Highly undersampled supraaortic MRA at 3.0 T: initial results with parallel imaging in two directions using a 16-channel neurovascular coil and parallel imaging factors up to 16.
OBJECTIVE
To present the feasibility of highly undersampled contrast-enhanced MRA (CE-MRA) of the supraaortic arteries with a 16-channel neurovascular coil at 3.0 T using parallel imaging in two directions with parallel imaging factors (PIF) up to 16.


METHODS
Institutional review board approval and informed consent were obtained. In a prospective study, MRA protocols including PIF of 1, 2, 4, 9 and 16 yielding a spatial resolution from 0.81×0.81×1.0 mm(3) to 0.46×.46×0.98 mm(3) were acquired. In 32 examinations, image quality and vascular segments were rated independently by two radiologists. SNR estimations were performed for all MRA protocols.


RESULTS
The use of high PIF allowed to shorten acquisition time from 2:09 min down to 1:13 min and to increase the anatomic coverage while maintaining or even increasing spatial resolution down to 0.46×0.46×0.98 mm(3). The larger anatomic coverage that was achieved with the use of high PIF allowed for visualization of vascular structures that were not covered by the standard protocols. Despite the resulting lower SNR using high PIF, image quality was constantly rated to be adequate for diagnosis or better in all cases.


CONCLUSIONS
The use of high PIF yielded diagnostic image quality and allowed to increase the anatomic coverage while maintaining or even improving spatial resolution and shortening the acquisition time.
Kukuk
Guido M
GM
Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. guido.kukuk@ukb.uni-bonn.de
Hadizadeh
Dariusch R
DR
Gieseke
Jürgen
J
von Falkenhausen
Marcus
M
Böhm
Ingrid
I
Semrau
Renate
R
Urbach
Horst
H
Koscielny
Arne
A
Verrel
Frauke
F
Wilhelm
Kai
K
Schild
Hans H
HH
Willinek
Winfried A
WA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D001158:Arteries / Q000473:pathology*; D003251:Constriction, Pathologic; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D003287:Contrast Media