MR angiography without subtraction.
A new NMR method for producing angiograms with strong suppression of the static spin signal and without the need for subtraction is described and demonstrated. A velocity-selective pulse sequence was implemented whereby the magnetization of all stationary spins is driven to the -z axis and is not detected, while maximizing the signal intensity of the moving spins. A theory of the method is presented and gives good agreement with experimental results obtained on a flow phantom. It is shown theoretically and experimentally that high-quality velocity-independent angiograms of the head and neck can be obtained with strong suppression of static spin signal when TR approximately T1. The method can be extended to produce three-dimensional angiograms.
Zur
Y
Y
Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge 02139.
Zou
X
X
Neuringer
L J
LJ
D000792:Angiography; D015901:Angiography, Digital Subtraction; D001775:Blood Circulation; D001783:Blood Flow Velocity; D001808:Blood Vessels / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008955:Models, Cardiovascular; D008962:Models, Theoretical; D012212:Rheology