Interactive body magnetic resonance fluoroscopy using modified single-shot half-Fourier rapid acquisition with relaxation enhancement (RARE) with multiparameter control.
OBJECTIVE
To develop a technique for interactive fluoroscopic abdominal magnetic resonance imaging (MRI) based on a single-shot half-Fourier rapid acquisition and relaxation-enhanced sequence.


METHODS
The sequence was modified by incorporating inner-volume excitation, driven-equilibrium signal enhancement, and reduced flip angle refocusing pulses. Contrast control was provided by integrating "on-the-fly" selection of phase encoding view order, fat suppression, and section thickness. The resulting sequence was evaluated with phantom experiments to quantify the signal-to-noise ratio (SNR) effects of the modifications and in healthy volunteers for imaging the bile ducts, stomach, and duodenum using water and gaseous contrast media.


RESULTS
Observed SNR relating to driven-equilibrium and flip angle scaling matched theoretical predictions. Volunteer examinations demonstrated the ability of the modified sequence to provide interactive, artifact-free imaging of the abdomen, including switching between conventional proton density-weighted, T2-weighted imaging and "hydrographic" projection imaging.


CONCLUSIONS
Refinement of this technique may provide an abdomino-pelvic imaging capability similar in concept to real-time ultrasound, but with the advantages of MRI.
Department of Radiology, University of Cambridge and Addenbrooke's Hospital, United Kingdom.
Malek
M
Makki
M J
MJ
Graves
D J
DJ
Lomas
D000005:Abdomen / Q000033:anatomy & histology*; D005471:Fluoroscopy; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D014867:Water / Q000737:chemistry
D014867:Water