iDose4迭代重建算法对前瞻性和回顾性心电门控冠状动脉计算机断层血管造影中图像质量和辐射剂量的影响

Effect of iDose4 iterative reconstruction algorithm on image quality and radiation exposure in prospective and retrospective electrocardiographically gated coronary computed tomographic angiography.

作者信息

Kordolaimi Sofia D, Argentos Stylianos, Mademli Maria, Stathis George, Pantos Ioannis, Ploussi Agapi, Katritsis Demosthenes, Efstathopoulos Efstathios P

机构信息

From the *Second Department of Radiology, School of Medicine, University of Athens; and †Department of Cardiology, Athens Euroclinic, Athens, Greece.

出版信息

J Comput Assist Tomogr. 2014 Nov-Dec;38(6):956-62. doi: 10.1097/RCT.0000000000000137.

DOI:10.1097/RCT.0000000000000137

PMID:25119063

Abstract

OBJECTIVES

The aims of this study were to compare a commercially available reconstruction algorithm (iDose4) with filtered back projection (FBP) in terms of image quality (IQ) for both retrospective electrocardiographically gated and prospective electrocardiographically triggered cardiac computed tomographic angiography (CCTA) protocols and to evaluate the achievable radiation dose reduction.

METHODS

A total cohort of 58 patients underwent either prospective CTCA or retrospective CTCA with full or reduced tube current-time product (in milliampere-second) protocol on a 64-slice multidetector computed tomographic scanner. All images were reconstructed with FBP, whereas the reduced milliampere-second images were also reconstructed using 2 levels (levels 4 and 6) of iDose4. Subjective and objective IQ was evaluated.

RESULTS

Dose reductions of 43% in the retrospective CCTA protocol and 27% in the prospective CCTA protocol were achieved without compromising IQ. In the prospective CCTA protocol, the reduced-dose images were highly scored; thus, additional reduction of exposure settings is feasible. In the retrospective acquisition, dose reduction has led to similar IQ scores between the reduced-dose iDose4 images and the full-dose FBP images. Considering different reconstructions (FBP, iDose-L4 and -L6) of the same acquisition data, increase in iDose4 level resulted in less noisy images. A slight improvement was also noticed in all IQ indices; however, this improvement was not statistically significant for both acquisition protocols.

CONCLUSIONS

This study demonstrated that the application of iDose at CCTA facilitates significant radiation dose reduction by maintaining diagnostic quality. The combination of iDose4 with prospective acquisition is able to significantly reduce effective dose associated with CTCA at values of approximately 2 mSv and even lower.

摘要

目的

本研究旨在比较商用重建算法（iDose4）与滤波反投影（FBP）在回顾性心电门控和前瞻性心电触发心脏计算机断层血管造影（CCTA）协议下的图像质量（IQ），并评估可实现的辐射剂量降低情况。

方法

58例患者在64层多探测器计算机断层扫描仪上接受前瞻性CTCA或回顾性CTCA检查，采用全剂量或降低管电流-时间乘积（以毫安秒为单位）协议。所有图像均采用FBP重建，而降低毫安秒的图像也使用iDose4的2个级别（4级和6级）进行重建。评估主观和客观IQ。

结果

在不影响IQ的情况下，回顾性CCTA协议的剂量降低了43%，前瞻性CCTA协议的剂量降低了27%。在前瞻性CCTA协议中，降低剂量的图像得分很高；因此，进一步降低曝光设置是可行的。在回顾性采集中，剂量降低导致降低剂量的iDose4图像和全剂量FBP图像之间的IQ得分相似。考虑到相同采集数据的不同重建（FBP、iDose-L4和-L6），iDose4级别增加导致图像噪声减少。在所有IQ指标中也注意到了轻微改善；然而，对于这两种采集协议，这种改善在统计学上并不显著。