代谢时间对直肠癌患者18F-FDG PET检查SUV和MTV的影响分析

目的分析不同代谢时间对直肠癌患者18F-FDG PET影像最大标准率摄取值(Max Standard Uptake Value,SUVmax)、靶区/本底标准率摄取值之比(target/background Standard Uptake Value,SUVt/b)与代谢组织体积(Metabolic Tissue Volume,MTV)的影响,指导临床精准采集。方法选取2018年10月至2018年12月间病理确诊直肠癌的患者20例,行PET/CT检查,采集每例患者代谢40、50、60、70、80 min时的18F-FDG PET影像,共发现病灶29处。分别测量病灶不同代谢时间点的SUVmax、SUVt/b和MTV值,进行折线图走势分析及统计学分析。结果随着代谢时间的延长,患者病灶SUVmax值呈现波动上升的趋势;SUVt/b值与MTV值则呈现先增高后下降的趋势,SUVt/b值的拐点出现在70 min,MTV值的拐点出现在60分钟。两折线峰值数据与前后数据差异具有统计学意义(P<0.05)。结论直肠癌患者在行PET/CT检查时,技师应根据检查目的的不同,选择最佳的代谢时间,保证定量参数SUVt/b值与MTV值的准确性以及可重复比较性。

Effect of Metabolic Time on SUV and MTV in Patients with Rectal Cancer Underwent 18F-FDG PET Examinations

Objective To analyze the effects of different metabolic time on max standard uptake value(SUVmax),target/background standard uptake value(SUVt/b)and metabolic tissue volume(MTV)in patients with rectal cancer when undergoing 18F-FDG PET examination.Methods Twenty patients with rectal cancer diagnosed pathologically from October 2018 to December 2018 were examined by PET/CT.18F-FDG PET images were collected at 40,50,60,70 and 80 min after metab olism for each patient.A total of 29 lesions were found.SUVmax,SUVt/b and MTV values at different metabolic time points of the lesion were measured and analyzed.Results With the prolongation of metabolic time,the SUVmax value fluctuated upward,while the SUVt/b value and MTV value increased first and then decreased.The inflection point of SUVt/b value appeared in 70 min,and the inflection point of MTV value appeared in 60 min.The difference between the peak value of two broken lines and the data before and after was statistically significant(P<0.05).Conclusion When performing PET examination on patients with rectal cancer,technicians should choose the best metabolic time according to the different purposes of the examination to ensure the accuracy and repeatability of the quantitative param eters SUVt/b and MTV.