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

Autor: Tatsugami, Fuminari, Higaki, Toru, Nakamura, Yuko, Yamagami, Takuji, Date, Shuji, Fujioka, Chikako, Kiguchi, Masao, Kihara, Yasuki, Awai, Kazuo
Předmět:
Zdroj: European Radiology; Jan2015, Vol. 25 Issue 1, p41-48, 8p
Abstrakt: 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. Key Points: • We introduce a new method for image noise reduction at cardiac CT. • Multiple data acquisitions of an object and their averaging yield lower noise. • Our method uses multi-phase images reconstructed from unused redundant imaging data. • It reduces image noise by averaging multi-phase images transformed by non-rigid registration. • This method achieves a 20 % image noise reduction at cardiac CT. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: