正常剂量扫描导引的低剂量心血管CT造影图像恢复

Low-dose CT angiography image restoration using normal dose scan-induced non-local means algorithm

目的探讨如何在保证诊断用心血管CT造影(CTA)图像质量的前提下降低X射线辐射剂量的最佳方法。方法本文利用先前正常剂量扫描导引的非局部平均(ndiNLM)方法,结合先前正常剂量扫描的心血管CTA高质量图像,对当前低剂量扫描的心血管CTA图像进行恢复。结果仿真和临床心血管CTA数据实验表明,同传统非局部平均方法(NLM)相比,ndiNLM方法在抑制CTA图像噪声与伪影的同时,还可以实现心血管增强结构信息的优质保持。结论 ndiNLM方法可为CTA成像中的辐射剂量降低提供有力的方法学支撑。

Objective To minimize of the radiation dose of cardiovascular CT angiography （CTA） imaging while preserving the image quality. Methods To reduce the radiation dose in CTA imaging, the normal-dose scan induced non-local means （ndiNLM） algorithm was adapted for low-mAs scanned CTA image restoration by using the previous scanned high-quality image. Results Qualitative and quantitative evaluations were carried out on both simulated phantom and clinical CTA scans in terms of accuracy and resolution properties. Compared to the original NLM algorithm, the ndiNLM method could achieve noticeable gains in terms of noise-induced artifacts suppression and enhanced structure preservation. Conclusion The ndiNLM algorithm is a potential useful technique to reduce the radiation dose in CTA imaging.