Nobukazu Tanaka MS, Presenter: Nothing to Disclose

Noriko Mizoguchi RT, Abstract Co-Author: Nothing to Disclose

Saki Yamaguchi RT, Abstract Co-Author: Nothing to Disclose

Akiko Hattori RT, Abstract Co-Author: Nothing to Disclose

Hidetake Yabuuchi MD, Abstract Co-Author: Nothing to Disclose

Junji Morishita PhD, Abstract Co-Author: Research Grant, Eizo Nanao Corporation

Toyoyuki Kato RT, Abstract Co-Author: Nothing to Disclose

Yuki Yano RT, Abstract Co-Author: Nothing to Disclose

Kiyo Iwakiri RT, Abstract Co-Author: Nothing to Disclose

Chihiro Matsuo RT, Abstract Co-Author: Nothing to Disclose

Yoshiyuki Umezu RT, Abstract Co-Author: Nothing to Disclose

Yasuhiko Nakamura RT, Abstract Co-Author: Nothing to Disclose

To evaluate the improvement in image quality of a new direct conversion type flat panel detector system employing optical switching technology.

The direct FPD system employing optical switching technology (AMULET, Fujifilm) and a computed radiographic (CR) system (FCR PROFECT CS, Fujifilm) were used in this study. Two conventional photostimulable phosphor plates (HR-BD for dual-side reading (DSR) and HR-V for single-side reading (SSR), Fujifilm) were used for comparison. An X-ray beam quality of RQA-M2 defined by the International Electrotechnical Commission 62220-1-2 was employed in this study. The presampled modulation transfer function (MTF), the Wiener spectrum (WS), and the detective quantum efficiency (DQE) were measured in 0.10, 0.21, and 0.42 mGy. Contrast-detail (CD) diagram obtained by use of a CDMAM phantom and a software (CDMAM analyzer, Artinis) of the direct FPD system was compared with the DSR system. Detectability of small signals with subtle contrast was evaluated in terms of the image quality figure (IQF).

The presampled MTFs of the direct FPD system were 0.77 and 0.50 at 2 and 4 cycle/mm, respectively. On the other hand, the presampled MTFs of both the DSR and SSR systems were 0.59 and 0.22 at 2 and 4 cycle/mm, respectively. The WSs of the direct FPD system were comparable to those of the DSR system at 0.10 and 0.21 mGy. However, the WS of the direct FPD system was lower than those of the DSR and SSR systems at 0.42 mGy. The DQE of the direct FPD system was about 1.5 and 2.8 times higher than those of the DSR and SSR systems, respectively. In the result of IQF, detectability of the direct FPD system was superior to that of the DSR system under the same exposure condition.

The resolution property and the detective quantum efficiency of the direct FPD system were significantly superior to those of the DSR and SSR systems. The direct FPD system has potential usefulness to improve the detectability compared to the conventional CR system.

The new direct FPD system with high resolution and low noise will improve the detectability of small signals as microcalcifications compared to the conventional CR system.

Tanaka, N, Mizoguchi, N, Yamaguchi, S, Hattori, A, Yabuuchi, H, Morishita, J, Kato, T, Yano, Y, Iwakiri, K, Matsuo, C, Umezu, Y, Nakamura, Y, Imaging Properties of a New Direct Conversion Type Flat Panel Detector System Employing Optical Switching Technology.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043874.html