螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断价值

Utility of triphasic contrast enhanced spiral CT for diagnosing extrahepatic terminal cholangiocarcinoma

目的评价螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断及鉴别诊断价值,重点探讨延迟期扫描的意义,以进一步提高CT诊断的准确性。方法47例肝外末端胆管细胞癌均行平扫及三期增强扫描,100mL对比剂以2.5mL/s注射速度,延迟25～33s行动脉期扫描;延迟60～70s行实质期扫描;延迟3～5min行延迟期扫描。测量胆管细胞癌及正常胰腺组织的强化CT值,观察胆管细胞癌的三期强化特征,并对结果进行统计学分析。结果47例肝外末端胆管细胞癌平扫表现为等或略低密度,与正常胰腺组织无法区分,动脉期11例为略低密度,9例为等密度,26例为高密度,平均CT值83.25±11.56HU,与正常胰腺组织平均CT值(86.46±21.50HU)相差-7.91±8.01HU,定量比较差异无显著性意义(t=1.3,P>0.05),实质期35例表现为高密度,12例为略低密度,平均CT值108.161±9.67HU,与正常胰腺组织CT值(86.39±17.46HU)相差18.08±4.35HU,定量比较差异有非常显著性意义(t=5.3,P<0.01),延迟期均表现为高密度,平均CT值95.31±12.55,与正常胰腺组织平均CT值(70.93±17.49HU)相差22.58±14.01HU,定量比较差异有非常显著性意义(t=8.3,P<0.01)。结论螺旋CT三期增强扫描对肝外末端胆管细胞癌的诊断及鉴别诊断有重要价值,尤其是延迟期扫描。

Objective To evaluate the diagnostic value of triphasie, especially the delayed phase, contrast enhanced CT scans for extrahepatic terminal cholangiocarcinoma so as to raise CT diagnostic accuracy. Methods Spiral CT scanning of pre enhanced and post enhanced arterial phase, essential phase and delayed phase was performed in 47 patients with extraphepatic terminal cholangiocarcinoma proved by surgically and pathologically. The enhancement was administrated with venous injection of 2.5 ml/s, totally 100 ml omnipaque. Arterial phase of contrast - enhanced scanning started 25 - 30 s, essential phase 60 - 70 s and delayed scanning 5 min after the injection of contrast medium. The degrees of the enhancement of cholangiocarcinoma and normal tissues of pancres in the three contrast-enhanced phases were calculated and compared statistically. Result In plain CT, the lesions were iso-density and slight hypodensity in 47 case, which was hardly distinguished from the normal tissue. In the arterial phase, the lesion showed iso-density in 11 cases, slight hypodensity in 9 case and slight enhancement in 26 cases, compared with normal tissue of pancreas（ - 7. 91±8.01 ） HU, there were no statistic differences（ t = 1.3, P 〉 0. 05）. In essential phase, the lesions showed marked enhancement in 35 cases and iso - density in 12 cases, compared with normnal tissue of pancreas（ 18. 08± 4.35）HU, there were statistic differences（ t = 5.3, P 〈 0.01 ）. In all 47 cases the lesion showed marked enhancement in the delayed phase compared with normal tissue of pancreas（22.58±4.01 ） HU, there were markedly statistic differences（ t = 8. 3, P 〈 0. 01） ）. Conclusion Triphasic contrast enhanced spiral CT scan, especially the delayed phase scan, is valuable in detecting and differentiating extrabepatic terminal cholangiocareinoma.