Search results
Results from the WOW.Com Content Network
Any deviation from this value is considered a V/Q mismatch. Maintenance of the V/Q ratio is crucial for preservation of effective pulmonary gas exchange and maintenance of oxygenation levels. A mismatch can contribute to hypoxemia and often signifies the presence or worsening of an underlying pulmonary condition. [3]
The V/Q ratio can be measured with a two-part ventilation/perfusion scan (V/Q scan). [1] Using a small amount of inhaled or injected radioactive material called a tracer for visualization, a V/Q scan is a type of nuclear medical imaging that allows for localization and characterization of blood flow ( perfusion scan ) and measurement of airflow ...
A pulmonary ventilation-perfusion scan (lung V/Q scan) can be used to diagnose the V/Q mismatch. A ventilation scan is used to measure airflow spread and a perfusion scan for blood flow distribution in the lungs. A radioactive tracer is used to scan the whole lung and the ventilation and perfusion function. [21]
A pulmonary shunt is the passage of deoxygenated blood from the right side of the heart to the left without participation in gas exchange in the pulmonary capillaries. It is a pathological condition that results when the alveoli of parts of the lungs are perfused with blood as normal, but ventilation (the supply of air) fails to supply the perfused region.
A ventilation/perfusion scan, [96] also called a V/Q lung scan, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, [97] [98] in order to determine the ventilation/perfusion ratio. The ventilation part of the test looks at the ability of air to reach all ...
Hypoxemia refers to the low level of oxygen in arterial blood. Tissue hypoxia refers to low levels of oxygen in the tissues of the body and the term hypoxia is a general term for low levels of oxygen. [2]
A ventilation/perfusion lung scan, also called a V/Q lung scan, or ventilation/perfusion scintigraphy, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, [1] [2] in order to determine the ventilation/perfusion ratio.
For example, in high altitude, the arterial oxygen PaO 2 is low but only because the alveolar oxygen (PAO 2) is also low. However, in states of ventilation perfusion mismatch, such as pulmonary embolism or right-to-left shunt, oxygen is not effectively transferred from the alveoli to the blood which results in an elevated A-a gradient.