• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.60-79
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• 2022

The U-Net architecture-based segmentation models attained remarkable performance in numerous medical image segmentation missions like skin lesion segmentation. Nevertheless, the resolution gradually decreases and the loss of spatial information increases with deeper network. The fusion of adjacent layers is not enough to make up for the lost spatial information, thus resulting in errors of segmentation boundary so as to decline the accuracy of segmentation. To tackle the issue, we propose a new deep learning-based segmentation model. In the decoding stage, the feature channels of each decoding unit are concatenated with all the feature channels of the upper coding unit. Which is done in order to ensure the segmentation effect by integrating spatial and semantic information, and promotes the robustness and generalization of our model by combining the atrous spatial pyramid pooling (ASPP) module and channel attention module (CAM). Extensive experiments on ISIC2016 and ISIC2017 common datasets proved that our model implements well and outperforms compared segmentation models for skin lesion segmentation.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.436-442
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• 2017

A novel method of Skin lesion segmentation based on the combination of Texture and Neural Network is proposed in this paper. This paper combines the textures of different pixels in the skin images in order to increase the performance of lesion segmentation. For segmenting skin lesions, a two-step process is done. First, automatic border detection is performed to separate the lesion from the background skin. This begins by identifying the features that represent the lesion border clearly by the process of Texture analysis. In the second step, the obtained features are given as input towards the Recurrent Echo state neural networks in order to obtain the segmented skin lesion region. The proposed algorithm is trained and tested for 862 skin lesion images in order to evaluate the accuracy of segmentation. Overall accuracy of the proposed method is compared with existing algorithms. An average accuracy of 98.8% for segmenting skin lesion images has been obtained.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2826-2840
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• 2018

Traditional methods based active contours or region merging are powerless in processing images with blurring border or hair occlusion. In this paper, a structure based convolutional neural networks is proposed to solve segmentation of skin lesion image. The structure mainly consists of two networks which are segmentation net and discrimination net. The segmentation net is designed based U-net that used to generate the mask of lesion, while the discrimination net is designed with only convolutional layers that used to determine whether input image is from ground truth labels or generated images. Images were obtained from "Skin Lesion Analysis Toward Melanoma Detection" challenge which was hosted by ISBI 2016 conference. We achieved segmentation average accuracy of 0.97, dice coefficient of 0.94 and Jaccard index of 0.89 which outperform the other existed state-of-the-art segmentation networks, including winner of ISBI 2016 challenge for skin melanoma segmentation.

• 스마트미디어저널
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• 제13권3호
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• pp.53-61
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• 2024

본 논문은 기존 방법보다 우수한 성능을 달성하는 피부 병변 분할을 위한 새로운 M자 모양 인코더-디코더 아키텍처를 제안한다. 제안된 아키텍처는 왼쪽과 오른쪽 다리를 활용하여 다중 스케일 특징 추출을 가능하게 하고, 스킵 연결 내에서 어텐션 메커니즘을 통합하여 피부 병변 분할 성능을 더욱 향상시킨다. 입력 영상은 네 가지 다른 패치로 분할되어 입력되며 인코더-디코더 프레임워크 내에서 피부 병변 분할 성능의 향상된 처리를 가능하게 한다. 제안하는 방법에서 어텐션 메커니즘을 통해 입력 영상의 특징에 더 많은 초점을 맞추어 더욱 정교한 영상 분할 결과를 도출하는 것이다. 실험 결과는 제안된 방법의 효과를 강조하며, 기존 방법과 비교하여 우수한 정확도, 정밀도 및 Jaccard 지수를 보여준다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권3호
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• pp.678-700
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• 2023

Diagnosing breast diseases using ultrasound (US) images remains challenging because it is time-consuming and requires expert radiologist knowledge. As a result, the diagnostic performance is significantly biased. To assist radiologists in this process, computer-aided diagnosis (CAD) systems have been developed and used in practice. This type of system is used not only to assist radiologists in examining breast ultrasound images (BUS) but also to ensure the effectiveness of the diagnostic process. In this study, we propose a new approach for breast lesion localization and segmentation using a multi-scale pyramid of the ultrasound image of a breast organ and a convolutional semantic segmentation network. Unlike previous studies that used only a deep detection/segmentation neural network on a single breast ultrasound image, we propose to use multiple images generated from an input image at different scales for the localization and segmentation process. By combining the localization/segmentation results obtained from the input image at different scales, the system performance was enhanced compared with that of the previous studies. The experimental results with two public datasets confirmed the effectiveness of the proposed approach by producing superior localization/segmentation results compared with those obtained in previous studies.

