[MR coronary angiography with MS-325, a blood pool contrast agent: comparison of an inversion recovery steady-state free precession with an inversion recovery fast low angle shot sequence in volunteers].
OBJECTIVE
To compare the signal-to-noise and contrast-to-noise ratio as well as the image quality of 3D inversion recovery steady-state free precession (IR-SSFP) and 3D inversion recovery fast low angle shot (IR-FLASH) sequences for contrast-enhanced breath-hold MRCA.


METHODS
24 healthy volunteers (10 female, 14 male, mean age 29.8 +/- 6.1 years) were involved in this study. All examinations were performed on a 1.5 T MR scanner (Magnetom Sonata, Siemens, Germany) after injection of 0.05 mmol/kg body weight MS-325 (EPIX Pharmaceuticals, Cambridge, MA and Schering AG, Berlin, Germany). MRCA was performed using IR-SSFP (TR 3.8 ms, TE 1.6 ms, FA 65 degrees , 35 phase encoded steps, bandwidth 540 Hz/pixel, slice thickness 1.5 mm, in-plane resolution 1.2 x 0.9 - 1.4 x 1.0 mm) and IR-FLASH (TR 3.8 ms, TE 1.6 ms, FA 25 degrees , bandwidth 490 Hz/pixel, slice thickness 1.5 mm, in-plane resolution 1.2 x 0.9 - 1.4 x 1.0 mm) sequences. For all scans the inversion time was set to null the signal intensity of the myocardium. Signal-to-noise ratio (SNR) as well as contrast-to-noise ratio (CNR) measurements (blood versus myocardium) were performed. The image quality was assessed based on a 5-point scale ranging from 1 (excellent) to 5 (non-diagnostic) by two radiologists in consensus.


RESULTS
The mean signal-to-noise ratio of blood (27.7 +/- 4.7 vs. 22.6 +/- 4.9, P < 0.0001) and the contrast-to-noise ratio (21.0 +/- 4.3 vs. 15.8 +/- 4.3, P < 0.0001) showed significantly higher values for IR-SSFP sequences. The mean image quality scores were significantly higher for SSFP (3.6 +/- 0.7) than FLASH (2.8 +/- 0.9) sequences (P < 0.05).


CONCLUSIONS
IR-SSFP sequences show a considerable overall improvement in image quality compared to IR-FLASH sequences for MRCA after injection of a gadolinium-based blood pool contrast agent.
Abteilung für Diagnostische und Interventionelle Radiologie und Neuroradiologie, Universitätsklinikum Essen. Kai.Nassenstein@uni-essen.de
K
K
Nassenstein
K-U
KU
Waltering
H
H
Eggebrecht
T
T
Schlosser
P
P
Hunold
J
J
Barkhausen
D000328:Adult; D003287:Contrast Media; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D005682:Gadolinium; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008962:Models, Theoretical; D009942:Organometallic Compounds
D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium