Institute of Imaging & Computer Vision, RWTH Aachen University, Aachen, Germany,
Eur J Nucl Med Mol Imaging. 2014 Mar;41(3):536-47. doi: 10.1007/s00259-013-2551-3. Epub 2013 Sep 13.
We developed and tested a single acquisition rest (99m)Tc-sestamibi/stress (201)Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT).
The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress (99m)Tc and rest (99m)Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available.
Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected (201)Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the (201)Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and (99m)Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the (99m)Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow-up information was available for evaluation.
The proposed SDI protocol has the potential to improve clinical workflow and patient comfort and suggests improved accuracy as demonstrated in the clinical feasibility study.
我们开发并测试了一种单采集期（99m）Tc-甲氧基异丁基异腈/负荷（201）Tl 双同位素方案（SDI），旨在改善心肌灌注单光子发射计算机断层扫描（SPECT）的临床工作流程和患者舒适度。
通过对标准 SPECT 相机进行一系列人体模型研究，评估 SDI 的技术可行性。衰减图通过移动传输线源创建。迭代重建包括衰减校正、分辨率恢复和散射的蒙特卡罗模拟，用于同时重建双示踪剂分布。对于临床评估，将患者研究与在 2 天方案中获得的负荷（99m）Tc 和静息（99m）Tc 参考图像进行比较。如果有冠状动脉造影（CAG）和血流储备分数（FFR）等临床随访检查，也包括在评估中。
人体模型研究表明 SDI 具有技术可行性。在模拟缺血的人体模型中插入的人工病变可以清晰识别。在 51/53 名患者中，图像质量足以进行临床评估。对于另外两名体重指数（BMI）>32 的肥胖患者，74 MBq 的注入（201）Tl 剂量不足以进行临床评估。为了解决这个问题，在研究的其余部分中，对肥胖患者的（201）Tl 剂量进行了调整。在 31 名患者中，SDI 和（99m）Tc 参考图像的临床评估结果相当。在 20 名患者中发现了显著差异。在这些 20 名患者中的 18 名，有额外的检查可用。在 15 名患者中，基于 SDI 图像的诊断结果得到了 CAG 或 FFR 的证实。在这些患者中，SDI 图像比（99m）Tc 参考研究更准确。在 3 名患者中，通过 SDI 检测到轻微的缺血性病变，但未得到 CAG 的证实。在其中一个病例中，这可能是由于明显的心尖变薄引起的。对于两名患者，没有相关的临床随访信息可用于评估。
所提出的 SDI 方案有可能改善临床工作流程和患者舒适度，并在临床可行性研究中表明了更高的准确性。
