目的对低剂量扫描肾动脉CTA 检查原始数据分别运用自适应迭代重建 技术(AIDR)和滤波反投影法(FBP)两种方 法获得的图像进行比较，探讨AIDR的图 像质量优势及临床应用价值。方法 对20 例采用640层动态容积CT进行肾动脉CTA 检查的患者原始图像数据，在工作站上 分别使用AIDR和FBP两种方法进行图像重 建，测量腹主动脉、肾动脉、竖脊肌CT 值、背景SD并计算SNR及CNR值，对重建 图像进行主、客观评分并进行图像质量 的比较。结果 主观评价比较中，AIDR组 图像质量整体评分及血管锐利度评分高 于FBP组(P＜0.01)，两组图像MRP、VR和 MIP血管分支显示方面均无显著统计学差 异(P＞0.05)。客观评价指标比较中，两 组腹主动脉、肾动脉、竖脊肌及空气CT 值分均无统计学差异(P＞0.05)，AIDR组 SNR、CNR较FBP组增高(P＜0.05)而噪声 减低(P＜0.05)。结论 相对于FBP重建方 法，AIDR在相同扫描条件下可以提高肾 动脉CTA图像质量、降低图像噪声。

Objective To compare the image qualities of low tube voltage renal artery computed tomography angiography (CTA) using adaptive iterative dose reduction (AIDR) and filter back projection (FBP) algorithm, and evaluate the clinical application value of AIDR. Mehtods Twenty consecutive patients underwent renal artery CTA. The collected raw data were reconstructed by ADIR and FBP algorithm respectively. CT and background SD value of abdominal arota, renal artery and erector muscle of spine were measured, the SNR and CNR were calculated, and the image quality were compared with subjective grading. Results In subjective evaluation of the image quality as a whole and blood vessel sharpness, the AIDR group was higher than that in FBP group. There were no significant differences in the vessel branches displayed on MRP, VR and MIP. For objective evaluation, there were no significant differences of the CT value of abdominal arota, renal artery and erector muscle of spine between two groups. The SNR and CNR in AIDR group were higher than that in FBP group, the SD values were lower than that in FBP group. Conclusion The image quality of AIDR group was better than that of FBP. AIDR could reduce the imaging noise, improve the image quality and has the potential of radiation reduction.