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Hepatic sinusoidal obstruction syndrome (HSOS),a toxic liver injury,can lead to multiple organ failure in severe cases and is even fatal.Early diagnosis is of great significance for the selection of treatment regimens and prognosis.Currently,ultrasound,as the preferred diagnostic method for liver diseases,has been recommended in expert consensus and criteria for the diagnosis of HSOS.However,there are no definitive imaging diagnostic standards.This paper summarizes the sonographic features of ultrasound and new ultrasound technologies in HSOS research.Analyzing the characteristic sonographic images from gray-scale ultrasonography,Doppler ultrasonography,ultrasound elastography,and contrast-enhanced ultrasonography at different stages of the disease enables the establishment and refining of the corresponding imaging diagnostic standards and provides effective auxiliary examination methods for the early diagnosis and differential diagnosis of HSOS.

Copyright of Journal of International Reproductive Health/Family Planning is the property of Editorial Board of the Journal of International Reproductive Health/Family Planning and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of International Reproductive Health/Family Planning is the property of Editorial Board of the Journal of International Reproductive Health/Family Planning and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cardiovascular surgery has a high risk of neurological complications, which can increase the burden of disease. Perioperative real-time monitoring of neurological function in cardiovascular surgery can assist clinicians to detect neurological abnormalities as early as possible, intervene and reduce the risk of neurological complications in time. The main monitoring indicators include cerebral oxygen saturation (ScO2), EEG, cerebral blood flow (CBF), etc. In this paper, the common perioperative neuromonitoring techniques and their research advances in cardiovascular surgery are reviewed to provide theoretical basis for reducing neurological complications and improve the prognosis of patients. [ABSTRACT FROM AUTHOR]

The patients with hepatic alveolar echinococcosis have unapparent early symptoms due to invasive and slow growth, and the disease is usually at an advanced stage upon diagnosis, which has a poor prognosis. Early diagnosis of hepatic alveolar echinococcosis is therefore of great importance. The advances in the ultrasound techniques continues to improve the accuracy for the diagnosis of hepatic alveolar echinococcosis, and ultrasound plays a critical role in the treatment and assessment of therapeutic efficacy for hepatic alveolar echinococcosis. This paper mainly reviews the application of ultrasound in the diagnosis and treatment of hepatic alveolar echinococcosis.

The ultrasound endoscopic probes with very small size transducers are normally imaging by focused ultrasound beamforming technology. So the imaging frame rate is not very high, which cannot meet the needs of some clinical applications based on high imaging rate. In recent years, plane-wave ultrafast imaging technology can obtain high image frame rate and guarantee the image quality. In this paper, a plane wave ultra-fast imaging technique based on a home-made small line array ultrasound transducer is presented. Feasibility of the method is verified by simulation estimations and phantom experiments. The results show that for the small size transducer design of plane wave ultrafast imaging, it is necessary to fully consider the combination of the array element width and the number of array elements. So that a good plane wave imaging quality can be obtained. It lays a foundation for the ultra-fast imaging of plane wave in the interventional ultrasound imaging and ultrasound endoscopy.

This paper explored the feasibility of using ultrasonic Nakagami statistic parameter imaging to evaluate the thermal lesion induced by microwave ablation (MWA) in porcine models. In this paper, thermal lesions were induced in livers and kidneys in 5 swines using a clinical MWA system. During this treatment progress, ultrasonic radiofrequency (RF) data were collected. The dynamic changes of Nakagami parameter in the thermal lesion were calculated, and the ultrasonic B-mode images and Nakagami images were reconstructed simultaneously. The contrast-to-noise ratio (CNR) between the thermal lesion and the surrounding normal tissue was calculated over the MWA procedure. After MWA, a bright hyperechoic region appeared in the ultrasonic Nakagami image as an indicator of the thermal lesion and this bright spot enlarged with lesion development during MWA exposure. The mean value of Nakagami parameter in the liver and kidney increased from 0.78 and 0.79 before treatment to 0.91 and 0.92 after treatment, respectively. During MWA exposure, the mean values of CNR calculated from the Nakagami parameter increased from 0.49 to 1.13 in the porcine liver and increased from 0.51 to 0.85 in the kidney, which were both higher than those calculated from the B-mode images. This in vivo study on porcine models suggested that the ultrasonic Nakagami imaging may provide an alternative modality for monitoring MWA treatment.

