MR angiography of the carotid arteries: parameters affecting image quality.
OBJECTIVE
This study was performed to evaluate the relationship between dose levels of contrast medium and image quality in magnetic resonance (MR) angiography of the carotid arteries with fluoroscopically monitored, manually triggered, elliptically ordered image acquisitions.


METHODS
Twenty-five patients with clinical indications for angiography of the carotid arteries were examined with MR at 1.5 T by using a fluoroscopically monitored, manually triggered, elliptically ordered pulse sequence with the administration of one of three different volumes of gadolinium-based contrast medium. The signal intensities of the vessel lumen and the surrounding tissues were measured in single partitions at the origin of the common carotid artery, the carotid bifurcation, and the intracranial internal carotid arteries. The contrast-to-noise ratio in these regions of interest also was measured. Maximum intensity projection image quality was appraised for blurring, artifacts, venous enhancement, background suppression, and contrast medium distribution.


RESULTS
No artifacts or venous enhancement was observed. The position of the fluoroscopic section affected the distribution of contrast medium along the vessel, as evidenced by the difference between the contrast-to-noise ratio at the origin of the common carotid artery and the ratio at the carotid bifurcation and the intracranial internal carotid arteries (P < .01). The contrast medium dose administered was strongly correlated with image quality (r = 0.90).


CONCLUSIONS
Contrast medium dose is related to image quality in MR angiography of the carotid arteries performed with elliptical ordering, fluoroscopic monitoring, and manual triggering.
Luccichenti
Giacomo
G
Department of Radiology, University of Parma, Via A. Gramsci 14, 43100 Parma, Italy.
Cademartiri
Filippo
F
Lucidi
Vincenzo
V
Marchesi
Giuseppe
G
Ugolotti
Ugo
U
Pavone
Paolo
P
D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000175:diagnosis; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D005471:Fluoroscopy; D005682:Gadolinium / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008536:Meglumine / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D009942:Organometallic Compounds / Q000008:administration & dosage*
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine; D005682:Gadolinium