侵袭性和非侵袭性胸腺瘤的CT鉴别诊断

目的 :评价CT对侵袭性和非侵袭性胸腺瘤的鉴别诊断价值。方法 :由两位放射科医师采用双盲法对 2 9例侵袭性胸腺瘤和 2 4例非侵袭性胸腺瘤进行单独评价 ,分析CT诊断侵袭性或非侵袭性胸腺瘤的可靠性 ,并与手术病理结果对照。结果 :侵袭性胸腺瘤 ( 2 1例 ,占 72 %)较非侵袭性胸腺瘤 ( 7例 ,占 2 9%)有明显的分叶 (P <0 .0 5 )。侵袭性胸腺瘤囊变率 ( 2 3例 ,占 79%)较非侵袭性胸腺瘤 ( 6例 ,占 2 3 %)高 (P <0 .0 1) ;侵袭性胸腺瘤增强后较非侵袭性胸腺瘤有明显强化。结论 :肿瘤边缘分叶或不规则、囊变或坏死、增强前后CT值相差 2 0HU、纵隔脂肪线消失等CT征象提示侵袭性胸腺瘤。

CT differential diagnosis of invasive and noninvasive thymoma

Objective:The purpose of the study was to evaluate the CT features of thymoma and study the manifestations in differentiating invasive from noninvasive thymoma.Methods:The CT scans from 29 cases with invasive thymoma and 24 cases with noninvasive were independently assessed by two radiologist without knowledge of their history.Reliability of CT diagnosis to differentiate invasive thymoma from noninvasive thymoma was analysed and the CT diagnosis was correlated with pathologic findings.Results:Invasive thymoma was more likely to have lobulation (21/29,72%) than noninvasive thymoma (7/24,29%, P <0.05).Invasive thymoma had a higher prevalence of low attenuation areas within the tumor (23/29, 79%) than noninvasive thymoma (6/24,23%, P <0.01).Invasive thymoma had more marked enhancement than noninvasive thymoma.Conclusion:The presence of lobulation,cyst formation or necrosis,increase of CT value more than 20HU after contrast enhancement,and mediastinal fat obliteration are suggestive of invasive thymoma.