Ultrasonic Imaging最新文献

{"title":"Nonlinear Harmonic Distortion of Complementary Golay Codes.","authors":"Fraser Hamilton,&nbsp;Peter Hoskins,&nbsp;George Corner,&nbsp;Zhihong Huang","doi":"10.1177/01617346221147820","DOIUrl":"https://doi.org/10.1177/01617346221147820","url":null,"abstract":"<p><p>Recent advances in electronics miniaturization have led to the development of low-power, low-cost, point-of-care ultrasound scanners. Low-cost systems employing simple bi-level pulse generation devices need only utilize binary phase modulated coded excitations to significantly improve sensitivity; however the performance of complementary codes in the presence of nonlinear harmonic distortion has not been thoroughly investigated. Through simulation, it was found that nonlinear propagation media with little attenuative properties can significantly deteriorate the Peak Sidelobe Level (PSL) performance of complementary Golay coded pulse compression, resulting in PSL levels of -62 dB using nonlinear acoustics theory contrasted with -198 dB in the linear case. Simulations of 96 complementary pairs revealed that some pairs are more robust to sidelobe degradation from nonlinear harmonic distortion than others, up to a maximum PSL difference of 17 dB between the best and worst performing codes. It is recommended that users consider the effects of nonlinear harmonic distortion when implementing binary phase modulated complementary Golay coded excitations.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"45 1","pages":"22-29"},"PeriodicalIF":2.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9893299/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10644752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"B-line Elastography Measurement of Lung Parenchymal Elasticity.","authors":"Ren Koda,&nbsp;Hayato Taniguchi,&nbsp;Kei Konno,&nbsp;Yoshiki Yamakoshi","doi":"10.1177/01617346221149141","DOIUrl":"https://doi.org/10.1177/01617346221149141","url":null,"abstract":"<p><p>This paper proposes a method to determine the elasticity of the lung parenchyma from the B-line Doppler signal observed using continuous shear wave elastography, which uses a small vibrator placed on the tissue surface to propagate continuous shear waves with a vibration frequency of approximately 100 Hz. Since the B-line is generated by multiple reflections in fluid-storing alveoli near the lung surface, the ultrasonic multiple-reflection signal from the B-line is affected by the Doppler shift due to shear waves propagating in the lung parenchyma. When multiple B-lines are observed, the propagation velocity can be estimated by measuring the difference in propagation time between the B-lines. Therefore, continuous shear wave elastography can be used to determine the elasticity of the lung parenchyma by measuring the phase difference of shear wave between the B-lines. In this study, three elastic sponges (soft, medium, and hard) with embedded glass beads were used to simulate fluid-storing alveoli. Shear wave velocity measured using the proposed method was compared with that calculated using Young's modulus obtained from compression measurement. Using the proposed method, the measured shear wave velocities (mean ± S.D.) were 3.78 ± 0.23, 4.24 ± 0.12, and 5.06 ± 0.05 m/s for soft, medium, and hard sponges, respectively, which deviated by a maximum of 5.37% from the values calculated using the measured Young's moduli. The shear wave velocities of the sponge phantom were in a velocity range similar to the mean shear wave velocities of healthy and diseased lungs reported by magnetic resonance elastography (3.25 and 4.54 m/s, respectively). B-line elastography may enable emergency diagnoses of acute lung disease using portable ultrasonic echo devices.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"45 1","pages":"30-41"},"PeriodicalIF":2.