Synthetic phased arrays for intraluminal imaging of coronary arteries

O’Donnell, Matthew; Eberle, M.J.; Stephens, Douglas N.; Litzza, J.L.; Vicente, K. San; Shapo, B.M.

doi:10.1109/58.658335

Cited by 100 publications

(38 citation statements)

References 13 publications

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“…Synthetic aperture techniques were first developed for radar [19] and later adapted to ultrasound imaging [20]. Synthetic aperture was first used with linear arrays with reconstruction in the spatial domain [21], but it since has been modified for use with circular arrays [22], [23], and frequency-domain reconstruction methods also have been developed [24]. For the standard linear array method, a single processing channel is time multiplexed across all N transducer elements [ Fig.…”

Section: Introductionmentioning

confidence: 99%

Coherent-array imaging using phased subarrays. Part I: basic principles

Johnson

Karaman

Khuri-Yakub

2005

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

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Abstract-The front-end hardware complexity of a coherent array imaging system scales with the number of active array elements that are simultaneously used for transmission or reception of signals. Different imaging methods use different numbers of active channels and data collection strategies. Conventional full phased array (FPA) imaging produces the best image quality using all elements for both transmission and reception, and it has high front-end hardware complexity. In contrast, classical synthetic aperture (CSA) imaging only transmits on and receives from a single element at a time, minimizing the hardware complexity but achieving poor image quality. We propose a new coherent array imaging method-phased subarray (PSA) imaging-that performs partial transmit and receive beamforming using a subset of adjacent elements at each firing step. This method reduces the number of active channels to the number of subarray elements; these channels are multiplexed across the full array and a reduced number of beams are acquired from each subarray. The low-resolution subarray images are laterally upsampled, interpolated, weighted, and coherently summed to form the final high-resolution PSA image. The PSA imaging reduces the complexity of the front-end hardware while achieving image quality approaching that of FPA imaging.

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Section: Introductionmentioning

confidence: 99%

Coherent-array imaging using phased subarrays. Part I: basic principles

Johnson

Karaman

Khuri-Yakub

2005

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

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“…For example, the ultrasound transducer of this Princeps (Dumed, Rijswijk, The Netherlands) catheter is mounted at an angle of 10 • with respect to the rotating axis. Note that the angle φ 0 will be zero for array IVUS catheters [23].…”

Section: Tilted Catheter In Center Of the Lumenmentioning

confidence: 99%

Influence of catheter position on estimated strain in intravascular elastography

Korte

Cespedes²,

Steen³

1999

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

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In elastography, an erroneous strain estimate is obtained when the radial strain and the probing ultrasound beam are not properly aligned: the "strain projection artifact". In practice, an angle between the strain and the ultrasound beam will be present in most of the cases due to inhomogeneities or nonuniform compression. In this study, a theoretical function describing the strain projection artifact is derived as a function of the angle between the radial strain and the ultrasound beam. Two main factors for an angle between strain and ultrasound beam in intravascular elastographic experiments are eccentricity and tilt of the transducer. The theoretical functions describing these errors are corroborated with strain estimates from an experiment with a circular, homogeneous gel-based vessel phantom. Comparison between the theoretical functions and the experimental results reveals that the strain projection artifact is well described by the theoretical findings. As a result, the experimental data can be corrected for this artifact. The corrected elastograms reveal that correct strain estimates are obtained when the eccentricity of the intravascular catheter is less than 63%. An "off-the-wall" device may be required to advance intravascular elastography to in vivo implementation.

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“…These motion artifacts introduce large noise components and preclude strain imaging in vessels. Rotational artifacts may be minimised by using array catheters such as the synthetic phased array catheter described by O'Donnell et al (1997), and an interface to acquire rf signals from such devices currently is being developed. Although the use of array catheters minimises rotational artefacts, two-dimensional search algorithms will be necessary for in vivo experiments.…”

Section: Discussionmentioning

confidence: 99%

Intravascular Ultrasound Elastography in Human Arteries: Initial Experience In Vitro

Korte

Steen

Cespedes

et al. 1998

Ultrasound in Medicine & Biology

171

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Abstract-Intravascular elastography is a new technique to obtain the local mechanical properties of the vessel wall and its pathology using intravascular ultrasound (IVUS). Knowledge of these mechanical properties may be useful for guiding interventional procedures. An experimental set-up is described for assessment of the strain data of arteries. Using a 30-MHz IVUS catheter, radio frequency data are acquired with a custom-made high-performance data acquisition system. High-resolution, local tissue displacement estimation by crosscorrelation is followed by computation of local strain. An algorithm that uses a priori knowledge of the correlation coefficient function was applied to filter the obtained strain data. With this experimental set-up, intravascular elastograms containing 400 angles/revolution with a radial resolution of 200 m can be produced. The feasibility of intravascular elastography with this experimental set-up is demonstrated using two diseased human femoral arteries. Qualitative comparison of the elastograms with the echograms and the histology demonstrates the potential of intravascular elastography to obtain mechanical information from the vessel wall and from plaque. © 1998 World Federation for Ultrasound in Medicine & Biology.

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Synthetic phased arrays for intraluminal imaging of coronary arteries

Cited by 100 publications

References 13 publications

Coherent-array imaging using phased subarrays. Part I: basic principles

Coherent-array imaging using phased subarrays. Part I: basic principles

Influence of catheter position on estimated strain in intravascular elastography

Intravascular Ultrasound Elastography in Human Arteries: Initial Experience In Vitro

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