多模态MRI对腮腺多形性腺瘤和腺淋巴瘤的诊断价值

Value of multimodal MRI in diagnosis of parotid pleomorphic adenoma and adenolymphoma

目的:评估常规磁共振成像、扩散加权成像(DWI)、动态对比增强(DCE)MRI对腮腺多形性腺瘤与腺淋巴瘤的诊断及鉴别价值。方法:回顾性分析44例经手术病理证实的腮腺多形性腺瘤和腺淋巴瘤(共49个病灶,其中多形性腺瘤25例共26个病灶,腺淋巴瘤19例共23个病灶)患者的3.0T常规MRI、DWI和DCE-MRI等多模态影像资料,分析各序列图像上病灶主要征象或参数值的诊断效能。结果:(1)26个多形性腺瘤中20个(20/26)位于腮腺浅叶上极,23个腺淋巴瘤中17个(17/23)位于腮腺深叶下极,2组间病变部位的差异具有统计学意义(χ~2=12.663,P<0.05);(2)多形性腺瘤的平均ADC值为1.838×10^(-3) mm^2/s,腺淋巴瘤为0.899×10-3 mm2/s,两组间的差异有统计学意义(t=-10.106,P<0.05);(3)DCE-MRI获得病灶的时间-信号强度曲线(TIC),26个多形性腺瘤中22个为TIC-A型(持续流入型),23个腺淋巴瘤病灶中20个为TIC-B型(廓清型),两组间的差异具有统计学意义(χ~2=42.117,P<0.05);(4)DCE-MRI获得的病灶的定量参数中,与腺淋巴瘤比较,多形性腺瘤的Ktrans、Kep和iAUC值较低,Ve值较高,其中Ktrans和Ve值的组间差异有统计学意义(t值分别为=-2.177和4.241,P<0.05)。结论:多模态MRI对腮腺多形性腺瘤与腺淋巴瘤的诊断和鉴别诊断具有较高的临床应用价值。

Objective:To evaluate the value of conventional MRI,diffusion weighted imaging(DWI)and dynamic contrast enhanced(DCE)MRI in the diagnosis and differential diagnosis of paro-tid leomorphic adenoma(PA)and adenolymphoma(AL).Methods:The imaging findings(including conventional MRI,DWI and DCE-MRI at a 3.0T scanner)of 44 cases(49 lesions)with parotid pleomorphic adenoma(26 lesions of 25 cases)and adenolymphoma(23 lesions of 19 cases)were retrospectively analyzed,and the diagnostic efficiency of main imaging signs and indexes obtained in each imaging technique were evaluated.Results:①20 lesions(20/26)of the pleomorphic adenoma were located in the upper pole of the superficial lobe;17 lesions(17/23)of the adenolymphoma were located in the deep lobe and the lower pole of the deep lobe.There was statistically significant difference as for location between the two groups(χ^2=12.663,P<0.05).②The average ADC value of pleomorphic adenoma was 1.838×10^-3mm^2/s,and that of adenolymphoma was 0.899×10^-3mm^2/s.There was statistically significant difference of ADC value between the two groups(t=-10.106,P<0.05).③DCE-MRI TIC of 22(22/26)pleomorphic adenomas were type A(continuous inflow type)and TIC of 20(20/23)adenolymphoma were type B(washout type).There was statistically significant difference in TIC types between the two groups(χ^2=42.117,P<0.05).④Compared with the adenolymphomas,the pleomorphic adenomas had lower values of K trans,K ep and iAUC,but higher V e values.There was statistically significant difference in the K trans and V e values between the two groups(t=-2.177 and t=4.241,both P<0.05).Conclusion:Multimodality MRI techiniques have high application efficiency in diagnosis and differential diagnosis of parotid pleomorphic adenoma and adenolymphoma.