Items tagged “mri image quality”
3 results found
Article
Noise
Noise, variability that is not part of a desired signal, is present in all electronic systems, and originates from a number of sources including electronic interference. It appears as an irregular granular pattern in all images and degrades image information. It may be inapparent or render image...
Article
Acquisition time
The time of acquisition for a conventional spin echo or gradient echo sequence is the product of the repetition time, phase encoding steps, and number of averages (TR x phase steps x NEX).
For example, with a one-second TR, 128 phase steps, and two averages, we would get an acquisition time of...
Article
Relaxation
Relaxation is the process in which spins release the energy received from a radiofrequency pulse. MRI signal is influenced, among other factors, by different types of relaxation:
T1 relaxation (spin-lattice or longitudinal relaxation)
T2 relaxation (spin-spin or transverse relaxation)
T2* rel...