講演情報
[10p-E204-10]In Vivo Time-Resolved Imaging Using a Two-Dimensional Scintillator-Based Photon-Counting CT with Hepatocyte-Specific Contrast Enhancement
〇(D)Fitri Lucyana1, Makoto Arimoto1, Minori Oshima1, Yu Furuta1, Shuma Midorikawa1, Hiroki Kawashima1, Satoshi Kobayashi1, Kenichiro Okumura1, Naoki Ohno1, Asuka Mizutani1, Jun Kataoka2, Takahiro Ro2, Kazuhiro Murakami3, Shinsuke Terazawa4, Yuta Maeno4 (1.Kanazawa Univ., 2.Waseda Univ., 3.Ishikawa Prefectural Univ., 4.Proterial Ltd.)
キーワード：
scintillator-based PC-CT、2-dimensional detector、dynamic imaging
Photon-counting computed tomography (PC-CT) enables energy-resolved imaging capability by recording individual X-ray photons and has demonstrated potential for dynamic contrast-enhanced imaging using semiconductor detectors. To explore the potential of scintillator-based detectors for such applications, a two-dimensional PC-CT system was constructed using a 16 × 64 yttrium–gadolinium–aluminum–gallium garnet (YGAG) scintillator array coupled to a multi-pixel photon counter (MPPC) array, yielding 1024 channels with a voxel size of 1 × 1 × 1 mm3 and six energy thresholds. This study evaluates the capability of the developed system for in vivo time-resolved imaging following administration of a hepatocyte-specific gadolinium contrast agent. Fig.1 shows the experimental setup. A mouse was scanned before and after intravenous administration of a hepatocyte-specific gadolinium (Gd) contrast agent. Whole-body imaging was performed using three axial detector positions, with 120 projection views acquired over a 180° rotation at each position. The X-ray tube was operated at 100 kV and 0.2 mA, and six energy bins were obtained using thresholds of 30, 40, 50, 60, 70, and 85 keV. Gd concentration maps were estimated from reconstructed spectral CT data using a least-squares fitting method based on energy-dependent attenuation coefficients. Temporal changes in Gd distribution were successfully visualized after contrast administration. Three-dimensional reconstructed images, generated by overlaying the estimated Gd distribution onto a Ca-based attenuation map shown in Fig.2, revealed accumulation in the liver and bladder corresponding to uptake and excretion of the hepatocyte-specific contrast agent. These results demonstrate the capability of the developed PC-CT system to capture the spatial and temporal dynamics of contrast enhancement in vivo. We will briefly report the result of the detailed evaluation.