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Estimating mean trabecular bone spacing based on the combination of Hilbert transform and fundamental frequency estimation

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Science Foundation in China 2017年第3期25卷 57-71页

作者：李颖徐峰刘成成许凯亮他得安王威琪 Department of Electronic Engineering Fudan UniversityShanghai 200433China Institute of Acoustics Tongji UniversityShanghai 200092China Sorbonne Université UPMC Univ Paris 06INSERM UMR-S 1146CNRS UMR 7371Laboratoired'ImagerieBiomédicaleF-75006ParisFrance State Key Laboratory of ASIC and System Fudan UniversityShanghai 200433China Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention(MICCAI)of Shanghai Shanghai 200032China

Ultrasonic backscatter signals from cancellous bone are sensitive to the microstructure of trabecular bone,and thus enable the feasibility to extract microstructural information of trabecular *** mean trabecular bone spacing(MTBS)is an important parameter for characterizing bone *** paper proposes an MTBS estimation method based on the combination of Hilbert transform and fundamental frequency estimation(CHF). The CHF was verified with ultrasonic backscatter signals from simulations and in vitro measurements at a central frequency of *** CHF method was compared with the simplified inverse filter tracking(SIFT)method,Simons' Quadratic Transformation(QT)method,Singular Spectrum Analysis(SSA)method,and Spectral Autocorrelation(SAC)***-Carlo simulations were performed by varying the MTBS,signal-to-noise ratio(SNR),standard deviation of regular spacing(SDRS),amplitude ratio of diffuse scattering to regular scattering(Ad)and frequency dependent attenuation(nBUA).The simulation results showed that the CHF method had a better performance in MTBS estimation under almost all the examination conditions except for *** estimation percentage correct(EPC)was greater than 90% when the MTBS was in the range of 0.4to *** the in vitro measurements,the estimated EPC by the CHF method was91.25±7.81%(mean±standard deviation).A significant correlation was observed for the CHF-estimated MTBS and micro-computed tomography(μ-CT)-measured values(R^2=0.75,p<0.01).These results demonstrate that the CHF method is anti-interference for MTBS estimation and can be used to estimate trabecular bone spacing.

关键词： Ultrasonic backscatter Mean trabecular bone spacing estimation Hilbert transform and fundamental frequency estimation Cancellous bone microstructure

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Adaptive scaled Wiener postfilter beamformer for ultrasound imaging

Adaptive scaled Wiener postfilter beamformer for ultrasound ...

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URSI Asia-Pacific Radio Science Conference (URSI AP-RASC)

作者： Saeid Aliabadi Yuanyuan Wang Jinhua Yu Department of Electronic Engineering Fudan University Shanghai China The key laboratory of medical imaging computing and computer assisted intervention of shanghai Shanghai China

In ultrasound imaging Wiener postfilter and coherent factor (CF) concepts were combined with minimum variance (MV) and eigenspace-based MV (ESBMV) beamformers to future suppress sidelobes and to improve the imaging contrast and the spatial resolution. CF, which can be considered as a scaled Wiener postfilter with high noise power weighting, provides high imaging resolution. The high resolution, however, is achieved with the contrast as a sacrifice. On other hand, Wiener postfilter, provides better signal intensity restoration and imaging contrast than CF but with lower imaging resolution. To pursue the optimal imaging contrast of Wiener postfilter and the high resolution of CF at the same time, an adaptive scaled Wiener postfilter beamformer (ASC-Wiener) is proposed. In proposed method, the noise power weighting of Wiener postfilter is adjusted adaptively so that related to the output SNR inversely needless to estimate the input SNR. Simulation and real data experiment for target point imaging show the high performance of the proposed beamformer in terms of the imaging resolution and sidelobes suppression. Cyst phantom imaging also shows that the ASC-Wiener preserves the speckle intensity and improves the imaging contrast. The contrast ratio (CR) and the contrast-to-noise ratio (CNR) are improved by 6.2/0.35 dB over ESBMV-Wiener and by 20.7/0.65 over ESBMV-CF. These results solidly prove that the imaging contrast and the imaging resolution are improved significantly and simultaneously.

