Radiation Dose Survey: Comparison between New-generation Computed Tomography and 64-slice Multidetector Computed Tomography

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GG Lo, JKF Chan, CW Lau, H Geng, SK Yu

Hong Kong J Radiol 2010;12:107-12

Objective: To evaluate the radiation dose benefit of new-generation computed tomography compared with 64-slice multidetector computed tomography.

Methods: In this retrospective study, the radiation doses for patients undergoing new-generation computed tomography during a 9-month period were compared with those of patients undergoing multidetector computed tomography during a 12-month period. The scans included brain, thorax, abdomen biphasic, abdomen triphasic, and urogram examinations. Patient dose was estimated as the product of the measured dose-length product and the corresponding conversion coefficient for each type of scan. The average estimated patient dose was compared between the 2 scanners using Mann-Whitney U test.

Results: A significantly lower radiation dose was observed for all new-generation computed tomography examinations than for multidetector computed tomography (p < 0.05). The average dose was 1.9 ± 0.4 mSv for brain, 6.9 ± 2.3 mSv for thorax, 13.4 ± 9.1 mSv for abdomen biphasic, 20.9 ± 12.7 mSv for abdomen triphasic, and 9.3 ± 6.6 mSv for urogram scans. Compared with multidetector computed tomography, the radiation dose was lower for new-generation computed tomography by 44% for brain, 72% for thorax, 66% for abdomen biphasic, 61% for abdomen triphasic, and 49% for urogram examinations.

Conclusion: With the development of new-generation computed tomography, it is possible to deliver a significantly lower radiation dose to patients than with 64-slice multidetector computed tomography.




羅吳美英、 陳家發、 劉智華、 耿輝、余兆基


方法:將九個月間接受新一代電腦斷層造影的病人的放射劑量與在12個月間接受64排多切面電腦斷 層造影的病人的放射劑量比較。有關掃瞄包括腦掃瞄、胸腔掃瞄、雙相腹部掃瞄、三相腹部掃瞄及 泌尿系掃瞄。病人在每種掃瞄中接受的劑量以劑量長度積及相關轉換系數計算。再用Mann-Whitney U 統計比較兩組病人接受的放射劑量差別的顯著性。

結果:新一代電腦斷層造影的放射劑量明顯比多切面電腦斷層造影為低(p < 0.05)。以平均劑量計, 腦掃瞄為1.9 ± 0.4 mSv,胸腔掃瞄為6.9 ± 2.3 mSv,雙相腹部掃瞄為13.4 ± 9.1 mSv,三相腹部掃瞄為 20.9 ± 12.7 mSv,而泌尿系掃瞄為9.3 ± 6.6 mSv。與多切面電腦斷層造影相比,新一代電腦斷層造 影的放射劑量在腦掃瞄降低44%,胸腔掃瞄降低72%,雙相腹部掃瞄降低66%,三相腹部掃瞄降低 61%,泌尿系掃瞄降低49%。

結論:隨著新一代電腦斷層造影的發展,可以為病人提供比64排多切面電腦斷層造影更低放射劑量 的檢查服務。