摘要目的:探讨多参数动态增强磁共振成像（DCE-MRI）对泪腺良恶性上皮性肿瘤的鉴别诊断价值。方法:回顾性收集北京同仁医院2011年1月至2017年12月间行眼眶MRI扫描并符合入组标准的104例泪腺上皮性肿瘤的临床及影像资料，其中男48例，女56例，年龄12~77（43±7）岁。良性上皮性肿瘤63例，恶性上皮性肿瘤41例，均行DCE-MRI检查。DCE-MRI半定量参数包括达峰时间（Tpeak）、最大强化率（ERmax）、斜率（Slope）、流出率（WR）、时间-信号强度曲线（TIC）类型，定量参数包括对比剂容积转移常数（K trans）、血管外细胞外间隙体积分数（V e）和对比剂转移速率常数（K ep）。对差异有统计学意义的DCE-MRI参数，行受试者工作特征（ROC）曲线分析，计算曲线下面积（AUC），确定诊断阈值，评价其诊断效能。通过logistic回归分析确定鉴别泪腺良恶性上皮性肿瘤的最佳参数。 结果:DCE-MRI半定量参数分析：泪腺恶性上皮性肿瘤的Tpeak小于良性上皮性肿瘤［（103.77±57.87）比（187.80±77.01）s， P<0.001］，ERmax、Slope［ M（ Q1， Q3）］及WR大于良性上皮性肿瘤［（1.55±0.39）比（1.36±0.33），1.76（0.97，2.27）比0.62（0.50，0.93），7.70%（1.40%，21.60%）%比0（0，0）；均 P<0.05］，良性上皮性肿瘤TIC曲线以持续上升型为主（49/63），而恶性上皮性肿瘤则以平台型为主（25/41）。定量参数分析：泪腺恶性上皮性肿瘤的K trans、K ep值［ M（ Q1， Q3）］大于良性上皮性肿瘤［（0.99±0.52）/min比（0.43±0.23）/min，1.33（0.83，1.55）/min比0.55（0.46，0.68）/min］（均 P<0.001），V e值之间的差异无统计学意义［（0.76±0.20）比（0.73±0.22）， P=0.467］。经统计学分析表明，在预测泪腺恶性上皮性肿瘤的诊断效能上，参数TIC类型（ OR=3.887，95% CI：1.409~10.725）和K trans（ OR=50.979，95% CI：6.046~429.830）的诊断价值更高，相应的灵敏度、特异度分别为78.05%、77.78%和70.73%、95.24%，且定量参数K trans的综合诊断表现优于半定量参数TIC，AUC差异具有统计学意义［0.875（0.796~0.932）比0.798（0.708~0.870）， P=0.049］。 结论:多参数DCE-MRI有助于泪腺良恶性上皮性肿瘤的鉴别诊断，其中TIC类型和K trans的诊断价值更高，且K trans的诊断效能优于TIC。

abstractsObjective:To investigate the diagnostic performance of multiparametric dynamic contrast-enhanced MRI(DCE-MRI) for the differentiation between benign and malignant larcrimal gland epithelial tumors.Methods:The clinical and imaging data of 104 patients with epithelial tumors of the lacrimal gland who underwent orbital MRI scan and met the inclusion criteria in Beijing Tongren Hospital from January 2011 to December 2017 were retrospectively collected, including 48 males and 56 females, aged from 12 to 77 (43±7) years. Sixty-three cases of benign epithelial tumors and 41 cases of malignant epithelial tumors were examined by DCE-MRI. The parameters of semiquantitative analysis including: time to peak enhancement (Tpeak), maximum enhancement ratio (ERmax), Slope, washout ratio (WR) and time-signal intensity curve (TIC) types. The parameters of quantitative analysis including: volume transfer constant (K trans), the extravascular extracellular volume fraction (V e) and rate constant (K ep). Receiver operating characteristic (ROC) curve analysis was performed for DCE-MRI parameters with statistically significant differences, the area under the curve (AUC) was calculated, the diagnostic threshold was determined, and the diagnostic performance was evaluated. Logistic regression analysis was used to determine the best parameters for differential diagnosis of benign and malignant epithelial tumors of the lacrimal gland. Results:For the semiquantitative analysis of DCE-MRI, malignant lacrimal gland epithelial tumor had a significantly shorter Tpeak than benign masses [(103.77±57.87) s vs (187.80±77.01) s, P<0.001)], while had a higher value in ERmax, Slope [ M( Q1, Q3)] and WR in malignant masses compared with benign one [1.55±0.39 vs 1.36±0.33; 1.76 (0.97,2.27) vs 0.62 (0.50,0.93); 7.70%(1.40%, 21.60%)% vs 0(0, 0),all P<0.05)].The TICs of benign lacrimal tumors mainly showed a persistent type (49/63),while most malignant lacrimal tumors mainly showed a plateau type (25/41). For the quantitative analysis of DCE-MRI, the values of K trans and K ep[ M( Q1, Q3)] in malignant tumors were significantly greater than those of benign tumors (0.99±0.52/min vs 0.43±0.23/min, P<0.001; 1.33(0.83, 1.55)/min vs 0.55(0.46, 0.68)/min, P<0.001). No significant difference in V e was found between the groups (0.76±0.20 vs 0.73±0.22, P=0.467). Through the statistical analysis, TIC types ( OR=3.887,95% CI: 1.409-10.725) and K trans( OR=50.979,95% CI: 6.046-429.830) can provide superior diagnostic performance for predicting malignant lacrimal gland epithelial tumors, with a sensitivity of 78.05%, specificity of 77.78%,and sensitivity of 70.73%, specificity of 95.24%, respevtively. Furthermore, the comprehensive diagnostic performance of K trans in AUC was proven to be significantly better than that of TIC [0.875 (0.796-0.932) vs 0.798 (0.708-0.870), P=0.049]. Conclusions:Multiparametric DCE-MRI is helpful for the differential diagnosis of benign and malignant epithelial tumors of lacrimal gland. TIC type and K trans have higher diagnostic value, and the diagnostic performance of Ktrans is better than that of TIC.