• 대한의용생체공학회:의공학회지
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• 제20권2호
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• pp.149-154
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• 1999

자기공명영상은 다른 의료영상에 비해서 보다 정확한 해부학적인 진단 정보를 제공해 주므로 널리 이용되고 있다. 본 논문에서는 이차원 축단면 뇌 자기총명영상을 분할하는 자동화 알고리즘과 병별에 의해서 손상된 슬라이스를 검출하는 알고리즘을 제안하였다. 영상분활 과정은 두단계로 구성되어 있는데, 첫 단계에서는 이진화와 형태학적 연산을 이용하여 대뇌영역을 추출하고, 둘째 단계에서는 FCM(Fuzzy C-means)알고리즘을 이용하여 추출된 대뇌 내부의 각 조직을 분할하였다. FCM알고리즘은 분할하는 조직의 수가 증가할수록 급격하게 많은 실행시간을 요구하므로 제안하는 두단계 영상분할 과정을 통하여 실행시간을 향상시켰다. 병변 인식은 해부학적지식과 패턴매칭을 이용하였다.

• 한국정보통신학회논문지
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• 제26권4호
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• pp.533-540
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• 2022

전문의는 피부암을 조기에 발견하기 위해 피부경을 사용하여 진단하지만 다양한 형태로 인해 피부 병변을 판단하는 데 어려움이 있다. 최근 높은 성능을 보인 딥러닝을 이용한 피부 병변 분할 방법이 제안되었지만 피부와 피부 병변 경계가 명확하지 않아서 피부 병변을 분할하는 데 문제점이 있었다. 이러한 문제를 개선하기 위해 제안하는 방법은 효과적으로 피부 병변을 분할하기 위해 트랜스포머 블록을 구성하였으며, 네트워크의 각 계층마다 윤곽선 디코더를 구성하여 피부 병변을 자세히 분할하였다. 실험 결과, 제안하는 방법은 기존의 방법보다 Dice coefficient 기준 0.041 ~ 0.071, Jaccard Index 기준 0.067 ~ 0.112의 성능 향상을 보인다.

• 한국컴퓨터그래픽스학회논문지
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• 제30권1호
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• pp.11-17
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• 2024

폐암은 크기가 다양하고 유사한 밝기값을 갖는 주변 구조물이 존재하기 때문에 흉부 CT 영상에서 폐암을 정확하게 분할하는 것이 어렵다. 이러한 문제를 해결하기 위해 본 논문에서는 심층 감독을 포함하고 UNet3+를 백본으로 사용하는 폐암 분할 네트워크를 제안한다. 또한, 픽셀 기반, 영역 기반 및 형태 기반의 3가지 구성 요소로 이루어진 하이브리드 병변 초점 손실함수를 제안한다. 이를 통해 배경에 비해 작은 영역을 차지하는 폐암 부분에 집중하고, 불명확한 경계를 처리하는데 도움이 되는 형태 정보를 고려할 수 있다. 제안 방법을 UNet 및 UNet3+와 비교 실험을 통해 검증하였고, 제안 방법은 모든 폐암 크기에서 DSC 측면에서 가장 우수한 성능을 보였다.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.24-34
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• 2019

In this research, a practical deep learning framework to differentiate the lesions and nodules in breast acquired with ultrasound imaging has been proposed. 7408 ultrasound breast images of 5151 patient cases were collected. All cases were biopsy proven and lesions were semi-automatically segmented. To compensate for the shift caused in the segmentation, the boundaries of each lesion were drawn using Fully Convolutional Networks(FCN) segmentation method based on the radiologist's specified point. The data set consists of 4254 benign and 3154 malignant lesions. In 7408 ultrasound breast images, the number of training images is 6579, and the number of test images is 829. The margin between the boundary of each lesion and the boundary of the image itself varied for training image augmentation. The training images were augmented by varying the margin between the boundary of each lesion and the boundary of the image itself. The images were processed through histogram equalization, image cropping, and margin augmentation. The networks trained on the data with augmentation and the data without augmentation all had AUC over 0.95. The network exhibited about 90% accuracy, 0.86 sensitivity and 0.95 specificity. Although the proposed framework still requires to point to the location of the target ROI with the help of radiologists, the result of the suggested framework showed promising results. It supports human radiologist to give successful performance and helps to create a fluent diagnostic workflow that meets the fundamental purpose of CADx.

• 한국멀티미디어학회논문지
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• 제24권8호
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• pp.979-987
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• 2021

Multiple Sclerosis (MS) can be early diagnosed by detecting lesions in brain magnetic resonance images (MRI). Unsupervised anomaly detection methods based on autoencoder have been recently proposed for automated detection of MS lesions. However, these autoencoder-based methods were developed only for 2D images (e.g. 2D cross-sectional slices) of MRI, so do not utilize the full 3D information of MRI. In this paper, therefore, we propose a novel 3D autoencoder-based framework for detection of the lesion volume of MS in MRI. We first define a 3D convolutional neural network (CNN) for full MRI volumes, and build each encoder and decoder layer of the 3D autoencoder based on 3D CNN. We also add a skip connection between the encoder and decoder layer for effective data reconstruction. In the experimental results, we compare the 3D autoencoder-based method with the 2D autoencoder models using the training datasets of 80 healthy subjects from the Human Connectome Project (HCP) and the testing datasets of 25 MS patients from the Longitudinal multiple sclerosis lesion segmentation challenge, and show that the proposed method achieves superior performance in prediction of MS lesion by up to 15%.