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High-resolution synthetic aperture ultrasound imaging with minimum variance beamforming and spiking deconvolution 具有最小方差波束形成和尖峰反卷积的高分辨率合成孔径超声成像
Pub Date : 2016-04-01 DOI: 10.1117/12.2217212
Junseob Shin, Lianjie Huang
Minimum variance beamforming (MVBF) is an adaptive beamforming technique, which aims to improve the lateral resolution by computing and applying signal-dependent apodization rather than predetermined apodization as typically done in conventional delay-and-sum (DAS) beamforming. Although studies have shown that the improvement in lateral resolution associated with MVBF is significant, the axial resolution remains unaffected. In this work, we combine MVBF and spiking deconvolution to improve both lateral and axial resolutions in synthetic aperture ultrasound imaging. We implement our new method and evaluate its performance using experimental datasets from a tissue-mimicking phantom. Our results show that our new method yields improved axial and lateral resolutions as well as image contrast.
最小方差波束形成(MVBF)是一种自适应波束形成技术,其目的是通过计算和应用信号相关的波束化来提高横向分辨率,而不是像传统的延迟和波束形成(DAS)那样进行预定波束化。虽然研究表明,MVBF对侧向分辨率的改善是显著的,但轴向分辨率不受影响。在这项工作中,我们结合MVBF和尖峰反卷积来提高合成孔径超声成像的横向和轴向分辨率。我们实现了我们的新方法,并使用来自组织模拟幻影的实验数据集评估其性能。我们的结果表明,我们的新方法提高了轴向和横向分辨率以及图像对比度。
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引用次数: 3
Optimization-based reconstruction for reduction of CBCT artifact in IGRT 基于优化重建的IGRT中CBCT伪影减少方法
Pub Date : 2016-04-01 DOI: 10.1117/12.2217234
D. Xia, Zheng Zhang, P. Paysan, D. Seghers, M. Brehm, P. Munro, E. Sidky, C. Pelizzari, Xiaochuan Pan
Kilo-voltage cone-beam computed tomography (CBCT) plays an important role in image guided radiation therapy (IGRT) by providing 3D spatial information of tumor potentially useful for optimizing treatment planning. In current IGRT CBCT system, reconstructed images obtained with analytic algorithms, such as FDK algorithm and its variants, may contain artifacts. In an attempt to compensate for the artifacts, we investigate optimization-based reconstruction algorithms such as the ASD-POCS algorithm for potentially reducing arti- facts in IGRT CBCT images. In this study, using data acquired with a physical phantom and a patient subject, we demonstrate that the ASD-POCS reconstruction can significantly reduce artifacts observed in clinical re- constructions. Moreover, patient images reconstructed by use of the ASD-POCS algorithm indicate a contrast level of soft-tissue improved over that of the clinical reconstruction. We have also performed reconstructions from sparse-view data, and observe that, for current clinical imaging conditions, ASD-POCS reconstructions from data collected at one half of the current clinical projection views appear to show image quality, in terms of spatial and soft-tissue-contrast resolution, higher than that of the corresponding clinical reconstructions.
