Microvascular imaging: techniques and opportunities for clinical physiological measurements

Area of Science:

• Physiology
• Medical Imaging
• Biomedical Engineering

Background:

• Microvascular physiological measurement is challenging due to spatial inhomogeneity and temporal perfusion variability.
• Accurate assessment of microcirculation is vital for diagnosing and managing various clinical conditions.

Purpose of the Study:

• To provide a clinical overview of current and emerging microvascular imaging techniques.
• To discuss the applications and potential of these methods in clinical practice and research.

Main Methods:

• Review of established techniques: Laser Doppler perfusion imaging, laser speckle contrast imaging, and nailfold capillaroscopy.
• Description of infrared thermography and its limited applications.
• Exploration of emerging technologies: imaging photoplethysmography, optical coherence tomography, photoacoustic tomography, hyperspectral imaging, and tissue viability imaging.

Main Results:

• Established techniques like laser Doppler and laser speckle imaging have proven clinical utility (e.g., burn-depth assessment).
• Nailfold capillaroscopy is supported by literature for diagnosing microangiopathy in Raynaud's phenomenon.
• Emerging technologies offer potential for broader clinical microvascular assessment.

Conclusions:

• A wide array of microvascular imaging methods are available, with varying degrees of clinical acceptance.
• Continued development in perfusion imaging presents significant opportunities for microvascular research and improved patient outcomes.