螺旋CT灌注成像评估直肠癌血管生成状态的研究

Correlation between spiral CT perfusion imaging and tumor angiogenesis in rectal carcinoma

目的探讨螺旋CT灌注成像对直肠癌血管生成状态评估的价值。方法对30例直肠癌患者进行螺旋CT灌注成像检查。选定肿瘤平面后进行同平面两层动态增强扫描，绘制所选层面的癌灶、靶动脉的感兴趣区的时间-密度曲线（TDC）。根据TDC计算出病灶的血流灌注量（BF）、血容量（BV）、平均弥散时间（MTT）、表面弥散性（PS）。术后选择对应扫描平面标本癌组织4μm切片进行免疫组织化学染色（SP），经鼠抗人CD34单克隆抗体标记肿瘤组织内血管内皮细胞，测定癌组织微血管密度（Microvessel Density MVD）。结果MVD、BF、MTT在PTNM不同分期、不同浸润深度、有无淋巴结转移比较中差异有统计学意义（P〈0．01）；MVD、BF随着病理分期的增高呈升高趋势，两者呈显著正相关（r=0．723，P〈0．01）；MTT随病理分期的增加而缩短，与MVD呈显著负相关（r=-0．656，P〈0．01）。BV随分期增加、浸润深度增加、淋巴结转移呈增高趋势，但无统计学意义（P〉0．05）；PS随分期增加有下降趋势，但差异无统计学意义（P〉0．05）。结论直肠癌的MVD与血流灌注量之间呈正相关、与平均弥散时间呈负相关；螺旋CT灌注成像能从活体较好地反映肿瘤的微循环功能，可提供非侵入性监测肿瘤血管生成状态的方法。

Objective To evaluate the correlation between spiral CT （SCT） perfusion imaging and microvessel density （MVD） in rectal cancer. Methods Perfusion CT of rectal adencarcinoma was performed with 64-section detector row CT in 30 patients who had been proven rectal carcinoma histologically. The largest axial surface of the primary tumor was searched on unenhanced spiral CT images, and at this level the enhanced dynamic scan series were acquired. Time-density curves （TDC） were created from the region of interest drawn over the tumor and target artery by SIEMENS 64 -Slices spiral CT. Tissue blood flow （BF） ,blood volume （BV） ,mean transit time （MTT） ,and vascular permeability-surface area product （PS） were calculated. Then MVD was evaluated by using immunohistochemical （SP） staining of surgical specimens with anti-CD34, and then MVD was correlated with perfusion parameter and pathological factors. Results MVD, BF and MTT were associated with invasive depth,metastasis and disease stage （P 〈 0.01 ） ,and MVD and BF were increased with the increased PTNM stage,invasive depth and lymph node metastasis,while MTT decreased. The positive correlation between MVD and BF was found （ r = 0. 723, P 〈 0.01 ） , while the negative correlation was found between MVD and MTT （r = -0. 656,P 〈 0.01 ）. No significant correlation was found between BV or PS and clinicopathological factors. Conclusion There is a positive correlation between BF and MVD, but a negative correlation between MTT and MVD. Spiral CT perfusion imaging may be more suitable for assessing tumorigenesis than histological MVD technique in vivo.