ventilation-perfusion scan

scan

 [skan]

1. to examine or map the body, or one or more organs or regions of it, by gathering information with a sensing device, such as a moving detector or a sweeping beam of radiation.

2. the data or image so obtained, often designated according to the organ under examination, such as a brain scan, kidney scan, or thyroid scan.

3. shortened form of scintiscan.

A-scan display on a cathode ray tube of ultrasonic echoes, in which one axis represents the time required for return of the echo and the other corresponds to the strength of the echo.

B-scan display on a cathode ray tube of ultrasonic echoes, in which the position of a bright dot on the tube corresponds to the time elapsed and the brightness of the spot to the strength of the echo; movement of the transducer across the skin surface yields a two-dimensional cross-sectional display.

CAT scan (CT scan) the image generated by computerized axial tomography.

HIDA scan a type of scan using a technetium 99m complex to assess hepatobiliary function.

thallium scan a scintiscan involving use of thallium 201; see also thallium scan.

ventilation-perfusion scan (V/Q scan) a scintigraphic technique for demonstrating perfusion defects in normally ventilated areas of the lung in the diagnosis of pulmonary embolism, consisting of the imaging of the distribution of an inhaled radionuclide followed by the imaging of the perfusion of the lungs by an injected radionuclide.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

ven·ti·la·tion-·per·fu·sion scan

a lung function test, especially useful for pulmonary embolism, employing an inhaled radionuclide for ventilation and an intravenous radionuclide for perfusion; their respective distributions in the lung are recorded scintigraphically.

Farlex Partner Medical Dictionary © Farlex 2012

ventilation-perfusion scan

Radionuclide scan of lung, V/Q scan Cardiology, Pulmonology A noninvasive radionuclide test that provides functional information as a ratio of pulmonary ventilation–V to blood flow–perfusion, Q through the lungs; in one common protocol, the scan is performed after inhaling 133Xe –20 mCi, 148 MBq and IV injection of 99mTc microacroaggregated albumin, for assessing inspiratory airflow, lung volume, air trapping and adequacy of perfusion; 'indeterminant' studies are not uncommon, and are more frequent in those with underlying lung disease. See Lung volumes, Pulmonary panel.

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

ven·ti·la·tion-per·fu·sion scan

(ven'ti-lā'shŭn-pĕr-fyū'zhŭn skan)

A lung function test, especially useful in the diagnosis of pulmonary embolism, employing an inhaled radionuclide for ventilation and an intravenous radionuclide for perfusion; their respective distributions in the lung are recorded scintigraphically.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012