Department of Medical Physics and Engineering, Level 1, Bexley Wing, St. James' University Hospital, Leeds, LS9 7TF, UK,
Ann Nucl Med. 2013 Nov;27(9):855-61. doi: 10.1007/s12149-013-0760-2. Epub 2013 Aug 8.
The aim of this study was to assess variation of qualitative and quantitative PET/CT image quality parameters with acquisition time, injection activity and body mass for a representative group of adults undergoing whole-body PET/CT imaging.
PET scan data from sixty patients were reconstructed with a scan time of 1, 2 and 3 min/bed position. These images were visually scored and three quantitative parameters were calculated: noise equivalent counts per axial length (NECpatient), noise equivalent count density (NECdensity) and liver signal to noise ratio (liver SNR). The ability of the three quantitative parameters to discriminate qualitative image quality was assessed using ROC analysis.
The quantitative parameters were shown to discriminate images of good/excellent quality from those of poorer image quality with a high degree of accuracy (ROC area >0.9); further, NECpatient had significantly higher discrimination than either NECdensity or liver SNR (ROC area = 0.97).
NECpatient, NECdensity and liver SNR all have high discrimination for qualitatively assessed PET image quality. NECpatient in particular is an effective objective indicator of patient image quality, which will help to assess and standardise scan protocols for purposes such as multi-centre research trials.
本研究旨在评估定性和定量 PET/CT 图像质量参数随采集时间、注射活动和体重的变化，为接受全身 PET/CT 成像的代表性成人组。
对 60 例患者的 PET 扫描数据进行重建，扫描时间为 1、2 和 3 分钟/床位。这些图像进行了视觉评分，并计算了三个定量参数：每个轴向长度的噪声等效计数（NECpatient）、噪声等效计数密度（NECdensity）和肝信噪比（liver SNR）。使用 ROC 分析评估了三个定量参数区分定性图像质量的能力。
定量参数能够以高度准确性区分质量良好/优秀的图像与质量较差的图像（ROC 面积>0.9）；此外，NECpatient 比 NECdensity 或 liver SNR 具有更高的区分能力（ROC 面积=0.97）。
NECpatient、NECdensity 和 liver SNR 均能高度区分定性评估的 PET 图像质量。特别是 NECpatient 是患者图像质量的有效客观指标，这将有助于评估和标准化扫描方案，例如用于多中心研究试验。
