Final answer:
A V/Q, or ventilation-perfusion, scan is employed to examine the balance of airflow and blood flow within the lungs and diagnose areas of mismatch which may be due to diseases or obstructions. This approach allows doctors to detect 'dead space' where gas exchange in the lungs is ineffective. A V/Q scan is an essential tool, often used in diagnosing conditions like pulmonary embolism.
Step-by-step explanation:
The subject question references a V/Q scan, which stands for ventilation-perfusion scan. This scan is used not for the heart, brain, or kidneys, but for the b) Lungs. The key purpose of the V/Q scan is to assess the balance or mismatch of airflow (ventilation) and blood flow (perfusion) within the lungs.
Ventilation is the movement of air into and out of the lungs, whereas perfusion refers to the flow of blood through the pulmonary capillaries. When these two aspects are in balance, gas exchange in the lung is efficient. However, there can be instances, often due to disease or physical obstructions, that cause a ventilation/perfusion (V/Q) mismatch. These mismatches can create 'dead space,' or areas of the lung that lack effective gas exchange, leading to less oxygen in the blood and a rise in carbon dioxide levels.
Therefore, a V/Q scan is a valuable diagnostic tool used to evaluate this ventilation and perfusion in the lungs, usually in the diagnosis of conditions like pulmonary embolism.
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