Backscatter properties of two-layer phantoms using a high-frequency ultrasound annular array

Abstract In a previous study, an annular-array transducer was employed to characterize homogeneous scattering phantoms and excised rat livers using backscatter envelope statistics and frequency domain analysis. A sound field correction method was also applied to take into account the average attenuation of the entire scattering medium. Here, we further generalized the evaluation of backscatter coefficient (BSC) using the annular array in order to study skin tissues with a complicated structure. In layered phantoms composed of two types of media with different scattering characteristics, the BSC was evaluated by the usual attenuation correction method which revealed an expected large difference from the predicted BSC. In order to improve the BSC estimate, a correction method that applied the attenuation of each layer as a reference combined with a method that corrects based on the attenuation of the analysis position were applied. It was found that the method using the average attenuation of each layer is the most effective. This correction method is well adapted to the extended depth of field provided by an annular array.

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Dual-concentric transducer with phase apodization for wide depth of field of high-frequency ultrasound imaging

2014 IEEE International Ultrasonics Symposium ◽

10.1109/ultsym.2014.0385 ◽

2014 ◽

Author(s):

Jong Seob Jeong ◽

Sung Min Kim

Keyword(s):

Ultrasound Imaging ◽

High Frequency ◽

Depth Of Field ◽

High Frequency Ultrasound ◽

High Frequency Ultrasound Imaging ◽

Frequency Ultrasound

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Dual-Element Transducer with Phase-Inversion for Wide Depth of Field in High-Frequency Ultrasound Imaging

Sensors ◽

10.3390/s140814278 ◽

2014 ◽

Vol 14 (8) ◽

pp. 14278-14288 ◽

Cited By ~ 1

Author(s):

Jong Jeong

Keyword(s):

Ultrasound Imaging ◽

High Frequency ◽

Phase Inversion ◽

Depth Of Field ◽

High Frequency Ultrasound ◽

High Frequency Ultrasound Imaging ◽

Frequency Ultrasound

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

Sensors ◽

10.3390/s19194094 ◽

2019 ◽

Vol 19 (19) ◽

pp. 4094 ◽

Cited By ~ 1

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.

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DESIGN AND FABRICATION OF A 20 MHz ANNULAR ARRAY FOR MEDICAL ULTRASOUND

Journal of Innovative Optical Health Sciences ◽

10.1142/s1793545811500106 ◽

2012 ◽

Vol 05 (01) ◽

pp. 1150010

Author(s):

ZHENHUA HU ◽

JUE PENG

Keyword(s):

Focal Point ◽

Impedance Matching ◽

Center Frequency ◽

Depth Of Field ◽

Single Element ◽

Medical Ultrasound ◽

Annular Array ◽

Array Transducer ◽

Small Depth

Most high frequency (> 15 MHz) medical ultrasound systems are based on single element transducers mechanically scanned. These systems can provide images with excellent resolution. However, single element transducers are often limited by the fixed focal point and small depth of field. Annular arrays consisting of concentric rings of elements are focused electronically. These arrays are desirable to avoid the fixed focal point of the single element transducers and improve the depth of field. This paper reports the design, fabrication, and characterization of a 5-element equal-area annular array transducer. After electrical impedance matching, the average center frequency was 20 MHz and -6 dB bandwidths ranged from 34 to 42%. The ILs for the matched annuli ranged from 6.1 to 26.5 dB.

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