X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging

Area of Science:

• Biomedical Imaging
• Developmental Biology
• Musculoskeletal Research

Background:

• High-resolution imaging of muscular structure is crucial for understanding muscle diseases and evaluating treatments.
• Current histological methods require tissue excision, fixation, and staining, limiting in vivo studies.
• There is a need for non-invasive imaging techniques capable of resolving subcellular details in whole animal models.

Purpose of the Study:

• To demonstrate the capability of X-ray phase-contrast tomography for imaging unstained whole zebrafish with sub-5 μm detail.
• To assess the potential of this technique for diagnosing muscular dystrophy and other muscle-related conditions.
• To establish a method for high-resolution, whole-body imaging of soft tissues in animal models.

Main Methods:

• Utilized a laboratory-based propagation-based X-ray phase-contrast system.
• Optimized the system for detecting low-contrast subcellular myofibrils (4-6 μm).
• Applied the technique to unstained, whole zebrafish larvae (20 days post fertilization).

Main Results:

• Achieved sub-5 μm resolution imaging of three-dimensional muscular structure in whole zebrafish.
• Confirmed the resolution of individual myofibrils through comparative histology.
• Differentiated between healthy zebrafish with structured muscle patterns and dystrophin-deficient (sapje) zebrafish exhibiting unstructured patterns characteristic of Duchenne muscular dystrophy.

Conclusions:

• X-ray phase-contrast tomography enables non-invasive, whole-body imaging of subcellular muscle detail in zebrafish.
• This technique provides a valuable tool for studying muscular diseases and assessing therapeutic interventions in vivo.
• The method holds promise for extending high-resolution soft tissue imaging to other animal models.