Objective: To investigate the possession of ultrasound equipment and use of point-of-care ultrasound (POCUS) in emergency department of tertiary hospitals in China to figure out the present condition of POCUS in the emergency department., Methods: Questionnaire survey was performed through the internet, which included equipment possession, usage, and the sterile technique of the probe in the emergency department of tertiary hospitals., Results: Between September and December in 2018, a total of 2 994 questionnaires link was clicked, and 718 survey responses were collected. After removing duplicated and non-tertiary hospitals questionnaires, the final questionnaire survey covered 300 tertiary hospitals, of which 250 were tertiary A hospitals (83.3%). The number of emergency department which own bedside ultrasound machine was 173 (57.7%), 40.6% (122) of the departments had only one ultrasonic machine. The main sources of equipment were new bought machines (119, 68.8%), given (38, 22.0%) or rented old machines from the ultrasound department (42, 24.3%). None of the emergency physicians in 92 (30.7%) departments mastered the POCUS skills, and 52.7% of the response hospital had less than a quarter emergency physicians grasp the skills. Fees of the POCUS could be charged in 52 (30.1%) of them. The main methods to clean or sterilize the probes were to wipe the probe by cleaning dry paper (97, 56.1%), sterile wet paper (69, 39.9%) or special probe disinfector (23, 13.3%), and used probe protective sleeve and sterile gel (12, 6.9%) as necessary; 79 (45.7%) departments had no conventional probe disinfection measures. When the ultrasonic was used to guide the punctures, the prevention of infection policies were the sterile gloves and saline (106, 61.3%), disposable probe protective sleeve and sterile gel (55, 31.8%)., Conclusions: The propagation of POCUS in emergency department is needed to develop in tertiary hospitals in China. The right way to clean the probes need to be emphasized.

Thyroid nodules are extremely common. Ultrasonography is the most effective imaging modality to diagnose and differentiate thyroid nodules. There are many versions of thyroid image reporting and data system(TI-RADS) evaluated by ultrasound, but some classification system indexes are complicated and clinical application is chaotic. In 2017, the American College of Radiology (ACR) published white papers that introduced a TI-RADS classification system based on conventional ultrasound to reduce the dependence on operators and facilitate communication with physicians. The purpose of the ACR TI-RADS is to establish the risk classification system for managing thyroid nodules and guide the physicians to make professional judgments. The ACR TI-RADS risk classification system is interpreted in this article, including the development, overview and feature categories of ACR TI-RADS, and authors' experiences in clinical application.

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Multi-angle plane-wave beamforming algorithm is the basis of ultra-fast ultrasonic imaging. It can be used to improve the imaging frame rate and resolution of traditional focused ultrasound. However, the existing multi-angle plane-wave technology can not satisfy the real-time imaging requirements due to the huge amount of computation required by CPU. In this paper, We proposed a parallel processing method to reduce the computation time based on compute unified device architecture(CUDA). Simulation analysis and contrast experiment were conducted to verify its performance. Experimental results show that the execution time based on GPU is much less than that based on CPU, thus the computational speed is accelerated significantly to satisfy the demand of ultrafast imaging.

The paper described the hemodynamics of blood flow based on fluid mechanics and its corresponding formulas, and revealed the limitation of blood flow velocity measurement for non-laminar flow when using the conventional pulse wave Doppler. The paper demonstrated the calculation of turbulence for blood flow based on velocity directions and quantified the turbulence according to the presented formulas. Two methods were introduced and the simulated results were analyzed. An example using real data based on ultrasound vector flow imaging for calculating the turbulence of blood flow was presented in the end.

