Effective radiation attenuation calibration for breast density: compression thickness influences and correction.
Effective radiation attenuation calibration for breast density: compression thickness influences and correction.
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DOI：
10.1186/1475-925x-9-73
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发表时间：
2010-11-16
影响因子：
3.9
通讯作者：
Thomas JA
中科院分区：
文献类型：
--
作者：
Heine JJ;Cao K;Thomas JA
校准乳房X线照片以产生用于乳腺癌风险分析的标准化乳房密度测量值需要对压缩的乳房厚度进行准确的空间测量。标称系统读出值和压迫板方向导致的厚度不准确性会导致校准中出现不可接受的误差。使用完全指定的双组分替代乳房模型开发和评价厚度校正。一个先前开发的校准方法的基础上，有效的辐射衰减系数测量中使用的分析。水和油被用来构建模型，以复制乳房的可变形特性。由测量的水和油的比例组成的校准曲线用于估计校准误差而不进行校正，评估厚度校正，并研究在压缩厚度变化下的各种校准表示的再现性。由于压迫板翘曲引起的平均厚度不确定度被表征为在0.5 mm内。校正后的相对校准误差从48-68%降低到7%。归一化的有效辐射衰减系数（平面）表示是可重复的样品内压缩厚度变化相比，校准的体积测量。将该厚度校正应用到刚性乳腺组织等效校准方法中应提高使用可再现平面校准测量进行风险评估的乳房X线照片的校准准确性。
Calibrating mammograms to produce a standardized breast density measurement for breast cancer risk analysis requires an accurate spatial measure of the compressed breast thickness. Thickness inaccuracies due to the nominal system readout value and compression paddle orientation induce unacceptable errors in the calibration. A thickness correction was developed and evaluated using a fully specified two-component surrogate breast model. A previously developed calibration approach based on effective radiation attenuation coefficient measurements was used in the analysis. Water and oil were used to construct phantoms to replicate the deformable properties of the breast. Phantoms consisting of measured proportions of water and oil were used to estimate calibration errors without correction, evaluate the thickness correction, and investigate the reproducibility of the various calibration representations under compression thickness variations. The average thickness uncertainty due to compression paddle warp was characterized to within 0.5 mm. The relative calibration error was reduced to 7% from 48-68% with the correction. The normalized effective radiation attenuation coefficient (planar) representation was reproducible under intra-sample compression thickness variations compared with calibrated volume measures. Incorporating this thickness correction into the rigid breast tissue equivalent calibration method should improve the calibration accuracy of mammograms for risk assessments using the reproducible planar calibration measure.