1.Oral panorama reconstruction method based on pre-segmentation and Bezier function.
Changpeng HOU ; Fudong ZHU ; Gaohua ZHANG ; Zhen LYU ; Yunfeng LIU ; Weidong ZHU
Journal of Biomedical Engineering 2023;40(5):894-902
For patients with partial jaw defects, cysts and dental implants, doctors need to take panoramic X-ray films or manually draw dental arch lines to generate Panorama images in order to observe their complete dentition information during oral diagnosis. In order to solve the problems of additional burden for patients to take panoramic X-ray films and time-consuming issue for doctors to manually segment dental arch lines, this paper proposes an automatic panorama reconstruction method based on cone beam computerized tomography (CBCT). The V-network (VNet) is used to pre-segment the teeth and the background to generate the corresponding binary image, and then the Bezier curve is used to define the best dental arch curve to generate the oral panorama. In addition, this research also addressed the issues of mistakenly recognizing the teeth and jaws as dental arches, incomplete coverage of the dental arch area by the generated dental arch lines, and low robustness, providing intelligent methods for dental diagnosis and improve the work efficiency of doctors.
Humans
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Radiography, Panoramic/methods*
;
Cone-Beam Computed Tomography/methods*
;
Head
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Image Processing, Computer-Assisted/methods*
2.Deep learning method for magnetic resonance imaging fluid-attenuated inversion recovery image synthesis.
Jianing ZHOU ; Hongyu GUO ; Hong CHEN
Journal of Biomedical Engineering 2023;40(5):903-911
Magnetic resonance imaging(MRI) can obtain multi-modal images with different contrast, which provides rich information for clinical diagnosis. However, some contrast images are not scanned or the quality of the acquired images cannot meet the diagnostic requirements due to the difficulty of patient's cooperation or the limitation of scanning conditions. Image synthesis techniques have become a method to compensate for such image deficiencies. In recent years, deep learning has been widely used in the field of MRI synthesis. In this paper, a synthesis network based on multi-modal fusion is proposed, which firstly uses a feature encoder to encode the features of multiple unimodal images separately, and then fuses the features of different modal images through a feature fusion module, and finally generates the target modal image. The similarity measure between the target image and the predicted image in the network is improved by introducing a dynamic weighted combined loss function based on the spatial domain and K-space domain. After experimental validation and quantitative comparison, the multi-modal fusion deep learning network proposed in this paper can effectively synthesize high-quality MRI fluid-attenuated inversion recovery (FLAIR) images. In summary, the method proposed in this paper can reduce MRI scanning time of the patient, as well as solve the clinical problem of missing FLAIR images or image quality that is difficult to meet diagnostic requirements.
Humans
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Deep Learning
;
Magnetic Resonance Imaging/methods*
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Image Processing, Computer-Assisted/methods*
3.Non-local attention and multi-task learning based lung segmentation in chest X-ray.
Liang XIONG ; Xiaolin QIN ; Xin LIU
Journal of Biomedical Engineering 2023;40(5):912-919
Precise segmentation of lung field is a crucial step in chest radiographic computer-aided diagnosis system. With the development of deep learning, fully convolutional network based models for lung field segmentation have achieved great effect but are poor at accurate identification of the boundary and preserving lung field consistency. To solve this problem, this paper proposed a lung segmentation algorithm based on non-local attention and multi-task learning. Firstly, an encoder-decoder convolutional network based on residual connection was used to extract multi-scale context and predict the boundary of lung. Secondly, a non-local attention mechanism to capture the long-range dependencies between pixels in the boundary regions and global context was proposed to enrich feature of inconsistent region. Thirdly, a multi-task learning to predict lung field based on the enriched feature was conducted. Finally, experiments to evaluate this algorithm were performed on JSRT and Montgomery dataset. The maximum improvement of Dice coefficient and accuracy were 1.99% and 2.27%, respectively, comparing with other representative algorithms. Results show that by enhancing the attention of boundary, this algorithm can improve the accuracy and reduce false segmentation.
