Department of Radiation Physics, Skåne University Hospital, Lund, Sweden.
Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, 221 85, Lund, Sweden.
J Nucl Cardiol. 2019 Dec;26(6):1984-1991. doi: 10.1007/s12350-018-1296-6. Epub 2018 May 23.
In myocardial perfusion imaging (MPI), single-photon emission tomography (SPECT) soft-tissue attenuation by the abdomen, breasts, and lateral chest wall may create artifacts that mimic true perfusion defects. This may cause misdiagnosis of myocardial perfusion. The aim of the present study was to compare the localization, extent, and depth of attenuation artifacts in MPI SPECT for a multi-pinhole cadmium zinc telluride (CZT) camera vs a conventional gamma camera.
Phantom and patient measurements were performed using a CZT camera (GE NM 530c) and a conventional gamma camera (GE Ventri). All images were attenuation corrected with externally acquired low-dose computed tomography. The localization, extent, and depth of the attenuation artifact were quantified by comparing attenuation-corrected and non-attenuation-corrected images.
Attenuation artifacts were shifted from the inferolateral wall to the lateral wall using the CZT camera compared to a conventional camera in both the patient and the phantom. The extent of the attenuation artifact was significantly larger for the CZT camera compared to the conventional camera (23 ± 5% vs 15 ± 5%, P < .001) for patients and the result was similar for the phantom (28% vs 19%). Furthermore, the depth of the attenuation artifact (percent of maximum counts) was less pronounced for the CZT camera than for the conventional camera, both for phantom measurements (73% vs 67%) and patients (72 ± 3% vs 68 ± 4%, P < .001).
Attenuation artifacts are found in different locations to different extents and depths when using a CZT camera vs a conventional gamma camera for MPI SPECT. This should be taken into consideration when evaluating MPI SPECT studies to avoid misinterpretation of myocardial perfusion distribution.
在心肌灌注成像（MPI）中，腹部、胸部和侧胸壁的单光子发射断层扫描（SPECT）软组织衰减可能会产生类似于真正灌注缺陷的伪影。这可能导致心肌灌注的误诊。本研究旨在比较多针孔碲锌镉（CZT）相机与传统伽马相机在 MPI SPECT 中的衰减伪影的定位、程度和深度。
使用 CZT 相机（GE NM 530c）和传统伽马相机（GE Ventri）进行了体模和患者测量。所有图像均采用外部采集的低剂量计算机断层扫描进行衰减校正。通过比较衰减校正和未校正图像来量化衰减伪影的定位、程度和深度。
与传统相机相比，使用 CZT 相机时，衰减伪影从下外侧壁转移到了外侧壁，无论是在患者还是体模中都是如此。与传统相机相比，CZT 相机的衰减伪影程度明显更大（患者为 23±5%比 15±5%，P<0.001；体模为 28%比 19%）。此外，与传统相机相比，CZT 相机的衰减伪影深度（最大计数的百分比）较小，无论是体模测量（73%比 67%）还是患者（72±3%比 68±4%，P<0.001）。
与传统伽马相机相比，使用 CZT 相机进行 MPI SPECT 时，衰减伪影的位置、程度和深度不同。在评估 MPI SPECT 研究时，应考虑到这一点，以避免对心肌灌注分布的误解。
