18F-FDG PET/CT显像中连续采集和步进采集的比较

目的 比较连续采集(continuous bed motion, CBM)和步进采集(step and shoot, SS)对¹⁸F-脱氧葡萄糖(fluorodeoxyglucose, FDG) 正电子发射型计算机断层显像/电子计算机断层显像(positron emission tomography/computed tomography,PET/CT)图像质量和定量分析的影响。 方法 选择50例PET/CT受检者分别采用CBM和SS模式在Siemens Biograph Vision 600 PET/CT设备中完成躯干部图像采集,测量纵隔血池、肺、肝、肌肉、骨骼的平均标准化摄取值(mean standardized uptake value, SUV_mean)及标准差(standard deviation, SD),并用SD来评价图像噪声,采用配对t检验或配对秩和检验及Pearson相关分析和Bland-Altman图评价两组数据之间的差异和关系。 结果 在先后两次扫描中,纵隔血池和肝SUV_mean显著降低(t =5.630和4.993,P ＜0.05),腰椎SUV_mean显著增加(t =－3.320,P ＜0.05),而肺和肌肉SUV_mean差异无统计学意义(P ＞0.05)。在不同进床模式中,所有组织SUV_mean差异均无统计学意义(t =－1.626～-0.311,P ＞0.05),且存在高度相关(r=0.903～0.985),Bland-Altman图显示纵隔血池、肺、肝、竖脊肌、腰椎、大腿肌肉各组织的均值差分别为-0.02(95% CI:-0.27～0.24)、-0.01(95% CI:-0.05～0.03)、0.00(95% CI:-0.19～0.18)、-0.01(95% CI:-0.08～0.06)、-0.03(95% CI:-0.28 ～0.22)、0.00(95% CI:-0.07～0.08)。除大腿肌肉SD差异无统计学意义(Z =－1.163,P ＞0.05)外,其余各组织SS_SD均小于CBM_SD(Z =－4.406、-2.856、-5.556、-2.954和-3.104,P ＜0.05)。 结论 CBM采集方案灵活,能够提供与SS相当的定量信息,是PET/CT图像采集方法的有效补充。

Comparison of continuous-bed-motion and step-and-shoot acquisition modes on 18F-FDG PET/CT imaging

Objective To investigate the effects of continuous-bed-motion (CBM) and step-and-shoot (SS) acquisition modes on image quality and quantitative analysis in ¹⁸F-FDG(fluorodeoxyglucose) PET/CT (positron emission tomography/computed tomography) . Methods A total of 50 patients were prospectively selected and undertake PET image acquisition in Siemens Biograph Vision 600 PET/CT equipment with CBM and SS modes. Mean standardized uptake value (SUV_mean) and standard deviation (SD) of mediastinal blood pool, lung, liver, muscle, and bone were measured, and evaluate image noise with SD. Paired t test, Paired rank sum testPearson correlation analysis and Bland-Altman Figure were used to evaluate the difference and relationship between the data of two groups. Results In different acquisition sequences, the SUV_mean of mediastinal bloodPool and liver were decreased significantly (t= 5.630 and 4.993, all P<0.05), the SUV_mean of lumbar vertebra was increased significantly (t=-3.320, P<0.05), while the SUV_mean of lung and muscle was not significantly different (all P>0.05). In different acquisition modes, there were no significant difference in SUV_mean of all tissues (t values:from-1.626 to-0.311, P>0.05), and there were high correlation with them (r values: from 0.903 to 0.985),the Bland-Altman Figure shows that the mean difference of each tissues are-0.02(95%CI:-0.27 to 0.24), -0.01(95%CI:-0.05 to 0.03), 0.00(95%CI:-0.19 to 0.18), -0.01(95%CI:-0.08 to 0.06), -0.03(95%CI:-0.28 to 0.22),and 0.00(95%CI:-0.07 to 0.08). Except for the SD of thigh muscle (Z= -1.163, P>0.05), the SS_SD of other tissues was lower than that of CBM_SD (Z=-4.406, -2.856, -5.556, -2.954 and -3.104, all P<0.05). Conclusion CBM is a flexible acquisition method, which can provide the same quantitative information as SS. It is an effective supplement to PET/CT image acquisition method.