肾上腺神经鞘瘤和嗜铬细胞瘤的CT鉴别诊断价值

Differentiation of Adrenal Schwannoma from Pheochromocytoma and its Diagnostic Significance on CT

目的探讨CT在肾上腺神经鞘瘤(AS)和嗜铬细胞瘤(PHEO)鉴别中的诊断价值。方法回顾性分析经手术病理证实的8例AS和48例PHEO患者的临床和CT资料,对肿瘤的大小、位置、形态、强化方式、渐进性强化、'花边样'强化、囊变、钙化、出血以及临床资料进行分析。计数资料的比较采用χ2检验,计量资料的比较采用独立样本t检验。采用受试者工作特征曲线(ROC)分析有意义连续变量鉴别肾上腺PHEO和AS的效能。结果AS组8个病灶,PHEO组52个病灶(4例双侧)。两组的分类变量中,除'花边样'强化(P<0.05)外其余分类变量及临床资料差异均无统计学意义(P均>0.05)。两组的连续变量中,平扫、动脉期、静脉期、动脉期增强幅度及静脉期增强幅度的CT值差异有统计学意义(P均<0.05)。ROC曲线分析显示当平扫CT值<29.9 HU时,曲线下面积(AUC)、敏感度、特异度分别是0.918、87.5%(7/8)、88.5%(53/60);当动脉期CT值<55.5 HU时,AUC、敏感度、特异度分别是0.918、87.5%(7/8)、84.6%(51/60);当静脉期CT值<75.0 HU时,其AUC、敏感度、特异度分别为0.911、87.5%(7/8)、81.7%(49/60);当动脉期和静脉期增强幅度CT值分别<26.6 HU和53.3 HU时,其AUC、敏感度、特异度分别为0.843和0.819、87.5%(7/8)和100%(8/8)、73.1%(44/60)和65.4%(39/60)。结论CT特征中,无'花边样'强化、平扫CT值<29.9 HU、动脉期CT值<55.5 HU、静脉期CT值<75.0 HU、动脉期和静脉期增强幅度CT值分别<26.6 HU和53.3 HU时有助于AS从PHEO中鉴别开。

Objective To investigate the differentiation between adrenal schwannoma(AS)and pheochromocytoma(PHEO)and its diagnostic significance on CT.Methods We retrospectively analyzed clinical and CT data of AS(n=8)and PHEO(n=48)which were pathologically confirmed.The size,location,contour,pattern of enhancement,gradual enhancement,lacelike enhancement,necrosis,calcification,hemorrhage,as well as,the clinical data of the patients were evaluated.Among these CT findings,statistically analysis includedχ2 test and independent t-test.Receiver operating characteristic(ROC)curves were employed to assess the significant continuous variables to diagnose AS from PHEO.Results AS group showed 8 lesions,and 52 lesions(bilateral 4 cases)were detected in all 48 patients with PHEO.There was no statistical significant difference in the categorical variables of two groups(all P>0.05)except lace-like enhancement(P<0.05).Unenhanced,arterial phase,portal venous phase,degree of enhancement in arterial and portal venous phase showed significant difference in CT values between AS and PHEO(all P<0.05).The cutoff values of the unenhanced was29.9 HU,resulting in that the area under ROC curve,sensitivity and specificity were 0.918,87.5%(7/8),88.5%(53/60),respectively.In contrast,the cutoff values of the arterial and portal venous phase reached at 55.5 HU and 75.0 HU,the area under ROC curve,sensitivity and specificity were 0.918,87.5%(7/8),84.6%(51/60)and 0.911,87.5%(7/8),81.7%(49/60),respectively.CT value was defined at less than 26.6 HU and 53.3 HU during arterial and portal venous phase respectively and in consequence three research variables aforementioned were 0.843 and 0.819,87.5%(7/8)and 100%8(/8),73.1%(44/60)and 65.4%(39/60),respectively.Conclusion CT feature including non-lacelike enhancement,unenhanced(<29.9 HU),arterial phase(<55.5 HU),portal venous phase(<75.0 HU),degree of enhancement in arterial(<26.6 HU)and portal(<53.3 HU)venous phase could help differentiating AS from PHEO.