X-Rays
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Algorithms
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Diagnosis, Computer-Assisted
;
Thorax/diagnostic imaging*
;
Lung/diagnostic imaging*
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Image Processing, Computer-Assisted
4.An attention-guided network for bilateral ventricular segmentation in pediatric echocardiography.
Jun PANG ; Yongxiong WANG ; Lijun CHEN ; Jiapeng ZHANG ; Jinlong LIU ; Gang PEI
Journal of Biomedical Engineering 2023;40(5):928-937
Accurate segmentation of pediatric echocardiograms is a challenging task, because significant heart-size changes with age and faster heart rate lead to more blurred boundaries on cardiac ultrasound images compared with adults. To address these problems, a dual decoder network model combining channel attention and scale attention is proposed in this paper. Firstly, an attention-guided decoder with deep supervision strategy is used to obtain attention maps for the ventricular regions. Then, the generated ventricular attention is fed back to multiple layers of the network through skip connections to adjust the feature weights generated by the encoder and highlight the left and right ventricular areas. Finally, a scale attention module and a channel attention module are utilized to enhance the edge features of the left and right ventricles. The experimental results demonstrate that the proposed method in this paper achieves an average Dice coefficient of 90.63% in acquired bilateral ventricular segmentation dataset, which is better than some conventional and state-of-the-art methods in the field of medical image segmentation. More importantly, the method has a more accurate effect in segmenting the edge of the ventricle. The results of this paper can provide a new solution for pediatric echocardiographic bilateral ventricular segmentation and subsequent auxiliary diagnosis of congenital heart disease.
Adult
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Humans
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Child
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Heart Ventricles/diagnostic imaging*
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Echocardiography
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Image Processing, Computer-Assisted
5.Review on ultrasonographic diagnosis of thyroid diseases based on deep learning.
Fengyuan QI ; Min QIU ; Guohui WEI
Journal of Biomedical Engineering 2023;40(5):1027-1032
In recent years, the incidence of thyroid diseases has increased significantly and ultrasound examination is the first choice for the diagnosis of thyroid diseases. At the same time, the level of medical image analysis based on deep learning has been rapidly improved. Ultrasonic image analysis has made a series of milestone breakthroughs, and deep learning algorithms have shown strong performance in the field of medical image segmentation and classification. This article first elaborates on the application of deep learning algorithms in thyroid ultrasound image segmentation, feature extraction, and classification differentiation. Secondly, it summarizes the algorithms for deep learning processing multimodal ultrasound images. Finally, it points out the problems in thyroid ultrasound image diagnosis at the current stage and looks forward to future development directions. This study can promote the application of deep learning in clinical ultrasound image diagnosis of thyroid, and provide reference for doctors to diagnose thyroid disease.
Humans
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Algorithms
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Deep Learning
;
Image Processing, Computer-Assisted/methods*
;
Thyroid Diseases/diagnostic imaging*
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Ultrasonography
6.MRI-derived radiomics models for diagnosis, aggressiveness, and prognosis evaluation in prostate cancer.
Xuehua ZHU ; Lizhi SHAO ; Zhenyu LIU ; Zenan LIU ; Jide HE ; Jiangang LIU ; Hao PING ; Jian LU
Journal of Zhejiang University. Science. B 2023;24(8):663-681
Prostate cancer (PCa) is a pernicious tumor with high heterogeneity, which creates a conundrum for making a precise diagnosis and choosing an optimal treatment approach. Multiparametric magnetic resonance imaging (mp-MRI) with anatomical and functional sequences has evolved as a routine and significant paradigm for the detection and characterization of PCa. Moreover, using radiomics to extract quantitative data has emerged as a promising field due to the rapid growth of artificial intelligence (AI) and image data processing. Radiomics acquires novel imaging biomarkers by extracting imaging signatures and establishes models for precise evaluation. Radiomics models provide a reliable and noninvasive alternative to aid in precision medicine, demonstrating advantages over traditional models based on clinicopathological parameters. The purpose of this review is to provide an overview of related studies of radiomics in PCa, specifically around the development and validation of radiomics models using MRI-derived image features. The current landscape of the literature, focusing mainly on PCa detection, aggressiveness, and prognosis evaluation, is reviewed and summarized. Rather than studies that exclusively focus on image biomarker identification and method optimization, models with high potential for universal clinical implementation are identified. Furthermore, we delve deeper into the critical concerns that can be addressed by different models and the obstacles that may arise in a clinical scenario. This review will encourage researchers to design models based on actual clinical needs, as well as assist urologists in gaining a better understanding of the promising results yielded by radiomics.
