In Vivo Imaging Techniques for the Human Scalp: A Systematic Review of the Literature

This systematic review evaluates 42 studies on noninvasive in vivo imaging techniques for diagnosing scalp conditions, particularly alopecia, to reduce the need for invasive biopsies. Techniques such as optical coherence tomography (OCT), high-frequency ultrasound (HFUS), and reflectance confocal microscopy (RCM) are highlighted for their potential in providing detailed scalp imaging and enhancing diagnostic accuracy. OCT is effective in assessing vascular changes and follicular counts, while HFUS is recommended for examining follicle depth and distinguishing scalp lesions. RCM is useful for differentiating scarring from non-scarring alopecia. Despite their promise, these techniques face challenges like the need for large-scale studies and operator dependency, and none have yet replaced histopathology as the gold standard.