2,174 research outputs found
Weakly-supervised localization of diabetic retinopathy lesions in retinal fundus images
Convolutional neural networks (CNNs) show impressive performance for image
classification and detection, extending heavily to the medical image domain.
Nevertheless, medical experts are sceptical in these predictions as the
nonlinear multilayer structure resulting in a classification outcome is not
directly graspable. Recently, approaches have been shown which help the user to
understand the discriminative regions within an image which are decisive for
the CNN to conclude to a certain class. Although these approaches could help to
build trust in the CNNs predictions, they are only slightly shown to work with
medical image data which often poses a challenge as the decision for a class
relies on different lesion areas scattered around the entire image. Using the
DiaretDB1 dataset, we show that on retina images different lesion areas
fundamental for diabetic retinopathy are detected on an image level with high
accuracy, comparable or exceeding supervised methods. On lesion level, we
achieve few false positives with high sensitivity, though, the network is
solely trained on image-level labels which do not include information about
existing lesions. Classifying between diseased and healthy images, we achieve
an AUC of 0.954 on the DiaretDB1.Comment: Accepted in Proc. IEEE International Conference on Image Processing
(ICIP), 201
Detection-aided liver lesion segmentation using deep learning
A fully automatic technique for segmenting the liver and localizing its
unhealthy tissues is a convenient tool in order to diagnose hepatic diseases
and assess the response to the according treatments. In this work we propose a
method to segment the liver and its lesions from Computed Tomography (CT) scans
using Convolutional Neural Networks (CNNs), that have proven good results in a
variety of computer vision tasks, including medical imaging. The network that
segments the lesions consists of a cascaded architecture, which first focuses
on the region of the liver in order to segment the lesions on it. Moreover, we
train a detector to localize the lesions, and mask the results of the
segmentation network with the positive detections. The segmentation
architecture is based on DRIU, a Fully Convolutional Network (FCN) with side
outputs that work on feature maps of different resolutions, to finally benefit
from the multi-scale information learned by different stages of the network.
The main contribution of this work is the use of a detector to localize the
lesions, which we show to be beneficial to remove false positives triggered by
the segmentation network. Source code and models are available at
https://imatge-upc.github.io/liverseg-2017-nipsws/ .Comment: NIPS 2017 Workshop on Machine Learning for Health (ML4H
Automated Retinal Lesion Detection via Image Saliency Analysis
Background and objective:The detection of abnormalities such as lesions or leakage from retinal images is an important health informatics task for automated early diagnosis of diabetic and malarial retinopathy or other eye diseases, in order to prevent blindness and common systematic conditions. In this work, we propose a novel retinal lesion detection method by adapting the concepts of saliency. Methods :Retinal images are firstly segmented as superpixels, two new saliency feature representations: uniqueness and compactness, are then derived to represent the superpixels. The pixel level saliency is then estimated from these superpixel saliency values via a bilateral filter. These extracted saliency features form a matrix for low-rank analysis to achieve saliency detection. The precise contour of a lesion is finally extracted from the generated saliency map after removing confounding structures such as blood vessels, the optic disc, and the fovea. The main novelty of this method is that it is an effective tool for detecting different abnormalities at pixel-level from different modalities of retinal images, without the need to tune parameters. Results:To evaluate its effectiveness, we have applied our method to seven public datasets of diabetic and malarial retinopathy with four different types of lesions: exudate, hemorrhage, microaneurysms, and leakage. The evaluation was undertaken at pixel-level, lesion-level, or image-level according to ground truth availability in these datasets. Conclusions:The experimental results show that the proposed method outperforms existing state-of-the-art ones in applicability, effectiveness, and accuracy
Efficient Pyramid Channel Attention Network for Pathological Myopia Detection
Pathological myopia (PM) is the leading ocular disease for impaired vision
and blindness worldwide. The key to detecting PM as early as possible is to
detect informative features in global and local lesion regions, such as fundus
tessellation, atrophy and maculopathy. However, applying classical
convolutional neural networks (CNNs) to efficiently highlight global and local
lesion context information in feature maps is quite challenging. To tackle this
issue, we aim to fully leverage the potential of global and local lesion
information with attention module design. Based on this, we propose an
efficient pyramid channel attention (EPCA) module, which dynamically explores
the relative importance of global and local lesion context information in
feature maps. Then we combine the EPCA module with the backbone network to
construct EPCA-Net for automatic PM detection based on fundus images. In
addition, we construct a PM dataset termed PM-fundus by collecting fundus
images of PM from publicly available datasets (e.g., the PALM dataset and ODIR
dataset). The comprehensive experiments are conducted on three datasets,
demonstrating that our EPCA-Net outperforms state-of-the-art methods in
detecting PM. Furthermore, motivated by the recent pretraining-and-finetuning
paradigm, we attempt to adapt pre-trained natural image models for PM detection
by freezing them and treating the EPCA module and other attention modules as
the adapters. The results show that our method with the
pretraining-and-finetuning paradigm achieves competitive performance through
comparisons to part of methods with traditional fine-tuning methods with fewer
tunable parameters.Comment: 12 page
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