Accurate segmentation of bladder cancer is the basis for determining the staging of bladder cancer. In our previous study, we have segmented the inner and outer surface of bladder wall and obtained the candidate region of bladder cancer, however, it is hard to segment the cancer region from the candidate region. To segment the cancer region accurately, we proposed a voxel-feature-based method and extracted 1159 features from each voxel of candidate region. After feature extraction, the recursive feature elimination-based support vector machine classifier (SVM-RFE) method was adopted to obtain an optimal feature subset for the classification of the cancer and the wall regions. According to feature selection and ranking, 125 top-ranked features were selected as the optimal subset, with an area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity of 1, 99.99%, 99.98%, and 1. Using the optimal subset, we calculated the probability value of each voxel belonging to the cancer region, then obtained the boundary to separate the tumor and wall regions. The mean DSC of the segmentation results in the testing set is 0.9127, indicating that the proposed method can accurately segment the bladder cancer region.
Purpose: To 1) find effective texture features from multimodal MRI that can distinguish IDH mutant and wild status, and 2) propose a radiomic strategy for preoperatively detecting IDH mutation patients with glioma. Materials and Methods: 152 patients with glioma were retrospectively included from the Cancer Genome Atlas. Corresponding T1-weighted image before- and post-contrast, T2-weighted image and fluid-attenuation inversion recovery image from the Cancer Imaging Archive were analyzed. Specific statistical tests were applied to analyze the different kind of baseline information of LrGG patients. Finally, 168 texture features were derived from multimodal MRI per patient. Then the support vector machine-based recursive feature elimination (SVM-RFE) and classification strategy was adopted to find the optimal feature subset and build the identification models for detecting the IDH mutation. Results: Among 152 patients, 92 and 60 were confirmed to be IDH-wild and mutant, respectively. Statistical analysis showed that the patients without IDH mutation was significant older than patients with IDH mutation (p<0.01), and the distribution of some histological subtypes was significant different between IDH wild and mutant groups (p<0.01). After SVM-RFE, 15 optimal features were determined for IDH mutation detection. The accuracy, sensitivity, specificity, and AUC after SVM-RFE and parameter optimization were 82.2%, 85.0%, 78.3%, and 0.841, respectively. Conclusion: This study presented a radiomic strategy for noninvasively discriminating IDH mutation of patients with glioma. It effectively incorporated kinds of texture features from multimodal MRI, and SVM-based classification strategy. Results suggested that features selected from SVM-RFE were more potential to identifying IDH mutation. The proposed radiomics strategy could facilitate the clinical decision making in patients with glioma.
Ischemic stroke has great correlation with carotid atherosclerosis and is mostly caused by vulnerable plaques. It’s
particularly important to analysis the components of plaques for the detection of vulnerable plaques. Recently plaque
analysis based on multi-contrast magnetic resonance imaging has attracted great attention. Though multi-contrast MR
imaging has potentials in enhanced demonstration of carotid wall, its performance is hampered by the misalignment of
different imaging sequences. In this study, a coarse-to-fine registration strategy based on cross-sectional images and wall
boundaries is proposed to solve the problem. It includes two steps: a rigid step using the iterative closest points to register
the centerlines of carotid artery extracted from multi-contrast MR images, and a non-rigid step using the thin plate spline
to register the lumen boundaries of carotid artery. In the rigid step, the centerline was extracted by tracking the crosssectional
images along the vessel direction calculated by Hessian matrix. In the non-rigid step, a shape context descriptor
is introduced to find corresponding points of two similar boundaries. In addition, the deterministic annealing technique is
used to find a globally optimized solution. The proposed strategy was evaluated by newly developed three-dimensional,
fast and high resolution multi-contrast black blood MR imaging. Quantitative validation indicated that after registration,
the overlap of two boundaries from different sequences is 95%, and their mean surface distance is 0.12 mm. In conclusion,
the proposed algorithm has improved the accuracy of registration effectively for further component analysis of carotid
plaques.
Differentiating bladder tumors from wall tissues is of critical importance for the detection of invasion depth and cancer staging. The textural features embedded in bladder images have demonstrated their potentials in carcinomas detection and classification. The purpose of this study was to investigate the feasibility of differentiating bladder carcinoma from bladder wall using three-dimensional (3D) textural features extracted from MR bladder images. The widely used 2D Tamura features were firstly wholly extended to 3D, and then different types of 3D textural features including 3D features derived from gray level co-occurrence matrices (GLCM) and grey level-gradient co-occurrence matrix (GLGCM), as well as 3D Tamura features, were extracted from 23 volumes of interest (VOIs) of bladder tumors and 23 VOIs of patients’ bladder wall. Statistical results show that 30 out of 47 features are significantly different between cancer tissues and wall tissues. Using these features with significant differences between these two types of tissues, classification performance with a supported vector machine (SVM) classifier demonstrates that the combination of three types of selected 3D features outperform that of using only one type of features. All the observations demonstrate that significant textural differences exist between carcinomatous tissues and bladder wall, and 3D textural analysis may be an effective way for noninvasive staging of bladder cancer.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.