MicroCT liver contrast agent enhancement over time, dose, and mouse strain

Area of Science:

• Biomedical Imaging
• Pharmacokinetics
• Preclinical Research

Background:

• Fenestra liver contrast agent (LC) is used in preclinical imaging.
• Understanding strain-specific uptake and potential interference with other imaging modalities is crucial.

Purpose of the Study:

• To investigate strain differences in Fenestra LC uptake in Nude, C57, and SCID mice.
• To determine optimal Fenestra LC dosing for microPET/CT imaging.
• To assess potential attenuation effects of Fenestra LC on 2-deoxy-2[F-18]fluoro-D-glucose (FDG) uptake.

Main Methods:

• Mice of different strains (Nude, C57, SCID) were injected with varying doses of Fenestra LC (5.0-15.0 ml/kg).
• Micro computed tomography (microCT) was used to image contrast uptake over 7 days.
• MicroPET/CT imaging with FDG was performed with and without Fenestra LC to evaluate attenuation effects.

Main Results:

• Significant strain-dependent variations in Fenestra LC uptake were observed, with SCID mice showing higher spleen uptake and C57 mice higher liver uptake.
• Spleen exhibited higher contrast uptake and longer signal duration than the liver across all strains.
• Significant attenuation of FDG uptake was only observed in the heart following contrast administration.

Conclusions:

• Fenestra LC uptake and signal duration are strain-specific.
• Effective imaging duration is 1 day at 7.5 ml/kg and up to 1 week at 15 ml/kg.
• Fenestra LC at 15 ml/kg is suitable for combined microPET imaging as it minimally affects FDG uptake in most tissues.