A method to expedite data acquisition for multiple spatial-temporal analyses of tissue perfusion by contrast-enhanced ultrasound
21 Apr 2009-IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control (IEEE)-Vol. 56, Iss: 3, pp 507-519
TL;DR: An approach of interleaved imaging is presented which is applicable, among others, to contrast perfusion imaging using the replenishment method, and the total acquisition time is decreased by sequentially scanning image planes twice for short time spans.
Abstract: For semiquantitative analyses of tissue perfusion using contrast-enhanced ultrasound the acquisition and processing of time intensity curves (TIC) is required. These TICs can be computed for each pixel of an image plane, yielding parametric images of classification numbers like "blood volume" and "flow rate." The expenditure of time for data acquisition and analysis typically limits semiquantitative perfusion imaging to a single image plane in 2-D. 3-D techniques, however, provide a higher diagnostic value since more information (e.g., of an entire lesion) is obtained. Moreover, spatial compounding, being a 2-D-technique where an object is imaged from different viewing angles, is known to improve image quality by reducing artifacts and speckle noise. Both techniques, 3-D and compounding, call for optimized acquisition and processing of TICs in several image planes (3-D) or in several (overlapping) sections of the same image plane (compounding) to decrease the time needed for data acquisition. Here, an approach of interleaved imaging is presented which is applicable, among others, to contrast perfusion imaging using the replenishment method. The total acquisition time is decreased by sequentially scanning image planes twice for short time spans-first, immediately after microbubble destruction to record the initial rise of the TICs, and second, a sufficient time thereafter to assess final values of the TIC. Data from both periods are combined to fit a model function from which parameters are extracted such as perfusion rate and blood volume. This approach was evaluated by in vitro measurements on a perfusion-mimicking phantom for both, individual images such as would be used for volume reconstruction in 3-D and compound images obtained from full angle spatial compounding (FASC, 360deg). An error analysis is conducted to derive the deviation of the extracted parameters of the proposed method compared with the conventional one. These deviations are entailed by a reduction in acquisition time of the proposed method, which can be adjusted by several parameters, depending on the prevailing flow. Optimization strategies are proposed to find optimal values for those settings.
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TL;DR: These issues are addressed in terms of sound-speed image reconstruction, using edge-preserving regularized algebraic reconstruction in combination with synthetic aperture focusing, and the critical points of the implementation are discussed, because they are crucial to enable a complete 3-D image reconstruction.
Abstract: The paper is focused on sound-speed image reconstruction in 3-D ultrasound transmission tomography. Along with ultrasound reflectivity and the attenuation coefficient, sound speed is an important parameter which is related to the type and pathological state of the imaged tissue. This is important in the intended application, breast cancer diagnosis. In contrast to 2-D ultrasound transmission tomography systems, a 3-D system can provide an isotropic spatial resolution in the x-, y-, and z-directions in reconstructed 3-D images of ultrasound parameters. Several challenges must, however, be addressed for 3-D systems-namely, a sparse transducer distribution, low signal-to-noise ratio, and higher computational complexity. These issues are addressed in terms of sound-speed image reconstruction, using edge-preserving regularized algebraic reconstruction in combination with synthetic aperture focusing. The critical points of the implementation are also discussed, because they are crucial to enable a complete 3-D image reconstruction. The methods were tested on a synthetic data set and on data sets measured with the Karlsruhe 3-D ultrasound computer tomography (USCT) I prototype using phantoms. The sound-speed estimates in the reconstructed volumes agreed with the reference values. The breast-phantom outlines and the lesion-mimicking objects were also detectable in the resulting sound-speed volumes.
61 citations
Cites background from "A method to expedite data acquisiti..."
...The group of H. Ermert (ruhr-Universitaet bochum, bochum, Germany) [6] has developed a precise positioning system for a system of a reflector on one side of the breast and a curved array probe of a conventional ultrasound scanner on the opposite side....
