Computed Tomography Cholangiography Using the Magnetic Resonance Contrast Agent Gadoxetate Disodium: A Phantom Study

Objective The purpose of this work is to determine whether low doses of gadoxetate disodium (Eovist; Bayer Healthcare LLC, Whippany, NJ), a gadolinium-based contrast agent used for magnetic resonance liver imaging, can be visualized for computed tomography (CT) cholangiography using a phantom setup. Materials and Methods Vials containing 4 concentrations of gadoxetate disodium (1.9, 3.4, 4.8, and 9.6 mg Gd/mL) were placed in a 35 × 26-cm2 water phantom and imaged on 2 CT scanners: Siemens Somatom Flash and Force (Siemens Healthcare, Erlangen, Germany). These concentrations correspond to the estimated concentration in the bile duct for a 40-, 70-, or 100-kg patient, and twice the concentration of a 100-kg patient, respectively. Single-energy (SE) scans were acquired at 70, 80, 90, 100, 120, and 140 kVp, and dual-energy scans were acquired at 90/150Sn (Force) and 100/150 (Flash) for 2 dose levels (CTDIvol 13 and 23 mGy). Virtual monoenergetic images at 50 keV were created (Mono+; Siemens Healthcare, Erlangen, Germany). The mean intensity and standard deviation for each concentration of gadoxetate disodium and the water background were extracted from each image set and used to compute the contrast and contrast-to-noise ratio (CNR). To determine whether the signal provided by gadoxetate disodium was clinically sufficient, the measures were compared with those acquired from 12 clinical CT cholangiography examinations performed with iodine-containing iodipamide meglumine. Re...
Source: Investigative Radiology - Category: Radiology Tags: Original Articles Source Type: research