Copyright of Imaging Science & Photochemistry is the property of Imaging Science & Photochemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Imaging Science & Photochemistry is the property of Imaging Science & Photochemistry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultrasonic plane wave imaging is one of the hot topics in the study of ultrasound imaging, but the plane wave ultra-high frequency ultrasound has brought a large amount of data. If these data are transmitted directly through the hardware, it will not only bring a great burden on the hardware, but also put a requirement for the ability of the hardware processing data. In order to reduce the problem caused by the high frame frequency and large amount of data, the data compression methods are used to reduce the amount of data acquisition and transmission. In this paper both lossy compression and lossless compression are studied, where LZW compression algorithm is chosen to test lossless compression effect, and based on the plane wave characteristics, the frequency domain cutting compression algorithm is developed as a lossy compression method. In this paper, the LZW algorithm is implemented in FGPA, and it can achieve a certain compression ratio after testing the ultra sonic simulation data. Under the condition of known fractional bandwidth, it is found that the main bandwidth can be preserved in the spectrum, while the rest of the frequency signal has little effect on the image. By testing the ultrasonic simulation data, the frequency domain cutting algorithm can achieve high compression ratio, and the difference between the original image and the reconstructed image is relatively smal . So from the point of the compression ratio, the frequency domain cutting algorithm is the primary choice of the ultrasonic data compression algorithm.

The successful suppression of clutter arising from stationary or slowly moving tissue is one of the key issues in medical ultrasound color blood imaging. Remaining clutter may cause bias in the mean blood frequency estimation and results in a potentially misleading description of blood-flow. In this paper, based on the principle of general wall-filter, the design process of three classes of filters, infinitely impulse response with projection initialization (Prj-IIR), polynomials regression (Pol-Reg), and eigen-based filters are previewed and analyzed. The performance of the filters was assessed by calculating the bias and variance of a mean blood velocity using a standard autocorrelation estimator. Simulation results show that the performance of Pol-Reg filter is similar to Prj-IIR filters. Both of them can offer accurate estimation of mean blood flow speed under steady clutter conditions, and the clutter rejection ability can be enhanced by increasing the ensemble size of Doppler vector. Eigen-based filters can effectively remove the non-stationary clutter component, and further improve the estimation accuracy for low speed blood flow signals. There is also no significant increase in computation complexity for eigen-based filters when the ensemble size is less than 10.

B-type ultrasound images have important applications in medical diagnosis. However, the widely spread intensity inhomogeneity, low-scale contrast, constructed defect, noise and blurred edges all make it difficult to implement automatic segmentation of lesion in the images. Based on region level set method, a subordinate degree region level set model was proposed, in which subordinate degree probability of each pixel was defined to reflect the pixel subjection grade to target and background respectively. Pixels were classified to either target or background by calculation of their subordinate degree probabilities, and edge contour was obtained by region level set iterations. In this paper, lesion segmentation is regarded as local segmentation of specific area, and the calculation is restrained to the local sphere abide by the contour, which greatly reduce the calculation complexity. Experiments on B-type ultrasound images showed improved results of the proposed method compared to those of some popular level set methods.

Copyright of Tianjin Medical Journal is the property of Tianjin Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of International Reproductive Health/Family Planning is the property of Editorial Board of the Journal of International Reproductive Health/Family Planning and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, 2460 pregnant women were selected as research objects, and the application value of ultrasound in prenatal diagnosis of pregnant women was discussed. At 20-28 gestational weeks, the fetal congenital heart disease was diagnosed by ultrasonic electrocardiogram, the abnormal fetus was examined by ultrasound at 11-32 gestational weeks, and the chromosomal invasion was performed at 18-23 gestational weeks. The results showed that the final diagnosis of 110 cases of congenital heart disease fetus, ultrasonic ECG detection of a total of 102 cases, the diagnostic accuracy rate was 92. 73%. Finally, 131 cases of abnormal fetus were diagnosed, 118 cases were diagnosed by prenatal ultrasound, and the diagnostic accuracy rate was 90.08%. Chromosomal abnormalities were detected in 12 cases by chromosome invasion examination, which may be one of the factors causing fetal malformation. Therefore, prenatal ultrasound is an effective means to diagnose congenital heart disease and fetal malformation, which can play an important role in reducing birth defects. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Clinical Healthcare is the property of Chinese Journal of Clinical Healthcare and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ultrasound images are easily corrupted by speckle noise, which limits its further application in medical diagnoses. An image de-noising method combining dual-tree complex wavelet transform (DT-CWT) with nonlinear diffusion is proposed in this paper. Firstly, an image is decomposed by DT-CWT. Then adaptive-contrast-factor diffusion and total variation diffusion are applied to high-frequency component and low-frequency component, respectively. Finally the image is synthesized. The experimental results are given. The comparisons of the image de-noising results are made with those of the image de-noising methods based on the combination of wavelet shrinkage with total variation diffusion, the combination of wavelet/multiwavelet with nonlinear diffusion. It is shown that the proposed image de-noising method based on DT-CWT and nonlinear diffusion can obtain superior results. It can both remove speckle noise and preserve the original edges and textural features more efficiently.

