Department of Radiology, Wonkwang University School of Medicine, Jeonbuk 570-749, Republic of Korea.
Invest Radiol. 2012 Dec;47(12):683-7. doi: 10.1097/RLI.0b013e31826badfb.
The feasibility of using monochromatic x-ray imaging generated from an x-ray tube and a multilayer reflector for digital mammography with a low radiation dose was examined.
A multilayer mirror was designed to select the x-ray peak with an energy of 21.5 keV generated from an x-ray tube with a tungsten target and was fabricated by the ion-beam sputtering deposition system. Monochromatic x-ray images were obtained from an experimental digital mammography setup with a scanning stage. The performance of the system was evaluated using a breast phantom, a spectrometer, and a radiation dosimeter. We measured the contrast-to-noise ratio and performed the 10% modulation function test to determine image quality and resolution.
The monochromatic beam from the multilayer reflector had a full-width-at-half-maximum of 0.9 keV at 21.5 keV, and the reflectivity was 0.70, which was 90% of the designed value. The polychromatic and monochromatic x-rays showed radiation doses of 0.497 and 0.0415 mGy, respectively. The monochromatic x-ray image shows fibers, calcifications, and masses more clearly than the polychromatic x-ray images do. The image contrast of the monochromatic x-rays was 1.85 times higher than that of the polychromatic x-rays. The experimental mammography setup had a spatial resolution of 7 lp/mm with both x-rays.
Monochromatic x-rays generated using a multilayer mirror may be a useful diagnostic tool for breast examination by providing high contrast imaging with a low radiation dose.
研究使用单层反射镜从具有钨靶的 X 射线管产生的单色 X 射线对低剂量数字乳腺成像的可行性。
设计了一个多层镜，以选择能量为 21.5keV 的 X 射线峰，该 X 射线由具有钨靶的 X 射线管产生，并通过离子束溅射沉积系统制造。使用具有扫描台的实验性数字乳腺成像设备获得单色 X 射线图像。使用乳房体模、光谱仪和辐射剂量计评估系统性能。我们测量了对比度噪声比，并进行了 10%调制函数测试，以确定图像质量和分辨率。
多层反射镜的单色光束在 21.5keV 时的半峰全宽为 0.9keV，反射率为 0.70，为设计值的 90%。多色和单色 X 射线的辐射剂量分别为 0.497 和 0.0415mGy。单色 X 射线图像比多色 X 射线图像更清晰地显示纤维、钙化和肿块。单色 X 射线的图像对比度比多色 X 射线高 1.85 倍。两种 X 射线的实验性乳腺摄影设备的空间分辨率均为 7lp/mm。
使用多层反射镜产生的单色 X 射线可能是一种有用的乳腺检查诊断工具，因为它可以提供高对比度且低剂量的成像。
