Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, noninvasively and in real time. In this study, we present the first implementation of Ultrafast...

Certain pathological conditions, such as malignant tumours, manifest themselves as changes in the tissue's mechanical stiffness. This is the basis for palpation. Several techniques for imaging tissue elasticity using ultrasound have been proposed: compression elastography (strain imaging), transient elastography and vibration sonoelastography. The latter involves imaging of vibration patterns r...

Doppler ultrasound is widely used diagnostic tool for measuring and detecting blood flow. To get a Doppler ultrasound spectrum image with a good quality, the clutter signals generated from stationary and slowly moving tissue must be removed completely. Without enough clutter rejection, low velocity blood flow cannot be measured, and estimates of higher velocities will have a large bias. In most...

One recognized limitation of carotid Doppler/ultrasound is its accuracy in differentiating occlusion from near-total occlusion of the internal carotid artery, which is a crucial issue in management decisions. Clinical histories were reviewed in 58 patients with apparent occlusion of an internal carotid artery diagnosed by Doppler/ultrasound who also underwent angiography. False-positive results...

Purpose. The aim of this study was to determine the value of 3D and 3D Power Doppler sonography in the detection of tumor malignancy in breast lesions and to find new diagnostic criteria for differential diagnosis. Methods. One hundred and twenty five women with clinically or mammographically suspicious findings were referred for 3D Power Doppler ultrasound prior to surgery. Histological diagno...

Twenty-four patients with suspected aortic stenosis (Group I) were evaluated noninvasively by continuous wave Doppler ultrasound before undergoing cardiac catheterization. Twenty normal subjects served as the control group (Group II). Maximal velocity measurements in the ascending aorta ranged from 3.0 to 5.8 m/s (mean 4.34 +/- 0.65) in Group I versus 1.0 to 1.6 m/s (mean 1.28 +/- 0.16) in Grou...

Figure 1. Spectral analysis and the Doppler display. The fast Fourier transform (FFT) separates the Doppler signal into its component Doppler-shift frequencies and determines the amplitude at each frequency. Most ultrasound machines calculate Doppler-shifted frequencies over 5 msec increments and convert this to velocity information. These velocities are then displayed in a bin whose brightness...

Sir, In a recent technical note, Zanen et al. reported poor agreement between different Doppler flow measurements in dialysis shunts, such as conventional Doppler (CD), quantitative colour velocity index (CVI-Q) and ultrasound dilution (DU) w1x. In particular, results of CD measurements did not correlate with those obtained with CVI-Q and DU, respectively. We share the experience of the investi...

Conventional ultrasound in combination with colour Doppler imaging is still the standard diagnostic procedure for patients after renal transplantation. However, while conventional ultrasound in combination with Doppler imaging can diagnose renal artery stenosis and vein thrombosis, it is not possible to display subtle microvascular tissue perfusion, which is crucial for the evaluation of acute ...

We report the first use of sonoelastic Doppler ultrasound for in vivo and in vitro clinical studies of intraocular pressure (IOP). The method involves low-amplitude and low-frequency sonic excitation of the eye, and detection of the resulting vibration using Doppler ultrasound. A dependence of the frequency of resonance of the eye on the IOP has been observed in both in vitro and in vivo experi...