SPIE Medical Imaging最新文献_第6页

Blood flow velocity in the popliteal vein using transverse oscillation ultrasound 横振荡超声测定腘静脉血流速度

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2216725

Thor Bechsgaard, K. Hansen, A. Brandt, S. Holbek, L. Lönn, C. Strandberg, N. Bækgaard, M. B. Nielsen, J. Jensen

{"title":"Blood flow velocity in the popliteal vein using transverse oscillation ultrasound","authors":"Thor Bechsgaard, K. Hansen, A. Brandt, S. Holbek, L. Lönn, C. Strandberg, N. Bækgaard, M. B. Nielsen, J. Jensen","doi":"10.1117/12.2216725","DOIUrl":"https://doi.org/10.1117/12.2216725","url":null,"abstract":"Chronic venous disease is a common condition leading to varicose veins, leg edema, post-thrombotic syndrome and venous ulcerations. Ultrasound (US) is the main modality for examination of venous disease. Color Doppler and occasionally spectral Doppler US (SDUS) are used for evaluation of the venous flow. Peak velocities measured by SDUS are rarely used in a clinical setting for evaluating chronic venous disease due to inadequate reproducibility mainly caused by the angle dependency of the estimate. However, estimations of blood velocities are of importance in characterizing venous disease. Transverse Oscillation US (TOUS), a non-invasive angle independent method, has been implemented on a commercial scanner. TOUS's advantage compared to SDUS is a more elaborate visualization of complex flow. The aim of this study was to evaluate, whether TOUS perform equal to SDUS for recording velocities in the veins of the lower limbs. Four volunteers were recruited for the study. A standardized flow was provoked with a cuff compression-decompression system placed around the lower leg. The average peak velocity in the popliteal vein of the four volunteers was 151.5 cm/s for SDUS and 105.9 cm/s for TOUS (p <0.001). The average of the peak velocity standard deviations (SD) were 17.0 cm/s for SDUS and 13.1 cm/s for TOUS (p <0.005). The study indicates that TOUS estimates lower peak velocity with improved SD when compared to SDUS. TOUS may be a tool for evaluation of venous disease providing quantitative measures for the evaluation of venous blood flow.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116908293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Experimental characterization, comparison and image quality assessment of two ultrasound contrast agents: Optison and Definity 两种超声造影剂的实验表征、比较和图像质量评估:选择性和清晰度

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2217741

Amy C. Hughes, S. Day, C. Linte, K. Schwarz

{"title":"Experimental characterization, comparison and image quality assessment of two ultrasound contrast agents: Optison and Definity","authors":"Amy C. Hughes, S. Day, C. Linte, K. Schwarz","doi":"10.1117/12.2217741","DOIUrl":"https://doi.org/10.1117/12.2217741","url":null,"abstract":"Microbubble-based contrast agents are commonly used in ultrasound imaging to help differentiate the blood pool from the endocardial wall. It is essential to use an agent which produces high image intensity relative to the surrounding tissue, commonly referred to contrast effect. When exposed to ultrasound waves, microbubbles produce an intense backscatter signal in addition to the contrast produced by the fluctuating size of the microbubbles. However, over time, the microbubble concentration depletes, leading to reduced visual enhancement. The retention time associated with contrast effect varies according to the frequency and power level of the ultrasound wave, as well as the contrast agent used. The primary objective of this study was to investigate and identify the most appropriate image acquisition parameters that render optimal contrast effect for two intravenous contrast agents, Optison™ and Definity™. Several controlled in vitro experiments were conducted using an experimental apparatus that featured a perfused tissue-emulating phantom. A continuous flow of contrast agent was imaged using ultrasound at different frequencies and power levels, while a pulse wave Doppler device was used to monitor the concentration of the contrast agent solution. The contrast effect was determined based on the image intensity inside the flow pipe mimicking the blood-pool relative to the intensity of the surrounding phantom material mimicking cardiac tissue. To identify the combination of parameters that yielded optimal visualization for each contrast agent tested, the contrast effect was assessed at different microbubble concentrations and different ultrasound imaging frequencies and transmission power levels.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128079855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Volumetric synthetic aperture imaging with a piezoelectric 2D row-column probe 基于压电二维排柱探头的体积合成孔径成像

