Multistep phase difference phase contrast imaging.
A new technique for multistep phase-contrast image processing is presented. The N-step method consists of simply forming the linear average of the N-1 adjacent phase-difference signals. It has similar noise reduction properties as other multistep techniques, but the simplicity of the noise variance of the N-step technique allows intuitive insight into phase-difference phase-contrast processing and noise reduction, which can aid in the design of efficient and improved phase-contrast imaging sequences. As well, the computational simplicity of the N-step phase-difference technique compared with any other known multistep technique is advantageous. Like other multistep techniques, it has far more efficient noise reduction properties than simple two-step, multiple average phase-contrast imaging, even when normalized for total scan time. A three-step phase-difference velocity image has 50% less variance than an image acquired with two steps and two scans averaged but is obtained in 25% less scan time. Given its advantages, it should now be the chosen technique for increasing velocity-to-noise and contrast-to-noise ratios in all phase-difference phase-contrast clinical applications.
Lamothe
M J
MJ
Department of Diagnostic Radiology and Nuclear Medicine, University of Western Ontario, Canada.
Rutt
B K
BK
D001783:Blood Flow Velocity; D003198:Computer Simulation; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008955:Models, Cardiovascular; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity
D003287:Contrast Media