关键词： imaging Radar imaging Image resolution Signal resolution Meteorology Ultrasonic imaging

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Improvement of ultrasound contrast imaging with adaptive beamformer based on pulse inversion plane wave transmission

Improvement of ultrasound contrast imaging with adaptive bea...

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URSI Asia-Pacific Radio Science Conference (URSI AP-RASC)

作者： Yurong Huang Jinhua Yu Yuanyuan Wang Shuying Li Yi Chen Department of Electronic Engineering Fudan University Shanghai China The key laboratory of medical imaging computing and computer assisted intervention of shanghai Shanghai China

Study of ultrasound contrast imaging is of great importance in recent years thanks to its wide application in ultrasonic diagnosis. Plane wave imaging has been considered as a good method with high frame rate and low mechanical index. High frame rate can improve the temporal resolution of contrast imaging. Meanwhile, low mechanical index is essential to contrast imaging since high mechanical index in traditional B-mode imaging could break micro-bubbles easily. However, plane wave contrast imaging suffers from low signal-to-noise ratio (SNR) and contrast (CR) which leads to poor image quality. In this paper, adaptive beamformer and pulse inversion (PI) technique were combined to solve the shortcomings of the plane wave contrast imaging. For the adaptive beamformer, eigenspace based minimum variance (ESBMV) with coherence factor (ESBMVCF) was proposed. Experimental results show that ESBMVCF offers an enhancement of 1.1dB, 13dB and 0.8dB in CR, contrast-to-tissue ratio (CTR) and contrast-to-noise ratio (CNR) respectively compared with minimum variance and coherence factor (MVCF). Besides, PI offers 1.5dB, 15dB and 15dB enhancement in CR, CTR and CNR compared with traditional pulse-echo imaging.

关键词： Radar imaging Meteorology imaging Meteorological radar Image resolution Radar antennas

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Denoising of 3D magnetic resonance images with multi-channel residual learning of convolutional neural network

arXiv

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arXiv 2017年

作者： Jiang, Dongsheng Dou, Weiqiang Vosters, Luc Xu, Xiayu Sun, Yue Tan, Tao Digital Medical Research Center School of Basic Medical Science Fudan University Shanghai China Shanghai Key Laboratory of Medical Image Computing and Computer-Assisted Intervention Shanghai China Department of Radiology and Nuclear Medicine Radboud University Medical Center Nijmegen Netherlands Department of Electrical Engineering Eindhoven University of Technology Eindhoven Netherlands Xian Jiaotong University Xian710049 China Key Laboratory of Biomedical Information Engineering of Ministry of Education School of Life Science and Technology Xian Jiaotong Universty Xian710049 China Department of Biomedical Engineering Eindhoven University of Technology Eindhoven Netherlands ScreenPoint Medical Nijmegen Netherlands

The denoising of magnetic resonance (MR) images is a task of great importance for improving the acquired image quality. Many methods have been proposed in the literature to retrieve noise free images with good performances. Howerever, the state-of-the-art denoising methods, all needs a time-consuming optimization processes and their performance strongly depend on the estimated noise level parameter. Within this manuscript we propose the idea of denoising MRI Rician noise using a convolutional neural network. The advantage of the proposed methodology is that the learning based model can be directly used in the denosing process without optimization and even without the noise level parameter. Specifically, a ten convolutional layers neural network combined with residual learning and multi-channel strategy was proposed. Two training ways: training on a specific noise level and training on a general level were conducted to demonstrate the capability of our methods. Experimental results over synthetic and real 3D MR data demonstrate our proposed network can achieve superior performance compared with other methods in term of both of the peak signal to noise ratio and the global of structure similarity index. Without noise level parameter, our general noise-applicable model is also better than the other compared methods in two datasets. Furthermore, our training model show good general applicability. Copyright © 2017, The Authors. All rights reserved.

