Publications by authors named "L T M Keijzer"

Ultrasound-based shear wave elastography is a promising technique to non-invasively assess the dynamic stiffness variations of the heart. The technique is based on tracking the propagation of acoustically induced shear waves in the myocardium of which the propagation speed is linked to tissue stiffness. This measurement is repeated multiple times across the cardiac cycle to assess the natural variations in wave propagation speed.

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Article Synopsis
  • Dairy cattle are commonly disbudded or dehorned, yet the role of horns in thermoregulation is not well understood.
  • This study utilized infrared thermography to assess the temperature of horns, eyes, and ears in dairy cows, finding that horn temperature increased with heat load, suggesting horns help dissipate heat.
  • Dehorned cows exhibited higher eye temperatures, indicating potential physiological impacts from horn removal, but the study found no significant temperature changes related to rumination, highlighting the need for cautious interpretation regarding the consequences of dehorning.
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Background: Echo-Particle Image Velocimetry (echoPIV) tracks speckle patterns from ultrasound contrast agent(UCA), being less angle-sensitive than colour Doppler. High frame rate (HFR) echoPIV enables tracking of high velocity flow in the left ventricle (LV). We aimed to demonstrate the potential clinical use of HFR echoPIV and investigate the feasibility and accuracy in patients.

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Shear wave elastography (SWE) has the potential to determine cardiac tissue stiffness from non-invasive shear wave speed measurements, important, e.g., for predicting heart failure.

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High-frame-rate (HFR) echo-particle image velocimetry (echoPIV) is a promising tool for measuring intracardiac blood flow dynamics. In this study, we investigate the optimal ultrasound contrast agent (UCA: SonoVue) infusion rate and acoustic output to use for HFR echoPIV (PRF = 4900 Hz) in the left ventricle (LV) of patients. Three infusion rates (0.

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