Department of Nuclear Medicine, University of Munich, Marchioninistr. 15, 81377, Munich, Germany,
Ann Nucl Med. 2014 Feb;28(2):103-11. doi: 10.1007/s12149-013-0789-2. Epub 2013 Nov 20.
Dopamine transporter imaging with SPECT is a valuable tool for both clinical routine and research studies. Semi-quantitative analysis plays a key role in interpreting the scans, but is dependent on numerous factors, rotational radius being one of them. This study systematically evaluates the potential influence of radius of rotation on apparent tracer binding and describes methods for correction.
Monte Carlo simulation scans of a digital brain phantom with various disease states and various radii of rotation ranging from 13 to 30 cm were analyzed using 4 different methods of semi-quantification. Different volumes of interest as well as a method with partial volume correction were applied.
For conventional 3D semi-quantification methods the decrease of measured striatal binding per cm additional radius rotation lied in the range between 2.5 and 3.1 %, whereas effects were negligible when applying recovery-corrected quantification. Effects were independent of disease state.
Partial volume effects with increasing radius of rotation can lead to considerable decrease of measured binding ratios, particularly when applying dopamine transporter imaging in a research setting. Standardization of acquisition radius can avoid the effect; correction seems feasible, but the correction factors depend on the quantification approach applied.
使用单光子发射计算机断层扫描（SPECT）进行多巴胺转运体显像，是临床常规和研究的有价值的工具。半定量分析在解释扫描结果中起着关键作用，但取决于许多因素，旋转半径就是其中之一。本研究系统评估了旋转半径对示踪剂结合的潜在影响，并描述了校正方法。
使用 4 种不同的半定量分析方法，对具有不同疾病状态和从 13 到 30cm 不同旋转半径的数字脑模型进行了蒙特卡罗模拟扫描。应用了不同的感兴趣体积以及具有部分容积校正的方法。
对于常规的 3D 半定量分析方法，每增加 1cm 旋转半径，测量的纹状体结合的减少范围在 2.5%至 3.1%之间，而应用恢复校正定量时，影响可以忽略不计。该影响与疾病状态无关。
随着旋转半径的增加，部分容积效应会导致测量的结合比显著下降，特别是在研究中应用多巴胺转运体成像时。采集半径的标准化可以避免该影响；校正似乎是可行的，但校正因子取决于应用的定量方法。
