Temporal resolution improvement in dynamic imaging.
In some dynamic imaging applications, only a fraction, 1/n, of the field of view (FOV) may show considerable change during the motion cycle. A method is presented that improves the temporal resolution for a dynamic region by a factor, n, while maintaining spatial resolution at a cost of square root of n in signal-to-noise ratio (SNR). Temporal resolution is improved, or alternatively, total imaging time is reduced by reducing the number of phase encodes acquired for each temporal frame by 1/n. To eliminate aliasing, a representation of the signal from the static outer portion of the FOV is constructed using all the raw data. The k-space data derived from this representation is subtracted from the original data sets, and the differences correspond to the dynamic portion of the FOV. Improved resolution results are presented in phantom studies, and in vivo phase contrast quantitative flow imaging.
Fredrickson
J O
JO
Richard M. Lucas Center for Magnetic Resonance Spectroscopy and Imaging, Stanford University, California, USA.
Pelc
N J
NJ
D000465:Algorithms; D001013:Aorta, Thoracic / Q000033:anatomy & histology; D003331:Coronary Vessels / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D011651:Pulmonary Artery / Q000033:anatomy & histology; D011673:Pulsatile Flow