Evaluation of error factors depending on ultrasonic transmitted beamwidth in measurement of myocardial minute velocity

Abstract

A measurement by transmitting ultrasonic non-focusing beams increases the temporal resolution but causes an error in the velocity measurements because of the lower signal-to-noise ratio (SNR) caused by the lower transmitted power and the lower spatial resolution. In the present study, we evaluated the relationship between the SNR and the transmitted beamwidth by the phantom experiment. The SNR decreased as the beamwidth became wider, and the measurement error increased when SNR was lower than 10 dB. Furthermore, the error factor due to the low spatial resolution more affected the measurement error than that due to the low transmitted power.

Determination of thermal and mechanical indices of an ultrasound probe with an inclined beam-axis in accordance with the new JIS (or IEC Standards)

“…Research on ultrasonic diagnosis [1][2][3][4][5][6][7][8][9][10][11][12][13] and ultrasonic therapy 14,15) are important in developing safe and highperformance medical ultrasonic equipment. As for ultrasonic diagnostic equipment, precise and practical test methods for the determination of thermal and mechanical indices related to medical diagnostic ultrasonic fields are required to ensure the safety of patients in diagnosis.…”

High-speed measurement of two-dimensional displacement of myocardium using element RF data of ultrasonic probe

“…[21][22][23][24][25] As unfocused wave transmission realises a spatially wider range of measurements, this technique significantly improves the temporal resolution and achieves a high density of scan lines in the lateral direction. 26,27) However, signals from other scatterers that move independently are also added and spatially averaged, which contaminates the amplitude of the receiving beam and affects the measurement of the 2D dimensional displacement.…”