Nonenhanced free-breathing ECG-gated steady-state free precession 3D MR angiography of the renal arteries: comparison between 1.5 T and 3 T.
OBJECTIVE
The purpose of our study was to compare the image quality of free-breathing ECG-gated nonenhanced steady-state free precession (SSFP) MR angiography of renal arteries at 1.5 T and 3 T.


METHODS
Twenty volunteers (11 men, nine women; mean age, 23.2 +/- 2.3 years) without a history of renovascular disease participated in the study. Nonenhanced SSFP MR angiography was performed on all subjects at both 1.5 T and 3 T with a maximum interval of 2 weeks between the imaging sessions. The subjective image quality of axial and coronal maximum-intensity-projection reconstructions of four segments (1, abdominal aorta and ostium of renal artery; 2, main renal artery; 3, segmental branches outside renal parenchyma; 4, segmental branches inside renal parenchyma) was evaluated independently by two radiologists using a 4-point scale (4, excellent; 1, nondiagnostic). Relative signal-to-noise ratio, contrast-to-noise ratio, and maximum visible vessel length of the right and left renal arteries also were determined.


RESULTS
No significant difference in image quality at 1.5 T and 3 T was found for segments 1 and 2. The mean image quality for segments 3 and 4 was significantly greater at 3 T (3.88 +/- 0.32, 3.17 +/- 0.70) than at 1.5 T (3.32 +/- 0.73, 2.09 +/- 0.81) (p < 0.001). At 3 T, the maximal vessel length of the right (9.85 +/- 0.82 cm) and left (8.3 +/- 0.79 cm) renal arteries was significantly greater than at 1.5 T (8.94 +/- 1.38 cm and 7.58 +/- 1.18 cm, respectively).


CONCLUSIONS
Performing nonenhanced SSFP MR angiography at 3 T significantly improves visualization of peripheral renal arterial segments in healthy subjects as compared to 1.5 T.
Lanzman
Rotem Shlomo
RS
Department of Radiology, University Hospital Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany.
Kröpil
Patric
P
Schmitt
Peter
P
Freitag
Sonja-Marie
SM
Ringelstein
Adrian
A
Wittsack
Hans Jörg
HJ
Blondin
Dirk
D
D004562:Electrocardiography; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D012077:Renal Artery / Q000033:anatomy & histology*; D018709:Statistics, Nonparametric; D055815:Young Adult