千电压锥束计算机断层扫描(CBCT)通过提供肿瘤的三维空间信息来优化治疗方案,在图像引导放射治疗(IGRT)中发挥着重要作用。在当前的IGRT CBCT系统中,使用解析算法(如FDK算法及其变体)获得的重构图像可能存在伪影。为了补偿伪影,我们研究了基于优化的重建算法,如ASD-POCS算法,以潜在地减少IGRT CBCT图像中的伪影。在这项研究中,我们使用物理幻影和患者受试者获得的数据,我们证明了ASD-POCS重建可以显著减少临床重建中观察到的伪影。此外,使用ASD-POCS算法重建的患者图像表明,软组织的对比度水平优于临床重建。我们还从稀疏视图数据进行了重建,并观察到,在目前的临床成像条件下,从目前临床投影视图的一半收集的数据中重建的ASD-POCS在空间和软组织对比度分辨率方面似乎显示出比相应的临床重建更高的图像质量。
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引用次数: 0
Perfusion imaging with non-contrast ultrasound 非对比超声灌注成像
Pub Date : 2016-04-01 DOI: 10.1117/12.2216901
Jaime Tierney, D. Dumont, B. Byram
A Doppler ultrasound clutter filter that enables estimation of low velocity blood flow could considerably improve ultrasound as a tool for clinical diagnosis and monitoring, including for the evaluation of vascular diseases and tumor perfusion. Conventional Doppler ultrasound is currently used for visualizing and estimating blood flow. However, conventional Doppler is limited by frame rate and tissue clutter caused by involuntary movement of the patient or sonographer. Spectral broadening of the clutter due to tissue motion limits ultrasound’s ability to detect blood flow less than about 5mm/s at an 8MHz center frequency. We propose a clutter filtering technique that may increase the sensitivity of Doppler measurements to at least as low as 0.41mm/s. The proposed filter uses an adaptive demodulation scheme that decreases the bandwidth of the clutter. To test the performance of the adaptive demodulation method at removing sonographer hand motion, six volunteer subjects acquired data from a basic quality assurance phantom. Additionally, to test initial in vivo feasibility, an arterial occlusion reactive hyperemia study was performed to assess the efficiency of the proposed filter at preserving signals from blood velocities 2mm/s or greater. The hand motion study resulted in initial average bandwidths of 577Hz (28.5mm/s), which were decreased to 7.28Hz (0.36mm/s) at -60 dB at 3cm using our approach. The in vivo power Doppler study resulted in 15.2dB and 0.15dB dynamic ranges between the lowest and highest blood flow time points for the proposed filter and conventional 50Hz high pass filter, respectively.
能够估计低速血流的多普勒超声杂波滤波器可以大大提高超声作为临床诊断和监测工具的能力,包括血管疾病和肿瘤灌注的评估。传统的多普勒超声目前用于观察和估计血流。然而,传统的多普勒受帧率和由患者或超声医师不自主运动引起的组织杂波的限制。由于组织运动导致的杂波频谱展宽限制了超声在8MHz中心频率下检测血流小于5mm/s的能力。我们提出了一种杂波滤波技术,可以将多普勒测量的灵敏度提高到至少低至0.41mm/s。提出的滤波器采用自适应解调方案,降低杂波的带宽。为了测试自适应解调方法在去除超声仪手部运动方面的性能,6名志愿者从基本质量保证模型中获取数据。此外,为了测试初步的体内可行性,进行了动脉闭塞反应性充血研究,以评估所提出的过滤器在保持血流速度为2mm/s或更高时的信号效率。手部运动研究的初始平均带宽为577Hz (28.5mm/s),使用我们的方法在-60 dB的3cm处降低到7.28Hz (0.36mm/s)。体内功率多普勒研究结果显示,该滤波器与传统的50Hz高通滤波器的最低和最高血流时间点之间的动态范围分别为15.2dB和0.15dB。
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引用次数: 3
Fast myocardial strain estimation from 3D ultrasound through elastic image registration with analytic regularization 基于解析正则化的三维超声图像弹性配准快速心肌应变估计
Pub Date : 2016-04-01 DOI: 10.1117/12.2216781
B. Chakraborty, B. Heyde, M. Alessandrini, J. D’hooge
Image registration techniques using free-form deformation models have shown promising results for 3D myocardial strain estimation from ultrasound. However, the use of this technique has mostly been limited to research institutes due to the high computational demand, which is primarily due to the computational load of the regularization term ensuring spatially smooth cardiac strain estimates. Indeed, this term typically requires evaluating derivatives of the transformation field numerically in each voxel of the image during every iteration of the optimization process. In this paper, we replace this time-consuming step with a closed-form solution directly associated with the transformation field resulting in a speed up factor of ~10-60,000, for a typical 3D B-mode image of 2503 and 5003 voxels, depending upon the size and the parametrization of the transformation field. The performance of the numeric and the analytic solutions was contrasted by computing tracking and strain accuracy on two realistic synthetic 3D cardiac ultrasound sequences, mimicking two ischemic motion patterns. Mean and standard deviation of the displacement errors over the cardiac cycle for the numeric and analytic solutions were 0.68±0.40 mm and 0.75±0.43 mm respectively. Correlations for the radial, longitudinal and circumferential strain components at end-systole were 0.89, 0.83 and 0.95 versus 0.90, 0.88 and 0.92 for the numeric and analytic regularization respectively. The analytic solution matched the performance of the numeric solution as no statistically significant differences (p>0.05) were found when expressed in terms of bias or limits-of-agreement.
