Anatomical and microstructural imaging of angiogenesis.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Vascular Biology

Background:

• Standard histological methods for microvessel analysis have limitations in capturing 3D architecture and vessel function.
• Assessing angiogenesis requires advanced techniques beyond simple microvessel density counts.

Purpose of the Study:

• To review and discuss various ex vivo and in vivo methods for visualizing microvessel architecture.
• To evaluate these techniques based on reliability, practicability, and availability.

Main Methods:

• Confocal fluorescence microscopy for 3D imaging.
• Multiphoton microscopy, optical coherence tomography, and optical frequency domain imaging for deeper tissue penetration and in vivo imaging.
• Corrosion casts with scanning electron microscopy and microcomputed tomography (microCT) for larger samples.
• 3D contrast-enhanced high-frequency ultrasound and MRI (T1-weighted angiography).
• Optoacoustic tomographic imaging for high-resolution in vivo mapping.

Main Results:

• Standard histology and coregistered immunostaining are time-consuming and lack accuracy for 3D vessel architecture.
• Confocal microscopy is limited to thin 3D stacks.
• Advanced microscopy and imaging techniques provide deeper insights and in vivo capabilities.
• MicroCT, ultrasound, MRI, and optoacoustic imaging offer diverse approaches for microvascular visualization with varying strengths.

Conclusions:

• Investigating angiogenesis requires methods that capture 3D architecture and functionality.
• Advanced imaging technologies like multiphoton microscopy, microCT, and optoacoustic imaging are crucial for accurate and in vivo microvessel analysis.
• These techniques enable longitudinal studies and offer new perspectives in vascular research.