Clutter filters adapted to tissue motion in ultrasound color flow imaging

Bjærum, S.; Torp, Hans; Kristoffersen, K.

doi:10.1109/tuffc.2002.1009328

Cited by 115 publications

(79 citation statements)

References 9 publications

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“…Reducing the number of variables by PCA before MANOVA has two benefits. Uncorrelated noise is expected to have a larger spread across the eigenvalue spectrum so eliminating lower variance eigenvectors improves the signal-to-noise ratio (SNR) of the data (Bjaerum et al 2002). Additionally, reducing the number of variables reduces the degrees of freedom thereby enhancing the statistical power of MANOVA (Green 1978).…”

Section: Feature Extraction and Statistical Analysismentioning

confidence: 99%

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

Kucewicz

Dunmire

Leotta

et al. 2007

Ultrasound in Medicine & Biology

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Functional tissue pulsatility imaging (fTPI) is a new ultrasonic technique being developed to map brain function by measuring changes in tissue pulsatility due to changes in blood flow with neuronal activation. The technique is based in principle on plethysmography, an older, non-ultrasound technology for measuring expansion of a whole limb or body part due to perfusion. Perfused tissue expands by a fraction of a percent early in each cardiac cycle when arterial inflow exceeds venous outflow and relaxes later in the cardiac cycle when venous drainage dominates. Tissue pulsatility imaging (TPI) uses tissue Doppler signal processing methods to measure this pulsatile "plethysmographic" signal from hundreds or thousands of sample volumes in an ultrasound image plane. A feasibility study was conducted to determine if TPI could be used to detect regional brain activation during a visual contrast-reversing checkerboard block paradigm study. During a study, ultrasound data were collected transcranially from the occipital lobe as a subject viewed alternating blocks of a reversing checkerboard (stimulus condition) and a static, gray screen (control condition). Multivariate Analysis of Variance (MANOVA) was used to identify sample volumes with significantly different pulsatility waveforms during the control and stimulus blocks. In 7 out 14 studies, consistent regions of activation were detected from tissue around the major vessels perfusing the visual cortex.

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Section: Feature Extraction and Statistical Analysismentioning

confidence: 99%

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

Kucewicz

Dunmire

Leotta

et al. 2007

Ultrasound in Medicine & Biology

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“…Clutter filtering has long been the subject of a number of investigations in focused ultrasound imaging [40], [41]. More investigations have to be made to further improve clutter filtering for parallel-beamforming-based imaging.…”

Section: B Speckle Tracking and Echo Cancelingmentioning

confidence: 99%

Ultrasound Vector Flow Imaging—Part II: Parallel Systems

Jensen

Nikolov

et al. 2016

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

101

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Abstract-The paper gives a review of the current state-of-theart in ultrasound parallel acquisition systems for flow imaging using spherical and plane waves emissions. The imaging methods are explained along with the advantages of using these very fast and sensitive velocity estimators. These experimental systems are capable of acquiring thousands of images per second for fast moving flow as well as yielding estimates of low velocity flow. These emerging techniques allow vector flow systems to assess highly complex flow with transitory vortices and moving tissue, and they can also be used in functional ultrasound imaging for studying brain function in animals. The paper explains the underlying acquisition and estimation methods for fast 2-D and 3-D velocity imaging and gives a number of examples. Future challenges and the potentials of parallel acquisition systems for flow imaging are also discussed.

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“…These include regression filters, based on the assumption that the slowly varying clutter components of the Doppler signal can be approximated by a low-order polynomial [19][20][21], and methods based on eigendecomposition [22][23][24][25][26][27][28].…”

Section: Filtersmentioning

confidence: 99%

Ultrasonic colour Doppler imaging

2011

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Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been found to be of great value in assessing blood flow in many clinical conditions. Although the method for obtaining the velocity information is in many ways similar to the method for obtaining the anatomical information, it is technically more demanding for a number of reasons. It also has a number of weaknesses, perhaps the greatest being that in conventional systems, the velocities measured and thus displayed are the components of the flow velocity directly towards or away from the transducer, while ideally the method would give information about the magnitude and direction of the three-dimensional flow vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new techniques that seek to overcome the vector problem mentioned above are described. Finally, some examples of vector velocity images are presented.

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Clutter filters adapted to tissue motion in ultrasound color flow imaging

Cited by 115 publications

References 9 publications

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

Ultrasound Vector Flow Imaging—Part II: Parallel Systems

Ultrasonic colour Doppler imaging

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