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9188483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving Image Quality by Deconvolution Recovery Filter in Ultrasound Imaging.","authors":"Jingwen Pan,&nbsp;Hu Peng,&nbsp;Zhihui Han,&nbsp;Dan Hu,&nbsp;Yadan Wang,&nbsp;Yuanguo Wang","doi":"10.1177/01617346221141634","DOIUrl":"https://doi.org/10.1177/01617346221141634","url":null,"abstract":"<p><p>Due to the advantages of non-radiation and real-time performance, ultrasound imaging is essential in medical imaging. Image quality is affected by the performance of the transducer in an ultrasound imaging system. For example, the bandwidth controls the pulse length, resulting in different axial resolutions. Therefore, a transducer with a large bandwidth helps to improve imaging quality. However, large bandwidths lead to increased system cost and sometimes a loss of sensitivity and lateral resolution in attenuating media. In this paper, a deconvolution recovery method combined with a frequency-domain filtering technique (DRF) is proposed to improve the imaging quality, especially for the axial resolution. In this method, the received low-bandwidth echo signals are converted into high-bandwidth signals, which is similar to the echo signals produced by a high-bandwidth transducer, and the imaging quality is improved. Simulation and experiment results show that, compared with Delay-and-sum (DAS) method, the DRF method improved axial resolution from 0.60 to 0.41 mm in simulation and from 0.62 to 0.47 mm in the tissue-mimicking phantom experiment. The contrast ratio performance is improved to some extent compared with the DAS in experimental and in-vivo images. Besides, the proposed method has the potential to further improve image quality by combining it with adaptive weightings, such as the minimum variance method.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"45 1","pages":"3-16"},"PeriodicalIF":2.3,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9200705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Deep Learning-based Method to Extract Lumen and Media-Adventitia in Intravascular Ultrasound Images.","authors":"Fubao Zhu,&nbsp;Zhengyuan Gao,&nbsp;Chen Zhao,&nbsp;Hanlei Zhu,&nbsp;Jiaofen Nan,&nbsp;Yanhui Tian,&nbsp;Yong Dong,&nbsp;Jingfeng Jiang,&nbsp;Xiaohong Feng,&nbsp;Neng Dai,&nbsp;Weihua Zhou","doi":"10.1177/01617346221114137","DOIUrl":"https://doi.org/10.1177/01617346221114137","url":null,"abstract":"<p><p>Intravascular ultrasound (IVUS) imaging allows direct visualization of the coronary vessel wall and is suitable for assessing atherosclerosis and the degree of stenosis. Accurate segmentation and lumen and median-adventitia (MA) measurements from IVUS are essential for such a successful clinical evaluation. However, current automated segmentation by commercial software relies on manual corrections, which is time-consuming and user-dependent. We aim to develop a deep learning-based method using an encoder-decoder deep architecture to automatically and accurately extract both lumen and MA border. Inspired by the dual-path design of the state-of-the-art model IVUS-Net, our method named IVUS-U-Net++ achieved an extension of the U-Net++ model. More specifically, a feature pyramid network was added to the U-Net++ model, enabling the utilization of feature maps at different scales. Following the segmentation, the Pearson correlation and Bland-Altman analyses were performed to evaluate the correlations of 12 clinical parameters measured from our segmentation results and the ground truth. A dataset with 1746 IVUS images from 18 patients was used for training and testing. Our segmentation model at the patient level achieved a Jaccard measure (JM) of 0.9080 ± 0.0321 and a Hausdorff distance (HD) of 0.1484 ± 0.1584 mm for the lumen border; it achieved a JM of 0.9199 ± 0.0370 and an HD of 0.1781 ± 0.1906 mm for the MA border. The 12 clinical parameters measured from our segmentation results agreed well with those from the ground truth (all <i>p</i>-values are smaller than .01). Our proposed method shows great promise for its clinical use in IVUS segmentation.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":" ","pages":"191-203"},"PeriodicalIF":2.3,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40634308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liver Fibrosis Assessment Using Radiomics of Ultrasound Homodyned-K imaging Based on the Artificial Neural Network Estimator.","authors":"Zhuhuang Zhou,&nbsp;Zijing Zhang,&nbsp;Anna Gao,&nbsp;Dar-In Tai,&nbsp;Shuicai Wu,&nbsp;Po-Hsiang Tsui","doi":"10.1177/01617346221120070","DOIUrl":"https://doi.org/10.1177/01617346221120070","url":null,"abstract":"<p><p>The homodyned-K distribution is an important ultrasound backscatter envelope statistics model of physical meaning, and the parametric imaging of the model parameters has been explored for quantitative ultrasound tissue characterization. In this paper, we proposed a new method for liver fibrosis characterization by using radiomics of ultrasound backscatter homodyned-K imaging based on an improved artificial neural network (iANN) estimator. The iANN estimator was used to estimate the ultrasound homodyned-K distribution parameters <i>k</i> and <i>α</i> from the backscattered radiofrequency (RF) signals of clinical liver fibrosis (<i>n</i> = 237), collected with a 3-MHz convex array transducer. The RF data were divided into two groups: Group I corresponded to liver fibrosis with no hepatic steatosis (<i>n</i> = 94), and Group II corresponded to liver fibrosis with mild to severe hepatic steatosis (<i>n</i> = 143). The estimated homodyned-K parameter values were then used to construct <i>k</i> and <i>α</i> parametric images using the sliding window technique. Radiomics features of <i>k</i> and <i>α</i> parametric images were extracted, and feature selection was conducted. Logistic regression classification models based on the selected radiomics features were built for staging liver fibrosis. Experimental results showed that the proposed method is overall superior to the radiomics method of uncompressed envelope images when assessing liver fibrosis. Regardless of hepatic steatosis, the proposed method achieved the best performance in staging liver fibrosis ≥<i>F1</i>, ≥<i>F4</i>, and the area under the receiver operating characteristic curve was 0.88, 0.85 (Group I), and 0.85, 0.86 (Group II), respectively. Radiomics has improved the ability of ultrasound backscatter statistical parametric imaging to assess liver fibrosis, and is expected to become a new quantitative ultrasound method for liver fibrosis characterization.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"44 5-6","pages":"229-241"},"PeriodicalIF":2.3,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33438466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized Reconstruction Procedure of Photoacoustic Imaging for Reflection Artifacts Reduction.","authors":"Yuexin Qi,&nbsp;Hui Cao,&nbsp;Guanjun Yin,&nbsp;Beilei Zhang,&nbsp;Jianzhong Guo","doi":"10.1177/01617346221116781","DOIUrl":"https://doi.org/10.1177/01617346221116781","url":null,"abstract":"<p><p>Photoacoustic (PA) imaging technology is of some value in medical diagnoses such as breast cancer detection, vasculature imaging, and surgery navigating. While as most imaging objects are bounded, the received RF signals consist of the direct-arrived signals (DAS) from the PA sources and the boundary-reflected signals (BRS). The undesired BRS will severely impair the quality during the image reconstruction. They will bring in many artifacts and confuse the actual shape and location of the PA sources. We improved the reconstruction procedure by removing the BRS before the regular reconstruction process to suppress those artifacts. To verify our proposed method, we compared the results of the conventional and optimized procedures experimentally. In terms of qualitative observation, the reconstructed images by the optimized procedure illustrate fewer artifacts and more accurate shapes of the PA sources. To quantitatively evaluate the traditional and the optimized imaging procedure, we calculated the Distribution Relative Error (DRE) between each experiment result and its standard drawing of the phantoms. For both phantoms and the ex-vivo sample, the DREs of reconstruction result by the optimized reconstruction procedure decrease significantly. The results suggest that the optimized reconstruction process can effectively suppress the reflection artifacts and improve the shape accuracy of the PA sources.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":" ","pages":"204-212"},"PeriodicalIF":2.3,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40617555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Review of Quantitative Ultrasound-Based Approaches to Thermometry and Ablation Zone Identification Over the Past Decade.","authors":"Sinan Li,&nbsp;Zhuhuang Zhou,&nbsp;Shuicai Wu,&nbsp;Weiwei Wu","doi":"10.1177/01617346221120069","DOIUrl":"https://doi.org/10.1177/01617346221120069","url":null,"abstract":"<p><p>Percutaneous thermal therapy is an important clinical treatment method for some solid tumors. It is critical to use effective image visualization techniques to monitor the therapy process in real time because precise control of the therapeutic zone directly affects the prognosis of tumor treatment. Ultrasound is used in thermal therapy monitoring because of its real-time, non-invasive, non-ionizing radiation, and low-cost characteristics. This paper presents a review of nine quantitative ultrasound-based methods for thermal therapy monitoring and their advances over the last decade since 2011. These methods were analyzed and compared with respect to two applications: ultrasonic thermometry and ablation zone identification. The advantages and limitations of these methods were compared and discussed, and future developments were suggested.