To evaluate the feasibility and accuracy of contrast-enhanced ultrasonography (CEUS) for the measurement of hemodialysis access recirculation (AR) and access flow rate (Qa), a two pump system was used to simulate access and dialyzer flow. AR and Qa under different conditions, such as reversal connection of dialysis lines and the needle orientation, were compared with each other. The value of access flow and recirculation flow were calculated based on the formulas introduced in this paper, and the correlation and consistency between true flow rate and calculated values were analyzed. The measured R correlated well with true value of flow rate (r = 0.57, P = 0.038, Qa > Qb; r = 0.95, P = 0.001, Qa < Qb). The Bland-altman test showed good agreement between the calculated value based on CEUS and true values. The CEUS can be used as a new advanced technology for AR and Qa measurement.

This paper combined the coded excitation with the technique of ophthalmic high-frequency ultrasonic imaging, and raised a new high-velocity data detection and signal processing method. 16 bit Golay complementarity sequences were produced by FPGA, which excited the probe to produce ultrasonic waves. Data detection circuit achieved the digitalized of the 15 MHz high-frequency ultrasonic echo signals in real time. Sampling rate was 120MHz, and sampling bit was 14 bit. Decoded compression arithmetic was realized by FPGA in real time, in which A code compression was alternated with B code compression. The return echo was correlated with the corresponding decode filter A and filter B respectively, and then the echo was delayed and summed to complete the decoding process. The experiment indicated that coded excitation can effectively increase the range of mainlobe and decrease the range of sidelobe. This technique can effectively raise the signal-to-noise ratio, and has significant research value in advancing the ophthalmic ultrasonic image quality and raising the safety of the equipment.

Developments of contrast agent and imaging technique have made it possible for using contrast-enhanced ultrasound (CEUS) to assess perfusion. As an irradiative, real time and repeatable technique, ultrasound is revealing its advantages in this field compared with nuclear medicine, CT and MRI. This paper introduces the mechanism and methods of the CEUS in the perfusion ultrasound. The advancement in the study of the time-intensity curve (TIC) in systemic organs is also reviewed in this paper.

This paper addressed the volume measurement of 3D ultrasound imaging system. Two different phantoms used in the measurement of volume of the 3D ultrasound imaging system were built, i.e., water phantom and agar phantom. The experiments demonstrated that as the increase of scan depth, the volume measurement accuracy is varied from 4% to 7% in water and 6% to 10% in agar. The phantoms and the volume measurement of the 3D ultrasound imaging system provides a basis for the establishment of testing standard and clinical application of 3D ultrasound imaging system.

The high frame rate (HFR) ultrasonic imaging system based on linear frequency-modulated (LFM) signal constructs images at a high frame rate; the signal-to-noise ratio (SNR) of this system can also be improved. Unfortunately, such pulse compression methods that increase the SNR usually cause range sidelobe artifacts. In an imaging situation, the effects of the sidelobes extending on either side of the compressed pulse will be self-noise along the axial direction and masking of weaker echoes. The improvement on high frame rate ultrasonic imaging system based on LFM signal is considered in this paper. In this proposed scheme, a predistorted LFM signal is used as excited signal and a mismatched filter is applied on receiving end. The results show that the proposed HFR ultrasonic imaging system can achieve higher SNR and the axial resolution is also improved.

