Songy Bernard, Guernou Mohamed, Lussato David, Queneau Mathieu, Geronazzo Ricardo
North Cardiology Hospital, CCN, Saint-Denis, Paris, France.
Nucl Med Commun. 2012 May;33(5):464-9. doi: 10.1097/MNM.0b013e3283504543.
Thallium-201 is efficient for myocardial perfusion imaging, but leads to relatively high radiation exposure in patients. The purpose of this study was to compare the efficiency of low-dose thallium-201 imaging with cadmium-zinc-telluride (CZT) cameras with regular-dose thallium-201 imaging with conventional cameras.
We prospectively studied 137 consecutive patients referred for stress myocardial perfusion imaging who had previously had a myocardial single-photon emission computed tomography with thallium-201. We injected at stress a low dose of thallium-201 (1.1 MBq/kg, 28 µCi/kg), performed a 5-7 min scan with a CZT camera (GE DNM 530c), and assessed redistribution imaging when the initial images were abnormal. We compared the CZT scan with the conventional dual-head tomographic camera scan taken previously with a regular dose of thallium-201.
The average delay between both scans was 22 months. The stress dose was 88 ± 16 (2.38 ± 0.43 mCi) versus 125 ± 13 MBq (3.38 ± 0.34 mCi; a 30% reduction). The time for camera acquisition was 6 versus 13 min (a 54% reduction). The myocardial counts were increased two-fold with CZT (mean: 446 Kcounts). The quality of CZT images was better in 69% of the cases. There were 59 artifacts with conventional cameras and 29 artifacts with CZT (P<0.01). The diagnostic agreement was calculated in patients without clinical or angiographic changes between both scans (115 patients) and was high (97%). The effective dose at stress was less than 12 mSv. High myocardial counting allowed for further decrease in the injected activity, leading to an effective dose as low as 8 mSv.
With reduced activities of thallium-201 and low effective doses, the CZT camera provides reliable, high-quality imaging.
铊 - 201对心肌灌注成像有效，但会使患者受到相对较高的辐射暴露。本研究的目的是比较使用碲化镉锌（CZT）相机进行低剂量铊 - 201成像与使用传统相机进行常规剂量铊 - 201成像的效率。
我们前瞻性地研究了137例连续转诊进行负荷心肌灌注成像的患者，这些患者之前曾接受过铊 - 201心肌单光子发射计算机断层扫描。我们在负荷状态下注射低剂量的铊 - 201（1.1 MBq/kg，28 μCi/kg），使用CZT相机（GE DNM 530c）进行5 - 7分钟的扫描，并在初始图像异常时评估再分布成像。我们将CZT扫描与之前使用常规剂量铊 - 201进行的传统双头断层相机扫描进行比较。
两次扫描之间的平均间隔时间为22个月。负荷剂量为88±16（2.38±0.43 mCi），而之前的为125±13 MBq（3.38±0.34 mCi；降低了30%）。相机采集时间为6分钟，而之前为13分钟（减少了54%）。使用CZT时心肌计数增加了两倍（平均：446 K计数）。在69%的病例中，CZT图像质量更好。传统相机有59个伪影，CZT有29个伪影（P<0.01）。在两次扫描之间无临床或血管造影变化的患者（115例）中计算诊断一致性，一致性较高（97%）。负荷状态下的有效剂量小于12 mSv。高心肌计数允许进一步降低注射活度，从而使有效剂量低至8 mSv。
使用降低活度的铊 - 201和低有效剂量时，但CZT相机可提供可靠、高质量的成像。