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2216074

H. Bouzari, Mathias Engholm, T. Christiansen, C. Beers, A. Lei, M. Stuart, S. Nikolov, E. Thomsen, J. Jensen

{"title":"Volumetric synthetic aperture imaging with a piezoelectric 2D row-column probe","authors":"H. Bouzari, Mathias Engholm, T. Christiansen, C. Beers, A. Lei, M. Stuart, S. Nikolov, E. Thomsen, J. Jensen","doi":"10.1117/12.2216074","DOIUrl":"https://doi.org/10.1117/12.2216074","url":null,"abstract":"The synthetic aperture (SA) technique can be used for achieving real-time volumetric ultrasound imaging using 2-D row-column addressed transducers. This paper investigates SA volumetric imaging performance of an in-house prototyped 3 MHz λ/2-pitch 62+62 element piezoelectric 2-D row-column addressed transducer array. Utilizing single element transmit events, a volume rate of 90 Hz down to 14 cm deep is achieved. Data are obtained using the experimental ultrasound scanner SARUS with a 70 MHz sampling frequency and beamformed using a delay-and-sum (DAS) approach. A signal-to-noise ratio of up to 32 dB is measured on the beamformed images of a tissue mimicking phantom with attenuation of 0.5 dB cm-1 MHz-1, from the surface of the probe to the penetration depth of 300λ. Measured lateral resolution as Full-Width-at-Half-Maximum (FWHM) is between 4λ and 10λ for 18% to 65% of the penetration depth from the surface of the probe. The averaged contrast is 13 dB for the same range. The imaging performance assessment results may represent a reference guide for possible applications of such an array in different medical fields.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124199117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Differential diagnosis of thyroid nodules with virtual touch tissue imaging of ARFI elastography ARFI弹性成像的虚拟触摸组织成像对甲状腺结节的鉴别诊断

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2216190

Tao Li, Pei Zhou, Mingyue Ding, Yongwei Mi, Yiyong Li, Ji Zhang

{"title":"Differential diagnosis of thyroid nodules with virtual touch tissue imaging of ARFI elastography","authors":"Tao Li, Pei Zhou, Mingyue Ding, Yongwei Mi, Yiyong Li, Ji Zhang","doi":"10.1117/12.2216190","DOIUrl":"https://doi.org/10.1117/12.2216190","url":null,"abstract":"The aim of this study was to evaluate the diagnostic performance of virtual touch tissue imaging (VTI) based on ARFI elastography technique for differentiating malignant from benign thyroid nodules. One hundred pathologically proven thyroid nodules (80 benign, 20 malignant) in 76 participants were recruited in this study. The likelihood of malignancy in the light of VTI features was scored into 6 levels by one experienced sonogist who was blinded to pathological results. In addition, the mean gray value within the thyroid nodule (mGVTN) derived from VTI image was calculated for quantitative analysis. Receiver-operating characteristic curve (ROC) analyses were performed to assess the diagnostic performance of VTI score and mGVTN. The frequency of malignant nodules (11/20) classified between VTI levels 4 to 6 was more than that of benign nodules (6/80) (p <0.001). The mGVTN of malignant nodules (45±23) was significantly lower than that of benign nodules (115±58) (p <0.001), where the range of mGVTN was from 0 to 255. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of VTI score were 55.0%, 92.5%, 85.0%, 64.7% and 89.2%, respectively. For mGVTN, those values were 70.0%, 90.0%, 86.0%, 63.6% and 92.3%, respectively. In conclusion, the VTI image seemed to be an effective tool in the differential diagnosis of thyroid nodules. The diagnosis performance of mGVTN was almost consistent with that of VTI score, which indicated that the mGVTN as a quantitative parameter might facilitate doctors diagnosing malignant thyroid nodules by VTI.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114356056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrasound breast imaging using frequency domain reverse time migration 超声乳房成像的频域逆时偏移

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2218366

O. Roy, M. Zuberi, R. Pratt, N. Duric

{"title":"Ultrasound breast imaging using frequency domain reverse time migration","authors":"O. Roy, M. Zuberi, R. Pratt, N. Duric","doi":"10.1117/12.2218366","DOIUrl":"https://doi.org/10.1117/12.2218366","url":null,"abstract":"Conventional ultrasonography reconstruction techniques, such as B-mode, are based on a simple wave propagation model derived from a high frequency approximation. Therefore, to minimize model mismatch, the central frequency of the input pulse is typically chosen between 3 and 15 megahertz. Despite the increase in theoretical resolution, operating at higher frequencies comes at the cost of lower signal-to-noise ratio. This ultimately degrades the image contrast and overall quality at higher imaging depths. To address this issue, we investigate a reflection imaging technique, known as reverse time migration, which uses a more accurate propagation model for reconstruction. We present preliminary simulation results as well as physical phantom image reconstructions obtained using data acquired with a breast imaging ultrasound tomography prototype. The original reconstructions are filtered to remove low-wavenumber artifacts that arise due to the inclusion of the direct arrivals. We demonstrate the advantage of using an accurate sound speed model in the reverse time migration process. We also explain how the increase in computational complexity can be mitigated using a frequency domain approach and a parallel computing platform.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121864799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage 定量头部超声测量以确定脑室内出血后需要介入治疗的早产儿的阈值

