A new technique for noise reduction at coronary CT angiography with multi-phase data-averaging and non-rigid image registration

作者：Tatsugami Fuminari^*; Higaki Toru; Nakamura Yuko; Yamagami Takuji; Date Shuji; Fujioka Chikako; Kiguchi Masao; Kihara Yasuki; Awai Kazuo

来源：European Radiology, 2015, 25(1): 41-48.

DOI：10.1007/s00330-014-3381-9

• Coronary CT angiography
• Image noise
• Non-rigid image registration
• Weighted average
• Radiation dose reduction

Objectives To investigate the feasibility of a newly developed noise reduction technique at coronary CT angiography (CTA) that uses multi-phase data-averaging and non-rigid image registration.
Methods Sixty-five patients underwent coronary CTA with prospective ECG-triggering. The range of the phase window was set at 70-80 % of the R-R interval. First, three sets of consecutive volume data at 70 %, 75 % and 80 % of the R-R interval were prepared. Second, we applied non-rigid registration to align the 70 % and 80 % images to the 75 % image. Finally, we performed weighted averaging of the three images and generated a de-noised image. The image noise and contrast-to-noise ratio (CNR) in the proximal coronary arteries between the conventional 75 % and the de-noised images were compared. Two radiologists evaluated the image quality using a 5-point scale (1, poor; 5, excellent).
Results On de-noised images, mean image noise was significantly lower than on conventional 75 % images (18.3 HU +/- 2.6 vs. 23.0 HU +/- 3.3, P<0.01) and the CNR was significantly higher (P<0.01). The mean image quality score for conventional 75 % and de-noised images was 3.9 and 4.4, respectively (P<0.01).
Conclusions Our method reduces image noise and improves image quality at coronary CTA.

• 出版日期2015-1