</p>","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":" ","pages":"213-228"},"PeriodicalIF":2.3,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40630715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstracts for the 2022 Symposium on Ultrasonic Imaging and Tissue Characterization","authors":"Bret McCandless, Marie Muller","doi":"10.1177/01617346221107728","DOIUrl":"https://doi.org/10.1177/01617346221107728","url":null,"abstract":"The Field II ultrasound simulation developed by recently reached its 25-yearanniversary. In that time, its impact on the development of novel methods and systems for medical imaging is hard to overstate. This software has been made freely available to the ultrasound community as citation ware( &gt; 2700 as of 2022) and is frequently updated to support modern versions of Matlab. I will provide a brief retrospec-tive on Field II including describing its simulation methods, capabilities, and limitations to put its use into context among a growing number of other simulation approaches for modern ultrasound research. This talk will highlight our group’s use of Field II in several areas of research to demonstrate how we leverage its linear simulation approach for fundamental acoustic studies. I will discuss best practices for simulation including generation of additive noise. I will demonstrate the combination of pre-computed targets for use in training machine learning applications. I will explore the use of the multistatic data set in the efficient creation and evaluation of various imaging sequences, especially for synthetic aperture imaging. Work from others that has been used to complement the capabilities of Field II will also be briefly introduced(e.g. introducing additive acoustic clutter models, generating imaging targets from natural images for machine learning, the use of simulated acoustic fields as input for mechanical simulations). sound speed Ultrasonic backscatter is associated to cardiac collagen deposition, while anisotropy in ultrasonic backscatter is associated with myo fiber alignment. Preliminary data from our lab suggested anisotropy in backscatter may be primarily associated with collagen that aligns parallel to myofibers, not the myofibers themselves. The purpose of the present study was to determine a relationship between myocardial collagen and anisotropy of ultrasonic backscatter in left ventricular short axis images. Hearts were excised from Sprague Dawley rats, aligned in the short axis with the anterior wall closest to the transducer, and perfused with a colla-genase-containing solution for either 10 (n=7) or 30 minutes (n=7)or control solution for 30 minutes(control n=8). Serial ultrasound images were acquired throughout collagenase digestion and ultrasonic backscatter was assessed where the collagen is primarily aligned perpendicular to the angle of insonification(anterior and posterior walls), and where collagen is primarily aligned parallel to the angle of insonification (lateral and septal walls). Our data suggested that collagenase digestion reduced backscatter anisotropy within the myocardium (p &lt; 0.001)with the lateral and septal walls (collagen parallel to ultrasound) showing the greatest change in backscatter intensity. Histology (Trichrome staining) and biochemistry (hydroxyproline assay) suggests that collagen remains present but is crosslinking is altered within 10 minutes(p &lt; 0.047). These data suggest the anis","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"2 1","pages":"162 - 186"},"PeriodicalIF":2.3,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77412606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Improved Parameter Estimator of the Homodyned K Distribution Based on the Maximum Likelihood Method for Ultrasound Tissue Characterization","authors":"Yang Liu, Yufeng Zhang, Bingbing He, Zhiyao Li, Xun Lang, Hong Liang, Jianhua Chen","doi":"10.1177/01617346221097867","DOIUrl":"https://doi.org/10.1177/01617346221097867","url":null,"abstract":"The homodyned K distribution (HK) can generally describe the ultrasound backscatter envelope statistics distribution with parameters that have specific