使用自由变形模型的图像配准技术在超声三维心肌应变估计中显示出有希望的结果。然而,由于高计算需求,这种技术的使用大多局限于研究机构,这主要是由于正则化项的计算负荷,以确保空间平滑的心脏应变估计。实际上,这个术语通常需要在每次迭代优化过程中对图像的每个体素中的变换场的导数进行数值计算。在本文中,我们用与转换场直接相关的封闭形式解决方案取代了这一耗时的步骤,对于典型的2503和5003体素的3D b模式图像,根据转换场的大小和参数化,速度因子约为10-60,000。通过对模拟两种缺血运动模式的合成三维心脏超声序列的跟踪和应变精度计算,对比了数值解和解析解的性能。在心动周期内,数值解和解析解的位移误差均值和标准差分别为0.68±0.40 mm和0.75±0.43 mm。收缩末期径向、纵向和周向应变分量的相关性分别为0.89、0.83和0.95,而数值正则化和解析正则化的相关性分别为0.90、0.88和0.92。解析解与数值解的表现相匹配,当用偏倚或一致限表示时,没有发现统计学显著差异(p>0.05)。
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引用次数: 7
Comparison of ultrasound B-mode, strain imaging, acoustic radiation force impulse displacement and shear wave velocity imaging using real time clinical breast images 超声b型、应变成像、声辐射力脉冲位移和剪切波速成像应用临床实时乳腺图像的比较
Pub Date : 2016-04-01 DOI: 10.1117/12.2217250
Kavitha Manickam, R. Machireddy, B. Raghavan
It has been observed that many pathological process increase the elastic modulus of soft tissue compared to normal. In order to image tissue stiffness using ultrasound, a mechanical compression is applied to tissues of interest and local tissue deformation is measured. Based on the mechanical excitation, ultrasound stiffness imaging methods are classified as compression or strain imaging which is based on external compression and Acoustic Radiation Force Impulse (ARFI) imaging which is based on force generated by focused ultrasound. When ultrasound is focused on tissue, shear wave is generated in lateral direction and shear wave velocity is proportional to stiffness of tissues. The work presented in this paper investigates strain elastography and ARFI imaging in clinical cancer diagnostics using real time patient data. Ultrasound B-mode imaging, strain imaging, ARFI displacement and ARFI shear wave velocity imaging were conducted on 50 patients (31 Benign and 23 malignant categories) using Siemens S2000 machine. True modulus contrast values were calculated from the measured shear wave velocities. For ultrasound B-mode, ARFI displacement imaging and strain imaging, observed image contrast and Contrast to Noise Ratio were calculated for benign and malignant cancers. Observed contrast values were compared based on the true modulus contrast values calculated from shear wave velocity imaging. In addition to that, student unpaired t-test was conducted for all the four techniques and box plots are presented. Results show that, strain imaging is better for malignant cancers whereas ARFI imaging is superior than strain imaging and B-mode for benign lesions representations.
观察到许多病理过程使软组织的弹性模量比正常情况下增加。为了利用超声波成像组织刚度,对感兴趣的组织施加机械压缩,并测量局部组织变形。基于机械激励的超声刚度成像方法分为基于外部压缩的压缩或应变成像和基于聚焦超声产生的力的声辐射力脉冲(ARFI)成像。超声聚焦于组织时,横向产生横波,横波速度与组织刚度成正比。本文介绍的工作是研究应变弹性成像和ARFI成像在临床癌症诊断中使用实时患者数据。50例患者(良性31例,恶性23例)采用西门子S2000超声b超显像、应变显像、ARFI位移和ARFI横波速度显像。根据测量的横波速度计算出真模量对比值。对b超、ARFI位移成像和应变成像,计算良恶性肿瘤的观察图像对比度和噪比。根据横波速度成像计算的真模量对比值,对观测到的对比值进行了比较。此外,对所有四种技术进行了学生未配对t检验,并给出了箱形图。结果表明,应变成像对恶性肿瘤的表现更好,而ARFI成像对良性病变的表现优于应变成像和b模式。
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引用次数: 0
Automated kidney detection for 3D ultrasound using scan line searching 使用扫描线搜索的3D超声自动肾脏检测
Pub Date : 2016-04-01 DOI: 10.1117/12.2217127
M. Noll, A. Nadolny, S. Wesarg
Ultrasound (U/S) is a fast and non-expensive imaging modality that is used for the examination of various anatomical structures, e.g. the kidneys. One important task for automatic organ tracking or computer-aided diagnosis is the identification of the organ region. During this process the exact information about the transducer location and orientation is usually unavailable. This renders the implementation of such automatic methods exceedingly challenging. In this work we like to introduce a new automatic method for the detection of the kidney in 3D U/S images. This novel technique analyses the U/S image data along virtual scan lines. Here, characteristic texture changes when entering and leaving the symmetric tissue regions of the renal cortex are searched for. A subsequent feature accumulation along a second scan direction produces a 2D heat map of renal cortex candidates, from which the kidney location is extracted in two steps. First, the strongest candidate as well as its counterpart are extracted by heat map intensity ranking and renal cortex size analysis. This process exploits the heat map gap caused by the renal pelvis region. Substituting the renal pelvis detection with this combined cortex tissue feature increases the detection robustness. In contrast to model based methods that generate characteristic pattern matches, our method is simpler and therefore faster. An evaluation performed on 61 3D U/S data sets showed, that in 55 cases showing none or minor shadowing the kidney location could be correctly identified.
