Ideguchi Tadamitsu, Higashida Yoshiharu, Kawaji Yasuyuki, Sasaki Mitsuo, Zaizen Makoto, Shibayama Rei, Nakamura Yumiko, Koyanagi Kimihiko, Ikeda Hirotaka, Ohki Masafumi, Toyofuku Fukai, Muranaka Toru
Department of Radiology, Clinical Research Institute, National Kyushu Medical Center, 1-8-1, Chigyohama, Chuo-ku, Fukuoka 810-0064, JAPAN.
Radiat Med. 2004 Jul-Aug;22(4):218-24.
To investigate the physical imaging properties and detection of simulated microcalcifications of a new computed radiography (CR) system with a pixel size of 50 microm for digital mammography.
New and conventional CR were employed in this study. The new CR system included a high-resolution imaging plate coupled with the FCR5000MA (50 microm pixel pitch) including transparent support and a dual-sided reader. The conventional CR system was coupled with the FCR9000 (100 microm pixel pitch). Modulation transfer functions (MTFs) and Wiener spectra (WS) of the new and conventional CR systems were measured. Observer performance tests were conducted to compare the effects of pixel size (50 microm vs. 100 microm) on the diagnostic accuracy of CR systems in the detection of simulated microcalcifications.
The presampling MTF of the new CR system was higher at high frequencies than the conventional CR system. The WS of the new CR system was comparable to that of the conventional CR system at all frequencies. The area under the receiver operating characteristic (ROC) curve (Az) obtained with the new CR and the conventional CR systems were 0.84 and 0.79, respectively. Results showed that the detection of simulated clustered microcalcifications was significantly improved by use of the new CR system compared with the conventional CR system (p<0.05).
The new CR mammography system improved physical imaging properties and detection of simulated microcalcifications over conventional CR mammography.
研究一种用于数字乳腺摄影的像素尺寸为50微米的新型计算机X线摄影（CR）系统的物理成像特性及对模拟微钙化的检测能力。
本研究采用新型和传统的CR系统。新型CR系统包括一个与FCR5000MA（像素间距50微米）耦合的高分辨率成像板，该成像板包括透明支撑体和双面阅读器。传统CR系统与FCR9000（像素间距100微米）耦合。测量新型和传统CR系统的调制传递函数（MTF）和维纳频谱（WS）。进行观察者性能测试，以比较像素尺寸（50微米与100微米）对CR系统检测模拟微钙化诊断准确性的影响。
新型CR系统的预采样MTF在高频时高于传统CR系统。新型CR系统的WS在所有频率下与传统CR系统相当。新型CR系统和传统CR系统获得的受试者操作特征（ROC）曲线下面积（Az）分别为0.84和0.79。结果表明，与传统CR系统相比，使用新型CR系统检测模拟簇状微钙化有显著改善（p<0.05）。
新型CR乳腺摄影系统在物理成像特性及对模拟微钙化的检测方面优于传统CR乳腺摄影。
