Caobelli Federico, Akin Muharrem, Thackeray James T, Brunkhorst Thomas, Widder Julian, Berding Georg, Burchert Ina, Bauersachs Johann, Bengel Frank M
Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany
Department of Clinical Cardiology, Hannover Medical School, Hannover, Germany.
Eur Heart J Cardiovasc Imaging. 2016 Sep;17(9):1036-43. doi: 10.1093/ehjci/jev312. Epub 2015 Nov 30.
Computed tomography (CT)-based attenuation correction (AC) improves the accuracy of standard myocardial perfusion SPECT. Most dedicated cadmium-zinc-telluride (CZT) SPECT cameras are not equipped with an integrated CT component. We aimed to determine the impact of AC on diagnostic performance of CZT SPECT using co-registration with an external low-dose CT.
Sixty patients underwent CZT SPECT (GE Discovery 530c) with (99m)Tc-sestamibi at rest and following regadenoson stress. Using commercial software, SPECT images were co-registered with a low-dose CT acquired on a separate system (GE Discovery 670NMCT). Attenuation corrected and non-corrected (NC) images were reconstructed using an iterative algorithm. Accuracy was measured in 44 patients who had undergone invasive angiography within 6 months. Normalcy was compared in the remaining 16 patients who had a low pre-test likelihood (<5%) of coronary artery disease (CAD).
Summed stress and rest scores were significantly lower in AC images (9 ± 8 vs. 13 ± 9 and 6 ± 7 vs. 10 ± 9, P = 0.01), while summed difference score did not differ. According to angiography, 38 patients had significant CAD in 71 vascular territories. Attenuation correction improved accuracy globally (P = 0.03) and in RCA territory (P = 0.008). Specificity improved both globally (100 vs. 40%, P < 0.05) and in each individual territory (LAD: 63 vs. 36%, LCX: 70 vs. 33%, RCA: 81 vs. 19%, P < 0.01). Normalcy was 100% for AC and 62.5% for NC images (P < 0.05).
Attenuation correction with a co-registered external CT is feasible using CZT cameras and improves diagnostic accuracy mostly by improving specificity over uncorrected images.
基于计算机断层扫描（CT）的衰减校正（AC）可提高标准心肌灌注单光子发射计算机断层扫描（SPECT）的准确性。大多数专用的碲化镉锌（CZT）SPECT相机未配备集成CT组件。我们旨在通过与外部低剂量CT进行配准来确定AC对CZT SPECT诊断性能的影响。
60例患者接受了CZT SPECT（GE Discovery 530c）检查，静息和注射雷加曲班负荷试验时使用（99m）锝-甲氧基异丁基异腈。使用商业软件，将SPECT图像与在单独系统（GE Discovery 670NMCT）上采集的低剂量CT进行配准。使用迭代算法重建衰减校正和未校正（NC）图像。在6个月内接受有创血管造影的44例患者中测量准确性。在其余16例冠心病（CAD）预测试验可能性较低（<5%）的患者中比较正常情况。
AC图像中的负荷和静息总分显著较低（9±8对13±9以及6±7对10±9，P = 0.01），而总分差值无差异。根据血管造影，71个血管区域中有38例患者患有显著CAD。衰减校正总体上提高了准确性（P = 0.03）以及右冠状动脉（RCA）区域的准确性（P = 0.008）。特异性总体上（100%对40%，P < 0.05）以及在每个单独区域（左前降支：63%对36%，左旋支：70%对33%，RCA：81%对19%，P < 0.01）均有所提高。AC图像的正常情况为100%，NC图像为62.5%（P < 0.05）。
使用CZT相机通过与外部CT配准进行衰减校正是可行的，并且主要通过提高特异性而非未校正图像来提高诊断准确性。
