Contrast timing in computed tomography: effect of different contrast media concentrations on bolus geometry

posted in: CT Concepts | 0

Mahnken AH, Jost G, Seidensticker P, et al.

Eur J Radiol 2012;81:e629-632.

OBJECTIVE: To assess the effect of low-osmolar, monomeric contrast media with different iodine concentrations on bolus shape in aortic CT angiography. MATERIALS AND METHODS: Repeated sequential computed tomography scanning of the descending aorta of eight beagle dogs (5 male, 12.7+/-3.1kg) was performed without table movement with a standardized CT scan protocol. Iopromide 300 (300mgI/mL), iopromide 370 (370mgI/mL) and iomeprol 400 (400mgI/mL) were administered via a foreleg vein with an identical iodine delivery rate of 1.2gI/s and a total iodine dose of 300mgI/kg body weight. Time-enhancement curves were computed and analyzed. RESULTS: Iopromide 300 showed the highest peak enhancement (445.2+/-89.1 HU), steepest up-slope (104.2+/-17.5 HU/s) and smallest full width at half maximum (FWHM; 5.8+/-1.0s). Peak enhancement, duration of FWHM, enhancement at FWHM and up-slope differed significantly between iopromide 300 and iomeprol 400 (p<0.05). Except for enhancement at FWHM there were no significant differences between iopromide 300 and iopromide 370 and iopromide 370 and iomeprol 400 (p>0.05). CONCLUSIONS: Low viscous iopromide 300 results in a better defined bolus with a significantly higher peak enhancement, steeper up-slope and smaller FWHM when compared to iomeprol 400. These characteristics potentially affect contrast timing.