暗盒性能评估：影响患者辐射剂量和图像对比度的物理因素。

Evaluation of cassette performance: physical factors affecting patient exposure and image contrast.

作者信息

Schmidt R A, Chan H P, Kodera Y, Doi K, Chen C T

出版信息

Radiology. 1983 Mar;146(3):801-6. doi: 10.1148/radiology.146.3.6828696.

DOI:10.1148/radiology.146.3.6828696

Abstract

Physical properties of four radiographic cassettes were investigated in combination with various screen/film systems. These properties included (a) transmittance of monoenergetic x rays over 14-96 keV and comparison with predictions based on attenuation coefficients; (b) relative patient exposure from 60 to 120 kV (from phantom measurements) and correlation with predictions based on measured transmittance as well as average energies and angles of incident radiation; and (c) amounts of scatter from various cassette materials and comparison with Monte Carlo calculations. The results provide a model of performance based on quantitation of cassette effects on system speed and image contrast. Carbon-fiber cassettes required the lowest patient exposure, produced the least scatter, and (in low-scatter situations) were capable of increased image contrast.

摘要

结合各种增感屏/胶片系统，对四种射线照相暗盒的物理特性进行了研究。这些特性包括：(a) 14 - 96 keV 单能 X 射线的透过率，并与基于衰减系数的预测值进行比较；(b) 60 至 120 kV 时相对患者的照射量（来自体模测量），以及与基于测量透过率、平均能量和入射辐射角度的预测值的相关性；(c) 各种暗盒材料的散射量，并与蒙特卡罗计算结果进行比较。结果基于对暗盒对系统速度和图像对比度影响的量化，提供了一个性能模型。碳纤维暗盒所需的患者照射量最低，产生的散射最少，并且（在低散射情况下）能够提高图像对比度。