降低毫安秒对新生儿头颅CT质量的影响

The Effect of Decreasing mAs on Image Qulity of the Newborn Brain.

目的探讨新生儿头颅CT扫描中降低mAs与图像质量的关系及低剂量CT扫描的可行性。方法将80例新生儿头颅CT检查随机分为三组进行前瞻性研究，其中100mAs组35例，225mAs组21例，260mAs组24例。由两名有经验的放射医师以双盲的方法使用4分制评分，对三组图像中头部六个部位的解剖结构的清晰度进行评分，说明CT图像质量的优良程度。使用方差分析检查三组图像质量评分有无显著性差异。结果所有图像质量均能满足诊断要求。2个阅读者对三组不同毫安秒图像中1～6解剖部位的总评分差异均无显著性，对每一个解剖部位的评分中，260mAs组及225mAs组稍高于100mAs组，但三组中两两比较无显著性差异（P〉0．05）。结论应用100mAs低剂量新生儿头颅CT扫描是可行的，图像质量能够满足临床要求。

Objective To determine wheather a lower radiation dose technique could be used in CT of the newborn brain without jeopardising the diagnostic accuracy of the images. Methods A group of 24 newborn underwent CT using 260 mAs, 21under scanning at 225mAs, 35 underwent scanning at 100 mAs, Anatomy details and the confidence level in reaching a diagnosis were evaluated by two radiologists in a double - blinded manner using a 4 - point scoring system. Results For both reader there was no statistically significant difference between three group total score of 1～6 anatomical detail and each of 6 anatomical detail although score for each of 6 anatomical detail in 260 mAs group and 225mAs group was a little higher than 100mAs group. Condution Radiation dose reduction in newborn brain CT is feassible in clinical use.