Male
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Humans
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Artificial Intelligence
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Magnetic Resonance Imaging/methods*
;
Prostatic Neoplasms/diagnostic imaging*
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Image Processing, Computer-Assisted/methods*
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Precision Medicine
;
Retrospective Studies
7.Application of U-Net network in automatic image segmentation of adenoid and airway of nasopharynx.
Lu WANG ; Zebin LUO ; Jianhui NI ; Yan LI ; Liqing CHEN ; Shuwen GUAN ; Nannan ZHANG ; Xin WANG ; Rong CAI ; Yi GAO ; Qingfeng ZHANG
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2023;37(8):632-641
Objective:To explore the effect of fully automatic image segmentation of adenoid and nasopharyngeal airway by deep learning model based on U-Net network. Methods:From March 2021 to March 2022, 240 children underwent cone beam computed tomography(CBCT) in the Department of Otolaryngology, Head and Neck Surgery, General Hospital of Shenzhen University. 52 of them were selected for manual labeling of nasopharynx airway and adenoid, and then were trained and verified by the deep learning model. After applying the model to the remaining data, compare the differences between conventional two-dimensional indicators and deep learning three-dimensional indicators in 240 datasets. Results:For the 52 cases of modeling and training data sets, there was no significant difference between the prediction results of deep learning and the manual labeling results of doctors(P>0.05). The model evaluation index of nasopharyngeal airway volume: Mean Intersection over Union(MIOU) s (86.32±0.54)%; Dice Similarity Coefficient(DSC): (92.91±0.23)%; Accuracy: (95.92±0.25)%; Precision: (91.93±0.14)%; and the model evaluation index of Adenoid volume: MIOU: (86.28±0.61)%; DSC: (92.88±0.17)%; Accuracy: (95.90±0.29)%; Precision: (92.30±0.23)%. There was a positive correlation between the two-dimensional index A/N and the three-dimensional index AV/(AV+NAV) in 240 children of different age groups(P<0.05), and the correlation coefficient of 9-13 years old was 0.74. Conclusion:The deep learning model based on U-Net network has a good effect on the automatic image segmentation of adenoid and nasopharynx airway, and has high application value. The model has a certain generalization ability.
Child
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Humans
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Adolescent
;
Adenoids/diagnostic imaging*
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Image Processing, Computer-Assisted/methods*
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Pharynx
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Cone-Beam Computed Tomography
;
Nose
8.Analysis on characteristic of stage Ⅰ occupational cement pneumoconiosis patients.
