A Modified Signal Intensity Equation of Carr-Purcell-Meiboom-Gill Pulse Sequence for MR Imaging

• Published in: The Tohoku Journal of Experimental Medicine Vol. 158; no. 3; pp. 203 - 209
• Main Authors: YAMADA, SUSUMU, MATSUZAWA, TAIJU, YAMADA, KENJI, YOSHIOKA, SEIRO, ONO, SHUICHI, HISHINUMA, TAKASHI
• Format: Journal Article
• Language: English
• Published: Japan Tohoku University Medical Press 1989
• Subjects: Carr-Purcell-Meiboom-Gill pulse sequence; Magnetic Resonance Imaging; Mathematics; signal intensity equation; T1 relaxation time; T2 relaxation time; Time Factors
• ISSN: 0040-8727; 1349-3329
• DOI: 10.1620/tjem.158.203

YAMADA, S., MATSUZAWA, T., YAMADA, K., YOSHIOKA, S., ONO, S. and HISHINUMA, T. A Modified Signal Intensity Equation of Carr-Purcell-Meiboom- Gill Pulse Sequence for MR Imaging. Tohoku J. Exp. Med., 1989, 158 (3), 203-209-The signal intensity equation of Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence for magnetic resonance imaging was modified to: S(n)=k•M0•exp (-n•Te/T2) [1-exp(-Tr/T1)] where S(n) is a signal intensity of “n-th” echo; k, constant; M0, initial longitudinal magnetization; n, echo number; Te, echo interval; and Tr, recovery time [Tr=TR-(N-1/2)•Te; TR, repetition time; N, number of echoes]. To evaluate the accuracies of T1 and T2 values calculated from this modified equation, a phantom experiment using five tubes filled with 0.5 to 8mM copper sulfate solutions was performed using a 0.14-T resistive whole-bo dy MR scanner and a spectrometer system. The differences between the image values by this equation and the bulk values by the spectrometer were less than 6.2% (mean±S.D., 3.3±2.1%) in T2 and 15.6% (10.4±4.9%) in T1 (except 8mM). By this modification, not only the image T2 value with a high accuracy but the image T1 value can be obtained simultaneously.