- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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An FPGA-Based Backend System for Intravascular Photoacoustic and Ultrasound Imaging
摘要： The integration of intravascular ultrasound (IVUS) and intravascular photoacoustic (IVPA) imaging produces an imaging modality with high sensitivity and specificity which is particularly needed in interventional cardiology. Conventional side-looking IVUS imaging with a single-element ultrasound (US) transducer lacks forward-viewing capability, which limits the application of this imaging mode in intravascular intervention guidance, Doppler-based flow measurement, and visualization of nearly or totally blocked arteries. For both side-looking and forward-looking imaging, the necessity to mechanically scan the US transducer limits the imaging frame rate, and therefore array-based solutions are desired. In this paper, we present a low-cost, compact, high-speed, and programmable imaging system based on a field-programmable gate array (FPGA) suitable for dual-mode forward-looking IVUS/IVPA imaging. The system has 16 US transmit and receive channels and functions in multiple modes including interleaved photoacoustic (PA) and US imaging, hardware-based high-frame-rate US imaging, software-driven US imaging, and velocity measurement. The system is implemented in the register-transfer level, and the central system controller is implemented as a finite state machine. The system was tested with a capacitive micromachined ultrasonic transducer (CMUT) array. A 170-frames-per-second (FPS) US imaging frame rate is achieved in the hardware-based high-frame-rate US imaging mode while the interleaved PA and US imaging mode operates at a 60-FPS US and a laser-limited 20-FPS PA imaging frame rate. The performance of the system benefits from the flexibility and efficiency provided by low-level implementation. The resulting system provides a convenient backend platform for research and clinical IVPA and IVUS imaging.
关键词： software/hardware co-design,velocity measurement,ultrasound imaging,Photoacoustic imaging,FPGA,data acquisition,finite state machine
更新于2025-09-10 09:29:36
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Special issue – Non-invasive vascular imaging
摘要： This special issue focusses on advances in non-invasive vascular imaging with some outstanding articles on cutting-edge imaging technologies and their clinical use. For many years, invasive catheter angiography with its attendant risks was the only method to obtain more detailed information on the vasculature than plain radiographs could provide, although only the outline of the lumen is visualised directly. Indeed, the risks of invasive angiography are such that they have had to be factored into risk assessment prior to embarking on imaging investigation. For example, the landmark NASCET trial of carotid endarterectomy was reported in terms of the number needed to both investigate and treat to provide bene?t in the secondary prevention of stroke since the investigation itself (invasive carotid arteriography) as well as the proposed surgical intervention could both cause precisely the morbidity/mortality that the strategy was intending to avoid, i.e., stroke. As such, a shift to non-invasive carotid imaging in this scenario if equally accurate would mean a lower number to treat for the same bene?t as the potential morbidity/mortality simply associated with investigation had been negated.
关键词： Non-invasive vascular imaging,angiography,CT,ultrasound,MRI
更新于2025-09-10 09:29:36
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Investigation of out-of-plane motion artifacts in two-dimensional noninvasive vascular ultrasound elastography
摘要： Ultrasound noninvasive vascular elastography (NIVE) has shown its potential to measure strains of carotid arteries to predict plaque instability. When two-dimensional (2-D) strain estimation is performed, either in longitudinal or cross-sectional view, only in-plane motions are considered. The motions in elevation direction (i.e., perpendicular to the imaging plane), can induce estimation artifacts affecting the accuracy of 2-D NIVE. The influence of such out-of-plane motions on the performance of axial strain and axial shear strain estimations has been evaluated in this study. For this purpose, we designed a diseased carotid bifurcation phantom with a 70% stenosis and an in vitro experimental setup to simulate orthogonal out-of-plane motions of 1 mm, 2 mm and 3 mm. The Lagrangian speckle model estimator (LSME) was used to estimate axial strains and shears under pulsatile conditions. As anticipated, in vitro results showed more strain estimation artifacts with increasing magnitudes of motions in elevation. However, even with an out-of-plane motion of 2.0 mm, strain and shear estimations having inter-frame correlation coefficients higher than 0.85 were obtained. To verify findings of in vitro experiments, a clinical LSME dataset obtained from 18 participants with carotid artery stenosis was used. Deduced out-of-plane motions (ranging from 0.25 mm to 1.04 mm) of the clinical dataset were classified into three groups: small, moderate and large elevational motions. Clinical results showed that pulsatile time-varying strains and shears remained reproducible for all motion categories since inter-frame correlation coefficients were higher than 0.70, and normalized cross-correlations between radiofrequency images were above 0.93. In summary, the performance of LSME axial strain and shear estimations appeared robust in the presence of out-of-plane motions (< 2 mm) as encountered during clinical ultrasound imaging.
