Evaluating quantitative proton-density-mapping methods.
Quantitative magnetic resonance imaging (qMRI) aims to quantify tissue parameters by eliminating instrumental bias. We describe qMRI theory, simulations, and software designed to estimate proton density (PD), the apparent local concentration of water protons in the living human brain. First, we show that, in the absence of noise, multichannel coil data contain enough information to separate PD and coil sensitivity, a limiting instrumental bias. Second, we show that, in the presence of noise, regularization by a constraint on the relationship between T1 and PD produces accurate coil sensitivity and PD maps. The ability to measure PD quantitatively has applications in the analysis of in-vivo human brain tissue and enables multisite comparisons between individuals and across instruments. Hum Brain Mapp 37:3623-3635, 2016. © 2016 Wiley Periodicals, Inc.
The Hebrew University of Jerusalem, Edmond and Lily Safra Center for Brain Sciences, Jerusalem, Israel.
Aviv
A
Mezer
The University of Washington, eScience Institute, Seattle, WA, USA.
Ariel
A
Rokem
The Hebrew University of Jerusalem, Edmond and Lily Safra Center for Brain Sciences, Jerusalem, Israel.
Shai
S
Berman
Stanford University, Department of Psychology, Stanford, CA, USA.
Trevor
T
Hastie
Stanford University, Department of Psychology, Stanford, CA, USA.|Stanford University, Center for Cognitive and Neurobiological Imaging, Stanford, CA, USA.
Brian A
BA
Wandell
D000328:Adult; D000465:Algorithms; D016477:Artifacts; D055592:Biophysical Phenomena; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology; D003198:Computer Simulation; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D011522:Protons; D012984:Software; D014867:Water; D066127:White Matter / Q000000981:diagnostic imaging / Q000502:physiology; D055815:Young Adult
D011522:Protons; D014867:Water
T1; coil sensitivity; parallel imaging; proton density; quantitative magnetic resonance imaging