超声(U/S)是一种快速且不昂贵的成像方式,用于检查各种解剖结构,例如肾脏。器官自动跟踪或计算机辅助诊断的一个重要任务是器官区域的识别。在这个过程中,关于传感器位置和方向的确切信息通常是不可用的。这使得实现这种自动方法极具挑战性。在这项工作中,我们想引入一种新的自动方法来检测3D U/S图像中的肾脏。这种新技术沿着虚拟扫描线分析U/S图像数据。在这里,寻找进入和离开肾皮质对称组织区域时的特征纹理变化。随后沿着第二个扫描方向的特征积累产生候选肾皮质的2D热图,从中分两步提取肾脏位置。首先,通过热图强度排序和肾皮质大小分析,提取最强候选及其对应候选;这个过程利用由肾盂区域引起的热图间隙。用这种联合皮质组织特征代替肾盂检测增加了检测的稳健性。与生成特征模式匹配的基于模型的方法相比,我们的方法更简单,因此更快。对61个3D U/S数据集进行的评估显示,在55个没有或轻微阴影的病例中,肾脏位置可以正确识别。
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引用次数: 3
Automated kidney morphology measurements from ultrasound images using texture and edge analysis 利用纹理和边缘分析从超声图像中自动测量肾脏形态
Pub Date : 2016-04-01 DOI: 10.1117/12.2216802
Hariharan Ravishankar, Pavan Annangi, M. Washburn, Justin D. Lanning
In a typical ultrasound scan, a sonographer measures Kidney morphology to assess renal abnormalities. Kidney morphology can also help to discriminate between chronic and acute kidney failure. The caliper placements and volume measurements are often time consuming and an automated solution will help to improve accuracy, repeatability and throughput. In this work, we developed an automated Kidney morphology measurement solution from long axis Ultrasound scans. Automated kidney segmentation is challenging due to wide variability in kidney shape, size, weak contrast of the kidney boundaries and presence of strong edges like diaphragm, fat layers. To address the challenges and be able to accurately localize and detect kidney regions, we present a two-step algorithm that makes use of edge and texture information in combination with anatomical cues. First, we use an edge analysis technique to localize kidney region by matching the edge map with predefined templates. To accurately estimate the kidney morphology, we use textural information in a machine learning algorithm framework using Haar features and Gradient boosting classifier. We have tested the algorithm on 45 unseen cases and the performance against ground truth is measured by computing Dice overlap, % error in major and minor axis of kidney. The algorithm shows successful performance on 80% cases.
