Imaging of flow: basic principles
نویسندگان
چکیده
Indicator dilution techniques for measuring blood flow have existed for more than 100 years. Indicators may be either intravascular, or freely diffusible. Early techniques establishing the mathematical framework for flow (the Fick principle, Kety–Schmidt method, and central volume principle) were mainly based on arterial and venous blood sampling. Tissue perfusion measured by MR techniques may be either based on bolus contrast agent injection, or non-invasive, endogenous “magnetic” labeling of inflowing blood. MR perfusion is one of a variety of techniques now available for tomographic imaging of flow; competing techniques such as SPECT, PET, and CT are also able to produce perfusion images.
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