This test is most commonly done in order to check for the presence of a blood clot or abnormal blood flow inside the lungs (such as a pulmonary embolism (PE) although computed tomography with radiocontrast is now more commonly used for this purpose. The<unk>  may be used in some circumstances where radiocontrast would be inappropriate, as in Allergy to contrast agent or kidney failure. A V/Q lung scan may be performed in the case of serious lung disorders such as chronic obstructive pulmonary disease (COPD) or pneumonia as well as a lung performance quantification tool pre- and post-lung lobectomy surgery. Significance of results<unk><unk>  scintigraphy in a woman taking oral contraceptives and valdecoxib with a pulmonary embolism. (A) After inhalation of 20 mCi of Xenon-133 gas, scintigraphic images were obtained in the posterior projection, showing uniform<unk>  to lungs.. (B) After intravenous injection of 4.1 mCi of Technetium-99m-labeled macroaggregated albumin, scintigraphic images were obtained, shown here in the posterior projection. This and other views showed decreased activity in the following regions: apical segment of right upper lobe, anterior segment of right upper lobe, superior segment of right lower lobe, posterior basal segment of right lower lobe, anteromedial basal segment of left lower lobe, and lateral basal segment of left lower lobe. +<unk>  Interpretation Result Interpretation Significance Normal No<unk>  deficit Excludes pulmonary thromboembolism Low probability<unk>  deficit with matched<unk>  deficit 80% probability of PE Decreased uptake of the inhaled radioisotope may indicate an impaired ability to breathe, airway obstruction, or possible pneumonia. Decreased circulation of the injected MAA indicates a problem with blood flow into or within the lungs. A localized area of decreased uptake, usually in a wedge shaped (or pie shaped) configuration with normal<unk>  images (mismatched defect) suggests a pulmonary embolus or blood clot in the lungs, which leads to reduced<unk>  beyond the obstruction.
Ventilation/perfusion scan
Carbon dioxide angiography
Perfusion scanning
Intravascular fluorescence
Intravascular imaging
Microangiography
Pulmonary angiography
Digital subtraction angiography