Bio-Medical Materials and Engineering - Volume 24, issue 6

Authors: Geng, Chen | Yang, Jian | Dai, Yakang | Liu, Zhaobang | Dong, Yuefang

Article Type: Research Article

Abstract: Computed tomography angiography (CTA) is a major noninvasive technology for imaging coronary artery disease, and effective and accurate vessel tracking method can help radiologists diagnose the disease more accurately. In this paper, a novel 3D vessel tracking method based on CTA data is presented. The method is comprised of preprocessing, a novel spherical operator, and hierarchical clustering, where the spherical operator consists of rays that are casted different directions in a spherical coordinate system. The vascular boundary is extracted by the spherical operator, and the tracking direction is also obtained by the hierarchical clustering. The method is evaluated with the …Rotterdam Coronary Artery Algorithm Evaluation Framework. Results indicate that our method outperforms current state-of-the-art methods in terms of the overlap ratio on the vessel tracking of coronary arteries in CTA data. Show more

Keywords: 3D vessel tracking, spherical operator, hierarchical clustering

DOI: 10.3233/BME-141147

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3251-3258, 2014

Authors: Zhang, Zulin | Yi, Xinzhong | Peng, Hong

Article Type: Research Article

Abstract: This paper proposes a tissue membrane system-based framework to deal with the optimal image fusion problem. A spatial domain fusion algorithm is given, and a tissue membrane system of multiple cells is used as its computing framework. Based on the multicellular structure and inherent communication mechanism of the tissue membrane system, an improved velocity-position model is developed. The performance of the fusion framework is studied with comparison of several traditional fusion methods as well as genetic algorithm (GA)-based and differential evolution (DE)-based spatial domain fusion methods. Experimental results show that the proposed fusion framework is superior or comparable to the …other methods and can be efficiently used for image fusion. Show more

Keywords: Membrane computing, membrane systems, tissue membrane systems, image fusion

DOI: 10.3233/BME-141148

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3259-3266, 2014

Authors: Yang, Jinzhu | Ma, Shuang | Sun, Qi | Tan, Wenjun | Xu, Mengjia | Chen, Nan | Zhao, Dazhe

Article Type: Research Article

Abstract: Traditional Hessian multiscale filter consider only the local geometric feature but not the global grayscale information. In medical image analysis, Hessian filter is usually used to enhance the blood vessels. However, it also produces some pseudo vascular structures or some isolate noise points, such as the nasal soft tissues that have the similar shape with the vessels in MRA data, which will increase the difficulty of cerebrovascular segmentation. To resolve this issue, an improved Hessian multiscale filter is proposed in this paper. An image grayscale factor is added to the vascular similarity function computed by Hessian matrix eigenvalue. This method …is experimented on brain MRA data and lung CTA data. Experimental results show that this method can enhance vascular structures, and simultaneously reduce the appearance of the pseudo vascular structures and the isolated noise points. Show more

Keywords: Hessian filter, multiscale enhancement, grayscale, CT image, MRA image

DOI: 10.3233/BME-141149

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3267-3275, 2014

Authors: Li, Hong | Liu, Kaihua | Sun, Hang | Bao, Nan | Wang, Xu | Tian, Shi | Qi, Shouliang | Kang, Yan

Article Type: Research Article

Abstract: Computed tomography (CT) radiation dose can be reduced significantly by region of interest (ROI) CT scan. Automatically positioning the heart in CT scout images is an essential step to realize the ROI CT scan of the heart. This paper proposed a fully automatic heart positioning method in CT scout image, including the anteroposterior (A-P) scout image and lateral scout image. The key steps were to determine the feature points of the heart and obtaining part of the heart boundary on the A-P scout image, and then transform the part of the boundary into polar coordinate system and obtain the whole …boundary of the heart using slant elliptic equation curve fitting. For heart positioning on the lateral image, the top and bottom boundary obtained from A-P image can be inherited. The proposed method was tested on a clinical routine dataset of 30 cases (30 A-P scout images and 30 lateral scout images). Experimental results show that 26 cases of the dataset have achieved a very good positioning result of the heart both in the A-P scout image and the lateral scout image. The method may be helpful for ROI CT scan of the heart. Show more

Keywords: CT scout, heart positioning, ROI scan, automatic positioning method

DOI: 10.3233/BME-141150

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3277-3286, 2014

Authors: Nawaz, Shoukat | Fu, Jian | Fan, Dekai

Article Type: Research Article

Abstract: X-ray computed tomography (CT) is a powerful clinical diagnosis tool and has been used widely in many clinical and biological settings. Metal artifacts, caused by high density implants, are commonly encountered in clinical CT applications, thereby affecting the detection of abnormal structures and undermining CT's diagnostic value. In this paper, we developed a metal artifact reduction approach based on image segmentation and forward-projection. We further demonstrate the usefulness of our approach by using a biomedical specimen consisting of muscles, bones and metals. Our aim is to remove the inaccurate metal artifact pixels in the original CT slices and exactly reconstruct …the soft-tissue using the forward projections with no metal information. During the reconstruction, artifacts are reduced by replacing the metal projection using the forward projection. The presented work is of interest for CT biomedical applications. Show more

