基于CT增强对肠系膜侵袭性纤维瘤病和胃肠道间质瘤的鉴别诊断

The differential diagnosis of mesenteric invasive fibromatosis and gastrointestinal stromal tumor based on CT enhancement

目的探讨肠系膜侵袭性纤维瘤病(MAF)与胃肠道间质瘤(GIST)的CT鉴别特征。方法回顾性分析53例经病理证实的MAF(14例)和GIST(39例)的CT表现。对病灶的位置、形态和边界、强化方式、病灶内坏死、血管和空气、钙化等征象进行分析。测量长径(LD)、短径(SD)、CT值,并计算LD/SD比值、强化程度。采用t检验和受试者操作特征(ROC)曲线确定有意义的CT征象。当使用单一或多个CT特征时,计算敏感度和特异度。结果MAF多位于胃肠道外(χ2=10.437,P=0.001)、卵圆形或不规则形(χ2=9.192,P=0.004)、强化均匀(χ2=12.458,P=0.000)、病灶内无坏死(χ2=6.632,P=0.014)及强化程度低(静脉期增加CT值约23.9±8.2 HU)。当联合强化均匀和LD/SD比值诊断MAF的敏感度和特异度分别为92.9%和97.4%。结论胃肠外肠系膜、卵圆形或不规则形、均匀强化、病灶内无坏死、LD/SD≥1.19、动脉期强期增加CT值≤22 HU、静脉期强期增加CT值≤31 HU等7个CT指标有助于鉴别MAF与GIST。

Objective To investigate the CT differential features of mesenteric invasive fibromatosis(MAF)and gastrointestinal stromal tumor(GIST).Methods CT images of 53 pathologically proven cases of MAF(n=14)and GIST(n=39)were retrospectively reviewed.Location,contour,border,enhancement pattern,presence of necrosis,vessels,and air within the lesion were analyzed.Long diameter(LD),short diameter(SD),LD/SD ratio,degree of enhancement were measured and calculated.Significant CT criteria were identified using t-test,and receiver operating characteristic(ROC)curve.Sensitivity and specificity values were calculated when single or multiple CT criteria were used.Results Most of the MAF were extra-gastrointestinal location(χ2=10.437,P=0.001),oval or irregular(χ2=9.192,P=0.004),homogeneous enhancement(χ2=12.458,P=0.000),absence of intra-lesional necrosis(χ2=6.632,P=0.014),lower degree of enhancement(the CT value of venous phase was 23.9±8.2 HU).When homogeneous enhancement and LD/SD ratio were combined,the sensitivity and specificity for diagnosing MAF were 92.9%and 97.4%,respectively.Conclusion The following seven CT features are helpful to distinguish MAF from GIST:extragastrointestinal location,oval or irregular shape,homogeneous enhancement,absence of intra-lesional necrosis,LD/SD≥1.19,increased CT value≤22 HU in arterial phase and CT value≤31 HU in arterial phase.