40‐MHz high‐frequency vector Doppler imaging for superficial venous valve flow estimation

2020 ◽  
Vol 47 (9) ◽  
pp. 4020-4031
Author(s):  
Hsin Huang ◽  
Pei‐Yu Chen ◽  
Chih‐Chung Huang
Keyword(s):  
High Frequency ◽  
Doppler Imaging ◽  
Frequency Vector ◽  
Venous Valve ◽  
Flow Estimation

scholarly journals How Can We Manage Gallbladder Lesions by Transabdominal Ultrasound?

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 784
Author(s):  
Shinji Okaniwa
Keyword(s):  
High Frequency ◽  
Layer Structure ◽  
Wall Layer ◽  
Pancreaticobiliary Maljunction ◽  
Doppler Imaging ◽  
Wall Thickening ◽  
Contrast Enhanced ◽  
Postural Changes ◽  
Venous Phase

The most important role of ultrasound (US) in the management of gallbladder (GB) lesions is to detect lesions earlier and differentiate them from GB carcinoma (GBC). To avoid overlooking lesions, postural changes and high-frequency transducers with magnified images should be employed. GB lesions are divided into polypoid lesions (GPLs) and wall thickening (GWT). For GPLs, classification into pedunculated and sessile types should be done first. This classification is useful not only for the differential diagnosis but also for the depth diagnosis, as pedunculated carcinomas are confined to the mucosa. Both rapid GB wall blood flow (GWBF) and the irregularity of color signal patterns on Doppler imaging, and heterogeneous enhancement in the venous phase on contrast-enhanced ultrasound (CEUS) suggest GBC. Since GWT occurs in various conditions, subdividing into diffuse and focal forms is important. Unlike diffuse GWT, focal GWT is specific for GB and has a higher incidence of GBC. The discontinuity and irregularity of the innermost hyperechoic layer and irregular or disrupted GB wall layer structure suggest GBC. Rapid GWBF is also useful for the diagnosis of wall-thickened type GBC and pancreaticobiliary maljunction. Detailed B-mode evaluation using high-frequency transducers, combined with Doppler imaging and CEUS, enables a more accurate diagnosis.

scholarly journals Monitoring of Adult Zebrafish Heart Regeneration Using High-Frequency Ultrasound Spectral Doppler and Nakagami Imaging

Sensors ◽  
2019 ◽  
Vol 19 (19) ◽  
pp. 4094 ◽  
Author(s):  
Sunmi Yeo ◽  
Changhan Yoon ◽  
Ching-Ling Lien ◽  
Tai-Kyong Song ◽  
K. Kirk Shung
Keyword(s):  
High Frequency ◽  
Doppler Imaging ◽  
Adult Zebrafish ◽  
High Frequency Ultrasound ◽  
In Vivo Experiments ◽  
Longitudinal Measurements ◽  
Array Transducer ◽  
Spectral Doppler ◽  
Frequency Ultrasound

This paper reports the feasibility of Nakagami imaging in monitoring the regeneration process of zebrafish hearts in a noninvasive manner. In addition, spectral Doppler waveforms that are typically used to access the diastolic function were measured to validate the performance of Nakagami imaging. A 30-MHz high-frequency ultrasound array transducer was used to acquire backscattered echo signal for spectral Doppler and Nakagami imaging. The performances of both methods were validated with flow and tissue-mimicking phantom experiments. For in vivo experiments, both spectral Doppler and Nakagami imaging were simultaneously obtained from adult zebrafish with amputated hearts. Longitudinal measurements were performed for five zebrafish. From the experiments, the E/A ratio measured using spectral Doppler imaging increased at 3 days post-amputation (3 dpa) and then decreased to the value before amputation, which were consistent with previous studies. Similar results were obtained from the Nakagami imaging where the Nakagami parameter value increased at 3 dpa and decreased to its original value. These results suggested that the Nakagami and spectral Doppler imaging would be useful techniques in monitoring the regeneration of heart or tissues.

scholarly journals High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

2015 ◽  
Vol 12 (103) ◽  
pp. 20141154 ◽  
Author(s):  
Bong Jin Kang ◽  
Jinhyoung Park ◽  
Jieun Kim ◽  
Hyung Ham Kim ◽  
Changyang Lee ◽  
...  
Keyword(s):  
Diastolic Dysfunction ◽  
High Frequency ◽  
Doppler Imaging ◽  
Flow Mode ◽  
Heart Regeneration ◽  
Adult Zebrafish ◽  
Dual Mode ◽  
Doppler Flow ◽  
Pulsed Wave Doppler ◽  
Zebrafish Heart

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s −1 with high accuracy ( p -value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E / E m < 10, E / A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation.

A Vector-Sensing Antenna System: A high-frequency, vector-sensing array based on the two-port loop antenna element.

