Gd-DTPA as a contrast agent in CT.

An evaluation was done of the effect of gadolinium diethylenetriaminepentaacetic acid (DTPA) on computed tomographic (CT) studies performed after magnetic resonance (MR) imaging. CT scans of two solutions of Gd-DTPA demonstrated substantial attenuation. In two patients who underwent CT after Gd-DTPA-enhanced MR imaging, the high attenuation of concentrated Gd-DTPA was seen in the urinary bladder and renal collecting system. However, in the concentration presently used in MR imaging, Gd-DTPA results in only minor enhancement of renal cortex.