White-ray computed tomography using a power light-emitting diode and self-wavelength selection

To image objects, including biomedical samples, we developed a white-ray computed tomography (WRCT) scanner using a white power light-emitting diode (LED) and a high-sensitivity photodiode (PD) module. The line beam forms using a 1.0-mm-diameter 10-mm-length graphite collimator and is irradiated to an object. Photons penetrating an object are detected using the PD module through a 0.7-mm-diameter, 10-mm-length diaphragm. The spatial resolutions were primarily determined by the diaphragm diameter attached to the detector and were ∼0.7 × 0.7 mm2. The WRCT was performed by repeating the reciprocating translations and rotations of the object, and the ray-sampling-translation and rotation steps were 0.1 mm and 0.5°, respectively. The WR consisted of visible and near-infrared photons, and rabbit blood in a vinyl tube was observed at high contrast.