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. 2. the data or image so obtained, often designated according to the organ under examination, as brain scan, kidney scan, thyroid scan, etc. 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, computerized axial tomography, or the image obtained from it.
Meckel scan, a technetium-99m pertechnetate gastric-mucosa scan used to demonstrate ectopic gastric mucosa, particularly in Meckel diverticulum.
M-mode scan, the image obtained using M-mode echocardiography, showing the motion (M) over time of a monodimensional (“icepick”) section of the heart.
PET scan, positron emission tomography, or the image obtained from it.
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.