Biomedical imaging techniques are often limited by the loss of resolution with depth due to light scattering inbiological tissue. Beyond a few millimeters in depth, diffuse transport dominates and makes high resolution imagingimpossible using conventional techniques. In this work, light sheet imaging using x-ray photons was developed witha keV x-ray source. This partially overcomes this scattering by generating light within tissue at depth. The lightexcites fluorescent probes that can be used for tumor tracking based upon molecular targeting. Most of the fluorescentprobes have a lifetime in the nanosecond range. In this study, the use of a portable linear accelerator delivering 30-nsx-ray pulses was explored. Using x-ray excitable fluorophores, light was generated within a tissue phantom. Imagestacks were acquired using an intensified camera (PiMAX4 – Princeton Instrument – USA) placed perpendicularly tothe slicing direction of the sample. A solid-state silicon photomultiplier was used to gate acquisition. Although thisdelayed acquisition slightly, it improved the fluorescence signal-to-noise ratio (SNR). A deconvolution algorithmcounteracted the blurring effects of tissue, and image stacks were converted to 3D reconstructions. In summary,nanosecond x-ray pulses can be used to excite fluorophores through radioluminescence phenomenon. Combined withslice imaging, this approach shows promise for time-resolved x-ray luminescence.
展开▼