2016 ◽  
Vol 58 (6) ◽  
pp. 57-63 ◽  
Author(s):  
John H. Meloling ◽  
John W. Rockway ◽  
Michael P. Daly ◽  
Aldo R. Monges ◽  
Jeffery C. Allen ◽  
...  
Keyword(s):  
High Frequency ◽  
Antenna System ◽  
Loop Antenna ◽  
Antenna Element ◽  
Frequency Vector ◽  
System A

High-frequency, vector-flow imaging in the left ventricle of FHF2 deficient murine heart

2020 ◽  
Author(s):  
Jeffrey A. Ketterling ◽  
Akshay Shekhar ◽  
Glenn I. Fishman ◽  
Orlando Aristizabal ◽  
Colin K.L. Phoon
Keyword(s):  
Left Ventricle ◽  
High Frequency ◽  
Flow Imaging ◽  
Frequency Vector

scholarly journals Motor cortex neurovascular coupling: inputs from ultra–high-frequency ultrasound imaging in humans

2019 ◽  
Vol 131 (5) ◽  
pp. 1632-1638 ◽  
Author(s):  
Fabien Almairac ◽  
Denys Fontaine ◽  
Thomas Demarcy ◽  
Hervé Delingette ◽  
Stéphanie Beuil ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Motor Cortex ◽  
High Frequency ◽  
Cortical Area ◽  
Neurovascular Coupling ◽  
Doppler Imaging ◽  
High Frequency Ultrasound ◽  
Local Cerebral Blood Flow ◽  
Frequency Ultrasound

OBJECTIVENeurovascular coupling reflects the link between neural activity and changes in cerebral blood flow. Despite many technical advances in functional exploration of the brain, including functional MRI, there are only a few reports of direct evidence of neurovascular coupling in humans. The authors aimed to explore, for the first time in humans, the local cerebral blood flow of the primary motor cortex using ultra–high-frequency ultrasound (UHF-US) Doppler imaging to detect low blood flow velocity (1 mm/sec).METHODSFour consecutive patients underwent awake craniotomy for glioma resection using cortical direct electrostimulation for brain mapping. The primary motor cortical area eliciting flexion of the contralateral forearm was identified. UHF-US color Doppler imaging of this cortical area was acquired at rest, during repeated spontaneous forearm flexion, and immediately after the movement’s termination. In each condition, the surface areas of the detectable vessels were measured after extraction of non–zero-velocity colored pixels and summed.RESULTSDuring movement, local cerebral blood flow increased significantly by 14.4% (range 5%–30%) compared with baseline. Immediately after the termination of movements, the local hyperemia decreased significantly by 8.6% (range 1.9%–15.7%).CONCLUSIONSTo the authors’ knowledge, this study is the first to provide a real-time demonstration of the neurovascular coupling in the human cortex by ultrasound imaging. They assume that UHF-US may be used to gather original and advanced data on brain functioning, which could be used to help in the identification of functional cortical areas during brain surgery.Clinical trial registration no.: NCT03179176 (clinicaltrials.gov)

scholarly journals Abdominal ultrasonographic imaging of laboratory animals - Current techniques

2017 ◽  
Vol 60 (3) ◽  
pp. 245
Author(s):  
K. MARINOU
Keyword(s):  
Blood Flow ◽  
Biomedical Research ◽  
High Frequency ◽  
Companion Animals ◽  
Three Dimensions ◽  
Doppler Imaging ◽  
Laboratory Animals ◽  
Ultra High Frequency ◽  
Abdominal Organs ◽  
Multiple Scan

Diagnostic ultrasonography is a non-invasive imaging technique developed and applicable both in reproductive and companion animals for the diagnosis of diseases. During the last years it has also been used in laboratory animals facilitating thus the advances of biomedical research. The ultrasonographic imaging of abdominal organs in laboratory animals may take place in soft tissue organs, such as the liver, the spleen, the kidneys, the urinary bladder, but also the uterus, especially before, during and after pregnancy, as well as during parturition. It has been proved to be extremely useful both for monitoring of organ architecture during several related experimental protocols and for diagnosing possible diseases that may occur during a laboratory animal's lifetime. During the last decade technological progress has been present in scientific life leading in several advances in ultrasonographic imaging. More specifically, ultra high frequency transducers, with a potential of using sophisticated software, are now able to provide researchers with extended field of view images even of small laboratory animals, such as mice. 3D ultrasonography relies on the acquisition of images in multiple scan planes from which a 3D image is created. 4D ultrasonography provides functional data in three dimensions, whereas microbubble contrast agents have shown clinical potential for characterizing blood flow in abdominal vessels, especially with the use of ultra high frequency transducers and 3D imaging. Doppler imaging provides information on blood flow and abdominal organs blood supply. Finally, ultrasound- guided biopsy and injection of substances are important tools in biomedical research protocols.

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