1
|
Forsberg F, Stanczak M, Sinanan JK, Blackman R. Second-Generation Differential Tissue Harmonic Imaging Improves the Visualization of Renal Lesions. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2023; 42:853-857. [PMID: 35920345 DOI: 10.1002/jum.16071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVES To compare to three nonlinear imaging techniques to conventional, grayscale ultrasound imaging of renal lesions. METHODS Twenty adults with a known renal lesion and a body mass index >25 kg/m2 were enrolled in this prospective, institutional review board approved study. Each subject was imaged with an Aplio 500 scanner (Canon Medical Systems, Tokyo, Japan) using grayscale ultrasound, tissue harmonic imaging (THI) and two dual-frequency, differential tissue harmonic imaging modes (DTHI and DTHI-II, respectively). In total 184 images were scored by three independent and blinded observers for detail resolution, image quality, margin delineation, and depth penetration. Quantitative contrast-to-noise ratios (CNRs) were also calculated. RESULTS Readers and CNR values showed that nonlinear imaging was superior to grayscale ultrasound (P < .0014). DTHI-II outperformed DTHI, THI, and grayscale ultrasound with respect to detail resolution, image quality, and margin delineation (P < .012). The depth penetration of DTHI and DTHI-II was similar (P = .16), but superior to grayscale ultrasound and THI (P < .001). Two observers saw improvements in detail resolution with DTHI-II over DTHI (P < .05), while image quality and margin delineation were considered similar by two readers (P > .07) and improved with DTHI-II by one (P < .017). CONCLUSIONS DTHI-II improves the imaging of renal lesions compared to DTHI, THI, and grayscale ultrasound, albeit based on a limited sample size.
Collapse
Affiliation(s)
- Flemming Forsberg
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Maria Stanczak
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jesse K Sinanan
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Rachel Blackman
- Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
2
|
Solberg S, Amini N, Zaza Y, Angelsen BAJ, Hansen R. Estimation of fat content in soft tissues using dual frequency ultrasound-A phantom study. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:1766. [PMID: 37002069 DOI: 10.1121/10.0017601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 02/25/2023] [Indexed: 05/18/2023]
Abstract
This paper presents an initial investigation into the use of dual frequency pulse-echo ultrasound, second order ultrasound field (SURF) imaging, to measure the fat content of soft tissues. The SURF imaging method was used to measure the non-linear bulk elasticity (NBE) of several fatty phantoms that were created by mixing different mass fractions of soybean oil uniformly into agar phantoms. The median of the measured NBE within the estimation region was found to increase linearly with fat mass fraction (R2 = 0.99), from 1.7 GPa-1 at 9.6% fat to 2.52 GPa-1 at 63.6% fat, thus, showing promise as a sensitive parameter for fat content measurement. Comparisons to mixture laws in earlier literature are made, and the most important error sources that need to be considered for the in vivo applications of the method are discussed.
Collapse
Affiliation(s)
| | | | - Yamen Zaza
- SURF Technology AS, 7491 Trondheim, Norway
| | - Bjørn A J Angelsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Rune Hansen
- Department of Health Research, SINTEF Digital, 7465 Trondheim, Norway
| |
Collapse
|
3
|
Kvam J, Solberg S, Myhre OF, Rodriguez-Molares A, Angelsen BAJ. Nonlinear bulk elasticity imaging using dual frequency ultrasound. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:2492. [PMID: 31671951 DOI: 10.1121/1.5129120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 09/22/2019] [Indexed: 06/10/2023]
Abstract
The nonlinear acoustic bulk properties of tissue, e.g., the coefficient of nonlinearity, βn, or the nonlinear bulk elasticity, βp=βnκ0, have been shown to be promising parameters for tissue characterization due to their sensitivity to tissue structure. Previously developed methods for imaging these parameters using single frequency ultrasound have shown success in a laboratory setting using the transmission mode. In the pulse-echo mode, however, unknown absorption, diffraction, and speckle produce unreliable estimates and instability, causing these methods to have achieved no clinical relevance. In this paper, a pulse-echo method for measurement of the nonlinear bulk elasticity is presented using a dual frequency approach. The method is less sensitive to diffraction and absorption due to a separate low frequency manipulation wave. The technique is tested in both simulations and in vitro in a heterogeneous phantom with two regions of different nonlinear properties. Both in simulations and in vitro, a spatial βp map is produced where the two regions are clearly distinguished. In addition, the quantitative estimates of βp obtained are close to the expected values, making the method a promising first step toward in vivo imaging of nonlinear bulk properties.
