Mankoff D A, Shields A F, Graham M M, Link J M, Krohn K A
Division of Nuclear Medicine, University of Washington, Seattle, USA.
J Nucl Med. 1996 Dec;37(12):2049-57.
The Patlak graphical analysis technique is a popular tool for estimating blood-to-tissue transfer constants from multiple-time uptake data. Our objective was to extend this technique to tracers with labeled metabolites, the presence of which can cause errors in the standard Patlak analysis.
Based on previously described formulations, we generalized the graphical technique for use under specific conditions. To test the extended graphical approach, we applied the method to both simulated and patient data using a preliminary compartmental model for the PET tumor proliferation marker, 2-[11C]-thymidine.
When given conditions are met, a linear relationship exists between the normalized tissue activity (tissue activity/blood activity) and a new set of graphical analysis basis functions, including a new definition of normalized time, which takes the presence of labeled metabolites into account. Graphical estimations of the tumor thymidine incorporation rate for simulated data were accurate and showed close agreement to the results of detailed compartmental analysis. In patient studies, the graphical and compartmental estimates showed good agreement but a somewhat poorer correlation than in the simulations.
The extended graphical analysis approach provides an efficient method for estimating blood-tissue transfer constants for tracers with labeled metabolites.
Patlak图形分析技术是一种用于从多次摄取数据估算血-组织转运常数的常用工具。我们的目标是将该技术扩展到含有标记代谢物的示踪剂，标记代谢物的存在会导致标准Patlak分析出现误差。
基于先前描述的公式，我们将图形技术推广到特定条件下使用。为了测试扩展后的图形方法，我们使用PET肿瘤增殖标志物2-[11C]-胸腺嘧啶核苷的初步房室模型，将该方法应用于模拟数据和患者数据。
在满足给定条件时，归一化组织活性（组织活性/血液活性）与一组新的图形分析基函数之间存在线性关系，包括考虑了标记代谢物存在的归一化时间的新定义。模拟数据的肿瘤胸腺嘧啶核苷掺入率的图形估计是准确的，并且与详细房室分析的结果显示出密切的一致性。在患者研究中，图形估计和房室估计显示出良好的一致性，但相关性略逊于模拟研究。
扩展后的图形分析方法为估算含有标记代谢物的示踪剂的血-组织转运常数提供了一种有效的方法。
