Effect of Low Tube Voltage on Image Quality, Radiation Dose, and Low-Contrast Detectability at Abdominal Multidetector CT: Phantom Study
Effect of Low Tube Voltage on Image Quality, Radiation Dose, and Low-Contrast Detectability at Abdominal Multidetector CT: Phantom Study
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DOI：
10.1155/2012/130169
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发表时间：
2012-01-01
影响因子：
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通讯作者：
Cao, Guoquan
中科院分区：
文献类型：
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作者：
Tang, Kun;Wang, Ling;Cao, Guoquan
目的。目的探讨低管电压(80kV)对腹部CT图像质量、辐射剂量和低对比度检测能力(LCD)的影响。材料和方法用CT扫描仪对含有低对比度物体的体模进行扫描，扫描电压为80和120千伏，管电流-时间乘积设置为150-650 mA。比较了在150~650 mA、80 kV和120 kV、300 mA条件下，图像噪声、对比噪声比(CNR)和LCD评分的差异。结果。随着管子电压的降低，图像噪声显著增加。然而，在相同剂量下，使用80kv的CNR比120kVCNR高。120千伏在300 mA与80千伏在550~650毫安之间CNR和LCD评分差异无统计学意义(P&gT；0.05)。80千伏时的相对剂量从550毫安时的58%到650毫安时的68%不等。结论。当腹部CT管电压从120千伏降至80千伏时，在不降低CNR和LCD的情况下，辐射剂量可减少32%~42%。
Purpose. To investigate the effect of low tube voltage (80 kV) on image quality, radiation dose, and low-contrast detectability (LCD) at abdominal computed tomography (CT). Materials and Methods. A phantom containing low-contrast objects was scanned with a CT scanner at 80 and 120 kV, with tube current-time product settings at 150-650 mAs. The differences between image noise, contrast-to-noise ratio (CNR), and scores of LCD obtained with 80 kV at 150-650 mAs and those obtained with 120 kV at 300 mAs were compared respectively. Results. The image noise substantially increased with low tube voltage. However, with identical dose, use of 80 kV resulted in higher CNR compared with CNR at 120 kV. There were no statistically significant difference in CNR and scores of LCD between 120 kV at 300 mAs and 80 kV at 550-650 mAs (P > 0.05). The relative dose delivered at 80 kV ranged from 58% at 550 mAs to 68% at 650 mAs. Conclusion. With a reduction of the tube voltage from 120 kV to 80 kV at abdominal CT, the radiation dose can be reduced by 32% to 42% without degradation of CNR and LCD.