Keywords: Computed tomography, metal artifacts, image segmentation, forward-projection

DOI: 10.3233/BME-141151

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3287-3293, 2014

Authors: Lee, Gihyoun | Na, Sung Dae | Cho, Jin-Ho | Kim, Myoung Nam

Article Type: Research Article

Abstract: This paper presents a voice activity detection (VAD) approach using a perceptual wavelet entropy neighbor slope (PWENS) in a low signal-to-noise (SNR) environment and with a variety of noise types. The basis for our study is to use acoustic features that have large entropy variance for each wavelet critical band. The speech signal is decomposed by the proposed perceptual wavelet packet decomposition (PWPD), and the VAD function is extracted by PWENS. Finally, VAD is decided by the proposed VAD decision rule using two memory buffers. In order to evaluate the performance of the VAD decision, many speech samples and a …variety of SNR conditions were used in the experiment. The performance of the VAD decision is confirmed using objective indexes such as a graph of the VAD decision and the relative error rate. Show more

Keywords: Voice activity detection, wavelet transform, wavelet decomposition, neighbor slope, entropy

DOI: 10.3233/BME-141152

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3295-3301, 2014

Authors: Na, Sung Dae | Lee, Gihyoun | Lee, Jyung Hyun | Kim, Myoung Nam

Article Type: Research Article

Abstract: In this paper, a new method for individual tooth segmentation was proposed. The proposed method is composed of enhancement and extraction of boundary and seed of watershed algorithm using trisection areas by morphological characteristic of teeth. The watershed algorithm is one of the conventional methods for tooth segmentation; however, the method has some problems. First, molar region detection ratio is reduced because of oral structure features that is low intensities in molar region. Second, inaccurate segmentation occurs in incisor region owing to specular reflection. To solve the problems, the trisection method using morphological characteristic was proposed, where three tooth areas …are made using ratio of entire tooth to each tooth. Moreover, the enhancement is to improve the intensity of molar using the proposed method. In addition, boundary and seed of watershed are extracted using trisection areas applied other parameters each area. Finally, individual tooth segmentation was performed using extracted boundary and seed. Furthermore, the proposed method was compared with conventional methods to confirm its efficiency. As a result, the proposed method was demonstrated to have higher detection ratio, better over segmentation, and overlap segmentation than conventional methods. Show more

Keywords: Segmentation, tooth, watershed, oral scanner

DOI: 10.3233/BME-141153

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3303-3309, 2014

Authors: Birtane, Sibel | Korkmaz, Hayriye

Article Type: Research Article

Abstract: In this paper, 2-steps software using image processing and enhancement technologies is developed to obtain a scoliosis patient's spine pattern from 2D coronal X-Ray images without manual land marking. Then, a Rule-based Fuzzy classifier is implemented on those images to classify the spine patterns using the King-Moe classification approach.

Keywords: Image processing, scoliosis, king-moe type classification, fuzzy logic, computer aided classification, rule-based classification

DOI: 10.3233/BME-141154

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3311-3319, 2014

Authors: Liu, Xi | Liu, Lixiong

Article Type: Research Article

Abstract: We analyzed the principle of the traditional local binary fitting operation, Gaussian kernel function weighted summation (GKFWS), to develop a novel level set model in this paper. In this model, the traditional GKFWS operation is replaced with the median filter operation in the second procedure of local fitting of the energy domain. Furthermore, we incorporated the edge stopping function of GAC model into it to introduce the edge information for segmentation. Experiments on synthetic and real images demonstrate that this model has promising performance in terms of computational cost, robustness to noises and segmentation of images with intensity inhomogeneity.

Keywords: Active contour, median filter, image segmentation, level set, edge information

DOI: 10.3233/BME-141155

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3321-3332, 2014

Authors: Yin, Lim Khai | Rajeswari, Mandava

Article Type: Research Article

Abstract: To segment an image using the random walks algorithm; users are often required to initialize the approximate locations of the objects and background in the image. Due to its segmenting model that is mainly reflected by the relationship among the neighborhood pixels and its boundary conditions, random walks algorithm has made itself sensitive to the inputs of the seeds. Instead of considering the relationship between the neighborhood pixels solely, an attempt has been made to modify the weighting function that accounts for the intensity changes between the neighborhood nodes. Local affiliation within the defined neighborhood region of the two nodes …is taken into consideration by incorporating an extra penalty term into the weighting function. Besides that, to better segment images, particularly medical images with texture features, GLCM variance is incorporated into the weighting function through kernel density estimation (KDE). The probability density of each pixel belonging to the initialized seeds is estimated and integrated into the weighting function. To test the performance of the proposed weighting model, several medical images that mainly made up of 174-brain tumor images are experimented. These experiments establish that the proposed method produces better segmentation results than the original random walks. Show more

Keywords: Random walks, weighting function, gray-level co-occurrence, kernel density estimation

DOI: 10.3233/BME-141156

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 6, pp. 3333-3341, 2014