在典型的超声扫描中,超声医师测量肾脏形态以评估肾脏异常。肾脏形态也可以帮助区分慢性和急性肾功能衰竭。卡钳的位置和体积测量通常非常耗时,自动化解决方案将有助于提高精度、可重复性和吞吐量。在这项工作中,我们开发了一种自动肾脏形态学测量解决方案,从长轴超声扫描。由于肾脏形状、大小的差异很大,肾脏边界的对比度较弱,并且存在隔膜、脂肪层等强边缘,因此自动肾脏分割具有挑战性。为了解决这些挑战并能够准确地定位和检测肾脏区域,我们提出了一种利用边缘和纹理信息结合解剖线索的两步算法。首先,我们使用边缘分析技术通过将边缘图与预定义模板匹配来定位肾脏区域。为了准确估计肾脏形态,我们在使用Haar特征和梯度增强分类器的机器学习算法框架中使用纹理信息。我们已经在45个未见的情况下测试了该算法,并通过计算骰子重叠,肾的长、小轴的%误差来衡量该算法对地面真实的性能。该算法在80%的情况下显示出成功的性能。
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引用次数: 6
Image-based temporal alignment of echocardiographic sequences 超声心动图序列的基于图像的时间对齐
Pub Date : 2016-04-01 DOI: 10.1117/12.2216192
A. Danudibroto, J. Bersvendsen, O. Mirea, O. Gérard, J. D’hooge, E. Samset
Temporal alignment of echocardiographic sequences enables fair comparisons of multiple cardiac sequences by showing corresponding frames at given time points in the cardiac cycle. It is also essential for spatial registration of echo volumes where several acquisitions are combined for enhancement of image quality or forming larger field of view. In this study, three different image-based temporal alignment methods were investigated. First, a method based on dynamic time warping (DTW). Second, a spline-based method that optimized the similarity between temporal characteristic curves of the cardiac cycle using 1D cubic B-spline interpolation. Third, a method based on the spline-based method with piecewise modification. These methods were tested on in-vivo data sets of 19 echo sequences. For each sequence, the mitral valve opening (MVO) time was manually annotated. The results showed that the average MVO timing error for all methods are well under the time resolution of the sequences.
超声心动图序列的时间序列通过在心脏周期的给定时间点显示相应的帧,可以公平地比较多个心脏序列。它对于回声体的空间配准也是必不可少的,其中几个采集相结合以增强图像质量或形成更大的视场。在本研究中,研究了三种不同的基于图像的时间对齐方法。首先,提出一种基于动态时间规整(DTW)的方法。其次,提出了一种基于样条的方法,利用一维三次b样条插值优化心脏周期时间特征曲线之间的相似性。第三,提出了一种基于样条法的分段修正方法。这些方法在19个回声序列的体内数据集上进行了测试。对于每个序列,人工标注二尖瓣打开(MVO)时间。结果表明,在序列的时间分辨率下,所有方法的平均MVO时序误差都很好。
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引用次数: 3
Resolution-enhancing hybrid, spectral CT reconstruction 增强分辨率的混合光谱CT重建
Pub Date : 2016-04-01 DOI: 10.1117/12.2216935
D. Clark, C. Badea
Spectral x-ray imaging based on photon-counting x-ray detectors (PCXD) is an area of growing interest. By measuring the energy of x-ray photons, a spectral CT system can better differentiate elements using a single scan. However, the spatial resolution achievable with most PCXDs limits their application, particularly in preclinical CT imaging. Consequently, our group is developing a hybrid micro-CT scanner based on a high-resolution, energy-integrating (EID) detector and a lower-resolution, PCXD. To complement this system, we propose and demonstrate a hybrid, spectral CT reconstruction algorithm which robustly combines the spectral contrast of the PCXD with the spatial resolution of the EID. Specifically, the high-resolution, spectrally resolved data (X) is recovered as the sum of two matrices: one with low column rank (XL) determined from the EID data and one with intensity gradient sparse columns (XS) corresponding to the upsampled spectral contrast obtained from the PCXD data. We test the proposed algorithm in a feasibility study focused on molecular imaging of atherosclerotic plaque using activatable iodine and gold nanoparticles. The results show accurate estimation of material concentrations at increased spatial resolution for a voxel size ratio between the PCXD and the EID of 500 μm3:100 μm3. Specifically, regularized, iterative reconstruction of the MOBY mouse phantom around the K-edges of iodine (33.2 keV) and gold (80.7 keV) reduces the reconstruction error by more than a factor of three relative to least-squares, algebraic reconstruction. Likewise, the material decomposition accuracy into iodine, gold, calcium, and water improves by more than a factor of two.
