time of flight(redirected from TOF sequence)
Also found in: Dictionary, Encyclopedia.
time of flight
the time for a photon created by annihilation of a positron-electron pair to reach a detector; because annihilation photons are created in pairs and travel in opposite directions at about 3 × 1010 cm/sec, measurement of the difference in arrival time at detectors with subnanosecond resolution allows calculation of the location of the event; the basic physics of positron emission tomography.
Farlex Partner Medical Dictionary © Farlex 2012
time of flightAn MRI term referring to a magnetic resonance angiography technique based solely on the flow of unsaturated blood into a magnetised presaturated slice. The difference between the unsaturated and presaturated spins creates a bright vascular image without needing contrast media.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
time of flight(tīm flīt)
magnetic resonance imaging Rate of flow in a given time; causes some flowing nuclei to receive only one radiofrequency pulse and therefore produce a signal void.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012