physical meaning. However, creating robust and reliable HK parameter estimates remains a crucial concern. The maximum likelihood estimator (MLE) usually yields a small variance and bias in parameter estimation. Thus, two recent studies have attempted to use MLE for parameter estimation of HK distribution. However, some of the statements in these studies are not fully justified and they may hinder the application of parameter estimation of HK distribution based on MLE. In this study, we propose a new parameter estimator for the HK distribution based on the MLE (i.e., MLE1), which overcomes the disadvantages of conventional MLE of HK distribution. The MLE1 was compared with other estimators, such as XU estimator (an estimation method based on the first moment of the intensity and tow log-moments) and ANN estimator (an estimation method based on artificial neural networks). We showed that the estimations of parameters α and k are the best overall (in terms of the relative bias, normalized standard deviation, and relative root mean squared errors) using the proposed MLE1 compared with the others based on the simulated data when the sample size was N = 1000. Moreover, we assessed the usefulness of the proposed MLE1 when the number of scatterers per resolution cell was high (i.e., α up to 80) and when the sample size was small (i.e., N = 100), and we found a satisfactory result. Tests on simulated ultrasound images based on Field II were performed and the results confirmed that the proposed MLE1 is feasible and reliable for the parameter estimation from the ultrasonic envelope signal. Therefore, the proposed MLE1 can accurately estimate the HK parameters with lower uncertainty, which presents a potential practical value for further ultrasonic applications.","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"17 1","pages":"142 - 160"},"PeriodicalIF":2.3,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87784238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Speckle Reduction in Ultrasound Images of the Common Carotid Artery Based on Integer and Fractional-Order Total Variation","authors":"Kun Wang, Zhiyao Li, Yufeng Zhang","doi":"10.1177/01617346221096840","DOIUrl":"https://doi.org/10.1177/01617346221096840","url":null,"abstract":"Designing a technique with higher speckle noise suppressing capability, better edge preserving performance, and lower time complexity is a research objective for the common carotid artery (CCA) ultrasound despeckling. Total variation based techniques have been widely used in the image denoising and have good performance in preserving the edges in the images. However, the total variation based filters can produce the staircase artifacts. To address this issue, second-order total variation based techniques have been proposed for the image denoising. However, the previous study has been proved that the fractional differential model has better performance in reducing the speckles in ultrasound despeckling compared with the second-order model. Thus, to improve the performance of ultrasound despeckling and edge preserving, a novel despeckling model based on integer and fractional-order total variation (IFOTV) is proposed for CCA ultrasound images. Moreover, the minimization problems in our despeckling model are solved by the alternating direction method of multiplier (ADMM). In results with synthetic images, the edge preservation index (EPI) values of proposed method are 0.9524, 0.8797, and 0.7351 as well as 0.9137, 0.8253, and 0.6847 under three different levels of noise, which are the highest among four advanced methods. In results with simulated CCA ultrasound images, the speckle suppression and mean preservation indices of proposed method are 0.5596, 0.6571, and 0.8106 under three different levels of noise, which are the best among four advanced methods. In results with clinical images, the average absolute error of intima-media thickness measurements of proposed method is 0.0660 ± 0.0679 (mean ± std in mm), which is the lowest among four advanced methods. In conclusion, the IFOTV method has improved performance in suppressing the speckle noise and preserving the edge, and is thus a potential alternative to the current filters for the CCA ultrasound despeckling.","PeriodicalId":49401,"journal":{"name":"Ultrasonic Imaging","volume":"1 1","pages":"123 - 141"},"PeriodicalIF":2.3,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83166230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}