多层螺旋CT灌注评价孤立性肺结节首过血流模式

Evaluation of blood flow patterns for first time of solitary pulmonary nodules with multi-slice spiral CT perfusion imaging

目的：探讨多层螺旋CT灌注在孤立性肺结节（SPN）首过时血流特征及鉴别诊断中的应用价值.方法：对99例直径2～4 cm的SPN先行32层螺旋CT平扫,再行多层同层连续动态增强扫描,在时间-密度曲线（TDC）的基础上,测量SPN增强峰值（PESPN）、病灶同层主动脉的增强峰值（PEAA）、病灶达峰时间（TTP）,并由此计算增强净增值（NE）、结节-主动脉强化峰值比（S/A）、灌注量（Pr）,进行统计学分析.结果：恶性与炎性SPN的PESPN、NE、S/A和Pr均高于良性SPN（P均〈0.05）,其TTP低于良性SPN（P〈0.05）;恶性SPN的PESPN、NE、S/A高于炎性SPN（P均〈0.05）;恶性结节的Pr高于炎性结节,但二者之间差异无显著性意义（P〉0.05）.以NE≥25 HU作为恶性病变的阈值,其敏感度为98.2%,特异度为52.0%,准确度为86.9%,阳性预测值为85.6%,阴性预测值为92.9%.良性、恶性及炎性结节的TDC形态不同.结论：多层螺旋CT灌注成像技术是定量评价SPN血流模式的无创性技术,有助于SPN的鉴别诊断.

Objective： To evaluate the blood flow patterns for first time and the differential diagnostic ability with multi-slice spiral CT perfusion imaging in solitary pulmonary nodules （SPNs）. Methods： A study was undertaken in 99 patients with SPNs of 2-4 cm in diameter using 32-slice spiral CT perfusion. The parameters of CT perfusion, including peak enhancement of SPN （PESPN） ,and aorta（PEAA）, net enhancement （NE）, ratio of peak height of the SPN , and aorta（S/A） and perfusion（Pr）, were measured on time-density curve （TDC）. The data gathered from average values were analyzed statistically. Results： PESPN, NE, S/A , and Pr of malignant and inflammatory SPNs were significantly higher than those of benign SPNs （all P〈 0.05）. PESPN, NE, S/A of malignant SPNs were significantly higher than those of inflammatory SPNs （all P 〈0.05）. Pr of malignant SPNs was higher than that of inflammatory SPNs,with no statistic significant differences（ P 〉0.05）. When NE≥ 25HU was set as the diagnostic threshold, the sensitivity, specificity, accuracy, positive predict value, negative predict value were 98.2%, 52%, 86.9%, 85.6%,92.9%, respectively. The TDC appeared different among the three groups. Conclusion： Multi-slice spiral CT perfusion imaging is a kind of non-invasive method for quantitative evaluation of the blood flow patterns for first time in solitary pulmonary nodules, and is helpful for differential diagnosis of SPNs.