摘要
Abstract
Objective To explore the value of the quantitative parameters based on stretch exponential diffusion model of the diffusion weighted image in the differential diagnosis of nasopharyngeal carcinoma and nasopharyngeal hyperplasia.Methods From October 2015 to June 2016,80 consecutive patients with suspected NPC were examined on a 1.5 T MR scanner.IVIM DWI was performed using a single-shot echo-planar sequence with different b-values (0,10,20,30,50,80,100,150,200,300,400,600,800 s/mm2).MR imaging was compared with endoscopy and biopsy for the detection of NPC.The subsequent nasopharyngeal biopsy was performed in 1 week after MRI examination.The subjects were divided into 2 groups according to the pathological results:nasopharyngeal carcinoma group and nasopharyngeal hyperplasia group.Through the AW4.6 Functiontool post-processing software,the ROI was outlined and DDC and α values were measured.Using the SPSS 19.0 statistical software,independent samples t test and two independent samples nonparametric test were used to compare the DDC value and the oα value between the two groups.The ROC curve was drawn to calculate the area under the curve and determine the threshold value and diagnostic efficiency.Results IVIM DWI was successful in 35 patients with nasopharyngeal carcinoma and 30 patients with nasopharyngeal hyperplasia.DDC value was significantly lower in nasopharyngeal carcinoma group than in nasopharyngeal hyperplasia group [(0.88 ± 0.29) × 10-3 mm/s vs (1.0 ± 0.5) × 10-3 mm/s,t =2.380,P ＜ 0.05].However,α value was 0.75 ± 0.08 in nasopharyngeal carcinoma group and 0.79 ± 0.1 in nasopharyngeal hyperplasia group (U =1.585,P ＞0.05).DDC ROC curves showed that the area under the DDC curve was 0.732,the best diagnostic threshold was 1.02 × 10-3 mm/s,and the sensitivity and specificity were 0.533 and 0.867.Conclusion The stretched model of incoherent motion imaging may quantitatively diagnose nasopharyngeal hyperplasia and nasopharyngeal carcinoma and reflect the heterogeneity of tumor,which suggests that DDC is an independent prognostic factor of nasopharyngeal carcinomna.关键词
拉伸指数模型/鼻咽癌/鼻咽炎性增生性疾病/鉴别诊断Key words
stretch exponential diffusion model/nasopharyngeal carcinoma/nasopharyngeal hyperplasia disease/differential diagnosis分类
医药卫生
