Are mono-exponential fits to a few echoes sufficient to determine T2 relaxation for in vivo human brain?
T2 relaxation decay curves from in vivo human brain tissue are rarely mono-exponential. Partial volume averaging further reduces the chance of mono-exponential decay. Moreover, the parameters derived from few-echo mono-exponential fits change with the measurement echo times and have the largest possible variance. In this note, multi-exponential fits to 32-echo relaxation decay curves from in vivo human brain are used to design simulations (where the truth is known) to demonstrate the pitfalls of few-echo mono-exponential interpretations.
Whittall
K P
KP
Department of Radiology, University of British Columbia, Vancouver, Canada.
MacKay
A L
AL
Li
D K
DK
D000465:Algorithms; D001921:Brain / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009103:Multiple Sclerosis / Q000473:pathology*