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...The project was supported by the research center dar, project number 1M0572 and also partly by the research frame cEZ Ms 0021630513, sponsored by the Ministry of Education, czech republic; further support was provided by the joint program of the German academic Exchange service (daad) and the academy of sciences of the czech republic (project number d17-cZ15/09-10). access to the Metacentrum computing facilities provided under the program “Projects of large Infrastructure for research, development, and Innovations,” lM2010005, funded by the Ministry of Education, youth, and sports of the czech republic is also acknowledged. r. Jiřík, I. Peterlík, J. Fousek, and J. Jan are with the department of biomedical Engineering, brno University of Technology, brno, czech republic (e-mail: jirik@feec.vutbr.cz). n. ruiter, r. dapp, and M. Zapf are with the Institute for data Processing and Electronics, Karlsruhe Institute of Technology, Eggenstein, Germany. digital object Identifier 10.1109/TUFFc.2012.2185 of images of the whole volume....
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...The first experimental setup for a full 3-d system (3-d UscT I) to investigate the feasibility of such a system has been developed at Karlsruhe Institute of Technology (KIT), Germany [8]....
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...Ermert (ruhr-Universitaet bochum, bochum, Germany) [6] has developed a precise positioning system for a system of a reflector on one side of the breast and a curved array probe of a conventional ultrasound scanner on the opposite side....
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TL;DR: The obtained experimental results indicate the potential of using HFUCT as a novel tool for monitoring the preclinical responses of testicular tumors in small animals using both transmission and pulse-echo modes.
Abstract: Purpose: This paper describes a feasibility study for developing a 35-MHz high-frequency ultrasound computed-tomography (HFUCT) system for imaging rat testicles. Methods: The performances of two kinds of HFUCT-attenuation and sound-speed UCT-based on transmission and pulse-echo modes were investigated in this study. Experiments were carried out using phantoms and actual rat testiclesin vitro. HFUCT images were reconstructed using a filtered backprojection algorithm. Results: The phantom experimental results indicated that all types of HFUCT can determine the dimensions of a plastic cylinder with a diameter of 500μm. Compared to sound-speed HFUCT, attenuation HFUCT exhibited a better performance in recognizing a tiny sclerosed region in a gelatin phantom. Therefore, the in vitro testicular experiments were performed using attenuation HFUCT based on transmission and pulse-echo modes. The experimentally measured attenuation coefficient and sound speed for healthy rat testicles were 2.92 ± 0.25 dB/mm and 1537 ± 25 m/s, respectively. Conclusions: A homogeneous texture was evident for healthy testicles using both modes. An artificial sclerosed tumor could also be clearly observed using two- and three-dimensional attenuation HFUCT in both modes. However, an object artifact was apparent in pulse-echo mode because of ultrasound beam refraction. All of the obtained experimental results indicate the potential of usingmore » HFUCT as a novel tool for monitoring the preclinical responses of testicular tumors in small animals.« less
9 citations
01 Sep 2009
TL;DR: An image based method to compute a mean Speed of Sound (SoS) for the breast on the basis of a typical double-line artifact in the FASC-image is developed.
Abstract: In Full Angle Spatial Compounding (FASC) single ultrasound images from aspect angles all around an object are incoherently superimposed to achieve a higher image quality. To apply FASC to breast imaging, we developed an add-on system to a conventional ultrasound echo scanner. With this system also the distribution of Speed of Sound (SoS) inside the breast can be reconstructed using a reflector behind the breast. Next to diagnostics, SoS-images are used to geometrically correct FASC-images and avoid artifacts. However, since attenuation in the breast and reflections at its boundary are high, the detection of the reflector and the SoS-reconstruction may fail. To still correct FASC-images, we developed an image based method to compute a mean SoS for the breast on the basis of a typical double-line artifact in the FASC-image.
7 citations
Cites background from "A method to expedite data acquisiti..."
...We have shown in vitro that FASC also improves contrast enhanced imaging [4-7]....
