Normal dynamic MRI enhancement patterns of the upper abdominal organs: gadoxetic acid compared with gadobutrol.
OBJECTIVE
The purpose of this study was to investigate whether, at dynamic MRI of the upper abdominal organs, contrast enhancement with gadoxetic acid, a hepatobiliary contrast agent, is comparable with that achieved with an extracellular contrast agent.


METHODS
Dynamic gadoxetic acid-enhanced MRI of the pancreas, spleen, kidney, liver, and abdominal aorta was performed on 50 patients; dynamic gadobutrol-enhanced MRI was performed on a control group of 50 patients; and the images were compared. Dynamic imaging with a T1-weighted volumetric interpolated breath-hold examination gradient-echo sequence (TR/TE, 3.35/1.35; flip angle, 12 degrees ) was performed before and 20 (arterial phase), 55 (portal venous phase), and 90 (hepatic venous phase) seconds after bolus injection of gadoxetic acid (0.25 mmol/mL) or gadobutrol (1.0 mmol/mL). Signal-to-noise ratios and enhancement indexes were calculated for each organ and time.


RESULTS
All MR images in both groups were of diagnostic quality. During the early dynamic phases, significantly lower mean enhancement indexes were found in the gadoxetic acid group than in the gadobutrol group in the pancreas (portal venous phase, 0.66, 1.39, p <or= 0.001; hepatic venous phase, 0.51, 1.36, p <or= 0.001), spleen (portal venous phase, 1.54, 2.41, p <or= 0.001; hepatic venous phase, 1.19, 2.23, p <or= 0.001), renal cortex (portal venous phase, 1.76, 2.63, p <or= 0.001; hepatic venous phase, 1.60, 2.63, p <or= 0.001), and liver (portal venous phase, 0.76, 0.94, p = 0.016; hepatic venous phase, 0.76, 1.04, p <or= 0.001). In the abdominal aorta, the mean enhancement index was greater after bolus injection of gadoxetic acid (arterial phase, 3.33, 2.24, p <or= 0.005).


CONCLUSIONS
Early dynamic MRI of the upper abdominal organs, especially the spleen, pancreas, and kidney, benefits from the higher gadolinium concentration of gadobutrol than in the organ-specific contrast agent gadoxetic acid. Higher protein binding resulting in increased relaxivity of gadoxetic acid compensates for the low gadolinium concentration in the abdominal aorta.
Department of Diagnostic Radiology, MRI Section, University of Greifswald, Mecklenburg Vorpommern, Germany. kuehn@uni-greifswald.de
Jens-Peter
JP
Kühn
Katrin
K
Hegenscheid
Werner
W
Siegmund
Claus-Peter
CP
Froehlich
Norbert
N
Hosten
Ralf
R
Puls
D000005:Abdomen / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D018709:Statistics, Nonparametric
D003287:Contrast Media; D009942:Organometallic Compounds; C073590:gadolinium ethoxybenzyl DTPA; C090600:gadobutrol; D019786:Gadolinium DTPA