Osteoporosis is a common metabolic disease which is characteristic of less bone mass and impaired bone microarchitecture, leading to the decreasing of bone strength as well as to the increasing of brittle bones and the risk of fracture. It was found that bone quality, including bone microarchitecture, the composition of mineral and organic matrix, microdamage and the status of bone repair, can influence bone strength as bone mineral density can do. Since the compositions of tissue material are generally similar in people, microarchitecture is used as the important index for the assessment of bone mechanical properties. Currently the none-invasive detective methods in use for bone have become a research topic. Such methods as ultrasonic imaging, computer tomography, magnetic resonance imaging and finite element analysis are reviewed in this paper.

Ultrasound image has a lot of speckle noise, which brings great difficulties to the feature extraction, recognition and analysis. Especially in the edge extraction, the conventional extraction algorithms are difficult to achieve the desired results because of the speckle noise. To solve this problem, an algorithm based on the anisotropic diffusion equation is presented. The new algorithm combines the robust estimation and considers the characteristic of the speckle noise, so it can suppress the speckle noise effectively and be more robust, thus the edge details of the ultrasound image can be preserved even enhanced, which can provide effective safeguard for the following edge extraction. Furthermore, the paper proposes a new method to compute speckle scale coefficients automatically, which reduces the influence of the human beings, and enhances the stability of the algorithm.

This paper mainly introduces the design of digital scanning converter (DSC) for medical endoscopic ultrasound imaging. Fast modified vector totational CORDIC (FMVR-CORDIC) arithmetic complete coordinate conversion is used to increase the speed of ultrasonic scanning imaging. FPGA is used as the kernel module to control data transferring, related circuits and relevant chips' working, and to accomplish data preprocessing. With the advantages of simple structure, nice flexibility and convenience, it satisfies the demand for real-time displaying in this system. Finally, the original polar coordinate image is transformed to rectangular coordinate grey image through coordinate transformation. The system performances have been validated by the experimental result.

Based on the pulse-coded transmitting and wide-band receiving system, this paper describes A research of phase inversion technique to extract high-frequency ultrasonic tissue harmonic information by making use of wide-band ultrasonic transducer on frequency of 20 MHz, 35 MHz and 50 MHz. The results indicate that adopting the method in this paper is with better fundamental frequency inhibition and at the same time can increase the amplitude of second harmonic information effectively. This method is superior to that traditoncal one by using RF filter to extract tissue harmonic information.

This paper mainly introduces the design and implementation of rotary scanning imaging for Endoscopic Ultrasonography System based on USB2.0. The ultrasonic pulse-echo imaging technique has been used. In the paper, we simply introduce the emission circuit, receiving circuit and isolation circuit. According to the character of rotary scanning, we design the synchronous control circuit based on FPGA and data transmission circuit based on USB2.0. Finally the original polar coordinate image is transformed to rectangular coordinate grey image through coordinate transformation. The system performances have been validated by the experimental result gotten by scanning a specific object with continuous rotary motor.

In this paper, we propose that, the need of the costly re-initialization procedure can be completely eliminated by using the variation formulation, thus increasing the speed of computing operations. The edge detecting function in the geodesic active contour model is improved by incorporating a prior knowledge. The accuracy of the segmentation algorithm can be enhanced by using the minimal variance. Experimental results show that the proposed algorithm can segment the prostate ultrasound images effectively and avoid the problem of contour leakage.

A digital beamformer in medical ultrasound imaging systems conventionally requires that the returning signals received by transducers are sampled at a rate significantly higher than the Nyquist rate. This paper presents a digital beamformer that employs zero padding followed by digital interpolation filtering to achieve vernier beamformer delays. The experimental results show that the digital interpolation beamformer can greatly decrease the complexity of A/D converter circuitry.

Speckle is the main reason which declines the quality of medical ultrasonic images. In this paper, the initial condition for the Downhill filter, a morphological reconstruction algorithm, is modified and applied in the speckle reduction. Firstly, the initial area and start position as the mark image was determined in the marker image. Then the modified Downhill filter was used in the ultrasonic marker image. The results showed that, in comparison with the other three filters, this modified Downhill filter, while maintaining the integrity of the contour,could reduce the speckle in the regions of cavity efficiently and rapidly.

