Low-dose, time-resolved, contrast-enhanced 3D MR angiography in the assessment of the abdominal aorta and its major branches at 3 Tesla.
OBJECTIVE
The aims of this study were to evaluate the effectiveness of low-dose, contrast-enhanced (CE), time-resolved, three-dimensional magnetic resonance angiography (MRA) in the assessment of the abdominal aorta and its major branches at 3 T and to compare the results with those of high-spatial resolution CE MRA.


METHODS
Twenty-two consecutive patients (eight men, 14 women; mean age, 43.9 +/- 17.9 years) underwent CE time-resolved three-dimensional MRA and high-spatial resolution three-dimensional MRA. Studies were performed using a 3-T magnetic resonance system; gadolinium-based contrast medium was administered at a dose of 3 to 5 mL for time-resolved MRA, followed by 0.1 mmol/kg gadopentetate dimeglumine for single-phase CE MRA. For analysis purposes, the abdominal arterial system was divided into 11 arterial segments, and image quality as well as the presence and degree of vascular pathology were evaluated by two independent magnetic resonance radiologists.


RESULTS
A total of 242 arterial segments were visualized with good image quality. Time-resolved MRA was able to visualize the majority of arterial segments with good definition in the diagnostic range. Vascular pathologies (stenosis, occlusion) or abnormal vascular anatomy was detected in 19 arterial segments, with good interobserver agreement (kappa = 0.78). All image findings were detected with time-resolved CE MRA by both observers and were confirmed by correlative imaging.


CONCLUSIONS
Low-dose, time-resolved MRA at 3 T yields rapid and important anatomic and functional information in the evaluation of the abdominal vasculature. Because of its limited spatial resolution, time-resolved MRA is inferior to CE MRA in demonstrating fine vascular details.
Kramer
Ulrich
U
Department of Diagnostic and Interventional Radiology, University of Tübingen, Tübingen, Germany. ulrich.kramer@med.uni-tuebingen.de
Fenchel
Michael
M
Laub
Gerhard
G
Seeger
Achim
A
Klumpp
Bernhard
B
Bretschneider
Christiane
C
Finn
J Paul
JP
Claussen
Claus D
CD
Miller
Stephan
S
D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D003287:Contrast Media; D019786:Gadolinium DTPA