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Funder: EPSRC IPES, We present a tomographic reconstruction algorithm (flOPT), which is applied to Optical Projection Tomography (OPT) images, that is robust to mechanical jitter and systematic angular and spatial drift. OPT relies on precise mechanical rotation and is less mechanically stable than large-scale computer tomography (CT) scanning systems, leading to reconstruction artefacts. The algorithm uses multiple (5+) tracked fiducial beads to recover the sample pose and the image rays are then back-projected at each orientation. The quality of the image reconstruction using the proposed algorithm shows an improvement when compared to the Radon transform. Moreover, when adding a systematic spatial and angular mechanical drift, the reconstruction shows a significant improvement over the Radon transform.

Funder: MedImmune, and Infinitus (China) Ltd., In optical microscopy, the slow axial scanning rate of the objective or the sample has traditionally limited the speed of volumetric imaging. Recently, by conjugating either a movable mirror to the image plane in a remote-focusing geometry or an electrically tuneable lens (ETL) to the back focal plane, rapid axial scanning has been achieved. However, mechanical actuation of a mirror limits the axial scanning rate (usually only 10–100 Hz for piezoelectric or voice coil-based actuators), while ETLs introduce spherical and higher-order aberrations that prevent high-resolution imaging. In an effort to overcome these limitations, we introduce a novel optical design that transforms a lateral-scan motion into a spherical aberration-free axial scan that can be used for high-resolution imaging. Using a galvanometric mirror, we scan a laser beam laterally in a remote-focusing arm, which is then back-reflected from different heights of a mirror in the image space. We characterize the optical performance of this remote-focusing technique and use it to accelerate axially swept light-sheet microscopy by an order of magnitude, allowing the quantification of rapid vesicular dynamics in three dimensions. We also demonstrate resonant remote focusing at 12 kHz with a two-photon raster-scanning microscope, which allows rapid imaging of brain tissues and zebrafish cardiac dynamics with diffraction-limited resolution.