Optimized 3D bright blood MRI of aortic plaque at 3 T.
OBJECTIVE
To evaluate the feasibility of an optimized bright blood MRI protocol at 3 T in combination with contrast agent administration for the detection and characterization of aortic high-risk plaques for the improved workup of acute stroke patients.


METHODS
ECG synchronized T1-weighted 3D gradient echo MRI was performed in 45 acute stroke patients. Data were acquired with high near isotropic spatial resolution (approximately 1 mm(3)) covering the entire thoracic aorta. To compensate for breathing and vessel motion artifacts, images were collected using respiratory navigator gating in combination with short diastolic data acquisition windows adjusted on a patient-by-patient basis. In patients with aortic plaques > or =3 mm in thickness, gadolinium contrast agent was administered and both pre- and post-contrast T1-weighted 3D measurements with identical vessel coverage were performed.


RESULTS
Bright blood 3D MRI detected 33 high-risk plaques with an average maximum plaque thickness of 4.2+/-1.0 mm in 23 of 45 acute stroke patients. The availability of pre- and post-contrast images acquired within the same session enhanced the identification of calcified plaque components in 77% of all analyzed plaques: post-contrast MRI clearly improved the delineation of hypointense plaque cores in 23 of 30 cases and assisted in the classification of core shape and of core fraction.


CONCLUSIONS
3D bright blood MRI at 3 T was feasible for the detection of aortic high-risk sources and may help to improve the detection of causes of cerebral embolism in acute stroke patients.
Markl
Michael
M
Department of Diagnostic Radiology, Medical Physics, University Hospital Freiburg, 79106 Freiburg, Germany. michael.markl@uniklinik-freiburg.de
Dudler
Patrick
P
Fydrychowicz
Alex
A
Strecker
Christoph
C
Weiller
Cornelius
C
Hennig
Jürgen
J
Harloff
Andreas
A
D000208:Acute Disease; D001018:Aortic Diseases / Q000150:complications* / Q000175:diagnosis*; D050197:Atherosclerosis / Q000150:complications* / Q000175:diagnosis*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D020766:Intracranial Embolism / Q000175:diagnosis* / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds; D020521:Stroke / Q000209:etiology*
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine