diceCT: A Valuable Technique to Study the Nervous System of Fish

Area of Science:

• Comparative anatomy
• Neuroimaging
• X-ray computed tomography

Background:

• Contrast-enhanced X-ray imaging offers non-destructive soft tissue contrast optimization.
• Diffusible iodine-based contrast-enhanced computed tomography (diceCT) uses Lugol's solution for enhanced soft tissue visualization.
• Optimal contrast is crucial for segmentation and volumetric analysis of nervous systems.

Purpose of the Study:

• To present an optimized diceCT staining method for fish brains.
• To achieve enhanced contrast between neural and background tissues in cartilaginous and bony fish.
• To facilitate digital segmentation and volumetric analysis of fish central nervous systems.

Main Methods:

• Applied diceCT using Lugol's solution to brownbanded bamboo sharks (C. punctatum) and goldfish (C. auratus).
• Scanned specimens before staining and at regular time intervals (48h for sharks, 24h for goldfish) to monitor contrast enhancement.
• Reconstructed X-ray CT data using calibration phantoms for quantitative comparison of stain intensities.

Main Results:

• Optimal brain contrast achieved at T=240h for C. punctatum and T=96h for C. auratus.
• Higher resolution whole-brain scans obtained at optimized staining times.
• diceCT demonstrated excellent contrast penetration within and between soft tissues, including the central nervous system.

Conclusions:

• Optimized diceCT protocols provide superior contrast for fish brain imaging.
• This technique is valuable for visualizing anatomical differences in fish nervous systems.
• diceCT enables detailed digital segmentation and volumetric analysis of fish neuroanatomy.