[Dynamic contrast-enhanced T(1) measuring MRI using variable flip angle SPGR].
We modified the multi-phase spoiled gradient recalled echo (SPGR) pulse sequence using the double-echo MR technique for estimation of T(1) during the first pass of contrast agent, and examined its precision. In the first half of the pulse sequence, the flip angle was varied systematically to calculate static T(1) values. It was necessary to choose optimal flip angles to minimize the calculation error of static T(1) values. In the latter half of this sequence, changes in absolute T(1) were calculated using differences in signal intensities before and after the injection of contrast agent. The optimal flip angle was 20 degrees for precise conversion to T(1) values under the short TR (33.3 ms) condition. Double echo MR data were used to minimize the T(2)* effect. The present method appears to be useful for quantitative estimation of dynamic contrast-enhanced MRI.
Radiological Center, Fukui Medical University Hospital.
Yoshiyuki
Y
Ishimori
Hirohiko
H
Kimura
Tsuyoshi
T
Matsuda
Hidemasa
H
Uematsu
Tomokazu
T
Ishida
Yuko
Y
Fukuya
Akinobu
A
Kita
D001932:Brain Neoplasms / Q000175:diagnosis; D003056:Cochlear Nerve; D003287:Contrast Media; D003390:Cranial Nerve Neoplasms / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D000160:Vestibulocochlear Nerve Diseases / Q000175:diagnosis
D003287:Contrast Media