850-nm near-infrared-ray computed tomography with high spatial resolutions

摘要

To improve the spatial resolution in near-infrared-ray computed tomography (NIR-CT), a first-generation scanner in the first-living-body window was constructed. The NIR photons are produced from an 850 nm laser module, and penetrating photons from an object are detected using a photodiode (PD). To improve the spatial resolution, we used a 1.0-mm-diam graphite pinhole and a 1.0-mm-diam 5.0-mm-length graphite collimator. To detect the penetrating photons, the pinhole is set behind the object, and the collimator is attached to the PD to improve the spatial resolution. The NIR-CT is accomplished by repeated translations and rotations of the object. The translation is performed by the object moving between the laser and the PD modules. The translation and rotation steps were 0.25 mm and 1.0°, respectively, and the spatial resolutions were determined as 1.0× 1.0 mm~2. The scanning time and the total rotation angle for CT were 9.8 min and 180°, respectively.