颈部恶性肿瘤侵犯颈动脉的多层螺旋CT评价

Assessment of carotid artery invasion in head and neck malignancy with MSCT

目的评价多层螺旋CT(MSCT)横断面及多平面重建(MPR)在颈部恶性肿瘤侵犯颈动脉方面的应用价值。方法对39个与颈动脉贴邻肿物均行MSCT扫描。2位医生进行盲法阅片,在横断面扫描图像上测量肿瘤包绕颈动脉的角度并分组(≥45°组、≥90°组和≥180°组);在MPR图像上测量肿瘤与颈动脉的最大交角并分组(≥45°组和≥90°组),测量肿瘤与动脉交界面长度、肿瘤最大纵径,计算交界面长度与最大纵径的比值并分组(≥05组、≥08组和=10组)。对比手术及病理结果,比较受侵动脉与未受侵动脉在以上方面的组间差异,并进行统计学分析。结果在横断面扫描图像上,≥90°组和≥180°组对颈动脉受侵判断的准确度高于≥45°组(P<005),≥90°组可兼顾敏感度和特异度。MPR上肿瘤和动脉交界面长径与肿瘤最大纵径的比值,≥08组和=10组对颈动脉受侵判断的准确度高于≥05组(P<005),≥08组的敏感度高于=10组(P<005)且特异度与后者相仿(P>005)。MPR上肿瘤与动脉交界面角度≥45°组和≥90°组对颈动脉受侵判断的准确度差异无统计学意义(P>005),而≥90°组可兼顾敏感度和特异度;MPR显示肿瘤与动脉交界面角度≥90°时,受侵动脉明显多于未受侵动脉(P<005)。结论对于颈动脉受侵的判断,横断面上肿瘤包绕颈动脉角度≥90°。

Objective To investigate the carotid artery invasion in patients with head and neck malignancy with multi-slice helical CT and MPR. Methods Thirty-nine masses adjacent to the carotic artery in head and neck were studied by using 8-slice helical CT scanner and underwent surgery. The angle between the mass and carotid in axial CT, the length of fatty plane obliteration between the mass and carotid, the longest diameter of the mass, and the cross-angle between the mass and carotid in MPR were measured, the ratio of the length of fatty plane obliteration between the tumor and the carotid to the longest diameter of the mass in MPR were calculated, and distributed into different group by two radiologists blindly. Results^In judgment of carotid involvement with axial CT, the accuracy of ≥90°group and ≥180°group were higher than that of ≥45°group (P<0.05) and the sensitivity and specificity of ≥90°group were acceptable. The judgement for involved arteries and non-involved arteries were significantly different with respect to the ratio of the length of fatty plane obliteration between the tumor and the carotid to the longest diameter of the mass with MPR (P<0.05). In judgment of carotid involvement with MPR, ≥0.8 group or =1.0 group had higher accuracy than ≥0.5 group (P<0.05) and ≥0.8 group was more sensitive than=1.0 group (P<0.05). The cross-angle of ≥90°had no statistical difference when compared with ≥45°in accuracy (P=0.329), the sensitivity and the specificity were acceptable. The arteries with ≥90°cross-angle in MPR tended to be involved more significantly(P=0.000). Conclusion The mass encompassing ≥90°of the artery wall in axial CT, the ratio ≥0.8 of the length of fatty plane obliteration between the mass and the carotid to the longest diameter of the mass in MPR, the cross-angle ≥90° between the mass and the carotid in MPR were predictive to possible carotid invasion.