Variations of quantitative perfusion measurement on dynamic contrast enhanced CT for colorectal cancer: implication of standardized image protocol.

摘要: Tumor angiogenesis is considered an important prognostic factor. With increasing emphasis on imaging evaluation of the tumor microenvironment, dynamic contrast enhanced-computed tomography (DCE-CT) has evolved as functional technique in this setting. Yet many questions remain to how and when these measurements should be performed for each agent type, what quantitative models used fitting process. In study, we evaluated variations perfusion measurement DCE-CT rectal cancer patients from (1) different tracer kinetic models, (2) scan acquisition lengths, (3) intervals. A total seven commonly were studied: adiabatic approximation tissue homogeneity (AATH) model, with fixed transit time (AATHFT) Tofts model (TM), extended (ETM), Patlak Logan model-free deconvolution method. Akaike's information criterion was identify best model. The interchangeability further using Bland-Altman analysis. All gave comparable blood volume (BV) except While transfer constant (Ktrans) estimation, AATHFT, AATH, ETM generated reasonable agreement among other but not models. Regarding flow (BF) measurement, no two interchangeable. addition, parameters compared four times (45, 65, 85, 105 s) temporal intervals (1, 2, 3, 4 s). No significant difference observed (Ktrans), BV, BF comparing data acquired over 65 s any DCE study. interval led a overestimation conclusion, indeed dependent image acquisition/processing dependent. radiation dose average 1.5-2 abdomen/pelvic CT, which insubstantial. To take forward biomarker oncology, prospective studies carefully designed optimal analysis technique.