常规MRI联合SWI对腮腺良恶性病变的鉴别诊断价值

The Diagnostic Value of Conventional MRI Combined with SWI in the Differential Diagnosis of Benign Parotid Gland Lesions

目的探讨磁共振磁敏感加权成像(SWI)对鉴别腮腺良恶性病变的应用价值。方法回顾性分析本院38例腮腺病变患者的临床及影像学资料,其中良性病变26例,恶性病变12例;均经病理证实,并于治疗前行MRI扫描,包括SWI及常规序列,获取其对应的磁敏感信号强度(ITSS)、病灶内静脉分布、最大静脉直径以及各常规MR参数;以病理结果为金标准,采用单因素分析研究腮腺良恶性病变各参数的差异,建立Logistic回归模型筛选新参数,并通过受试者工作特征曲线(ROC)分析新参数对评价腮腺病变良恶性的诊断效能。结果ITSS分级特点:腮腺良性病变以0~1级为主,恶性病变以2~3级为主,两者间的差异具有统计学意义(Z=-3.397,P<0.05);病灶内静脉分布:腮腺良性病变内静脉以周围分布为主,而恶性病变内静脉多分布于中央,良恶性病变的差异具有统计学意义(P<0.05);腮腺良性病变内最大静脉直径小于恶性病变[(1.19±0.36)mmvs(2.34±1.23)mm],两者间的差异同样具有统计学意义(t=-3.178,P<0.05)。Logistic回归结果显示仅病灶内ITSS与最大静脉直径对腮腺良恶性病变的定性诊断具有相关性,ROC分析结果显示:ITSS的最佳诊断阈值为1.5,对应的曲线下面积(AUC)以及敏感度、特异度分别为0.809、75.00%、84.62%;最大静脉直径的最佳诊断阈值为1.7mm,对应的AUC以及敏感度、特异度分别为0.821、75.00%、96.15%。结论常规MRI联合SWI能提高鉴别腮腺良恶性病变的诊断效能,具有重要的临床应用价值。

Objective To clarify the diagnostic value of susceptibility weighted MR imaging ( SWI) for distinguishingmalignant from benign parotid gland lesions. Methods The clinical and imaging data of 38 patients with parotid lesions,were retrospectively analyzed,including 26 benign lesions and 12 malignant lesions,were confirmed by surgical pathologylater. We evaluated preoperative SWI findings,and explored the intravenous distribution,the largest diameter of veins,andthe graduation of intratumoral susceptibility signal intensity ( ITSS) . We used the single factor analysis to study the differ-ences of the parameters of benign parotid gland lesions for comparing with pathological results. A Logistic regression modelwas established to select the new parameters,and the diagnosis efficiency of benign and malignant parotid lesions was evalu-ated by ROC analysis. Results the characteristics of ITSS classification: the benign lesion of the parotid gland was mainlyfrom 0 to 1,and the malignant lesion was mainly 2 ~ 3,and the difference was statistically significant ( Z = -3. 397,P <0. 05) . Intravenous distribution: The internal veins of benign parotid gland were mainly distributed in the surrounding are-a,while the internal veins of malignant lesions were distributed in the center,and the difference of benign and malignant le-sions was statistically significant ( P <0. 05) . The largest venous diameter of the benign parotid gland is shorter than malig-nant lesion [( 1. 19 ±0. 36) mm vs ( 2. 34 ±1. 23) mm],the difference was also statistically significant ( t = -3. 178,P <0. 05) . Logistic regression results showed that there was a correlation between the ITSS and the maximum diameter of thelesion in the diagnosis of parotid benign lesions. The ROC analysis results showed that the optimal diagnostic threshold ofITSS was 1. 5,with the corresponding curve area ( AUC) and sensitivity and specificity of 75. 00%,84. 62% and 0. 809 re-spectively. The optimal diagnostic threshold for the maximum vein diameter was 1. 7mm,the corresponding AUC and sensi-tivity and specificity were 75. 00%,96. 15% and 0. 821 respectively. Conclusion Conventional MRI combined with roccan improve the diagnostic efficacy of benign parotid lesions,and has important clinical application value.