Optimization of the contrast dose and injection rates in whole-body MR angiography at 3.0T.
OBJECTIVE
To optimize the contrast agent dose and delivery rate used in a novel whole-body magnetic resonance angiography (MRA) protocol using a 3.0T MR scanner.


METHODS
Six groups of 20 consenting volunteers underwent whole-body MRA, with each group receiving a different contrast dose and contrast delivery rate. The arterial tree was divided into 16 segments and the image quality at each of the anatomical locations, covering the whole body, was assessed. Qualitative analysis was carried out using a scoring assessment of image quality, and quantitative assessments were performed by measuring contrast-to-noise (CNR) and a signal-to-noise (SNR) index.


RESULTS
Reducing the contrast dose from 40 mL to 25 mL was found to significantly increase the CNR in several vessels of interest in the arterial tree. There was also a significant increase in the qualitative image quality score (P < 0.001).


CONCLUSIONS
This study demonstrates that reducing the contrast dose at 3.0T can result in an increase in the CNR in the vessels of interest without significantly affecting the SNR.
Department of Medical Physics, Ninewells Hospital, NHS Tayside, Dundee, UK. shelley.waugh@nhs.net
Shelley A
SA
Waugh
P Guntur
PG
Ramkumar
Stephen J
SJ
Gandy
R Stephen
RS
Nicholas
Patricia
P
Martin
Jill J F
JJ
Belch
Allan D
AD
Struthers
J Graeme
JG
Houston
D000328:Adult; D000368:Aged; D000792:Angiography / Q000379:methods*; D016477:Artifacts; D050197:Atherosclerosis / Q000473:pathology*; D003287:Contrast Media / Q000008:administration & dosage* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012306:Risk; D051598:Whole Body Imaging
D003287:Contrast Media