A rapid denoised contrast enhancement method digitally mimicking an adaptive illumination in submicron-resolution neuronal imaging

Abstract

Optical neuronal imaging often shows ultrafine structures, such as a nerve fiber, coexisting with ultrabright structures, such as a soma with a substantially higher fluorescence-protein concentration. Owing to experimental and environmental factors, a laser-scanning multiphoton optical microscope (MPM) often encounters a high-frequency background noise that might contaminate such weak-intensity ultrafine neuronal structures. A straightforward contrast enhancement often leads to the saturation of the brighter ones, and might further amplify the high-frequency background noise. We report a digital approach called rapid denoised contrast enhancement (DCE), which digitally mimics a hardware-based adaptive/controlled illumination technique by means of digitally optimizing the signal strengths and hence the visibility of such weak-intensity structures while mostly preventing the saturation of the brightest ones. With large field-of-view (FOV) two-photon excitation fluorescence (TPEF) neuronal imaging, we validate the effectiveness of DCE over state-ofthe-art digital image processing algorithms. With compute-unified-device-architecture (CUDA)-acceleration, a real-time DCE is further enabled with a reduced time complexity.

Rapid digital pathology of H&E-stained fresh human brain specimens as an alternative to frozen biopsy

“…Utilizing H&E dyes, the-RSTS protocol was applied consuming 6 minutes of duration. Subsequently, multi-channel mesoscale high-NFOM acquisition was performed with our mNLOG imaging platform with enabled real-time DCE 52 followed by real-time color-remapping. For additional information, see “Methods” section (Real-time color remapping to assist with a traditional histopathological visualization, and Digital boost via DCE).…”

“…To resolve this issue, we employed one of our recently published methods called Denoised Contrast Enhancement (DCE) 52 . Unlike alternative state-of-the-arts, such as contrast-limited adaptive histogram equalization, DCE first suppresses the background and then selectively optimizes the contrast of the structural details.…”

“…The single adjustment parameter is denoted as . For application, performance, and additional details regarding DCE, see our previous publication 52 . In this present study, the typically used and recommended values of for TPEF and THG channels are 5.0 and 8.0, respectively, which can be further optimized based on visual response.…”