Gewebeatmung

Grote, J.

doi:10.1007/978-3-642-87854-1_23

Cited by 3 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The blood oxygenation levels obtained in vivo with the multiecho gradient echo method ( Y MEGE = 0.55 ± 0.02) are not only in good agreement with values obtained for several vessels of the same volunteers by applying a different MRI method utilizing high resolution phase information ( Y PHS = 0.53 ± 0.03), but also with physiology (19) and with values obtained with different imaging methods, such as positron emission tomography (PET). Ito et al reported a cerebral oxygenation extraction fraction of OEF = 0.44 ± 0.06 (20) in 70 healthy volunteers, which corresponds to a blood oxygenation of Y ≈ 0.56.…”

Section: Discussionmentioning

confidence: 99%

Obtaining blood oxygenation levels from MR signal behavior in the presence of single venous vessels

Sedlacik

Rauscher

Reichenbach

2007

Magnetic Resonance in Med

View full text Add to dashboard Cite

The MR signal decay in gradient echo sequences includes signal loss due to spin dephasing caused by static magnetic field inhomogeneities. This decay can be calculated for different geometries of the susceptibility distribution, such as spheres, cylinders, or cylinder networks. In particular, the model of an infinitely long cylinder is a good approximation for single straight blood vessels. Blood oxygenation and blood volume fraction are important parameters, which influence the signal in a characteristic way. In this work the signal decays for a single cylindrical vessel were investigated and evaluated in simulations, phantom measurements as well as in vivo measurements of small single veins in the human brain by using a 3D multiecho gradient echo sequence.

show abstract

Section: Discussionmentioning

confidence: 99%

Obtaining blood oxygenation levels from MR signal behavior in the presence of single venous vessels

Sedlacik

Rauscher

Reichenbach

2007

Magnetic Resonance in Med

View full text Add to dashboard Cite

show abstract

“…The hepatic blood supply is supported by both arterial and venous systems; approximately 30% of blood flow to the liver is well-oxygenated blood provided by the hepatic artery, and the other 70% is poorly oxygenated blood derived from the portal vein. The normal range of p O 2 in the hepatic artery is 90–100 mmHg, whereas that in the portal vein p O 2 is 45–55 mmHg [8]. Consequently, the tissue oxygenation in liver is lower than that in other tissues.…”

Section: Introductionmentioning

confidence: 99%

Hypoxia‐Inducible Factor‐1 Is a Determinant of Lobular Structure and Oxygen Consumption in the Liver

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Liver blood flow is a combination of arterial and venous blood. About 30% of the blood flow to the liver is well-oxygenated blood provided by the hepatic artery and the other 70%, provided by the portal vein, is the poorly oxygenated blood venous outflow from the spleen and gastrointestinal tract 7 . Liver diseases such as fatty liver, shock, or tumor change the blood flow in the hepatic microcirculation.…”

Section: Representative Resultsmentioning

confidence: 99%

Visualization and Analysis of Blood Flow and Oxygen Consumption in Hepatic Microcirculation: Application to an Acute Hepatitis Model

Tsukada

Suematsu

2012

JoVE

View full text Add to dashboard Cite

There is a considerable discrepancy between oxygen supply and demand in the liver because hepatic oxygen consumption is relatively high but about 70% of the hepatic blood supply is poorly oxygenated portal vein blood derived from the gastrointestinal tract and spleen. Oxygen is delivered to hepatocytes by blood flowing from a terminal branch of the portal vein to a central venule via sinusoids, and this makes an oxygen gradient in hepatic lobules. The oxygen gradient is an important physical parameter that involves the expression of enzymes upstream and downstream in hepatic microcirculation, but the lack of techniques for measuring oxygen consumption in the hepatic microcirculation has delayed the elucidation of mechanisms relating to oxygen metabolism in liver. We therefore used FITC-labeled erythrocytes to visualize the hepatic microcirculation and used laser-assisted phosphorimetry to measure the partial pressure of oxygen in the microvessels there. Noncontact and continuous optical measurement can quantify blood flow velocities, vessel diameters, and oxygen gradients related to oxygen consumption in the liver. In an acute hepatitis model we made by administering acetaminophen to mice we observed increased oxygen pressure in both portal and central venules but a decreased oxygen gradient in the sinusoids, indicating that hepatocyte necrosis in the pericentral zone could shift the oxygen pressure up and affect enzyme expression in the periportal zone. In conclusion, our optical methods for measuring hepatic hemodynamics and oxygen consumption can reveal mechanisms related to hepatic disease. Video LinkThe video component of this article can be found at http://www.jove.com/video/3996/ Protocol Labeling Erythrocytes with Fluorescein Isothiocyanate Isomer I (FITC)All the experimental protocols we used were approved by the Animal Care Committee of Keio University School of Medicine. Preparation of Oxygen-sensitive Dye Animal Preparation

show abstract

Gewebeatmung

Cited by 3 publications

References 34 publications

Obtaining blood oxygenation levels from MR signal behavior in the presence of single venous vessels

Obtaining blood oxygenation levels from MR signal behavior in the presence of single venous vessels

Hypoxia‐Inducible Factor‐1 Is a Determinant of Lobular Structure and Oxygen Consumption in the Liver

Visualization and Analysis of Blood Flow and Oxygen Consumption in Hepatic Microcirculation: Application to an Acute Hepatitis Model

Contact Info

Product

Resources

About