关键词： ultrasound elastography,out-of-plane motion,carotid bifurcation phantom
更新于2025-09-10 09:29:36
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First-in-Human Images of Coronary Atherosclerosis and Coronary Stents Using a Novel Hybrid Intravascular Ultrasound and Optical Coherence Tomographic Catheter
摘要： We report the first-in-human images with any hybrid imaging catheter combining intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The catheter has a 2.8-F imaging window with a 40-MHz center frequency for IVUS imaging. The IVUS and OCT beams are aligned with each other, allowing inherent coregistration and immediate simultaneous image review. Imaging was performed in a 74-year-old male patient with a recent inferior ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention in the distal right coronary artery. Imaging was performed over 90 mm of the right coronary artery at a pull-back speed of 25 mm/s, with contrast flushing at 3 ml/s for 5 s. Figure 1 highlights the complementary roles of IVUS and OCT to characterize atherosclerotic plaque types. A nonculprit lesion was present in the mid left anterior descending coronary artery. Staged intervention was performed with implantation of a Promus 2.75 × 20 mm (Boston Scientific, Natick, Massachusetts) stent. Imaging was performed after stent implantation over a 70-mm length at a pull-back speed of 25 mm/s and contrast flush at 4 ml/s for 4 s. Imaging findings in the left anterior descending coronary artery and D1 are shown in Figure 2. The imaging pull-back shows a dissection distal to the left anterior descending coronary artery stent. Near-field findings of dissection and stent apposition are better appreciated on OCT, while deeper features such as side branches and plaque burden are better assessed on IVUS. This first in vivo experience of hybrid IVUS and OCT demonstrates the synergistic ability of these modalities to characterize coronary atherosclerosis and coronary interventions.
关键词： optical coherence tomography,intravascular imaging,intravascular ultrasound
更新于2025-09-10 09:29:36
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PACS-Based Multimedia Imaging Informatics (Basic Principles and Applications) || Digital Medical Imaging
摘要： The chapter discusses the fundamentals of digital medical imaging, including two-dimensional (2-D) and three-dimensional (3-D) imaging techniques, image compression, and the integration of imaging informatics with patient imaging workflows. It covers various imaging modalities such as computed radiography (CR), digital mammography, nuclear medicine imaging, ultrasound imaging, and magnetic resonance imaging (MRI), highlighting their principles, applications, and the challenges in archiving and transmitting large datasets.
关键词： digital medical imaging,computed radiography,ultrasound imaging,digital mammography,PACS,2-D imaging,image compression,3-D imaging,nuclear medicine imaging,magnetic resonance imaging
更新于2025-09-10 09:29:36
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Sonography in acute ocular pathology: a kaleidoscopic view
摘要： Ocular emergencies contribute to a large proportion of ocular pathologies. These may even be organ-threatening diseases such as central retinal artery and vein occlusion or globe rupture. Conventional physical examination may not always be feasible in emergency situations but decision-making in time is critical in the interest of patient in few of these conditions. Sonography in this setting plays an important role, allowing real-time, quick and dynamic evaluation. Common acute ocular pathologies such as retinal detachment, lens dislocation and globe rupture can be easily diagnosed by ultrasound. Vascular lesions can be identified using Doppler. This article illustrates the sonographic appearance in traumatic and non-traumatic acute ocular pathologies.
关键词： Ocular trauma,Globe rupture,Lens dislocation,Emergency ocular ultrasound,Retinal detachment,Ocular sonography
更新于2025-09-10 09:29:36
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Four-dimensional optoacoustic monitoring of tissue heating with medium intensity focused ultrasound
摘要： Medium-intensity focused ultrasound (MIFU) concerns therapeutic ultrasound interventions aimed at stimulating physiological mechanisms to reinforce healing responses without reaching temperatures that can cause permanent tissue damage. The therapeutic outcome is strongly affected by the temperature distribution in the treated region and its accurate monitoring represents an unmet clinical need. In this work, we investigate on the capacities of four-dimensional optoacoustic tomography to monitor tissue heating with MIFU. Calibration experiments in a tissue-mimicking phantom have confirmed that the optoacoustically-estimated temperature variations accurately match the simultaneously acquired thermocouple readings. The performance of the suggested approach in real tissues was further shown with bovine muscle samples. Volumetric temperature maps were rendered in real time, allowing for dynamic monitoring of the ultrasound focal region, estimation of the peak temperature and the size of the heat-affected volume.
