Title Information
Title
Segmentation of Glioblastoma Images Using Ensembles of Convolutional Neural Networks
Type of Resource
text
Name: Personal
Name Part
Montagut, Julian
Role
Role Term: Text
creator
Name: Personal
Name Part
Neretti, Nicola
Role
Role Term: Text
Reader
Name: Personal
Name Part
Srivastava, Vikas
Role
Role Term: Text
Reader
Name: Personal
Name Part
Lee, Jonghwan
Role
Role Term: Text
Advisor
Name: Corporate
Name Part
Brown University. Biology and Medicine: Biomedical Engineering
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2020
Physical Description
Extent
ix, 91 p.
digitalOrigin
born digital
Note: thesis
Thesis (Sc. M.)--Brown University, 2020
Genre (aat)
theses
Abstract
Brain cancer remains a pervasive public health issue. The use of CNN’s to segment brain tumor images has gained significant traction since 2012; however, most such studies utilized MRI data for these purposes, rather than stained histopathological samples used for initial diagnosis. Segmentation of these samples could provide valuable insight alongside other imaging modalities and methods. Therefore, we present patch-based segmentation of histopathological glioblastoma images using CNN’s, examining the results both in terms of AUC and MAP. After expert labeling of four primary H&E-stained histology images, we divided them into patches of size 30 x 30. We also performed data augmentation to increase the number of patches for effective training. We then grouped these patches into training, validation and testing sets. We built a modified AlexNet architecture by using Tensorflow. First, we determined optimal learning rates for AUC and MAP. Second, we used the CNN’s to generate heatmaps of the tumor probabilities of all patches in the testing set. We then further investigated the effects of heatmap averaging, median filtering and Gaussian filtering on the final predictions and identified the optimal settings over all test images. Finally, we optimized and applied thresholds to convert our probability heatmaps to classification mappings and compared the results to the reference labels. Overall, our trained CNN’s produced satisfactory segmentations, and the heatmap averaging and greater degrees of filtering tended to entail higher AUC and MAP values; however, the performance varied with which primary image was designated for testing. Furthermore, universally applying a single threshold across all test images degraded the quality of the segmentations. Selecting the optimal threshold using precision-recall curves instead of ROC curves resulted in fewer false positives, but more false negatives. The results in the MAP study were also more scattered than their AUC counterparts. Therefore, we recommend using MAP only where critical to control the frequency of false positives.
Subject
Topic
Machine Learning
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00957675")
Topic
Histology, Pathological
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00817247")
Topic
Artificial intelligence
Subject
Topic
Glioblastoma
Subject
Topic
Deep Learning
Subject
Topic
Image Segmentation
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00837592")
Topic
Brain--Cancer
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20200720
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Identifier: DOI
10.26300/dcax-ve55