Figure 1.
Simplified schematic of the in-house optical-CT/ECT system. (A) Optical-CT is the optical analogue of x-ray CT. Light is transmitted from a uniform backlight through an optically clear sample, and the resulting projection images are collected by a telecentric lens–CCD camera optical chain. (B) Optical-ECT is the optical analogue of SPECT. Proteins within the sample are stimulated to fluoresce by excitation light sources normal to the imaging axis. Appropriate narrow-bandwidth filters are used for selection of excitation light and collection of emitted light. Emission images are collected using the same imaging components as in (A).