Division of Medical Physics, University of Leeds, Leeds, UK.
J Magn Reson Imaging. 2013 Dec;38(6):1554-63. doi: 10.1002/jmri.24061. Epub 2013 Jul 15.
To identify the optimal tracer-kinetic modeling strategy for dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) data acquired at low temporal resolution.
DCE-MRI was performed on 13 patients with rheumatoid arthritis of the hand before and after anti-tumor necrosis factor alpha (TNFα) therapy, using a 3D sequence with a temporal resolution of 13 seconds, imaging for 4 minutes postcontrast injection. Concentration-time curves were extracted from regions of interest (ROIs) in enhancing synovium and fitted to the 3-parameter modified Tofts model (MT) and the 4-parameter two-compartment exchange model (2CXM). To assist the interpretation of the data, the same analysis was applied to simulated data with similar characteristics.
Both models fitted the data closely, and showed similar therapy effects. The MT plasma volume was significantly lower than with 2CXM, but the differences in permeability and interstitial volume were not significant. 2CXM was less precise than MT, with larger standard deviations relative to the mean in most parameters. The additional perfusion parameter determined with 2CXM did not provide a statistically significant trend due to low precision.
The standard MT model is the optimal modeling strategy at low temporal resolution. Advanced models improve the accuracy and generate an additional parameter, but these benefits are offset by low precision.
确定低时间分辨率下动态对比增强磁共振成像（DCE-MRI）数据的最佳示踪动力学建模策略。
对 13 例手部类风湿关节炎患者在使用 3D 序列进行抗 TNFα 治疗前后进行 DCE-MRI 检查，该序列时间分辨率为 13 秒，注射对比剂后 4 分钟进行成像。从强化滑膜的感兴趣区（ROI）中提取浓度-时间曲线，并拟合到 3 个参数修正 Tofts 模型（MT）和 4 个参数双室交换模型（2CXM）。为了辅助数据解释，对具有相似特征的模拟数据应用相同的分析。
两种模型均能很好地拟合数据，并显示出相似的治疗效果。MT 的血浆容积明显低于 2CXM，但通透性和间质容积的差异不显著。2CXM 的精度不如 MT，大多数参数的标准偏差相对于平均值较大。由于精度较低，2CXM 确定的附加灌注参数没有提供具有统计学意义的趋势。
标准的 MT 模型是低时间分辨率下的最佳建模策略。高级模型提高了准确性并生成了一个附加参数，但这些益处被低精度所抵消。
