Department of Nuclear Medicine, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo.
Department of Quantum Medical Technology, Institute of Medical Pharmaceutical and Health Sciences, Kanazawa University, Ishikawa.
Nucl Med Commun. 2021 Mar 1;42(3):267-275. doi: 10.1097/MNM.0000000000001338.
The present study used a phantom to determine the effects of various arm positions on bone SPECT/computed tomography (CT) images and the optimal arm position to acquire good-quality and quantitatively accurate images.
We designed a phantom study of five simulated arm positions that are assumed during SPECT image acquisition. All SPECT data were acquired during a total of 120 projections of 10 and 100 s/view over 360° in a non-circular mode and reconstructed using Flash 3D (Siemens Healthineers). We evaluated contrast (QH,17 mm), image noise (NB,17 mm), contrast-to-noise ratios (QNRs), and visual scores according to the guidelines for bone SPECT acquisition protocols published by the Japanese Society of Nuclear Medicine Technology. The SUVmean, SUVmax, and SUVpeak were calculated and quantitative errors were evaluated using the recovery coefficient (RC) and the root means square error (RMSE).
The spatial resolution of SPECT images was better when the arms were down than raised with simulated shoulder disorders. Raised arms with shoulder disorders significantly increased the NB,17 mm and decreased the QH,17 mm, and the QNR in each image differed over a range from 2.2 to 5.2. The visual score was >1.5 with the arms down, raised normally, and raised with moderate shoulder disorders. The SUVmax and SUVpeak were overestimated compared with 100-min data for all images, whereas SUVmean was underestimated. Raised arms with a shoulder disorder decreased RCmax, and RCmean and RCpeak suppressed differences among arm positions. In addition, RMSE with the arms down and raised normally were close to that for 100-min data.
Bone SPECT images with good quality and quantitative accuracy can be acquired with patients holding their arms down by their sides. This will help patients with shoulder pain who have difficulties raising their arms.
本研究使用一个模型来确定不同手臂位置对骨单光子发射计算机断层扫描（SPECT）/计算机断层扫描（CT）图像的影响，以及获取高质量、定量准确图像的最佳手臂位置。
我们设计了一项模型研究，包括在 SPECT 图像采集期间假设的五种模拟手臂位置。所有 SPECT 数据均在非圆形模式下采集，共采集 120 次投影，每次投影采集 10 秒和 100 秒，共采集 360°，使用 Flash 3D（西门子医疗）重建。我们根据日本核医学技术协会发布的骨 SPECT 采集协议指南，评估对比度（QH，17mm）、图像噪声（NB，17mm）、对比噪声比（QNRs）和视觉评分。计算 SUVmean、SUVmax 和 SUVpeak，并使用恢复系数（RC）和均方根误差（RMSE）评估定量误差。
当手臂向下时，SPECT 图像的空间分辨率优于手臂向上时，同时伴有模拟肩部疾病。患有肩部疾病的抬高手臂会显著增加 NB，17mm 并降低 QH，17mm，并且每个图像的 QNR 差异范围为 2.2 至 5.2。当手臂向下、正常抬起和适度抬起肩部疾病时，视觉评分>1.5。与 100 分钟数据相比，所有图像的 SUVmax 和 SUVpeak 均被高估，而 SUVmean 则被低估。患有肩部疾病的抬高手臂会降低 RCmax、RCmean 和 RCpeak，并抑制手臂位置之间的差异。此外，手臂向下和正常抬起时的 RMSE 接近 100 分钟数据。
对于肩部疼痛难以抬起手臂的患者，让患者将手臂放在身体两侧，可获得高质量和定量准确的骨 SPECT 图像。
