Harmonic Imaging Using Multitone Nonlinear Coding

Nowicki, Andrzej; Wójcik, Janusz; Secomski, Wojciech

doi:10.1016/j.ultrasmedbio.2007.02.001

Cited by 19 publications

(12 citation statements)

References 12 publications

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“…Since only half of the effective bandwidth of the transducer is utilized for either transmitting or receiving, the conventional method is referred to as the single-frequency (SF) harmonic imaging. Recently, dual-frequency (DF) tissue harmonic imaging has been proposed to fully take advantage of the entire bandwidth of the transducer by simultaneous transmission at both f 0 and 2f 0 bands [4,5]. With the DF transmission, not only the second harmonic signal at 2f 0 band but also the inter-modulation harmonic signal at f 0 band will be generated within the pass band of the transducer during the nonlinear propagation of the acoustic waveform.…”

Section: Introductionmentioning

confidence: 99%

Supplementary Golay pair for range side lobe suppression in dual-frequency tissue harmonic imaging

Shen

Peng

2015

Ultrasonics

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Section: Introductionmentioning

confidence: 99%

Supplementary Golay pair for range side lobe suppression in dual-frequency tissue harmonic imaging

Shen

Peng

2015

Ultrasonics

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“…In these studies image fusion was achieved offline. Nowicki et al [13] presented dual tone coding which can transmit a combined multi-cycled sinusoidal burst having both fundamental and harmonic frequencies. In this study, however, the axial resolution is worse than the lateral resolution because of the multiple cycled two-tone burst which may not be acceptable for visualizing blood vessel structures smaller than a few hundred microns with 40 MHz IVUS.…”

Section: Introductionmentioning

confidence: 99%

Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60MHz phantom and ex vivo results

Park

Zhou

et al. 2013

Ultrasonics

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The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than –60 dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 μm finer and –3 dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200 μm in diameter with 6 dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI.

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“…because only half of the effective bandwidth is utilized for either transmission or reception, the conventional sF method does not fully exploit the available system bandwidth. To take advantage of the full transducer bandwidth for harmonic imaging, dual-frequency (dF) transmit waveforms have been proposed [8], [9]. In transmission, the dF waveform comprises not only the f 0 transmit signal but also another transmit signal at around the 2f 0 frequency.…”

Section: Introductionmentioning

confidence: 99%

Chirp-encoded excitation for dual-frequency ultrasound tissue harmonic imaging

Shen

Lin

2012

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Dual-frequency (DF) transmit waveforms comprise signals at two different frequencies. With a DF transmit waveform operating at both fundamental frequency (f(0)) and second-harmonic frequency (2f(0)), tissue harmonic imaging can be simultaneously performed using not only the conventional 2f(0) second-harmonic signal but also using the f(0 )frequency-difference harmonic signal. Nonetheless, when chirp excitation is incorporated into the DF transmit waveform for harmonic SNR improvement, a particular waveform design is required to maintain the bandwidth of the f(0) harmonic signal. In this study, two different DF chirp waveforms are proposed to produce equal harmonic bandwidth at both the f(0) and 2f(0) frequencies to achieve speckle reduction by harmonic spectral compounding and to increase harmonic SNR for enhanced penetration and sensitivity. The UU13 waveform comprises an up-sweeping f(0) chirp and an up-sweeping 2f(0) chirp with triple bandwidth, whereas the UD11 waveform includes an up-sweeping f(0) chirp and a down-sweeping 2f(0) chirp with equal bandwidth. Experimental results indicate that the UU13 tends to suffer from a high range side lobe level resulting from 3f(0) interference. Consequently, the 2f(0) harmonic envelopes of the UD11 and the UU13 waveforms have compression qualities of 87% and 77%, respectively, when the signal bandwidth is 30%. When the bandwidth increases to 50%, the compression quality of the 2f(0) harmonic envelope degrades to 78% and 54%, respectively, for the UD11 and the UU13 waveforms. The compression quality value of the f0 harmonic envelope remains similar between the two DF transmit waveforms for all signal bandwidths. B-mode harmonic images also show that the UD11 is less contaminated by range side lobe artifacts than is the UU13. Compared with a short pulse with equal bandwidth, the UD11 waveform not only preserves the same spatial resolution after compression but also improves the image SNR by about 10 dB. Moreover, the image contrast-to-noise ratio (CNR), defined as the ratio of the mean to the standard deviation of image intensity in the speckle region, can be increased from 1.0 to about 1.2 when DF spectral compounding is performed. Therefore, it is concluded that the UD11 waveform is a potential solution for chirp-encoded DF harmonic imaging.

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Harmonic Imaging Using Multitone Nonlinear Coding

Cited by 19 publications

References 12 publications

Supplementary Golay pair for range side lobe suppression in dual-frequency tissue harmonic imaging

Supplementary Golay pair for range side lobe suppression in dual-frequency tissue harmonic imaging

Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60MHz phantom and ex vivo results

Chirp-encoded excitation for dual-frequency ultrasound tissue harmonic imaging

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