基于知识的迭代模型重建算法：超小剂量心脏 CT 能否适用于临床？

A knowledge-based iterative model reconstruction algorithm: can super-low-dose cardiac CT be applicable in clinical settings?

机构信息

Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Chuo-ku, Kumamoto, 860-8556, Japan.

出版信息

Acad Radiol. 2014 Jan;21(1):104-10. doi: 10.1016/j.acra.2013.10.002.

DOI:10.1016/j.acra.2013.10.002

PMID:24331272

Abstract

RATIONALE AND OBJECTIVES

To investigate whether "full" iterative reconstruction, a knowledge-based iterative model reconstruction (IMR), enables radiation dose reduction by 80% at cardiac computed tomography (CT).

MATERIALS AND METHODS

A total of 23 patients (15 men, eight women; mean age 64.3 ± 13.4 years) who underwent retrospectively electrocardiography-gated cardiac CT with dose modulation were evaluated. We compared full-dose (FD; 730 mAs) images reconstructed with filtered back projection (FBP) technique and the low-dose (LD; 146 mAs) images reconstructed with FBP and IMR techniques. Objective and subjective image quality parameters were compared among the three different CT images.

RESULTS

There was no significant difference in the CT attenuation among the three reconstructions. The mean image noise of LD-IMR (18.3 ± 10.6 Hounsfield units [HU]) was significantly lowest among the three reconstructions (41.9 ± 15.3 HU for FD-FBP and 109.9 ± 42.6 HU for LD-FBP; P < .01). The contrast-to-noise ratio of LD-IMR was better than that of FD-FBP and LD-FBP (P < .01). Visual evaluation score was also highest for LD-IMR.

CONCLUSIONS

The IMR can provide improved image quality at super-low-dose cardiac CT with 20% of the standard tube current.

摘要

背景与目的

研究是否“全”迭代重建（基于知识的迭代模型重建）能够使心脏 CT 检查的辐射剂量降低 80%。

材料与方法

共纳入 23 例患者（15 例男性，8 例女性；平均年龄 64.3±13.4 岁），这些患者均行回顾性心电门控心脏 CT 检查并采用剂量调制。我们比较了全剂量（730 mAs）图像采用滤波反投影（FBP）技术重建、低剂量（146 mAs）图像采用 FBP 和 IMR 技术重建的结果。比较了三种不同 CT 图像的客观和主观图像质量参数。

结果

三种重建图像之间的 CT 衰减无显著差异。低剂量-IMR 的平均图像噪声（18.3±10.6 HU）在三种重建图像中最低（FD-FBP 为 41.9±15.3 HU，LD-FBP 为 109.9±42.6 HU；P<.01）。低剂量-IMR 的对比噪声比优于 FD-FBP 和 LD-FBP（P<.01）。低剂量-IMR 的视觉评估评分也最高。