Use of high flip angle in T1-prepared FAST sequences for myocardial perfusion quantification.
This study reports on the first use of high flip angle and radio-frequency (RF) spoiling in T1-prepared fast acquisition in steady state (FAST) sequence for myocardial perfusion in patients. T1 dynamic range was measured in vitro with a FAST, an RF FAST and a snapshot fast low-angle shot (FLASH) sequences with a 90 degrees flip angle. Myocardial perfusion was then measured twice in 6 patients during the same MR session. The RF FAST and FLASH, but not the FAST sequence, demonstrated an extended T1 dynamic range; however, the FLASH images were degraded by artifacts not present on the RF FAST images. The myocardial perfusion indices K1 (first-order transfer constant from the blood to the myocardium for the Gd-DTPA) and Vd (distribution volume of Gd-DTPA in myocardium) did not differ significantly between the two injections. K1 was 0.48+/-0.12 ml/min g(-1) and Vd was 12.5+/-2.9%. With an extended T1 dynamic range and the sensitivity required for myocardial perfusion quantification, the RF FAST sequence with a 90 degrees flip angle outperformed the snapshot FLASH sequence in terms of image quality and the FAST sequence in terms of contrast dynamic range.
Vallée
Jean-Paul
JP
Division de Radiodiagnostic et Radiologie Interventionnelle, Hôpitaux Universitaires de Genève, 24 rue Micheli-du-Crest, 1211 Geneva, Switzerland. vallee@dim.hcuge.ch
Ivancevic
Marko
M
Lazeyras
François
F
Kasuboski
Larry
L
Chatelain
Pascal
P
Righetti
Alberto
A
Didier
Dominique
D
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D018709:Statistics, Nonparametric
D003287:Contrast Media; D019786:Gadolinium DTPA