Yi Mu ZHENG ; Zan Mei ZHAO ; Yan Lin ZHANG ; Li GUAN ; Xiao Xu GUAN ; Xiao LI
Chinese Journal of Industrial Hygiene and Occupational Diseases 2023;41(2):132-135
Objective: To analyze the clinical and imaging characteristics of stage Ⅰ occupational cement pneumoconiosis patients. Methods: In October 2021, the data of patients with occupational cement pneumoconiosis diagnosed by the Third Hospital of Peking University from 2014 to 2020 were collected, and the data of the patients' initial exposure age, dust exposure duration, diagnosis age, incubation period, chest X-ray findings, lung function and other data were analyzed retrospectively. Spearman grade correlation was used for correlation analysis of grade count data. The influencing factors of lung function were analyzed by binary logistic regression. Results: A total of 107 patients were enrolled in the study. There were 80 male patients and 27 female patients. The inital exposure age was (26.2±7.7) years, the diagnosis age was (59.4±7.9) years, the dust exposure duration was (17.9±8.0) years, and the incubation period was (33.1±10.3) years. The initial dust exposure age and the dust exposure duration in female patients were less than those in men, and the incubation period was longer than that in men (P<0.05). The imaging analysis showed the small opacities as"pp"accounted for 54.2%. 82 patients (76.6%) had small opacities distributed in two lung areas. The lung areas distribution of small opacities in female patients was less than that in male patients (2.04±0.19 vs 2.41±0.69, P<0.001). There were 57 cases of normal pulmonary function, 41 cases of mild abnormality and 9 cases of moderate abnormality. The number of lung regions with small opacities on X-ray was the risk factor for abnormal lung function in cement pneumoconiosis patients (OR=2.491, 95%CI=1.197-5.183, P=0.015) . Conclusion: The patients with occupational cement pneumoconiosis had long dust exposure duration and incubation period, light imaging changes and pulmonary function damage. The abnormal lung function was related to the range of pulmonary involvement.
Humans
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Female
;
Male
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Adolescent
;
Young Adult
;
Adult
;
Middle Aged
;
Aged
;
Retrospective Studies
;
Pneumoconiosis
;
Dust
;
Hospitals
;
Image Processing, Computer-Assisted
9.Application of Novel Down-sampling Method in Retinal Vessel Segmentation.
Zhijin LYU ; Xuefang CHEN ; Xiaofang ZHAO ; Huazhu LIU
Chinese Journal of Medical Instrumentation 2023;47(1):38-42
Accurate segmentation of retinal blood vessels is of great significance for diagnosing, preventing and detecting eye diseases. In recent years, the U-Net network and its various variants have reached advanced level in the field of medical image segmentation. Most of these networks choose to use simple max pooling to down-sample the intermediate feature layer of the image, which is easy to lose part of the information, so this study proposes a simple and effective new down-sampling method Pixel Fusion-pooling (PF-pooling), which can well fuse the adjacent pixel information of the image. The down-sampling method proposed in this study is a lightweight general module that can be effectively integrated into various network architectures based on convolutional operations. The experimental results on the DRIVE and STARE datasets show that the F1-score index of the U-Net model using PF-pooling on the STARE dataset improved by 1.98%. The accuracy rate is increased by 0.2%, and the sensitivity is increased by 3.88%. And the generalization of the proposed module is verified by replacing different algorithm models. The results show that PF-pooling has achieved performance improvement in both Dense-UNet and Res-UNet models, and has good universality.
Algorithms
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Retinal Vessels
;
Image Processing, Computer-Assisted
10.Evaluation of PET Mainstream Scattering Correction Methods.
Zhipeng SUN ; Ming LI ; Jian MA ; Jinjin MA ; Guodong LIANG
Chinese Journal of Medical Instrumentation 2023;47(1):47-53
OBJECTIVE:
Current mainstream PET scattering correction methods are introduced and evaluated horizontally, and finally, the existing problems and development direction of scattering correction are discussed.
METHODS:
Based on NeuWise Pro PET/CT products of Neusoft Medical System Co. Ltd. , the simulation experiment is carried out to evaluate the influence of radionuclide distribution out of FOV (field of view) on the scattering estimation accuracy of each method.
RESULTS:
The scattering events produced by radionuclide out of FOV have an obvious impact on the spatial distribution of scattering, which should be considered in the model. The scattering estimation accuracy of Monte Carlo method is higher than single scatter simulation (SSS).
CONCLUSIONS
Clinically, if the activity of the adjacent parts out of the FOV is high, such as brain, liver, kidney and bladder, it is likely to lead to the deviation of scattering estimation. Considering the Monte Carlo scattering estimation of the distribution of radionuclide out of FOV, it's helpful to improve the accuracy of scattering distribution estimation.
Positron Emission Tomography Computed Tomography
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Scattering, Radiation
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Computer Simulation
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Brain
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Monte Carlo Method
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Phantoms, Imaging
;
Image Processing, Computer-Assisted

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