关键词： photoacoustic imaging,thermal treatment monitoring,therapeutic ultrasound,temperature monitoring,optoacoustic tomography
更新于2025-09-10 09:29:36
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Integration of PSMA-targeted PET imaging into the armamentarium for detecting clinically significant prostate cancer
摘要： To explore the current state of using prostate-specific membrane antigen (PSMA)-targeted PET imaging to aid in the diagnosis of clinically significant prostate cancer. Prostate-specific antigen screening remains controversial, as it is associated with the underdetection of clinically significant prostate cancer as well as the overdetection and subsequent overtreatment of clinically insignificant disease. A diagnostic test that can accurately assess the presence of clinically significant prostate cancer and avoid detection of low-risk tumors is needed. Multiparametric magnetic resonance imaging (mpMRI) can aid in the detection of clinically significant prostate cancer and can be used with fusion-based biopsy platforms to target biopsies to specific lesions. However, there are several limitations of mpMRI including a modest negative predictive value for high-grade cancer. PSMA-targeted PET imaging has shown promise as a noninvasive test to aid in the detection of clinically significant prostate cancer while providing anatomical information to guide targeted biopsies. PSMA-targeted PET in combination with mpMRI offers a higher degree of diagnostic accuracy for imaging localized prostate cancer than either modality alone. PSMA-targeted PET imaging can aid in the identification of men with clinically significant prostate cancer. Further research is needed to determine the full potential of PSMA-targeted imaging in both the detection and treatment of localized prostate cancer.
关键词： focal therapy,MRI/ultrasound fusion,prostate-specific membrane antigen,prostate cancer,targeted biopsy
更新于2025-09-10 09:29:36
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AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON CURRENT PROGRESS IN MATHEMATICS AND SCIENCES 2017 (ISCPMS2017) - Bali, Indonesia (26–27 July 2017)] - Synthesize, characterization and photosonocatalytic activity of LaMnO3/ZnO nanocomposites for wastewater treatment
摘要： ZnO modified LaMnO3 nanocomposites were prepared using the sol-gel method. The prepared nanocomposite was synthesized in 4 variation of ZnO (1:0.1, 1:0.3, 1:0.5 and 1:1). The LaMnO3/ZnO nanocomposites were characterized using X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The LaMnO3/ZnO shows the orthorhombic structure of LaMnO3 nanoparticles and hexagonal wurtzite of ZnO nanoparticles. The photosonocatalytic activity of LaMnO3/ZnO was tested using methylene blue under the combination of UV or visible light and ultrasonic irradiation. The photosonocatalytic efficiencies performed that the present of ZnO could increase the degradation of MB. LaMnO3/ZnO nanocomposite with molar ratio 1:0.5 show the highest photosonocatalytc activity both under UV or visible and ultrasonic irradiation. Furthermore, the photosonocatalytic activity with combination of UV or visible light and ultrasound irradiation led to more complete degradation compared to use light or ultrasonic irradiation alone. The radical oxidative of the sample was examined by the addition of some scavengers and the results show that hole as the most active species to degrade MB under UV or visible and ultrasonic irradiation.
关键词： UV,visible,ultrasound,LaMnO3,ZnO,Perovskite
更新于2025-09-09 09:28:46
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[SpringerBriefs in Applied Sciences and Technology] Internet of Things and Personalized Healthcare Systems || Role of Imaging Modality in Premature Detection of Bosom Irregularity
摘要： Since last 60 years, bosom (breast) tumor is the major cause of death amid females worldwide. Earliest possible detection will raise the endurance rate of patients. Premature detection of bosom tumor is big challenge in medical science. Medical studies proven that imaging modalities like mammography, thermography, ultrasound, and magnetic resonance imaging (MRI) play a vigorous role to detect breast irregularity earliest. This paper enhances the knowledge on two imaging practices, one is mammography and another is thermography. It aids to identify the limitations in existing technologies and helps to plan the new methodology.
关键词： Bosom tumor,Ultrasound,MRI—magnetic resonance imaging,Mammography,Thermography
更新于2025-09-09 09:28:46