Optimal dose of hepatobiliary contrast agent for MR cholangiography: experimental study in rats.
The purpose of this study is to clarify the optimal dose of gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) for cholangiography in conventional T1-weighted imaging. We divided 30 rats into three dose groups (3, 10, and 30 micromol/kg). For the in vitro study, we collected bile and measured the concentration of gadolinium in bile after Gd-EOB-DTPA injection. T1-weighted images of the collected bile were obtained for measurement of signal intensity. For the in vivo study, we obtained T1-weighted images before and after injection and evaluated bile duct/liver contrast by the signal intensity ratio and visual assessment of the images. The gadolinium concentration had an early peak; however, the signal intensity of the bile had a later peak because of the high gadolinium concentration during the early phase, which induced a T2-shortening effect. Optimal bile duct/liver contrast was obtained in the 10-micromol/kg groups at all time points. We conclude that the optimal dose of Gd-EOB-DTPA for MR cholangiography in rats is 10 micromol/kg, one-third of the dose used in liver imaging.
Department of Radiology, Nara Medical University, Japan.
S
S
Hirohashi
R
R
Hirohashi
H
H
Uchida
S
S
Kitano
M
M
Akira
W
W
Ono
H
H
Ohishi
N
N
Kato
M
M
Takahashi
T
T
Miyazawa
D000818:Animals; D001652:Bile Ducts / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage*; D019786:Gadolinium DTPA / Q000008:administration & dosage; D008099:Liver / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA