Improving the Image Quality in Computed Tomographic Pulmonary Angiography With Dual-Energy Subtraction

Abstract

The objectives of this study were to assess quantitative and subjective image quality in computed tomographic pulmonary angiography using dual-energy subtraction methods compared with those of the monochromatic images using optimal contrast-to-noise ratios and those of the routine polychromatic images and to select the best dual-energy subtraction method. A total of 1 routine polychromatic image, 3 sets of dual-energy subtraction images (DESIs), and 2 sets of monochromatic images with different optimal contrast-to-noise ratios from 30 patients were obtained. The signal intensity and noise were measured; signal-to-noise ratio and contrast-to-noise ratio (CNR) were calculated. The global subjective image quality was subjectively assessed. The DESI 3 got the highest CNR and the DESI 1 got the second highest CNR. The DESI 1 got the highest global subjective image quality score. The 3 subtraction image sets got the highest score in visualization of the pulmonary artery branches. Computed tomographic pulmonary angiography with dual-energy subtraction technique is feasible. The DESI 1 afforded the best balance between the quantitative analysis and the subjective evaluation.