Embedded MR fluoroscopy: high temporal resolution real-time imaging during high spatial resolution 3D MRA acquisition.
A method termed "embedded fluoroscopy" for simultaneously acquiring a real-time sequence of 2D images during acquisition of a 3D image is presented. The 2D images are formed by periodically sampling the central phase encodes of the slab-select direction during the 3D acquisition. The tradeoffs in spatial and temporal resolution are quantified by two parameters: the "redundancy" (R), the fraction of the 3D acquisition sampled more than once; and the "effective temporal resolution" (T), the time between temporal updates of the central views. The method is applied to contrast-enhanced MR angiography (CE-MRA). The contrast bolus dynamics are portrayed in real time in the 2D image sequence while a high-resolution 3D image is being acquired. The capability of the 2D acquisition to measure contrast enhancement with only a 5% degradation of the spatial resolution of the 3D CE-MR angiogram is shown theoretically. The method is tested clinically in 15 CE-MRA patient studies of the carotid and renal arteries.
Fain
S B
SB
Department of Medical Physics, Clinical Sciences Center, University of Wisconsin-Madison, Madison, Wisconsin 53792, USA. fains@mr.radiology.wisc.edu
Riederer
S J
SJ
Huston
J
J
King
B F
BF
D005240:Feasibility Studies; D005471:Fluoroscopy; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008433:Mathematics; D019047:Phantoms, Imaging; D013997:Time Factors