定量磁共振灌注成像用于评价直肠癌的微血管灌注及渗透性

摘要

AIM:To investigate the perfusion parameters using dynamic contrast-enhanced magnetic resonance imaging ( DCE-MRI) in rectal cancer patients so as to explore its potential value in estimating the microvascular condition including perfusion and permeability .METHODS:The data of 38 rectal cancer patients examined with DCE-MRI was ret-rospectively analyzed .The perfusion parameters of carcinoma and normal rectal wall in each case were calculated , inclu-ding volume transfer constant (Ktrans), rate constant of back flux (Kep), extravascular extracellular space fractional volume (Ve) and initial area under curve (iAUC).The mean values of tumor and normal rectal wall , mucinous and nonmucinous carcinoma, poorly and moderately-to-well differentiated carcinoma , case with or without lymph node metastasis were com-pared.RESULTS:All the parameters of rectal cancer were higher than normal rectal wall (P<0.01).No significant difference was found between poorly and moderately-to-well differentiated carcinoma in terms of K trans, Kep and Ve, neither was the case with or without lymph node metastasis .The cases with lymph node metastasis had lower iAUC than those with-out (P<0.05).CONCLUSION:Quantitative perfusion DCE-MRI answered the microvascular perfusion and permeability change of rectal cancer compared with normal rectal wall , besides it could be used to distinguish between mucinous and nonmucinous carcinoma , which demonstrated its value in the evaluation of rectal cancer .However , it should not be recom-mended to predict the degrees of tumor cell differentiation and lymph node metastasis just according to the perfusion param -eters.%目的：采用定量磁共振（ MR）灌注成像测定直肠癌的各灌注参数，以探究MR灌注成像在评价肿瘤局部微血管灌注量及渗透性方面的应用价值。方法：回顾性分析行直肠动态对比增强磁共振（ DCE－MRI）扫描的直肠癌患者38例。计算肿瘤和正常肠壁感兴趣区（ROI）灌注参数[对比剂容积转换常数（Ktrans）、血浆与血管外细胞外间隙（EES）间的速率常数（Kep）、单位体积组织的EES 容量（Ve）及初始强化曲线下面积（iAUC）]的平均值，并对肿瘤与正常肠壁、黏液腺癌与非黏液腺癌、不同分化程度及是否伴淋巴结转移的患者各灌注参数值进行比较分析。结果：直肠癌的各灌注参数均较正常肠壁高，差异具有统计学意义（P＜0．01）。直肠黏液腺癌较非黏液腺癌的Ktrans值低（P＜0．05）。不同分化程度、伴有或不伴有淋巴结转移直肠癌患者的Ktrans、Kep及Ve 差异无统计学意义，伴有淋巴结转移的直肠癌iAUC较不伴者低。结论：定量MR灌注成像验证了直肠癌较正常肠壁局部微血管灌注及渗透性的改变，并可用于鉴别黏液腺癌与非黏液腺癌的组织学分型，具有一定的诊断应用价值。但是仅根据肿瘤的灌注值来判断肿瘤的分化程度及淋巴结转移尚不可靠。