In vivo imaging, particularly micro-computed tomography (micro-CT), uses contrast agents to visualize the subject's vasculature. Small rodents have small blood volumes which limit the injectable dosage of contrast agent into their blood. To increase the contrast enhancement of the reconstructed images, iodine concentration is increased, and the injectable volume is decreased from 0.01 mL/g of 50 mg/mL Fenestra VC to 0.005 mL/g of 100 mg/mL Fenestra HDVC. Fenestra VC and Fenestra HDVC were diluted into 9 iodine concentrations ranging between 0-50 mg/mL for Fenestra VC and 0- 100 mg/mL for Fenestra HDVC. The dilution vials were imaged using the in vivo micro-CT scanner and measured for the mean CT numbers and standard deviations. The results graphed on a dilution graph shows that Fenestra HDVC with half the dosage volume has the same contrast enhancement as Fenestra VC for the same iodine concentration. The micro- CT scans for ten C57BL/6 female mice were used to determine the mean CT numbers using MicroView for the right atrium, liver, air, bladder, leg muscle, kidney, spleen, and vena cava. These regions were measured using 1mm3 region of interest at 8 time points: pre-contrast, post-contrast at t = 0, 8, 24, 48, 72 hours, 1 and 2 weeks. These in vivo values were compared between mice injected with Fenestra VC and Fenestra HDVC to show that half the dosage volume using Fenestra HDVC enhances like the full dosage volume using Fenestra VC. Thus, Fenestra HDVC may be a safer choice for in vivo rodent imaging.
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