Real-time in vivo computed optical interferometric tomography

High-resolution real-time tomography of scattering tissues is important for many areas of medicine and biology. However, the compromise between transverse resolution and depth-of-field, in addition to low sensitivity deep in tissue, continues to impede progress towards cellular-level volumetric tomography. Computed imaging has the potential to solve these long-standing limitations. Interferometric synthetic aperture microscopy is a computed imaging technique enabling high-resolution volumetric tomography with spatially invariant resolution. However, its potential for clinical diagnostics remains largely untapped because full volume reconstructions required lengthy post-processing, and the phase-stability requirements have been difficult to satisfy in vivo. Here, we demonstrate how three-dimensional Fourier-domain resampling, in combination with high-speed optical coherence tomography, can achieve high-resolution in vivo tomography. Enhanced depth sensitivity was achieved over a depth of field extended in real time by more than an order of magnitude. This work lays the foundation for high-speed volumetric cellular-level tomography.