Department of Nuclear Medicine, Rambam Health Care Campus, P.O.B. 9602, 3109601, Haifa, Israel.
The Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
Med Biol Eng Comput. 2019 Jul;57(7):1581-1590. doi: 10.1007/s11517-019-01979-y. Epub 2019 Apr 25.
The accuracy of recently approved quantitative clinical software was determined by comparing in vivo/in vitro measurements for a solid-state cadmium-zinc-telluride SPECT/CT (single photon emission computed tomography/x-ray computed tomography) camera. Bone SPECT/CT, including the pelvic region in the field of view, was performed on 16 patients using technetium-99m methylene diphosphonic acid as a radiotracer. After imaging, urine samples from each patient provided for the measurement of in vitro radiopharmaceutical concentrations. From the SPECT/CT images, three users measured in vivo radiotracer concentration and standardized uptake value (SUV) for the bladder using quantitative software (Q.Metrix, GE Healthcare). Linear regression was used to validate any in vivo/in vitro identity relations (ideally slope = 1, intercept = 0), within a 95% confidence interval (CI). Thirteen in vivo/in vitro pairs were available for further analysis, after rejecting two as clinically irrelevant (SUVs > 100 g/mL) and one as an outlier (via Cook's distance calculations). All linear regressions (R ≥ 0.85, P < 0.0001) provided identity in vivo/in vitro relations (95% CI), with SUV averages from all users giving a slope of 0.99 ± 0.25 and intercept of 0.14 ± 5.15 g/mL. The average in vivo/in vitro residual difference was < 20%. Solid-state SPECT/CT imaging can reliably provide in vivo urinary bladder radiotracer concentrations within approximately 20% accuracy. This practical, non-invasive, in vivo quantitation method can potentially improve diagnosis and assessment of response to treatment. Graphical abstract.
最近批准的定量临床软件的准确性是通过比较体内/体外测量来确定的，这些测量是针对固态碲化镉锌 SPECT/CT（单光子发射计算机断层扫描/ X 射线计算机断层扫描）相机进行的。使用放射性示踪剂锝-99m 亚甲基二膦酸盐对 16 名患者进行了骨骼 SPECT/CT 检查，包括视野内的骨盆区域。成像后，从每位患者的尿液样本中测量了体外放射性药物浓度。从 SPECT/CT 图像中，三位用户使用定量软件（GE Healthcare 的 Q.Metrix）测量了体内放射性示踪剂浓度和膀胱标准化摄取值（SUV）。使用线性回归来验证体内/体外身份关系（理想情况下斜率= 1，截距= 0），置信区间为 95%。排除了两个因 SUV 过高（> 100 g/mL）而被认为与临床无关的体内/体外对，以及一个因偏离Cook 距离计算而被认为是异常值的对，共获得了 13 对可进一步分析的体内/体外对。所有线性回归（R ≥ 0.85，P < 0.0001）均提供了体内/体外身份关系（95%置信区间），所有用户的 SUV 平均值斜率为 0.99 ± 0.25，截距为 0.14 ± 5.15 g/mL。体内/体外残留差异的平均值<20%。固态 SPECT/CT 成像可以可靠地提供体内膀胱放射性示踪剂浓度，准确性约为 20%。这种实用、非侵入性的体内定量方法可能有助于提高诊断和评估治疗反应的能力。