Lower contrast and speckle noise are the main reasons which decline the quality of medical ultrasonic images. In this paper, a new method is proposed to filter the speckle noises and enhance the contrast simultaneously. Anisotropic diffusion filtering method was firstly applied to filter images. Then the loss of information, which the contrast function of contrast enhancement model lies on, was obtained. Finally, the contrast can be enhanced by using enhancement model. Experimental results show that the proposed method not only removes the speckle noises effectively, but also enhances the contrast obviously. This method supplies an effective approach for improving the quality of medical ultrasonic images.

Ultrasound medical imaging has been widely applied in clinic diagnoses because of its real-time, non-invasiveness and convenience. However, it suffers from severe speckle noises. Until now, a lot of filtering algorithms have been proposed, but none of them is satisfactory. In this paper, four nonlinear filter methods, based on median filter, wavelet decomposition and anisotropic diffusion, are systematically reviewed. Finally, the prospect of the nonlinear filtering method is discussed.

This paper introduces the design and realization of the FIR dynamic filter by EP1C6Q240 of Cyclone of Altera Corporation, showing the hardware diagram of the filter and the process of calculating parameters, and compares and analyzes the B mode ultrasound images created by using the dynamic filter and by using the constant filter.

In this paper, some familiar algorithms of edge detection in ultrasound B-scan images are analyzed and studied. The results show that Sobel, Prewitt and Laplacian operators are sensitive to noise, Hough transform adapts to the whole detection, while LoG algorithm's average is zero and it couldn't change the whole dynamic area. Accordingly LoG algorithm is preferable.

The high frame rate (HFR) ultrasonic imaging system, which is developed with limited diffraction beams, constructs images at a high frame rate. However the rectangular imaging area, to some extent, restricts the far field imaging information. At the same time, because of one transmission for constructing image, the system suffers from low SNR. In this paper we present a computationally efficient method to construct sector mode image and to increase the SNR in HFR system. The method uses Golay complementary sequence as excitation to realize two transmission events. Each event simultaneously transmits two plane waves with different transmission angle. Then the received echo signals related to different angle are separated according to orthogonality of Golay complementary sequence and used to construct two images of different area by HFR method. Finally the two images are synthesized to one frame of sector mode image.

Compared with medical ultrasonic pulse-echo imaging system, coded excitation system has the potential of higher SNR and deeper penetration depth. In this paper, the basic principle of coded excitation is introduced. Through acoustic intensity analysis, the maximum improvement of SNR of ultrasonic image with coded excitation is deduced. Then, guide lines to choose codes in ultrasonic imaging are introduced. Some codes, such as white noise, pseudo-random code, Golay code, Chirp and pseudo-chirp are described in details. At last, the applications of ultrasonic coded excitation in B-mode imaging, Doppler flow measurement, B-flow imaging and harmonics imaging are described.

A high frame rate (HFR) ultrasonic imaging method developed by Jianyu Lu has been attracting attention in the related imaging area. Because a special weighting on the received signal is needed to implement this method, the imaging system is complicated. This paper presents a new kind of theroetical analysis for the HFR imaging system in view of the angular spectrum concept. Based on the study, the special weighting process can be replaced by Fourier transform. Computer simulation demonstrates the correctness of the analysis. It shows that the constructed images by the new method have the same high quality as those obtained by using the original HFR method while the system implementation is greatly simplified.

This paper introduces double ultrasound pulse transmitting and receiving circuits used in ultrasound thermometry. Using the circuits, double ultrasound pulses could be made synchronously to satisfy the requirements of ultrasound thermometry, and the weak ultrasound echo signals are received successfully. The crux experiment waveform offered shows that the circuits have high reliability.

Playing an important role in PACS, ultrasound subsystem together with CT and X-radiography subsystems works as the image Provider and image processing center. In this paper, we propose a novel scheme on how to construct ultrasound subsystem and explain it with detailed work flow and software frame. We also give a discussion on how to expand such a subsystem.