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...For a detailed description of these steps see [4-7]....
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Patent•
17 Mar 2010TL;DR: In this paper, a planar region is used for motion tracking within a segment, and then the tracking is repeated for the next segment to synchronize the switch to yet another segment.
Abstract: Destruction for reperfusion in medical diagnostic ultrasound is synchronized to motion. Perfusion data for a volume is acquired sequentially for different segments of the volume. For a given segment, such as a planar region, motion tracking within the segment is performed. If sufficient registration or correlation exists at the completion of a sequence of scans for the current segment, then a lesser amount of movement is occurring. At this point, the transmission of contrast agent destructive acoustic energy is performed in the next segment. Tracking is repeated for the next segment to synchronize the switch to yet another segment. Other regions for tracking can be used. By controlling transmission of destruction pulses, more reliable perfusion quantities in a volume may be determined.
7 citations
TL;DR: In this paper, a dual-modality imaging system combining optoacoustic t omography (OAT) and laser-ultrasound tomography (UST) using computer models followed by experimental validation is presented.
Abstract: We developed the ¯rst prototype of dual-modality imager combining optoacoustic t omography (OAT) and laserultrasound tomography (UST) using computer models followed by experimental va lidation. The system designedfor preclinical biomedical research can concurrently yield images depicting both the abs orbed optical energydensity and acoustic properties (speed of sound) of an object. In our design of the UST imager, we seek toreplace conventional electrical generation of ultrasound waves by laser-induced ultra sound (LU). While earlierstudies yielded encouraging results [Manohar, et al., Appl. Phys. Lett, 131911, 2 007], they were limited totwo-dimensional (2D) geometries. In this work, we conduct computer-simulation st udies to investigate di®erentdesigns for the 3D LU UST imager. The number and location of the laser ultrasound emitters, which areconstrained to reside on the cylindrical surface opposite to the arc of detectors, are optimized. In addition tothe system parameters, an iterative image reconstruction algorithm was o ptimized. We demonstrate that highquality volumetric maps of the speed of sound can be reconstructed when only 32 emitt ers and 128 receivingtransducers are employed to record time-of-°ight data at 360 tomographic view ang les. The implications of theproposed system for small animal and breast-cancer imaging are discussed.Keywords: Laser ultrasound tomography, optoacoustic tomography, iterative ima ge reconstruction
4 citations
Cites background from "A method to expedite data acquisiti..."
...The development of UST breast cancer imaging is receiving renewed attention.(3,4) For example, a clinical ultrasound ring array scanner for breast cancer diagnosis (Computed Ultrasound Risk Evaluation (CURE)) has been proposed....
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...Other UST systems have also been reported.(3,4) However, (Send correspondence to F....
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References
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TL;DR: MBF can be quantified with myocardial contrast echocardiography during a venous infusion of microbubbles and has potential for measuring tissue perfusion in any organ accessible to ultrasound.
Abstract: Background—Ultrasound can cause microbubble destruction. If microbubbles are administered as a continuous infusion, then their destruction within the myocardium and measurement of their myocardial ...
1,631 citations
"A method to expedite data acquisiti..." refers background or methods in this paper
...on the other hand, there are methods to more quantitatively assess perfusion-related parameters like bolus, replenishment, or depletion methods [8]–[11], [15]–[17], [18]....
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..., [15]–[17], the TIcs are conventionally acquired in whole and sampled nonstop....
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...however, the proposed method can also be applied to a monoexponential model function as proposed in [15], as long as the “initial heel” is not strongly pronounced and does not “affect” the beginning of the TIc....
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29 Mar 1996TL;DR: In this article, the authors used phase shift estimation and time shift estimation for color flow mapping in medical ultrasound systems, including pulsed wave systems and continuous wave systems, to estimate color flow.
Abstract: Medical ultrasound systems Ultrasound Flow physics Ultrasound's interaction with blood Continuous wave systems Pulsed wave systems Color flow mapping using phase shift estimation Color flow mapping using time shift estimation Experimental systems Bibliography Appendices.
