320排CT肺三期增强扫描诊断孤立性肺病变

目的 探讨最佳320排CT肺三期增强扫描时相，评价其诊断孤立性肺病变（SPL）的临床价值。方法 对100例SPL患者 及40名健康成年人（D组）行320排CT容积灌注扫描，采用体部灌注软件处理得到时间-密度曲线（T-DC），记录并比较各组肺动脉峰值时间（PA-TTP）、左心房峰值时间（LA-TTP）、胸主动脉峰值时间（AO-TTP）和SPL强化峰值时间（SPL-TTP）。在平扫，肺动脉、左心房、胸主动脉和SPL达强化峰值时以及延迟3 min共6个时相测量病灶CT值，计算CT净增值（NE）。应用ROC曲线分析比较各时相NE对SPL的诊断效能。结果 A、B、C、D组PA-TTP、LA-TTP及AO-TTP差异均无统计学意义（P均>0.05）。A、B、C组SPL-TTP差异有统计学意义（F=52.163，P<0.001），C组SPL-TTP为（17.36±2.52）s，明显早于A、B组。A组中，应用SPL达强化峰值时（28 s）NE诊断周围型肺癌的ROC曲线下面积（AUC）最大，为0.872，敏感度92.7%，特异度80.0%。C组中，应用SPL达强化峰值时（18 s）NE诊断炎症的AUC最大，为0.985，敏感度100%，特异度88.5%。结论 以18 s、28 s、3 min为扫描时相，320排CT肺三期增强扫描对鉴别诊断SPL具有较高价值。

320-detector row CT three-phase enhanced scanning in diagnosis of solitary pulmonary lesion

Objective To explore the best phase of three-phase enhanced scanning of 320-detector CT (320-DCT), and to evaluate its value for solitary pulmonary lesion (SPL). Methods A total of 100 patients with SPL (group A peripheral lung cancer, n=55], group B benign tumor or chronic inflammation, n=23], group C active inflammation, n=22]) and 40 healthy adults (group D) underwent dynamic volume perfusion CT with 320-DCT. Body-perfusion software was used to get the time to density curve (T-DC), and then the peak enhancement time of pulmonary artery (PA-TTP), left atrium (LA-TTP), thoracic artery (AO-TTP) and SPL (SPL-TTP) were recorded and compared. CT value was measured at the following time point, i.e. pre-contrast, peak enhancement of pulmonary artery, left atrium, thoracic artery and SPL, delayed 3 min, and the net enhancement (NE) of CT value was calculated. The performance of NE in diagnosis of SPL at different phases were analyzed by using ROC curve. Results There was no significant difference of PA-TTP, LA-TTP, AO-TTP all 4 groups (all P<0.05). The peak enhancement time of group A, B and C had significant differences (F=52.163, P<0.001). SPL-TTP in group C was (17.36±2.52)s, much earlier than that in group B and C. In group A, NE at the phase of peak enhancement of SPL (28 s) had the greatest diagnostic efficacy, the area under ROC (AUC) was 0.872, indicating a sensitivity of 92.7%,specificity of 80.0% for identifying lung cancer. In group C, NE at the phase of peak enhancement of SPL (18 s) had the greatest diagnostic efficacy, AUC was 0.985, indicating a sensitivity of 100%, specificity of 88.5% for identifying acute inflammation. Conclusion Taking 18 s, 28 s, 3 min as the scan phases, 320-DCT three-phase enhanced scanning has great differential diagnosis value for patients with SPL.