NONINVASIVE ASSESSMENT OF MYOCARDIAL PERFUSION AND METABOLISM - FEASIBILITY OF REGISTERING GATED MR AND PET IMAGES
NONINVASIVE ASSESSMENT OF MYOCARDIAL PERFUSION AND METABOLISM - FEASIBILITY OF REGISTERING GATED MR AND PET IMAGES
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DOI：
10.2214/ajr.164.2.7839959
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发表时间：
1995-02-01
影响因子：
5
通讯作者：
SCHELBERT, HR
中科院分区：
文献类型：
--
作者：
SINHA, S;SINHA, U;SCHELBERT, HR
目的：正电子发射断层扫描(PET)是无创性评价在体心肌血流灌注和代谢的参考技术，但其分辨率有限、信噪比低。另一方面，心脏磁共振成像提供了出色的软组织对比度。本研究通过将心脏PET图像所描绘的局部心肌血流或底物代谢的三维叠加，结合这两种互补技术的信息的可行性。材料和方法：从6名正常志愿者和1名经冠状动脉造影发现的冠心病患者的心脏周期的不同时相获得心脏的三维门控PET和MR图像。开发了一种使用形态算子的交互式算法来在MR和PET图像上勾勒出左心室的轮廓。采用三维曲面拟合技术对左心室表面进行配准。使用6个志愿者扫描的80个内部地标评估配准的准确性。结果：这些技术产生的PET图像在横轴和短轴切面上与MR图像沿相同的空间位置和方向重新扫描。平均残差为26(+/-5.6)，舒张期为13(+/-6.1)，而当图像在两个方向上故意错位2 mm时，该指数从最佳拟合时的9.3增加到13.2。我们验证了MR和PET图像的对准精度可以达到1.95 mm(+/-1.6)，这大致等于两个像素大小中较大的一个(即PET图像上的1.6 mm)。结论：心脏同一心脏时相的MR和PET图像可以准确地重叠。可以获得横轴和短轴图像，后者对PET定量更有用。这项技术提供了表征收缩功能、血流和底物代谢之间的区域性相互作用的可能性，特别是当这些在心脏疾病中发生区域性改变时。
OBJECTIVE: Positron emission tomography (PET), the reference technique for in vivo noninvasive assessment of myocardial perfusion and metabolism, is hampered by limited resolution and low signal-to-noise ratio. Cardiac MR imaging, on the other hand, provides excellent soft-tissue contrast. This study examines the feasibility of combining the information of these two complementary techniques by the three-dimensional superimposition of regional myocardial blood flow or substrate metabolism as depicted in cardiac PET images on comparable MR images at the same cardiac phase and spatial location.SUBJECTS AND METHODS: Three-dimensional, gated PET and MR images of the heart were acquired at different phases of the cardiac cycle from six normal volunteers and from one patient with coronary artery disease that had been detected by coronary angiography. An interactive algorithm using morphologic operators was developed to contour the left ventricle on the MR and PET images. A three-dimensional surface-fitting technique was used to register the left ventricle surfaces. The accuracy of registration was estimated using 80 internal landmarks from six volunteer scans.RESULTS: These techniques yielded PET images resliced along the same spatial location and orientation as the MR images both in the transaxial and short-axis views. The average residual, a measure of the goodness of fit, was 26 (+/- 5.6) for the systolic and 13(+/- 6.1) for the diastolic images compared with an increase of that index from 9.3 at the best fit to 13.2 when the images were deliberately misaligned by 2 mm in each of two directions. We verified that MR and PET images could be aligned with an accuracy of 1.95 mm (+/- 1.6), which was approximately equal to the larger of the two pixel sizes (i.e., 1.6 mm on PET images).CONCLUSION: MR and PET images of the heart at identical cardiac phases can be accurately superimposed. Both transaxial and short-axis views can be obtained, the latter being more useful for PET quantification. This technique offers the potential for characterizing regional interactions among contractile function, blood flow, and substrate metabolism, especially when these are altered regionally in cardiac diseases.