557 citations
"A method to expedite data acquisiti..." refers background in this paper
...This flow velocity accords with blood flow in human capillaries, arterioles, and venules [32]....
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TL;DR: Initial results indicate that operator-independent, whole-breast imaging and the detection of breast masses are feasible, and future studies will focus on improved detection and differentiation of masses in support of the long-term goal of increasing the specificity of breast exams.
Abstract: Although mammography is the gold standard for breast imaging, its limitations result in a high rate of biopsies of benign lesions and a significant false negative rate for women with dense breasts. In response to this imaging performance gap we have been developing a clinical breast imaging methodology based on the principles of ultrasound tomography. The Computed Ultrasound Risk Evaluation (CURE) system has been designed with the clinical goals of whole breast, operator-independent imaging, and differentiation of breast masses. This paper describes the first clinical prototype, summarizes our initial image reconstruction techniques, and presents phantom and preliminary in vivo results. In an initial assessment of its in vivo performance, we have examined 50 women with the CURE prototype and obtained the following results. (1) Tomographic imaging of breast architecture is demonstrated in both CURE modes of reflection and transmission imaging. (2) In-plane spatial resolution of 0.5 mm in reflection and 4 mm in transmission is achieved. (3) Masses > 15 mm in size are routinely detected. (4) Reflection, sound speed, and attenuation imaging of breast masses are demonstrated. These initial results indicate that operator-independent, whole-breast imaging and the detection of breast masses are feasible. Future studies will focus on improved detection and differentiation of masses in support of our long-term goal of increasing the specificity of breast exams, thereby reducing the number of biopsies of benign masses.
363 citations
TL;DR: In this paper, the authors used harmonic ultrasonographic (US) imaging and a microbubble contrast agent to characterize blood flow in focal hepatic lesions with 30 patients with known hepatic masses.
Abstract: PURPOSE: To characterize blood flow in focal hepatic lesions with harmonic ultrasonographic (US) imaging and a microbubble contrast agent. MATERIALS AND METHODS: Thirty patients with known hepatic masses were examined after injection of a perfluorocarbon microbubble agent. Tumor vascularity was assessed with continuous, harmonic gray-scale imaging with a low mechanical index (MI). Tumor vascular volume was assessed with brief, high-MI insonation called interval-delay imaging, which caused microbubble destruction. As the total contrast agent volume in the liver reflects the total vascular volume, quantitation of lesion enhancement relative to normal hepatic enhancement helped determine the vascular volume of the tumor relative to that of normal parenchyma. RESULTS: Low-MI continuous harmonic imaging showed lesional vessels in hepatocellular carcinomas, minimal or no vessels in hemangiomas, and variable vascularization in metastases. High-MI interval-delay imaging showed greater enhancement in hepatocellula...
328 citations
"A method to expedite data acquisiti..." refers background in this paper
...such applications include tumor detection within various organs [2]–[4], examinations in cardiology [5]–[8] or of stroke patients [9]–[11], controlling and monitoring of transplantations [12], and so on....
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TL;DR: The experimentally determined correlations are used to derive the optimal spatial separation of images for speckle reduction and are presented for variable frequency, range, transducer length, focus error, and reflecting material.
Abstract: In order to design improved spatial compounding ultra- sound scanning systems it is necessary to determine the correlation of speckle patterns as a function of aperture translation. We have con- ducted experiments measuring the speckle correlation with lateral ap- erture translation for linear phased array pulse-echo ultrasonic im- aging systems. Results are presented for variable frequency, range, transducer length, focus error, and reflecting material. Tests were con- ducted on two commercially availahle and one research imaging sys- tem. The measured rates of correlation coefficient decrease are inde- pendent of frequency, reflecting material, and target range when the target is in the focal zone. The experimentally determined correlations are used to derive the optimal spatial separation of images for speckle reduction.
275 citations