[2B06-08] Medical Applications

11:00 AM - 11:15 AM JST(2:00 AM - 2:15 AM UTC)

[2B06] Integration and Performance Evaluation of a TlBr X-ray Imager for CT Imaging Systems

*Moh Hamdan¹, Kenji Shimazoe¹, Hiroyuki Takahashi¹, Mitsuhiro Nogami², Keitaro Hitomi², Takanori Tsunashima³, Takashi Nakamura³ (1. The University of Tokyo, 2. Tohoku University, 3. Japan Display Inc.)

Keywords:

Thallium Bromide (TlBr),Flat Panel Detectors,X-ray Imaging,Computed Tomography

Thallium Bromide (TlBr) is an attractive material for direct-conversion flat-panel detectors (FPDs) due to its suitable energy bandgap (2.68 eV), high atomic numbers (Z _Tl = 81, Z _Br = 35), and high density ( 7.56 g/cm³), enabling efficient X-ray absorption. This study focuses on the development and evaluation of an FPD with a TlBr film, ranging from 25 to 50 µm in thickness, for computed tomography (CT) imaging systems. The TlBr film, deposited via the evaporation method, features an active area of 29.61 × 39.48 mm². A pixelated sensor matrix with 168 × 126 pixels, each measuring 235 × 235 µm² , was fabricated using low-temperature polysilicon thin-film transistor (LTPS TFT) technology. Spatial resolution, measured using the slanted-edge method, achieved a Full Width at Half Maximum (FWHM) of 222 to 280 µm. CT imaging was performed with a cone beam X-ray source (25–50 kV, 0.25–2 mA), a source-to-detector distance of ~75 cm, and a rotation pitch of ~1°. Reconstruction using the Filtered Back Projection (FBP) method assessed the detector's sensitivity by imaging plastics and metals of varying densities.