Evaluation of functional tumor blood flow map using dynamic MRI and compartment analysis

血管生成与肿瘤的生长、侵袭和转移密切相关。虽然肿瘤血流量增加血管生成，它还没有建立在体内无创测量肿瘤血流量。在本研究项目中，我们开发了一种新的方法，定量测量肿瘤血流量（TBF）在体内使用动态对比增强磁共振成像（MRI）和房室分析。使用反转恢复-准备快速场回波（IR-FFE）序列（TR/TE/TT 7.7/3.9/280 msec，翻转角10 °，FOV 380 x 190 mm，矩阵256 x 128，层厚6 mm）进行动态对比增强MRI。通过对从动脉和肿瘤获得的信号强度-时间曲线进行去卷积分析，逐像素生成定量TBF图（ml/100 ml/min）。TBF图显示肿瘤周围TBF因血管生成而增加，而肿瘤中心TBF较低。在接受化疗的患者中，化疗周期后TBF发生了实质性变化，反映了治疗反应。在手术标本上，TBF图比传统的对比增强T1加权MR图像更好地预测了存活和非存活肿瘤细胞的分布以及化疗效果。因此，TBF图将是一个有前途的工具，用于评估肿瘤血流，并可能是有用的，以评估治疗反应。

Angiogenesis correlates with tumor growth, invasion and metastasis. Although tumor blood flow increased by angiogensis, it has not been established to noninvasively measure tumor blood flow in vivo. In this research project, we have developed a new method for quantitative measurement of tumor blood flow(TBF) in vivo by using dynamic contrast-enhanced magnetic resonance imaging(MRI) and compartment analysis. Dynamic contrast-enhanced MRI was performed using inversion recovery-preparation fast field echo(IR-FFE) sequence(TR/TE/TT 7.7/3.9/280msec, flip angle 10 degree, FOV 380x190mm, matrix 256x128, slice thickness 6mm). Quantitative TBF maps(ml/100ml/min) were generated pixel-by-pixel by deconvolution analysis of the signal intensity-time curves obtained from arteries and tumors. TBF map clearly demonstrated heterogeneity ofTBF, i.e. increased TBF in tumor periphery due to angiogenesis and low TBF in center of tumor. In patients who received chemotherapy, substantial changes of TBF were demonstrated after chemotherapeutic cycles, reflecting the therapeutic response. On surgical specimens, the distribution of viable and non-viable tumor cells and the chemotherapeutic effects were better predicted by the TBF maps rather than the conventional contrast-enhanced T1-weighted MR images. Thus, TBF map would be a promising tool for evaluating tumor blood flow and may be useful to evaluate treatment response.