Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, ON N6A 5K8, Canada.
J Cardiovasc Comput Tomogr. 2011 Nov-Dec;5(6):430-42. doi: 10.1016/j.jcct.2011.10.008. Epub 2011 Oct 25.
Quantitative myocardial CT perfusion (CTP) is susceptible to beam-hardening (BH) artifact from conventional single-energy (kVp) CT (SECT) scanning, which can mimic perfusion deficits.
We evaluated the minimization of BH artifact with dual-energy (kVp) CT (DECT) generated monochromatic CT images to improve perfusion estimates.
We investigated the performance of DECT with a scanner capable of rapid kVp switching with respect to (1) BH artifact in a myocardium phantom model comparing SECT with image-based DECT and projection-based DECT, (2) optimal imaging parameters for measuring iodine concentration at high contrast-to-noise ratio in a tissue characterization phantom model, and (3) the feasibility of a dynamic time-resolved scan protocol with the projection-based DECT technique to measure myocardial perfusion in normal (nonischemic) porcine.
In a myocardium phantom model, projection-based DECT 70 keV was better able to minimize the difference in the attenuation of the myocardium (19.9 HU) between having and not having contrast in the heart chambers in comparison to SECT using 80 kVp (30.4 HU) or 140 kVp ( 23.3 HU) and image-based DECT 70 keV (27.5 HU). Further, projection-based DECT 70 keV achieved the highest contrast-to-noise ratio (3.0), which exceeded that from imaged-based DECT 70 keV (2.0), 140 kVp SECT (1.3), and 80 kVp SECT (2.9). In 5 normal pigs, projection-based DECT at 70 keV provided a more uniform perfusion estimate than SECT.
By effectively reducing BH artifact, projection-based DECT may permit improved quantitative myocardial CTP compared with the conventional SECT technique.
传统单能（kVp）CT（SECT）扫描的定量心肌 CT 灌注（CTP）易受束硬化（BH）伪影的影响，该伪影可模拟灌注缺损。
我们评估了双能（kVp）CT（DECT）生成的单色 CT 图像对 BH 伪影的最小化，以改善灌注估计。
我们使用能够快速切换 kVp 的扫描仪研究了 DECT 的性能，该扫描仪在心肌体模模型中比较了 SECT 和基于图像的 DECT 和基于投影的 DECT，（2）在组织特征化体模模型中以高对比度噪声比测量碘浓度的最佳成像参数，以及（3）基于投影的 DECT 技术进行正常（非缺血）猪心肌灌注的动态时间分辨扫描方案的可行性。
在心肌体模模型中，与使用 80 kVp（30.4 HU）或 140 kVp（23.3 HU）的 SECT 相比，基于投影的 DECT 70 keV 能够更好地最小化心脏腔中有和没有对比剂时心肌衰减的差异（19.9 HU），而基于图像的 DECT 70 keV（27.5 HU）。此外，基于投影的 DECT 70 keV 实现了最高的对比度噪声比（3.0），超过了基于图像的 DECT 70 keV（2.0）、140 kVp SECT（1.3）和 80 kVp SECT（2.9）。在 5 头正常猪中，与 SECT 相比，基于投影的 DECT 70 keV 提供了更均匀的灌注估计。
通过有效减少 BH 伪影，与传统 SECT 技术相比，基于投影的 DECT 可能允许改进定量心肌 CTP。