基于光子计数x射线探测器(PCXD)的光谱x射线成像是一个越来越受关注的领域。通过测量x射线光子的能量,光谱CT系统可以通过一次扫描更好地区分元素。然而,大多数pcxd的空间分辨率限制了它们的应用,特别是在临床前CT成像方面。因此,我们的团队正在开发一种基于高分辨率能量积分(EID)探测器和低分辨率PCXD探测器的混合微型ct扫描仪。为了补充该系统,我们提出并演示了一种混合光谱CT重建算法,该算法将PCXD的光谱对比度与EID的空间分辨率稳健地结合在一起。具体来说,高分辨率的光谱分辨数据(X)被恢复为两个矩阵的和:一个是由EID数据确定的低列秩(XL),另一个是由PCXD数据获得的上采样光谱对比度对应的强度梯度稀疏列(XS)。我们在一项可行性研究中测试了所提出的算法,该研究聚焦于使用可活化的碘和金纳米颗粒对动脉粥样硬化斑块进行分子成像。结果表明,当PCXD和EID的体素尺寸比为500 μm3:100 μm3时,在提高空间分辨率的情况下,可以准确地估计物质浓度。具体来说,在碘(33.2 keV)和金(80.7 keV)的k边缘周围对MOBY小鼠幻影进行正则化的迭代重建,相对于最小二乘代数重建,将重建误差降低了三倍以上。同样,将物质分解为碘、金、钙和水的准确度提高了两倍以上。
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引用次数: 1
Real-time 3D image reconstruction of a 24×24 row-column addressing array: from raw data to image 实时三维图像重建24×24行-列寻址数组:从原始数据到图像
Pub Date : 2016-04-01 DOI: 10.1117/12.2216069
Chunyu Li, Jiali Yang, Xu Li, Xiaoli Zhong, J. Song, Mingyue Ding, M. Yuchi
This paper presents a work of real-time 3-D image reconstruction for a 7.5-MHz, 24×24 row-column addressing array transducer. The transducer works with a predesigned transmit/receive module. After the raw data are captured by the NI PXIe data acquisition (DAQ) module, the following processing procedures are performed: delay and sum (DAS), base-line calibration, envelope detection, logarithm compression, down-sampling, gray scale mapping and 3-D display. These procedures are optimized for obtaining real-time 3-D images. Fixed-point focusing scheme is applied in delay and sum (DAS) to obtain line data from channel data. Zero-phase high-pass filter is used to calibrate the base-line shift of echo. The classical Hilbert transformation is adopted to detect the envelopes of echo. Logarithm compression is implemented to enlarge the weak signals and narrow the gap from the strong ones. Down-sampling reduces the amount of data to improve the processing speed. Linear gray scale mapping is introduced that the weakest signal is mapped to 0 and the strongest signal 255. The real-time 3-D images are displayed with multi-planar mode, which shows three orthogonal sections (vertical section, coronal section, transverse section). A trigger signal is sent from the transmit/receive module to the DAQ module at the start of each volume data generation to ensure synchronization between these two modules. All procedures, include data acquisition (DAQ), signal processing and image display, are programmed on the platform of LabVIEW. 675MB raw echo data are acquired in one minute to generate 24×24×48, 27fps 3-D images. The experiment on the strong reflection object (aluminum slice) shows the feasibility of the whole process from raw data to real-time 3-D images.
本文介绍了一种7.5 mhz 24×24行列寻址阵列传感器的实时三维图像重建工作。换能器与预先设计的发送/接收模块一起工作。NI PXIe数据采集(DAQ)模块采集原始数据后,进行延迟和(DAS)、基线校准、包络检测、对数压缩、下采样、灰度映射和三维显示等处理程序。这些程序为获得实时三维图像进行了优化。在延迟求和(DAS)中采用定点聚焦方案从信道数据中获取线路数据。采用零相高通滤波器对回波的基线位移进行校正。采用经典的希尔伯特变换检测回波包络。采用对数压缩来放大弱信号,缩小与强信号的差距。下采样减少了数据量,从而提高了处理速度。引入线性灰度映射,将最弱的信号映射为0,最强的信号映射为255。实时三维图像采用多平面模式显示,显示3个正交切片(纵切面、冠状面、横切面)。在每个卷数据生成开始时,从发送/接收模块向DAQ模块发送一个触发信号,以确保这两个模块之间的同步。数据采集、信号处理、图像显示等程序均在LabVIEW平台上完成。在一分钟内获取675MB原始回波数据,生成24×24×48, 27fps的3d图像。在强反射物体(铝片)上的实验证明了从原始数据到实时三维图像全过程的可行性。
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引用次数: 3
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SPIE Medical Imaging
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