A design of a Digital Scan Converter(DSC) in B scanner and its implementation by using FPGA are presented in this paper, and some applied results are presented too here.

This paper explores the testing methods of the linear array transducer in regard to its integrality, Uniformity and independence.

Objective To investigate sex difference of dynamic cerebral autoregulation (dCA) in different body positions. Methods A total of 130 healthy adults (65 males and 65 females) who underwent physical examination in Xuanwu Hospital Capital Medical University from August 2021 to November 2022 were included. Non-invasive continuous blood pressure monitor and transcranial Doppler ultrasonography (TCD) were used to monitor beat-to-beat blood pressure and middle cerebral artery (MCA) cerebral blood flow velocity (CBFV), respectively. Transfer function analysis (TFA) was used to compare and analyze the dCA parameters (absolute gain value and percentage gain, phase, coherence) in the range of very low frequency (0.02-0.07 Hz), low frequency (0.07-0.20 Hz) and high frequency (0.20-0.50 Hz) of different positions and sex. Results The phase in very low frequency and low frequency were significantly lower in the standing position than in the supine position [(57.37 ± 12.45)° vs. (66.72 ± 16.64)°, t = -6.428, P = 0.000; (36.82 ± 11.59)° vs. (43.02 ± 11.51)°, t = - 6.052, P = 0.000], while the coherence in very low frequency and low frequency were significantly higher in the standing position than in the supine position (0.73 ± 0.06 vs. 0.66 ± 0.06, t = - 8.947, P = 0.000; 0.76 ± 0.06 vs. 0.73 ± 0.07, t = - 2.693, P = 0.007). In both supine and standing positions, absolute gain value of male in the low frequency [(0.91 ±0.23) cm/(s⋅mm Hg) vs. (1.04±0.23)cm/(s⋅mm Hg), t = 3.075, P = 0.003; (0.84±0.19)cm/(s⋅mm Hg) vs. (0.95 ±0.21)cm/(s⋅mm Hg), t = 3.102, P = 0.002] and high frequency [(0.94 ± 0.25) cm/(s⋅mm Hg) vs. (1.11 ± 0.27) cm/(s⋅mm Hg), t = 3.740, P = 0.000; (0.91 ±0.21) cm/(s-mm Hg) vs. (1.05 ±0.23) cm/(s⋅mm Hg), t = 3.747, P = 0.000] was lower than those of female, while the phase in the low frequency was higher than that of female [(45.25 ± 10.21)° vs. (40.81 ± 12.37)°, t = - 2.239, P = 0.027; (38.90 ± 12.25)° vs. (34.74 ± 10.57)°, t = - 2.072, P = 0.040]. Conclusions Postural changes can also affect the cerebral autoregulation, and dCA can be improved in the supine position; there is no significant difference in dCA between male and female in the very low frequency, but there is a certain difference between the sex in the low frequency and high frequency. [ABSTRACT FROM AUTHOR]

This paper introduces the value of three-dimensional ultrasonic imaging and it's different realizing approaches. It deliberately analyzes the key techniques used in three-dimensional ultrasonic imaging. These techniques include registration of two-dimensional images, accurate reconstruction of three-dimensional volume, projection of irregularly sampled plane and segmentation of three-dimensional image. The development status and future trend are also given in this paper.

In this paper we presented a new compression intension based on VQ with an in tension to provide an efficient approach to compressing medical ultrasonic images and thus make the establishment of a medical multimedia database possible. The major advantages of this coding scheme are: high compression rate, low distortion, higher speed of encoding procedure as compared with ordinary VQ. These benefits are mainly due to the unique design of the codebook and enhanced table look-up techniques. In addition, a comparison of this scheme with JPEG compression method (at high compression rate) was presented.

This paper reports the ultrasonographic diagnoses in 18 cases of parotid gland masses confirmed by surgery and biopsy and pathology. The diagnostic accuracy was 100% (18/18) in the judgement in locations and was 72% (13/18) in the judgement in the nature of the disease. The clinical value of ultrasonographic diagnosis in parotid gland masses and the features of the sonographic images in benign and malignant tumors were analysed and discussed.