Optimization of Monochromatic Imaging in Reducing Iodinated Contrast Dose in CT Pulmonary Angiography / 中国医学影像学杂志

ABSTRACT

Purpose To explore the feasibility of optimizing monochromatic images in reducing iodinated contrast dose in CT pulmonary angiography (CTPA). Materials and Methods Sixty-eight patients undergoing CTPA were randomly divided into two groups, with half in research group and half in conventional group to evaluate image quality. Research group underwent spectral CT imaging with the injection of 30 ml Omnipaque (300 mgI/ml) and optimal monochromatic images were postprocessed using the software of GSI viewer. Conventional group underwent conventional CTPA with the injection of 80 ml Ultravist (370 mgI/ml). The CT values were measured respectively in the main pulmonary artery, left pulmonary trunk, right pulmonary trunk, left lobe artery and right lobe artery. The contrast noise ratio (CNR) in two groups were calculated, and image quality were subjectively assessed. Results The total iodine intake in research group (9000 mg) was significantly lower than that of conventional group (29 600 mg). CNR in the main pulmonary artery, left pulmonary trunk, right pulmonary trunk, left lobe artery and right lobe artery in research group was significantly higher than that of conventional group (t=2.07-2.71, P0.05), while there was a good agreement between the two readers (Kappa=0.8, P<0.05). Conclusion It is possible to reduce iodinated contrast dose using spectral CT imaging and improve the image quality of CTPA.