基于分段读出平面回波序列的体素内不相干运动DWI在单纯性鼻炎和慢性肥厚性鼻炎中的应用

Intravoxel incoherent motion DWI based on readout segmentation echo-planar sequence in diagnosis of simple rhinitis and chronic hypertrophic rhinitis

目的研究基于分段读出平面回波序列(RS-EP)单指数模型DWI、双指数模型体素内不相关运动(IVIM)成像诊断单纯性鼻炎和慢性肥厚性鼻炎的价值。方法收集鼻阻塞患者20例,按病理结果分为单纯性鼻炎组和慢性肥厚性鼻炎组。所有受试者均接受RS-EP序列的IVIM和单指数模型DWI检查,获得IVIM参数纯扩散系数(D)、假性灌注系数(D~*)、灌注分数(f)和ADC参数图。分别测量2组下鼻甲黏膜的前、中、后部3个区域的参数值。比较2组和3个区域间各扩散参数值的差异,采用ROC曲线分析其诊断效能。结果慢性单纯性鼻炎组的ADC和D值分别为(1 938.84±170.46)×10^(-6)mm^2/s和(1 698.91±145.17)×10^(-6)mm^2/s,慢性肥厚性鼻炎组ADC值为(1 681.76±132.21)×10^(-6)mm^2/s,D值为(1 439.39±101.26)×10^(-6)mm^2/s,2组间差异有统计学意义(P均<0.05)。D~*和f值2组间差异无统计学意义(P均>0.05)。下鼻甲黏膜前、中、后部ADC值依次增高(P均<0.05);下鼻甲前、中、后部D~*值差异无统计学意义(P>0.05)。ROC曲线分析表明,D值的曲线下面积高于ADC值(0.932±0.044 vs 0.896±0.058,P<0.05),其敏感度、特异度、准确率、阳性预测值和阴性预测值分别为92.31%、93.75%、90.00%、93.75%、85.71%。结论基于RS-EP序列的IVIM成像和单指数DWI成像在鉴别单纯性鼻炎和慢性肥厚性鼻炎中具有较大的应用价值,其中基于IVIM模型的D值较常规ADC值具有更高的诊断效能。

Objective To investigate the value of dual-exponential model intravoxel incoherent motion （IVIM） DWI and conventional single-exponential DWI model based on readout segmentation echo-planar （RS-EP） sequence in differential diagnosis of simple rhinitis and chronic hypertrophic rhinitis. Methods Totally, 20 patients confirmed by pathology were enrolled in this study and all of them underwent IVIM DWI and conventional DWI. The pure diffusion （D）, pseudo-diffusion （D＊）, perfusion fraction （f） and conventional ADC maps were obtained respectively. The quantitative parameters of anterior, middle, posterior regions of inferior nasal concha mucosa were measured. Comparative statistical analysis was performed for comparing two groups and three regions. ROC analysis was conducted to assess the diagnostic performance. Results The ADC and D values in the simple rhinitis group were （1 938.84±170.46）×10-6 mm2/s, and （1 698.91±145.17）×10-6 mm2/s. In chronic hypertrophic rhinitis group, the ADC value was （1 681.76±132.21）×10-6 mm2/s, and the D value was （1 439.39±101.26）×10-6 mm2/s. There were significant differences between the two groups （both P〈0.05）. No significant differences were found for D＊ and f values between two groups （both P〉0.05）. ADC values increased significantly from anterior region, middle region to posterior region （all P〈0.05）. No significant difference was found for D＊ value among three regions （P〉0.05）. ROC analysis demonstrated a higher area under the curve （AUC） for D value than ADC value （0.932±0.044 vs 0.896±0.058） with sensitivity, specificity, accuracy, positive and negative predictive values of 92.31%, 93.75%, 90.00%, 93.75%, 85.71%. Conclusion Based on RS-EP sequence, both IVIM DWI model and conventional single-exponential DWI model demonstrated great value in differential diagnosis of simple rhinitis and chronic hypertrophic rhinitis, and the IVIM-derived D value exhibited a higher diagnostic performance than the conventional ADC value.