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  • Perfusion scanning


    Perfusion is the passage of fluid through the lymphatic system or blood vessels to an organ or a tissue. The practice of perfusion scanning, is the process by which this perfusion can be observed, recorded and quantified. The term perfusion scanning encompasses a wide range of medical imaging modalities.

  • Perfusion


    Lindbergh perfusion pump, c. 1935, an early device for simulating natural perfusionPerfusion is the passage of fluid through the circulatory system or lymphatic system to an organ or a tissue, usually referring to the delivery of blood to a capillary bed in tissue. Perfusion is measured as the rate at which blood is delivered to tissue, or volume of blood per unit time (blood flow) per unit tissue mass. The SI unit is m3/(s·kg), although for human organs perfusion is typically reported in ml/min/g. The word is derived from the French verb "perfuser" meaning to "pour over or through". All animal tissues require an adequate blood supply for health and life. Poor perfusion (malperfusion), that is, ischemia, causes health problems, as seen in cardiovascular disease, including coronary artery disease, cerebrovascular disease, peripheral artery disease, and many other conditions. Tests verifying that adequate perfusion exists are a part of a patient's assessment process that are performed by medical or emergency personnel. The most common methods include evaluating a body's skin color, temperature, condition (dry/soft/firm/swollen/sunken/etc), and capillary refill.

  • Myocardial perfusion imaging


    Myocardial perfusion imaging or scanning (also referred to as MPI or MPS) is a nuclear medicine procedure that illustrates the function of the heart muscle (myocardium). It evaluates many heart conditions, such as coronary artery disease (CAD), hypertrophic cardiomyopathy and heart wall motion abnormalities. It can also detect regions of myocardial infarction by showing areas of decreased resting perfusion. The function of the myocardium is also evaluated by calculating the left ventricular ejection fraction (LVEF) of the heart. This scan is done in conjunction with a cardiac stress test. The diagnostic information is generated by provoking controlled regional ischemia in the heart with variable perfusion. Planar techniques, such as conventional scintigraphy, are rarely used. Rather, Single-photon emission computed tomography (SPECT) is more common in the US. With multihead SPECT systems, imaging can often be completed in less than 10 minutes. With SPECT, inferior and posterior abnormalities and small areas of infarction can be identified, as well as the occluded blood vessels and the mass of infarcted and viable myocardium. The usual isotopes for such studies are either Thallium-201 or Technetium-99m.

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