直肠癌术前扩散加权成像层面及感兴趣区的选择对ADC值一致性及重复性的影响

发布时间：2018-03-10 06:09

本文选题：直肠癌　切入点：扩散加权成像　出处：《中国癌症杂志》2017年10期 　论文类型：期刊论文

【摘要】：背景与目的:扩散加权成像(diffusion weighted imaging,DWI)定量参数即表观扩散系数(apparent diffusion coefficient,ADC)的一致性及可重复性是众多研究关注的重点。既往研究结果显示b值、感兴趣区(region of interest,ROI)的选择等因素对ADC值一致性及可重复性均有一定影响。本研究将探讨直肠癌术前DWI层面及ROI的选择对ADC值一致性及重复性的影响。方法:回顾性分析80例病理证实为直肠腺癌的患者资料,此组患者均行直肠MR及DWI检查。2名不同年资的医师分别在ADC图像上采用肿瘤中心法及轮廓法勾画ROI,层面选择了肿瘤最大层、肿瘤最大层及其上下两层及肿瘤全层三种方法。其中肿瘤轮廓法采用手动勾画模式,尽量沿肿瘤轮廓勾画ROI。肿瘤中心法使用圆形ROI工具,肿瘤实性部分尽可能圈入而避开病变内坏死或囊变区。两名医师用三种层面和两种ROI放置法间隔2周进行重复测量。使用ANOVA法比较不同层面之间ADC值差异,配对t检验比较两种ROI之间ADC值差异。计算组内相关系数(interclass correlation coefficient,ICC),并分别比较同一医师前后两次及两名医师之间测量值的可重复性(BlandAltman法)。结果:将三种层面法测得ADC值进行两两比较,差异均无统计学意义(P0.05)。相同层面的情况下,肿瘤轮廓法测得ADC值均大于肿瘤中心法,且差异有统计学意义(P0.05)。选择肿瘤全层-肿瘤中心法及轮廓法测量ADC值,组内及组间一致性可达到0.931、0.803和0.913、0.822。医师1前后两次分别采用肿瘤中心法及肿瘤轮廓法测定ADC值,测得的ADC值95%一致性区间为(-0.089 3~0.083 1)×10~(-3)mm~2/s(P:Mean=0,P0.05),(-0.066 8~0.096 3)×10~(-3) mm~2/s(P:Mean=0,P0.05);医师1与医师2使用采用肿瘤中心法及肿瘤轮廓法测定ADC值,测得的ADC值95%一致性区间为(-0.127 5~0.141 6)×10~(-3)mm~2/s(P:Mean=0,P0.05),(-0.112 0~0.150 2)×10~(-3)mm~2/s(P:Mean=0,P0.05)。Bland-Altman散点图显示,肿瘤中心法较轮廓法在同一医师前后两次间及两名医师间重复测量一致性区间小,重复性好。结论:不同层面选择对直肠癌ADC值影响不大;而轮廓法测得ADC值大于中心法。肿瘤全层-肿瘤轮廓法及中心法测得ADC值一致性均较高。但肿瘤全层-中心法重复性稍好且操作简便;而肿瘤全层-轮廓法重复性较中心法稍差,但能反映肿瘤整体情况。
[Abstract]:Background & objective: the consistency and repeatability of diffusion weighted imaging diffusion weighted imaging (DWI) quantitative parameters, i.e. apparent diffusion coefficient, diffusion coefficient, are the focus of many studies. The selection of region of interest (ROI) has a certain influence on the consistency and repeatability of ADC value. This study will investigate the influence of DWI level and ROI selection on ADC value consistency and repeatability before rectal cancer operation. The data of 80 cases of rectal adenocarcinoma confirmed by pathology were analyzed. All patients in this group were examined by rectal Mr and DWI. 2 doctors with different years of age were used to draw ROI on ADC images by tumor center method and contour method respectively, and the largest layer of tumor was selected on each level. There are three methods of tumor maximum layer, its upper and lower layers and the whole tumor layer. Among them, the tumor contour method uses the manual drawing mode, and as far as possible along the tumor outline, ROI is delineated along the tumor contour. The tumor center method uses the circular ROI tool. The solid part of the tumor was enclosed as much as possible to avoid the necrosis or cystic zone of the lesion. The two physicians measured repeatedly with three layers and two ROI placement methods. The ANOVA method was used to compare the differences in ADC values between different layers. Matched t test was used to compare the difference of ADC value between two kinds of ROI. The interclass correlation coefficient was calculated, and the repeatability of the measured values before and after the same doctor and between two doctors were compared. Results: the three levels method was used to measure the values. The ADC value is pairwise compared, Under the same level, the ADC measured by tumor contour method was higher than that by tumor center method, and the difference was statistically significant (P 0.05). The ADC values were measured by tumor whole-tumor centroid method and contour method. The consistency within and between groups was 0.931 ~ 0.803 and 0.913 ~ 0.822 respectively. Before and after physician 1, the ADC values were measured by tumor center method and tumor contour method, respectively. The 95% consistency range of ADC measured was -0.089 3 / 0.083 1) 脳 10 ~ (-10) -3mm ~ (-3) mm ~ (-2) / s ~ (-1) P ~ (0.05) -0.066 80.096 ~ 3) 脳 10 ~ (10) ~ (-3) mm ~ (2) ~ (?) ~ (2)); physician 1 and physician 2 used tumor center method and tumor contour method to measure ADC value. The 95% consistency interval of ADC value was -0.127 50.141) 脳 10 ~ (-0) -3 mm ~ 2 mm ~ (2sg) ~ (-0.112 脳 0.112 脳 0.150) ~ (-0.112 脳 0.112 脳 0.150 ~ 0.150) ~ (-0.112 脳 0.112 脳 0.120 脳 0. 150) ~ (-1) and 3mm ~ (-1) PMean0P ~ (0.05) ~ (0. 05) mm ~ (-1) ~ (-1) ~ (-1)). The ADC value of physician 2 was determined by using tumor center method and tumor contour method. The range of ADC 95% consistency was -0.127 50.141) 脳 10 ~ (-10) -3 mm ~ (-3) mm ~ (?) ~ 2??? Compared with the contour method, the tumor center method had smaller consistency interval and better repeatability than the contour method. Conclusion: the ADC value of rectal cancer was not affected by the selection of different layers. The ADC measured by the contour method was higher than that by the central method. The consistency of the ADC values measured by the whole-tumor contour method and the centroid method was higher than that by the centroid method, but the reproducibility of the whole-laminal-centroid method was slightly better and the operation was simple. The reproducibility of the whole-layer-contour method is a little less than that of the central method, but it can reflect the overall situation of the tumor.
【作者单位】：复旦大学附属肿瘤医院放射诊断科复旦大学上海医学院肿瘤学系;上海影像医学研究所;
【基金】：国家自然科学基金(81501437)
【分类号】：R445.2;R735.37

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