MR angiography of the renal arteries: intraindividual comparison of double-dose contrast enhancement at 1.5 T with standard dose at 3 T.
OBJECTIVE
The purpose of this study was to compare prospectively and within subjects use of 0.1 mmol/kg of gadodiamide at 3 T with use of 0.2 mmol/kg of gadodiamide at 1.5 T for MR angiography of the renal arteries.


METHODS
Twenty-two patients (14 men, eight women; mean age, 66.5 years) underwent two MR angiographic examinations of the renal arteries separated by at least 24 hours on whole-body 1.5- and 3-T MRI systems with a phase-encoded 3D spoiled breath-hold pulse sequence. Two radiologists blinded to the dose of contrast material assessed all image data in consensus for renal arterial disease and for image quality on a five-point Likert-type scale. Quantitative evaluation (vessel signal-to-noise ratio and vessel-muscle contrast-to-noise ratio) was performed by a third radiologist.


RESULTS
Five renal arterial stenoses were detected with both techniques. The difference in mean image quality for the two doses and field strengths was not statistically significant. Overall vessel length and intraparenchymal branches, however, were better visualized with the double dose at 1.5 T. Signal-to-noise and contrast-to-noise ratios were significantly higher (both, p < 0.05) with the double dose at 1.5 T (125.7 and 64.2, respectively) compared with the standard dose at 3 T (112.3 and 59.7).


CONCLUSIONS
MR angiography can be performed with high diagnostic image quality at 3 T with 0.1 mmol/kg of gadodiamide. Signal-to-noise and contrast-to-noise ratios are higher with a double dose at 1.5 T.
Herborn
Christoph U
CU
Department of Radiology, Scott and White Clinic and Hospital, Temple, TX, USA.
Runge
Val M
VM
Watkins
David M
DM
Gendron
Jilene M
JM
Naul
L Gill
LG
D000368:Aged; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007206:Individuality; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D012077:Renal Artery / Q000473:pathology*; D012078:Renal Artery Obstruction / Q000175:diagnosis*; D012680:Sensitivity and Specificity
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA