基于核磁共振的玉米根系3维可视化研究  

Three-dimensional visualization of maize roots based on magnetic resonance imaging

作　　者：方孝荣[1] 王南飞[2,3] 张建锋[2,3] 龚向阳[4] 刘飞[2,3] 何勇[2,3] 

机构地区：[1]金华职业技术学院,浙江金华321017 [2]浙江大学生物系统工程与食品科学学院,杭州310058 [3]浙江大学唐仲英传感材料及应用研究中心,杭州310058 [4]浙江大学医学院附属邵逸夫医院放射科,杭州310016

出　　处：《浙江大学学报（农业与生命科学版）》2014年第2期181-187,共7页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家高技术研究发展计划(863计划)资助项目(2013AA102301);国家自然科学基金资助项目(31201137)

摘　　要：以玉米根系为研究对象，采用核磁共振成像技术原位无损检测玉米根系，研究土壤体积含水率对根系成像效果的影响；依据获取的根系核磁切片图像，借助于计算机图形学技术和可视化工具包 Visualization Toolkit 5.4实现玉米根系模型的重构；对根系模型的几何参数进行测量，验证重构模型的精度.结果表明：土壤体积含水率在5%~20%范围内变化时不会对玉米根系的核磁共振成像质量造成显著影响；模型的几何测量值与根系真实值之间的误差均小于3%，与标准方法测定结果具有很好的一致性.本研究可以用于植物根系的原位无损检测，实现根系几何参数的精确测量，对于认知根系与周围土壤介质的相互作用规律具有十分重要的作用.Summary Plant root system is plastic and dynamic,allowing plants to respond to their different environments in order to optimize acquisition of important soil resources.A number of root architecture parameters are known to be correlated with improved crop performance.Therefore,quantitative analysis of root architecture parameters,or the spatial configuration and distribution of root system in soil,will help to promote our understanding for root structure,function and their interactions with the soil in rhizosphere zone.The overall objective of the present work is to reconstruct 3D （three-dimensional） root architecture in situ non-destructively and to measure quantitatively geometric parameters of root system. The maize roots were used as research object,and the cross-section images of maize roots were performed on a whole-body magnetic resonance（MR）imaging system with a static magnetic field of 3.0 Tesla.The MR method was found to be very effective for capturing root slice images dynamically without any contact or perturbation of＆amp;nbsp;plant root system or growth medium.Based on the root slice image data for maize root architectures obtained by this non-destructive approach,3D root architecture parameters were measured.Root slice images were generated using a fast spin echo sequence with effective echo time of 10.2 ms,repetition time of 1 800 ms,slice thickness of 2 mm,and imaging matrix of 5 12 × 5 12 pixels.Although MR imaging is closely related to the water content of material,volumetric water contents of rhizosphere in the range of 5% 20% have not significant impact on the quality of root slice images.The reconstruction process consisted of the following steps：image format conversion, filtering,roots target extraction,root data encapsulation,model reconstruction.Radiant DICOM viewer and Matlab r2009b were employed to preprocess the original slice images,including：1） gray level transformation of the original gray level images;2）contourlet transform filtering for noise reduction and image

关 键 词：核磁共振成像 玉米根系 根系模型 几何参数 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] S124[自动化与计算机技术—计算机科学与技术]