关键词： Magnetic resonance imaging

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An Ultrasonic Backscatter Instrument for Cancellous Bone Evaluation in Neonates

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Engineering 2015年第3期1卷 336-343页

作者： Chengcheng Liu Rong Zhang Ying Li Feng Xu Dean Ta Weiqi Wang Department of Electronic Engineering Fudan University Department of Neonatology Children’s Hospital of Fudan University Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention (MICCAI) of Shanghai

Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic （UBBD） instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non- ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates （268 males and 199 females） at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay （-/-1） and duration （7-2） of the backscatter signal of interest （SOl） were varied, and the apparent integrated backscatter （AIB）, frequency slope of apparent backscatter （FSAB）, zero frequency intercept of apparent backscatter （FIAB）, and spectral centroid shift （SCS） were calculated. The results showed that the SOl selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age （｜R｜ up to 0.45, P 〈 0.001） when -/-1 was short （〈 8 μS）, while negative correlations （｜R｜ up to 0.56, P 〈 0.001） were commonly observed for T1 〉 10 IJS. Moderate positive correlations （IRI up to 0.45, P 〈 0.001） were observed for FSAB and SCS with gestational age when 71 was long （〉 10 μs）. The 7-2 mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOl selection and neonatal cancellous bone assessment.

关键词： ultrasonic backscatter cancellous bone evaluation signal of interest （SOI） backscatter instrument neonatal bone status

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Histological grade and type classification of glioma using Magnetic Resonance imaging

Histological grade and type classification of glioma using M...

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International Congress on Image and Signal Processing, Biomedical Engineering and Informatics (CISP-BMEI)

作者： Yuan Gao Zhifeng Shi Yuanyuan Wang Jinhua Yu Liang Chen Yi Guo Qi Zhang Ying Mao Department of Electronic Engineering Fudan University Shanghai China Department of Neurosurgery Fudan University Shanghai China Key laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai Shanghai China School of Communication and Information Engineering Shanghai University Shanghai China

ISBN: (纸本)9781509037117

Glioma is one of the most common brain tumors with high mortality and its histological grading and typing is important both in therapeutic decision and prognosis evaluation. This paper aims at using the high-throughput image feature analysis method to estimate the histological grade and type of a patient by using Magnetic Resonance imaging (MRI) instead of histological examination. The proposed method consists of the initial label definition, the region-of-interest delineation, the self-adaptive feature extraction, the feature subset selection, and the multi-class voting classification. Hereinto, a novel feature extraction strategy is designed, which could avoid the MRI scan diversity so as to get the robust feature extraction result and make the proposed framework more stable and effective. This method was validated on a database of 124 patients with the grade II to IV of 78, 25, and 21, and with astrocytoma, oligodendroglioma, oligoastrocytoma of 86, 16, and 22, respectively. We show that by using the leave-one-out cross-validation, the multi-class classification accuracy and macro average could reach 88.71%, 0.8362 respectively for the grade classification, and 70.97%, 0.5692 respectively for the type classification. It can be concluded that the histological grade and subtype information could be estimated from the MRI image analysis.

关键词： Feature extraction Magnetic resonance imaging Tumors Support vector machines Optimization Hospitals Image segmentation

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Research of an electromagnetic tracking method based on two electrically-controlled magnetic sources

Research of an electromagnetic tracking method based on two ...

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IEEE Advanced Information Technology, Electronic and Automation Control Conference, IAEAC 2015

作者： Sha, Min Wang, Yifeng Ding, Ning Fang, Zuxiang Wu, Xiaomei Department of Electronic Engineering Fudan University Shanghai China Shanghai Key Laboratory of Medical Image Computing and Computer Assisted Intervention Shanghai China

ISBN: (纸本)9781479919796

This paper presents an electromagnetic tracking method based on two electrically-controlled magnetic sources. Each source consists of three mutual orthogonal coils. The method can skillfully determine the rotation angles of the maximum magnetic flux density vector (MMFD V) generated by a magnetic source according to the Biot-Savart Law. Then the position of the sensor can be calculated with a noniterative geometrical algorithm in real time. Simulation results demonstrate a good performance of this method. © 2015 IEEE.

