The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Cardiac function has traditionally been studied using pressure-volume (PV) loop analysis. PV loops can be used to derive functional indices such as end-systolic pressure volume relationship (ESPVR)—a measure of myocardial contractility, end-diastolic pressure volume relationship (EDPVR) — a measure of myocardial compliance and relaxation time constant (τ) — a measure of left ventricular relaxation...
Myocardial strain imaging has been shown to add significant prognostic and diagnostic value to echocardiography. While the reliability of ultrasound-based strain measurement techniques has improved considerably in terms of regional consistency and inter-reader, inter-vendor agreement; most state-of-the-art strain imaging packages constrain their analyses to individual cardiac cycles. This limitation...
ARFI displacements have been shown to share an inverse relationship with shear wave speed — based estimates of tissue elasticity. In transthoracic imaging, induced shear waves have been observed during diastole, but only ARFI displacements have been accurately measured through both diastole and systole. We propose here a method for using diastolic shear wave speeds to calibrate ARFI displacement magnitudes,...
ARFI displacements have been shown to share an inverse relationship with shear wave speed — based estimates of tissue elasticity. Both ARFI and shear wave elasticity imaging (SWEI) have been used to track the stiffening and softening of myocardium through the cardiac cycle in open-chest, intracardiac, and Langendorff preparations. In transthoracic imaging, induced shear waves have been observed during...
Strain imaging is gaining traction as a means to assess cardiac function by tracking the cyclic deformation of the myocardium. Compared to traditional measures such as ejection fraction, global myocardial strain has been shown to be an earlier and more sensitive measure of overall ventricular function. Similarly, regional myocardial strain has been shown to be useful for identifying ischemia and myocardial...
Myocardial elastance, derived from pressure-volume (PV) loops in the left ventricle (LV), can be used to assess LV function and myocardial performance. This method requires an invasive intracardiac pressure-volume catheter to be inserted in the LV, limiting the method's utility in clinical screening and monitoring. Strain echocardiography and cardiac acoustic radiation force impulse (ARFI) imaging...
Poor quality ultrasound images and inadequate or suboptimal visualization of imaging targets is a common problem in individuals that are overweight or obese. Acoustic reverberation is an incoherent noise source that is a common factor in overweight and obese individuals and is a significant contributor to the poor image quality. Specifically, diffuse acoustic reverberation is problematic because it...
Measurement of myocardial stiffness using ultrasound-based transient elastography has received significant attention in recent years. The mechanical properties of myocardium not only undergo cyclic dynamic changes over the cardiac cycle but also change on a slower scale with physiological factors. They are also closely tied to several cardiovascular disorders such as heart failure, cardio-toxicity...
Myocardial elasticity is an important indicator of cardiac function and is affected in many disorders associated with heart failure. Ultrasound based interrogation of cardiac stiffness has been extensively studied in ex-vivo, open chest and intracardiac imaging environments. The ability to make these measurements robustly through non-invasive means such as transthoracic imaging would make them more...
Ultrasonography is the primary imaging modality used for diagnostic assessment of fetal and maternal health during pregnancy. However, a large proportion of fetal ultrasound exams suffer from inadequate or lack of visualization of clinically relevant structures due to acoustical noise or clutter. These undesirable effects are even more pronounced in overweight and obese mothers. In previous work our...
Conventional ultrasound backscatter imaging (B-scan) relies on geometric focusing of ultrasound echoes across an aperture. We have previously presented a new method, Shear Wave Induced Phase Encoding (SWIPE) imaging, in which lateral resolution of the target is obtained by using traveling shear waves to encode the lateral position of the scatters in the phase of the received echo. Here we extend the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.