood pool agents (BPAs) for contrast-enhanced magnetic resonance angiography (CE-MRA) allow prolonged imaging during the steady state when the agent is distributed through the complete vascular system. This increases both the spatial resolution and the contrast resolution. However, simultaneous venous and arterial enhancement hampers interpretation. For the pelvic region of the vasculature, it is shown that arterial visualization in this equilibrium phase can be improved if the central arterial axis (CAA) is known. However, manually obtaining this axis is not feasible in clinical practice. Therefore, a method is presented that utilizes images acquired during the first pass of the contrast agent to find the CAA in the steady-state data with minimum user initialization. The accuracy of the resulting CAA is compared with tracings of three observers in six patient datasets. It was found that the mean difference between the semiautomatic method and the manual delineation is 1.32 mm in the steady-state data, and that the resulting CAA was always within the arterial lumen, which is an important prerequisite for both improved visualization and segmentation.
用于对比增强磁共振血管造影（CE-MRA）的血池造影剂（BPA）可在造影剂分布于整个血管系统的稳态期间延长成像时间。这既提高了空间分辨率，也提高了对比分辨率。然而，静脉和动脉同时增强会妨碍解读。对于血管系统的盆腔区域，研究表明，如果已知中心动脉轴（CAA），则在此平衡期的动脉可视化可以得到改善。然而，在临床实践中手动获取该轴并不可行。因此，本文提出了一种方法，该方法利用在造影剂首次通过期间采集的图像，以最少的用户初始化在稳态数据中找到CAA。将所得CAA的准确性与六个患者数据集的三位观察者的描记结果进行比较。发现在稳态数据中，半自动方法与手动描绘之间的平均差异为1.32毫米，并且所得的CAA始终位于动脉腔内，这是改善可视化和分割的重要前提。