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2216870

J. Kishimoto, A. Fenster, F. Salehi, W. Romano, David S. C. Lee, S. de Ribaupierre

{"title":"Quantitative head ultrasound measurements to determine thresholds for preterm neonates requiring interventional therapies following intraventricular hemorrhage","authors":"J. Kishimoto, A. Fenster, F. Salehi, W. Romano, David S. C. Lee, S. de Ribaupierre","doi":"10.1117/12.2216870","DOIUrl":"https://doi.org/10.1117/12.2216870","url":null,"abstract":"Dilation of the cerebral ventricles is a common condition in preterm neonates with intraventricular hemorrhage (IVH). This post hemorrhagic ventricle dilation (PHVD) can lead to lifelong neurological impairment through ischemic injury due to increased intracranial pressure and without treatment, can lead to death. Clinically, 2D ultrasound (US) through the fontanelles ('soft spots') of the patients are serially acquired to monitor the progression of the ventricle dilation. These images are used to determine when interventional therapies such as needle aspiration of the built up cerebrospinal fluid (CSF) ('ventricle tap', VT) might be indicated for a patient; however, quantitative measurements of the growth of the ventricles are often not performed. There is no consensus on when a neonate with PHVD should have an intervention and often interventions are performed after the potential for brain damage is quite high. Previously we have developed and validated a 3D US system to monitor the progression of ventricle volumes (VV) in IVH patients. We will describe the potential utility of quantitative 2D and 3D US to monitor and manage PHVD in neonates. Specifically, we will look to determine image-based measurement thresholds for patients who will require VT in comparison to patients with PHVD who resolve without intervention. Additionally, since many patients who have an initial VT will require subsequent interventions, we look at the potential for US to determine which PHVD patients will require additional VT after the initial one has been performed.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122502327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Novel approaches to address spectral distortions in photon counting x-ray CT using artificial neural networks 利用人工神经网络解决光子计数x射线CT光谱畸变的新方法

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2217037

M. Touch, D. Clark, W. Barber, C. Badea

{"title":"Novel approaches to address spectral distortions in photon counting x-ray CT using artificial neural networks","authors":"M. Touch, D. Clark, W. Barber, C. Badea","doi":"10.1117/12.2217037","DOIUrl":"https://doi.org/10.1117/12.2217037","url":null,"abstract":"Spectral CT using a photon-counting x-ray detector (PCXD) can potentially increase accuracy of measuring tissue composition. However, PCXD spectral measurements suffer from distortion due to charge sharing, pulse pileup, and Kescape energy loss. This study proposes two novel artificial neural network (ANN)-based algorithms: one to model and compensate for the distortion, and another one to directly correct for the distortion. The ANN-based distortion model was obtained by training to learn the distortion from a set of projections with a calibration scan. The ANN distortion was then applied in the forward statistical model to compensate for distortion in the projection decomposition. ANN was also used to learn to correct distortions directly in projections. The resulting corrected projections were used for reconstructing the image, denoising via joint bilateral filtration, and decomposition into three-material basis functions: Compton scattering, the photoelectric effect, and iodine. The ANN-based distortion model proved to be more robust to noise and worked better compared to using an imperfect parametric distortion model. In the presence of noise, the mean relative errors in iodine concentration estimation were 11.82% (ANN distortion model) and 16.72% (parametric model). With distortion correction, the mean relative error in iodine concentration estimation was improved by 50% over direct decomposition from distorted data. With our joint bilateral filtration, the resulting material image quality and iodine detectability as defined by the contrast-to-noise ratio were greatly enhanced allowing iodine concentrations as low as 2 mg/ml to be detected. Future work will be dedicated to experimental evaluation of our ANN-based methods using 3D-printed phantoms.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"9 12","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131438230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris 基于股直肌超声图像特征的膝关节伸展强度估计系统的开发

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2214843

Hiroki Murakami, Tsuneo Watanabe, D. Fukuoka, N. Terabayashi, T. Hara, C. Muramatsu, H. Fujita

{"title":"Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris","authors":"Hiroki Murakami, Tsuneo Watanabe, D. Fukuoka, N. Terabayashi, T. Hara, C. Muramatsu, H. Fujita","doi":"10.1117/12.2214843","DOIUrl":"https://doi.org/10.1117/12.2214843","url":null,"abstract":"The word \"Locomotive syndrome\" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient’s height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.","PeriodicalId":228011,"journal":{"name":"SPIE Medical Imaging","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131598942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Iterative CT reconstruction using coordinate descent with ordered subsets of data 基于有序数据子集的坐标下降迭代CT重建

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2217558

F. Noo, K. Hahn, H. Schöndube, K. Stierstorfer

引用次数: 3

Direct reconstruction of enhanced signal in computed tomography perfusion 计算机断层扫描灌注增强信号的直接重建

SPIE Medical Imaging Pub Date : 2016-04-01 DOI: 10.1117/12.2216998

Bin Li, Qingwen Lyu, Jianhua Ma, Jing Wang

引用次数: 0