Calcium binding by gadolinium-based MR contrast agents.
OBJECTIVE
This study was conducted to characterize the alterations in ionic sodium, potassium, and calcium by gadolinium-based MR contrast agents.


METHODS
An electrolyte solution (ES) containing 1.2 mM/L calcium ions,120 mM/L sodium, and 4.0 mM/L potassium were diluted with various gadolinium compounds and alterations in ionized electrolytes were measured using an ion-specific electrometer. Gadolinium compounds including Gd-DTPA, Gd-DOTA, gadoteridol, gadodiamide, meglumine/sodium diatrizoate (76% Urografin), and isotonic saline as a control were investigated. The dilution ranged from 5% (ES/test solution = 100/5) to 100%. Alterations of ionic electrolytes were measured. Calcium-binding capacities caused by each gadolinium compound also were measured.


RESULTS
The alterations of ionic sodium and potassium by gadolinium compound were similar to those of isotonic saline. A significant reduction in ionized calcium was observed with Gd-DTPA and Gd-DOTA in comparison with gadoteridol and gadodiamide.


CONCLUSIONS
Ionic gadolinium compounds induced significant reductions of calcium ions in vitro compared with non-ionic gadolinium compounds.
Department of Radiology, Kyoto City Hospital, Nakagyo-ku, Kyoto 604-8845, Japan.
Katsumi
K
Hayakawa
Tatsuo
T
Nakamura
Yasuhiko
Y
Shimizu
D002118:Calcium / Q000378:metabolism*; D003287:Contrast Media / Q000378:metabolism*; D003974:Diatrizoate Meglumine / Q000378:metabolism; D005682:Gadolinium / Q000378:metabolism*; D007477:Ions / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009942:Organometallic Compounds / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D003287:Contrast Media; D007477:Ions; D009942:Organometallic Compounds; D003974:Diatrizoate Meglumine; D012964:Sodium; D005682:Gadolinium; D011188:Potassium; D002118:Calcium