Collapse
Affiliation(s)
- Johannes Kvam
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, 7030, Norway
| | - Stian Solberg
- SURF Technology AS, Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, P.O. Box 8905, 7491, Trondheim, Norway
| | - Ola F Myhre
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, 7030, Norway
| | - Alfonso Rodriguez-Molares
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, 7030, Norway
| | - Bjørn A J Angelsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, 7030, Norway
| |
Collapse
|
4
|
Kvam J, Holm S, Angelsen BAJ. Exploiting Ballou's rule for better tissue classification. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:2103. [PMID: 31046352 DOI: 10.1121/1.5096533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/09/2019] [Indexed: 06/09/2023]
Abstract
Ultrasound tissue characterization based on the coefficient of nonlinearity, βn = 1 + B/2A, has been demonstrated to produce added diagnostic value due to its large variation and sensitivity to tissue structure. However, the parameter has been observed to be significantly correlated to the speed of sound and density. These relationships are analyzed empirically as well as theoretically by developing a pressure-density relation based on a thermodynamic model and the Mie intermolecular potential. The results indicate that for many soft tissues, the coefficient of nonlinearity is largely determined by the isentropic compressibility, κs. Consequently, for tissue characterization, estimating the nonlinear response of the medium, given by βp = βnκs, appears to be beneficial due to correlated quantities.
Collapse
Affiliation(s)
- Johannes Kvam
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, P.O. Box 8905, N-7489, Trondheim, Norway
| | - Sverre Holm
- Department of Informatics, University of Oslo, P.O. Box 1080, NO-0316 Oslo, Norway
| | - Bjørn A J Angelsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, P.O. Box 8905, N-7489, Trondheim, Norway
| |
Collapse
|
5
|
Arif M, Ali MA, Shaikh MM, Freear S. Investigation of Non-linear Chirp Coding for Improved Second Harmonic Pulse Compression. ULTRASOUND IN MEDICINE & BIOLOGY 2017; 43:1690-1702. [PMID: 28483580 DOI: 10.1016/j.ultrasmedbio.2017.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 02/04/2017] [Accepted: 03/16/2017] [Indexed: 06/07/2023]
Abstract
Non-linear frequency-modulated (NLFM) chirp coding was investigated to improve the pulse compression of the second harmonic chirp signal by reducing the range side lobe level. The problem of spectral overlap between the fundamental component and second harmonic component (SHC) was also investigated. Therefore, two methods were proposed: method I for the non-overlap condition and method II with the pulse inversion technique for the overlap harmonic condition. In both methods, the performance of the NLFM chirp was compared with that of the reference LFM chirp signals. Experiments were performed using a 2.25 MHz transducer mounted coaxially at a distance of 5 cm with a 1 mm hydrophone in a water tank, and the peak negative pressure of 300 kPa was set at the receiver. Both simulations and experimental results revealed that the peak side lobe level (PSL) of the compressed SHC of the NLFM chirp was improved by at least 13 dB in method I and 5 dB in method II when compared with the PSL of LFM chirps. Similarly, the integrated side lobe level (ISL) of the compressed SHC of the NLFM chirp was improved by at least 8 dB when compared with the ISL of LFM chirps. In both methods, the axial main lobe width of the compressed NLFM chirp was comparable to that of the LFM signals. The signal-to-noise ratio of the SHC of NLFM was improved by as much as 0.8 dB, when compared with the SHC of the LFM signal having the same energy level. The results also revealed the robustness of the NLFM chirp under a frequency-dependent attenuation of 0.5 dB/cm·MHz up to a penetration depth of 5 cm and a Doppler shift up to 12 kHz.
Collapse
Affiliation(s)
- Muhammad Arif
- Department of Biomedical Engineering, Mehran University of Engineering and Technology, Jamshoro, Pakistan.
| | - Muhammad Asim Ali
- Department of Electrical Engineering, Sukkur Institute of Business Administration, Sukkur, Pakistan
| | - Muhammad Mujtaba Shaikh
- Department of Basic Sciences and Related Studies, Mehran University of Engineering and Technology, Jamshoro, Pakistan
| | - Steven Freear
- School of Electronic and Electrical Engineering, University of Leeds, Leeds, UK
| |
Collapse
|
6
|
Omari E, Lee H, Varghese T. Theoretical and phantom based investigation of the impact of sound speed and backscatter variations on attenuation slope estimation. ULTRASONICS 2011; 51:758-67. [PMID: 21477832 PMCID: PMC3183956 DOI: 10.1016/j.ultras.2011.03.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 03/01/2011] [Accepted: 03/06/2011] [Indexed: 05/22/2023]
Abstract
Quantitative ultrasound features such as the attenuation slope, sound speed and scatterer size, have been utilized to evaluate pathological variations in soft tissues such as the liver and breast. However, the impact of variations in the sound speed and backscatter due to underlying fat content or fibrotic changes, on the attenuation slope has not been addressed. Both numerical and acoustically uniform tissue-mimicking experimental phantoms are used to demonstrate the impact of sound speed variations on attenuation slope using clinical real-time ultrasound scanners equipped with linear array transducers. Radiofrequency data at center frequencies of 4 and 5 MHz are acquired for the experimental and numerical phantoms respectively. Numerical phantom sound speeds between 1480 and 1600 m/s in increments of 20 m/s for attenuation coefficients of 0.3, 0.4, 0.5, 0.6, and 0.7 dB/cm/MHz are simulated. Variations in the attenuation slope when the backscatter intensity of the sample is equal, 3 dB higher, and 3 dB lower than the reference is also evaluated. The sound speed for the experimental tissue-mimicking phantoms were 1500, 1540, 1560 and 1580 m/s respectively, with an attenuation coefficient of 0.5 dB/cm/MHz. Radiofrequency data is processed using three different attenuation estimation algorithms, i.e. the reference phantom, centroid downshift, and a hybrid method. In both numerical and experimental phantoms our results indicate a bias in attenuation slope estimates when the reference phantom sound speed is higher (overestimation) or lower (underestimation) than that of the sample. This bias is introduced via a small spectral shift in the normalized power spectra of the reference and sample with different sound speeds. The hybrid method provides the best estimation performance, especially for sample attenuation coefficient values lower than that of the reference phantom. The performance of all the methods deteriorates when the attenuation coefficient of the reference phantom is lower than that of the sample. In addition, the hybrid method is the least sensitive to sample backscatter intensity variations.
Collapse
Affiliation(s)
- Eenas Omari
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue Madison, WI 53706, USA
- Department of Electrical and Computer Engineering University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Heichang Lee
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue Madison, WI 53706, USA
- Department of Electrical and Computer Engineering University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| | - Tomy Varghese
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue Madison, WI 53706, USA
- Department of Electrical and Computer Engineering University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA
| |
Collapse
|
7
|
Näsholm SP, Hansen R, Angelsen BAJ. Post-processing enhancement of reverberation-noise suppression in dual-frequency SURF imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2011; 58:338-348. [PMID: 21342819 DOI: 10.1109/tuffc.2011.1811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A post-processing adjustment technique to enhance dual-frequency second-order ultrasound field (SURF) reverberation-noise suppression imaging in medical ultrasound is analyzed. Two variant methods are investigated through numerical simulations. They both solely involve post-processing of the propagated high-frequency (HF) imaging wave fields, which in real-time imaging corresponds to post-processing of the beamformed receive radio-frequency signals. Hence, the transmit pulse complexes are the same as for the previously published SURF reverberation-suppression imaging method. The adjustment technique is tested on simulated data from propagation of SURF pulse complexes consisting of a 3.5-MHz HF imaging pulse added to a 0.5-MHz low-frequency soundspeed manipulation pulse. Imaging transmit beams are constructed with and without adjustment. The post-processing involves filtering, e.g., by a time-shift, to equalize the two SURF HF pulses at a chosen depth. This depth is typically chosen to coincide with the depth where the first scattering or reflection occurs for the reverberation noise one intends to suppress. The beams realized with post-processing show energy decrease at the chosen depth, especially for shallow depths where, in a medical imaging situation, a body-wall is often located. This indicates that the post-processing may further enhance the reverberation- suppression abilities of SURF imaging. Moreover, it is shown that the methods might be utilized to reduce the accumulated near-field energy of the SURF transmit-beam relative to its imaging region energy. The adjustments presented may therefore potentially be utilized to attain a slightly better general suppression of multiple scattering and multiple reflection noise compared with non-adjusted SURF reverberation-suppression imaging.
Collapse
Affiliation(s)
- Sven Peter Näsholm
- Department of Circulation and Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
| | | | | |
Collapse
|