Low-dose low-scattering X-ray computed tomography with high-spatial-energy resolutions using a cooled cadmium telluride detector

Self Cite

To perform energy-dispersive x-ray computed tomography (EDCT), we constructed a computer program to amplify the digital values of raw radiograms. The CT scanner consists of an x-ray generator with a 0.1-mm-focus tube, a turntable, a flat panel detector (FPD), and a personal computer (PC). An object on the turntable is irradiated by the x-ray generator, 1.3-magnified 720 radiograms are taken by the FPD, and tomograms are reconstructed using the PC. Utilizing the digital amplifier, the object projections obtained using low-energy photons disappeared with increasing amplification factor at a constant maximum value, and the effective energy increased according to increases in the amplification factor by beam hardening. Using the beam-hardening CT (BHCT) scanner, high-contrast tomography for various objects was performed by controlling effective energy. In particular, fine blood vessels were observed by K-edge CT using iodine media.

Section: Introductionmentioning

confidence: 99%

Energy-dispersive x-ray computed tomography utilizing beam hardening

Sato,

Ito,

Moriyama

et al. 2023

Self Cite

“…Cadmium telluride (CdTe) detectors 1 are useful for measuring x-ray spectra, and the energy resolution has been improved to approximately 1% at 59.5 keV. Therefore, we developed several first-generation photon-counting x-ray computed tomography (PCCT) scanners [2][3][4][5] using a CdTe detector. Utilizing these scanners, we performed K-edge CT using iodine (I) and gadolinium (Gd) media, and fine blood vessel were observed at a high contrast.…”

Section: Introductionmentioning

confidence: 99%

Photon-counting x-ray computed tomography with high spatial resolutions

Ito,

Sato,

Moriyama

et al. 2023

Self Cite

Photon-counting x-ray computed tomography (PCCT) is useful for selecting optimal energy photons to image various portions of the target object, and we performed fundamental experiments of PCCT to carry out gadolinium (Gd) K-edge CT using Gd-based contrast media. The scanner mainly consists of an x-ray generator with a 0.1-mm-focus tube, a turntable, a cadmium-telluride (CdTe) flat panel detector (FPD) with pixel dimensions of 100 Pm, and a personal computer. An object on the turntable is irradiated by the x-ray generator, 720 radiograms are taken using the FPD, and tomograms are reconstructed. We used 1.3-time magnification tomography, the effective pixel dimensions were approximately 80 Pm, and Gd-K-edge CT was carried out using Gd-based contrast media at a tube voltage of 100 kV, a tube current of 0.40 mA, and a threshold energy of 50 keV.

“…To image fine blood vessels, we developed first-generation photon-counting x-ray computed tomography (PCCT) scanners. [1][2][3][4] Using the PCCT scanners, we performed K-edge CT using iodine (I) and gadolinium (Gd) contrast media, since photons with energies just beyond the K-edge energy are absorbed effectively by the contrast media. Recently, we developed a near-infrared-ray computed tomography (NIRCT) scanners [5][6][7] in the living-body range of 700-900 nm to observe thick blood vessels.…”

Section: Introductionmentioning

confidence: 99%

Red-ray computed tomography with high spatial resolutions

Hagiwara,

Sato,

Ito

et al. 2023

Self Cite

To image blood vessels, we performed fundamental experiments of a red-ray computed tomography (RRCT) scanner using 650-nm-laser and high-sensitivity-photodiode (PD) modules. The line laser beam is irradiated to an object, and the photons penetrating through the object are detected using the PD module through a 1.0-mm-diameter graphite pinhole and a 0.7-mm-diameter 5-mm-length graphite collimator for the PD. The spatial resolutions were primarily determined by the collimator diameter for the PD and were approximately 0.7×0.7 mm2. RRCT 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 image contrast was regulated using the digital amplifier, and the visible diameter of object was 0.5mm.