The Experts below are selected from a list of 46755 Experts worldwide ranked by ideXlab platform

Joseph V. Bonventre - One of the best experts on this subject based on the ideXlab platform.

  • High-Resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion
    Kidney international, 2016
    Co-Authors: Krisztina Fischer, F. Can Meral, Yongzhi Zhang, Mark Vangel, Ferenc A. Jolesz, Takaharu Ichimura, Joseph V. Bonventre
    Abstract:

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-Resolution, Pixel-by-Pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each Pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with High-Resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man.

Krisztina Fischer - One of the best experts on this subject based on the ideXlab platform.

  • High-Resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion
    Kidney international, 2016
    Co-Authors: Krisztina Fischer, F. Can Meral, Yongzhi Zhang, Mark Vangel, Ferenc A. Jolesz, Takaharu Ichimura, Joseph V. Bonventre
    Abstract:

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-Resolution, Pixel-by-Pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each Pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with High-Resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man.

Andrew E Arai - One of the best experts on this subject based on the ideXlab platform.

  • a quantitative Pixel wise measurement of myocardial blood flow by contrast enhanced first pass cmr perfusion imaging microsphere validation in dogs and feasibility study in humans
    Jacc-cardiovascular Imaging, 2012
    Co-Authors: Liyueh Hsu, Daniel W Groves, Anthony H Aletras, Peter Kellman, Andrew E Arai
    Abstract:

    Objectives The aim of this study was to evaluate fully quantitative myocardial blood flow (MBF) at a Pixel level based on contrast-enhanced first-pass cardiac magnetic resonance (CMR) imaging in dogs and in patients. Background Microspheres can quantify MBF in subgram regions of interest, but CMR perfusion imaging may be able to quantify MBF and differentiate blood flow at a much Higher Resolution. Methods First-pass CMR perfusion imaging was performed in a dog model with local hyperemia induced by intracoronary adenosine. Fluorescent microspheres were the reference standard for MBF validation. CMR perfusion imaging was also performed on patients with significant coronary artery disease (CAD) by invasive coronary angiography. Myocardial time-signal intensity curves of the images were quantified on a Pixel-by-Pixel basis using a model-constrained deconvolution analysis. Results Qualitatively, color CMR perfusion Pixel maps were comparable to microsphere MBF bull's-eye plots in all animals. Pixel-wise CMR MBF estimates correlated well against subgram (0.49 ± 0.14 g) microsphere measurements (r = 0.87 to 0.90) but showed minor underestimation of MBF. To reduce bias due to misregistration and minimize issues related to repeated measures, 1 hyperemic and 1 remote sector per animal were compared with the microsphere MBF, which improved the correlation (r = 0.97 to 0.98), and the bias was close to zero. Sector-wise and Pixel-wise CMR MBF estimates also correlated well (r = 0.97). In patients, color CMR stress perfusion Pixel maps showed regional blood flow decreases and transmural perfusion gradients in territories served by stenotic coronary arteries. MBF estimates in endocardial versus epicardial subsectors, and ischemic versus remote sectors, were all significantly different (p Conclusions Myocardial blood flow can be quantified at the Pixel level (∼32 μl of myocardium) on CMR perfusion images, and results compared well with microsphere measurements. High-Resolution Pixel-wise CMR perfusion maps can quantify transmural perfusion gradients in patients with CAD.

Mark Vangel - One of the best experts on this subject based on the ideXlab platform.

  • High-Resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion
    Kidney international, 2016
    Co-Authors: Krisztina Fischer, F. Can Meral, Yongzhi Zhang, Mark Vangel, Ferenc A. Jolesz, Takaharu Ichimura, Joseph V. Bonventre
    Abstract:

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-Resolution, Pixel-by-Pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each Pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with High-Resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man.

Yongzhi Zhang - One of the best experts on this subject based on the ideXlab platform.

  • High-Resolution renal perfusion mapping using contrast-enhanced ultrasonography in ischemia-reperfusion injury monitors changes in renal microperfusion
    Kidney international, 2016
    Co-Authors: Krisztina Fischer, F. Can Meral, Yongzhi Zhang, Mark Vangel, Ferenc A. Jolesz, Takaharu Ichimura, Joseph V. Bonventre
    Abstract:

    Alterations in renal microperfusion play an important role in the development of acute kidney injury with long-term consequences. Here we used contrast-enhanced ultrasonography as a novel method for depicting intrarenal distribution of blood flow. After infusion of microbubble contrast agent, bubbles were collapsed in the kidney and postbubble destruction refilling was measured in various regions of the kidney. Local perfusion was monitored in vivo at 15, 30, 45, 60 minutes and 24 hours after 28 minutes of bilateral ischemia in 12 mice. High-Resolution, Pixel-by-Pixel analysis was performed on each imaging clip using customized software, yielding parametric perfusion maps of the kidney, representing relative blood volume in each Pixel. These perfusion maps revealed that outer medullary perfusion decreased disproportionately to the reduction in the cortical and inner medullary perfusion after ischemia. Outer medullary perfusion was significantly decreased by 69% at 60 minutes postischemia and remained significantly less (40%) than preischemic levels at 24 hours postischemia. Thus, contrast-enhanced ultrasonography with High-Resolution parametric perfusion maps can monitor changes in renal microvascular perfusion in space and time in mice. This novel technique can be translated to clinical use in man.