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The precision of T R extrapolation in magnetic resonance image synthesis
Author(s) -
Lee James N.,
Riederer Stephen J.,
Bobman Stuart A.,
Johnson Jeffrey P.,
Farzaneh Farhad
Publication year - 1986
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.595954
Subject(s) - signal to noise ratio (imaging) , extrapolation , k space , image synthesis , imaging phantom , reduction (mathematics) , image (mathematics) , computer science , noise (video) , repetition (rhetorical device) , range (aeronautics) , noise reduction , artificial intelligence , contrast to noise ratio , image quality , synthetic data , magnetic resonance imaging , physics , mathematics , optics , materials science , statistics , linguistics , philosophy , medicine , radiology , geometry , composite material
We present a model of noise propagation from acquired magnetic resonance (MR) images to T R ‐extrapolated synthetic images. This model assumes that images acquired at two repetition times T R1and T R2are used to generate synthetic images at arbitrary repetition times T R . The predictions of the model are compared with experimentally acquired phantom data, and show excellent agreement. The model is utilized in an analysis of two applications of MR image synthesis: scan time reduction and multiple‐image synthesis. Scan time is reduced by acquiring data at two short repetition times, and synthesizing at a longer repetition time, with T R1+T R2less than T R . For T 1 =800 ms, a reduction of 20% in scan time results in a 45% reduction in signal‐to‐noise ratio SNR, when compared to direct acquisition. Reducing scan time by much more than 20% produces large noise levels in the synthetic image, and is unlikely to be useful. In multiple‐image synthesis, images are synthesized at any repetition time in the range 0 to T R1+T R2 , for contrast optimization. If T 1 =800 ms, and T R1+T R2 =2000 ms, the optimum combination of T R1, T Rresults in synthetic images whose SNR is at worst 22% less than the SNR of directly acquired images. For many values of T R , the synthetic images have SNR superior to that obtainable by direct acquisition.