波谱学杂志 ›› 2021, Vol. 38 ›› Issue (3): 356-366.doi: 10.11938/cjmr20212885

• 研究论文 • 上一篇    下一篇

一种用于前列腺区域分割的改进水平集算法

闫士举1,韩勇森2,*(),汤光宇2   

  1. 1. 上海理工大学 医疗器械与食品学院, 上海 200093
    2. 上海市第十人民医院 放射科, 上海 200072
  • 收稿日期:2021-01-26 出版日期:2021-09-05 发布日期:2021-08-26
  • 通讯作者: 韩勇森 E-mail:hanys@163.com
  • 基金资助:
    国家自然科学基金资助项目(81572530)

An Improved Level Set Algorithm for Prostate Region Segmentation

Shi-ju YAN1,Yong-sen HAN2,*(),Guang-yu TANG2   

  1. 1. School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
    2. Department of Radiology, Shanghai Tenth People's Hospital, Shanghai 200072, China
  • Received:2021-01-26 Online:2021-09-05 Published:2021-08-26
  • Contact: Yong-sen HAN E-mail:hanys@163.com

摘要:

前列腺区域的精确分割是提高计算机辅助前列腺癌诊断准确率的重要前提.本文提出了一种新的精确的前列腺区域分割模型,分为4个步骤:首先,读取T2加权磁共振(MR)图像;其次,利用半径为5个像素的8邻域模板(8x5)的局部二值模式(LBP)特征模板计算前列腺磁共振图像的LBP特征图;然后,利用改进的距离正则化水平集(DRLSE)模型对特征图进行分割,提取前列腺粗轮廓;最后将原始水平集能量函数进行优化,构造一个新的能量函数,提取局部灰度信息和梯度信息,并在此新的能量函数的基础上,将粗轮廓迭代演化为最终的细轮廓.本文将该模型在203组来自于国际光学与光子学学会-美国医学物理学家协会-国家癌症研究所(SPIE-AAPM-NCI)前列腺MR分类挑战数据库的T2W磁共振图像上进行了测试,并与医生手工分割结果进行了比较,结果表明本文提出模型得到的分割结果的Dice系数为0.94±0.01,相对体积差(RVD)为-1.21%±2.44%,95% Hausdorff距离(HD)为6.15±0.66 mm;与文献中现有的分割模型相比,使用本文提出的模型得到的前列腺区域分割结果更接近于手工分割的结果.

关键词: 局部灰度信息, 磁共振成像(MRI), 前列腺区域分割, 水平集, 计算机辅助诊断

Abstract:

Accurate segmentation of prostate region is an important prerequisite to improve the accuracy of computer-aided prostate cancer diagnosis. In this work, a new and accurate prostate segmentation algorithm is proposed and tested. The new algorithm consists of 4 steps: reading T2-weighted magnetic resonance images, calculating local binary pattern (LBP) feature map of prostate magnetic resonance images by using an 8x5 LBP feature template, segmenting the feature map with the improved distance regularization level set evolution (DRLSE) algorithm, and extracting coarse contour of the prostate. A new energy function is constructed to extract local gray scale information and gradient information, and the coarse contour is iteratively developed into the final fine prostate contour on the basis of this new energy function. The algorithm was tested with the SPIE-AAPM-NCI Prostate MR Classification Challenge Database. The segmentation results of the proposed algorithm were compared with that of manual segmentation by doctors. The results showed that the Dice coefficient obtained by using the proposed algorithm was 0.94±0.01, with a relative volume difference (RVD) of -1.21%±2.44% and a 95% Hausdorff distance (HD) of 6.15±0.66 mm. Compared with the existing segmentation algorithms, the segmentation results obtained with the algorithm proposed in this paper are closer to the manual segmentation results.

Key words: local gray scale information, magnetic resonance imaging (MRI), prostate region segmentation, level set, computer-aided diagnosis

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