关键词： Finite element method

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Recognition of temporal lobe epilepsy based on high throughput analysis of MRI images

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Yi Qi Yi Biao Xue Bao/Chinese Journal of Scientific Instrument 2016年 37卷 78-82页

作者： Lian, Yuxi Yu, Jinhua Wang, Yuanyuan Shi, Zhifeng Chen, Liang Department of Electronic Engineering Fudan University Shanghai200433 China Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai Shanghai200032 China Department of Neurosurgery Huashan Hospital Fudan University Shanghai200400 China

Temporal lobe epilepsy is a usual kind of epileptic *** recognition of temporal lobe epilepsyfrom MRI (magnetic resonance imaging) images can avoid the harm of radiation generated by PET (position emission computed tomography). An algorithm is proposed to recognize the temporal lobe epilepsybased onhigh throughput analysis of MRI ***, the brain MRI images are registered to the standardbrain atlas with SPM12 platform and the hippocampusregion is extracted as the ROI (Region of Interest) according to the AAL (anatomical automatic labeling) atlas in the same coordinate *** high throughput analysis is conducted to extract 540 image features from the ROI region. Finally, the Bagging method is used to distinguish normal persons and *** for 20 normal persons and 10 patients withtemporal lobe epilepsy are made to validate the proposed algorithm. The results indicate that the algorithm can obtain good classification performance with 100% accuracy. Hence, the proposed algorithm based on high throughout analysis and the Bagging classification method can be adopted to recognize temporal lobe epilepsy effectively. © 2016, Science Press. All right reserved.

关键词： Magnetic resonance imaging

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Ultrasound harmonic imaging with reducing speckle noise by an interlaced iterative frequency compounding approach

Ultrasound harmonic imaging with reducing speckle noise by a...

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International Conference on Biomedical Engineering and Informatics (BMEI)

作者： Wei Guo Yuanyuan Wang Jinhua Yu Department of Electronic Engineering Key laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai Fudan University Shanghai China

Speckle noise is a phenomenon inherent in any coherent imaging system and decreases the signal-to-noise ratio (SNR), which brings down the imaging quality. Speckle noise reduction is particularly important in the tissue harmonic imaging (THI) since it has the lower energy and the poorer SNR than the fundamental imaging (FI). Speckle can be reduced by frequency compounding (FC), which means incoherently averaging the images with different speckle patterns acquired by changing the center frequency of the pulse. As for the THI, the difference in the emission spectrum doubles when using the FC. In this paper, we propose an interlaced iterative frequency compounding (IIFC) method with the pulse inversion (PI) technique. The new method brings a good speckle suppression performance while the high frame rate is retained. To illustrate the performance of our method, experiments have been conducted on the simulated data. A nonlinear simulation platform based on the full-wave model is used in the harmonic imaging simulation. Results show that our method brings the SNR an improvement of up to 22% in comparison with the single frame THI while maintaining a far better performance in both terms of resolution and contrast than the FI. We also demonstrate that our method for THI retains the high frame rate although using PI.

关键词： imaging Speckle Harmonic analysis Signal to noise ratio Image resolution Ultrasonic imaging Iterative methods

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Automatic tumor detection in automated 3-D breast ultrasound using local phase information

Automatic tumor detection in automated 3-D breast ultrasound...

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International Conference on Biomedical Engineering and Informatics (BMEI)

作者： Xin Wang Yi Guo Yuanyuan Wang Department of Electronic Engineering Key laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai Fudan University Shanghai China

Tumor localization in automated whole breast ultrasound (ABUS) images is an important and challenging task in a computer-aided detection (CAD) system. In this study, a completely automatic tumor detection method using the local phase information was proposed to accurately locate the tumor in ABUS images, thus accelerate the segmenting process. The phase in the max-energy orientation (PMO) image of the preprocessed ABUS image was acquired and binarized as well as the preprocessed image and the composed image obtained from the sum of the preprocessed image and the PMO image. Then morphologic postprocessing was performed to remove non-tumor regions and a region selection algorithm was used to get the tumor region from these three binary 3-D images and generate the volume of interests (VOI). The performance of the method was evaluated using a dataset of 40 cases and the sensitivity achieved 75% and 100% with false positives per volume of 0.25 and 2, respectively. Besides, the average precision rate and average recall rate of the detected VOI were 92.4% and 20.1%. The results proved that the proposed method could deal with various breast tumors and accurately locate the tumor.

关键词： Breast Lesions Gabor filters Three-dimensional displays Ultrasonic imaging Design automation

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