Enhanced K-Edge Radiography Using a High-Spatial-Resolution Cadmium Telluride Array Detector

• 作者: Eiichi Sato Hiroshi Matsukiyo Hodaka Moriyama Manabu Watanabe Osahiko Hagiwara Shinya Kusachi Toshiyuki Enomoto Yasuyuki Oda
• 来源期刊: 医学物理学、临床工程、放射肿瘤学(英文)
• 学科: 医学
• 关键词: X-Ray Photon COUNTING CdTe-Array Detector DUAL-ENERGY Energy-Dispersive RADIOGRAPHY I-K-Edge RADIOGRAPHY Gd-K-Edge RADIOGRAPHY
• 年，卷（期）: 2018,（3）
• 页码范围: 296-307
• 页数: 12页
• 分类号: R73

摘要

To confirm the imaging effect of a dual-energy (DE) cadmium telluride (CdTe) array detector (XCounter, Actaeon) and to perform fundamental studies on DE computed tomography, we performed enhanced K-edge radiography using iodine (I) and gadolinium (Gd) media. DE radiography was performed using an X-ray generator with a 0.1-mm-diam-focus tube and a 0.5-mm-thick beryllium window, a 1.0-mm-thick aluminum filter for absorbing extremely low-energy photons, and the CdTe array detector with pixel dimensions of 0.1 × 0.1 mm2. Each pixel has a charge-sensitive amplifier and a dual-energy counter, and the event pulses from the amplifier are sent to the counter to determine two threshold energies. The tube current was a maximum value of 0.50 mA, and the tube voltages for I- and Gd-K-edge radiograms were 60 and 80 kV, respectively. In the I-K-edge radiography of a dog-heart phantom at an energy range of 33 - 60 keV, the muscle density increased, and fine coronary arteries were visible. Utilizing Gd-K-edge radiography of a rabbit head phantom at an energy range of 50 - 80 keV, the muscle density increased, and fine blood vessels in the nose were observed at high contrasts. Using the DE array detector, we confirmed the image-contrast variations with changes in the threshold energy.