Signal fading, erasure, and rescan in storage phosphor imaging
Signal fading, erasure, and rescan in storage phosphor imaging
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存储荧光成像中的信号衰落、擦除和重新扫描
DOI：
10.1117/12.59393
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
D. Gur
中科院分区：
文献类型：
--
作者：
C. Shaw;J. Herron;D. Gur
本文讨论了存储荧光成像中的三个问题：潜像信号的自然褪色，曝光板的正确擦除，以及第二次读出的重新扫描。测量信号和信噪比作为时间、擦除功率/时间或预扫描次数的函数，以研究这些问题。发现潜像信号在最初的几分钟内非常迅速地衰减，并在几小时后稳定下来。衰落效应导致可变的信号增益（每单位曝光的信号），这可能影响系统校准和图像数据的定量使用。潜像信号的完全擦除是必要的，以确保当板再次曝光时不存在残留图像信号。发现用于高曝光应用（GI，治疗成像）的板可能需要过长的擦除时间来准备它们用于低曝光应用（胸部成像）。虽然在读出过程中部分地擦除潜像，但有时可能需要重新扫描板以进行第二次或第三次读出。已经发现，由于针对每个X射线光子生成大量的能量陷阱，所以在第一次或第二次扫描之后，X射线信息的显著部分保持完整以供重新使用。给出了信号和信噪比的测量，以证明和讨论上述问题或影响。
This paper addresses three problems in storage phosphor imaging: natural fading of latent image signals, proper erasure of the exposed plates, and re-scanning for a second readout. Signal, and signal-to-noise ratios were measured as a function of time, erasure power/time, or number of pre-scans to study these problems. The latent image signals were found to decay very rapidly during the first several minutes and stabilize after several hours. The fading effect results in a variable signal gain (signal per unit exposure) which may affect the system calibration and quantitative use of the image data. Complete erasure of the latent image signals is necessary to ensure that no residual image signals are present when the plate is exposed again. It was found that plates used in high exposure applications (GI, therapeutic imaging) may require an excessively long erasure time to prepare them for use in low exposure applications (chest imaging). Although the latent image is partially erased during the readout process, it may sometimes become necessary to re-scan the plate for a second or third readout. It was found that because a large number of energy traps are generated for each x-ray photon, a significant portion of the x-ray information remains intact for reuse after the first or second scans. Measurement of the signals and signal-to-noise ratios are presented to demonstrate and discuss the aforementioned problems or effects.