Ort M G, Gregg E C, Kaufman B
Radiology. 1977 Jul;124(1):65-72. doi: 10.1148/124.1.65.
Subtraction radiography permits the use of 7-10 times less contrast material than is required without subtraction techniques. The first-order, second-order, and composite mask techniques are described and evaluated. While the second-order technique gives more complete cancellation of common structures, the more commonly used first-order technique was found to be adequate for most clinical uses. The smallest change in contrast which can be detected using subtraction radiography is limited by inherent background film noise in the original radiographs and not by statistical fluctuations in the x-ray quanta.
减影放射摄影术允许使用的对比剂比不使用减影技术时所需的少7到10倍。描述并评估了一阶、二阶和复合掩模技术。虽然二阶技术能更完全地消除常见结构，但发现更常用的一阶技术对大多数临床应用来说已足够。使用减影放射摄影术能够检测到的对比度最小变化受原始射线照片中固有的背景胶片噪声限制，而非受X射线量子的统计波动限制。
