Development of 64-channel LSI with ultrafast analog and digital signal processing dedicated for photon-counting computed tomography with multi-pixel photon counter
Abstract
X-ray computed tomography (CT) is non destructive visualization inside the human body. Recently, X-ray photon-counting CT (PC-CT) has drawn attention for reducing the high doses used for patients and acquiring spectral information to identify materials. To enable photon-counting imaging with a wide region (∼60 mm long) of a small animal, we developed a photon-counting system using a 64-channel multi-pixel photon counter (MPPC) array with a fast temporal response (a few nanoseconds) and a very large signal gain (∼ 106), combined with a 64-channel yttrium-gadolinium-aluminum-gallium garnet scintillator array. In particular, to realize ultra-fast analog and digital signal processing (> 10 MHz/channel), we developed a 64-channel large-scale integrated circuit (LSI) named MPPC-CT64. We had previously developed a 16-channel PC-CT system with a 16-channel LSI (MPPC-CT16). Although the MPPC-CT16 realized photon-counting imaging for a ∼16-mm-long phantom, there were some energy uncertainties in the LSI, which degraded the obtained CT image quality. The MPPC-CT64 implements a function for correcting the threshold energies and also increases the number of energy thresholds from four to six, which provides more precise measurements of CT values dependent on X-ray energy. In this paper, we briefly present the electric architecture and performance evaluation of the LSI combined with MPPCs.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- February 2023
- DOI:
- 10.1016/j.nima.2022.167721
- Bibcode:
- 2023NIMPA104767721A
- Keywords:
-
- X-ray;
- LSI;
- ASIC;
- MPPC