Evaluation of the Effect of the Arrhythmia Correction for the Image Quality in the Multidetector-Row Computed Tomography (MDCT) Coronary Angiography

Multidetector-Row Computed Tomography (MDCT) Coronary Agniography에서 Arrhythmia Correction이 영상의 질에 미치는 영향에 관한 연구

MDCT is a useful, non-invasive, diagnostic tool in the evaluation of coronary artery disease. However, the image quality is affected by an irregular heart rhythm of the patients. Especially, premature ventricular contraction induced stair-step artifacts in the reconstruction of 2-D or 3-D images of the heart including coronary arteries. In recent, we experienced some improving of the image quality after correcting the PVC. Accordingly, the purpose of our study was to evaluate the effectiveness of the arrhythmia correction method, which was commercially available software, in improving the quality of the reconstruction images of the heart. Image analysis was performed, in consensus, by two radiologists. The scores for image quality were ranked as follows; excellent is 4 (image quality is markedly improved and is helpful in the image evaluation), good is 3 (image quality is mildly improved, but is somewhat helpful in the image evaluation), fair is 2 (image quality is improved and is not helpful in the image evaluation), and poor is 1 (image quality is not improved). We used ANOVA method to evaluate the statistical significant differences in the image qualities among the correction methods of the arrhythmia with below 0.05 of p-value. The method of moving the R-R interval showed statistically significant differences in improving of the image quality in patients with arrhythmia. We concluded that the regulation of R-R interval in patients with arrhythmia was an effective method to improve the image quality in the reconstructions of the MDCT coronary angiograms.

MDCT는 비침습적인 방법으로 관상동맥 질환을 검사하는데 유용하다고 알려져 있다. 하지만 영상의 질에 있어서 환자의 심장박동이 결정적인 영향을 주게 된다. 특히 심장박동이 불규칙하거나 조기 심실수축 환자일 경우 영상을 재구성하는데 있어 왜곡 현상이 증가하여 진단에 어려움을 초래한다. 최근 본원에서 심장박동이 불규칙한 환자에서 영상 재구성시 불규칙한 R-R 간격을 조정한 후 얻은 영상이 artifact가 감소하는 현상을 경험한 바 있다. 따라서 본 연구에서는 다양한 교정 방법(disable, inesrt, R-R interval 교정)이 영상의 질에 어떤 영향이 있는지를 알아보고자 한다. 심박동이 불규칙한 24명의 환자에서 교정방법에 따라 영상을 재구성한 결과 R-R Interval 조정에서 통계학적으로 유의한 결과를 얻을 수 있었다(p<0.05). 본 연구에서는 R-R Interval 조정에서 가장 우수한 영상을 얻을 수 있었으며, 향후 심장 질환의 진단에 도움을 줄 수 있는 기초연구로서 그 가치가 충분하리라 사료된다.