Use of Iterative Reconstruction and a Small Contrast Volume in Rabbit Kidney CT: Comparison with Conventional Protocol

Abstract

Purpose: To investigate the quality of rabbit kidney computed tomography (CT) images obtained using a small contrast volume and iterative reconstruction (IR). Materials and Methods: Twenty sedated rabbits were used. Four milliliters of contrast material and the IR technique were used for the study group. In the control group, 6 mL of contrast and the filtered back projection (FBP) technique were used. The image quality was evaluated by two radiologists in consensus. For qualitative image assessment, the sharpness, noise, texture, and streak artifacts were rated. For quantitative analysis, the CT attenuation values, image noise, signal-to-noise ratios (SNR), contrast-to-noise ratios (CNR), and figures of merit (FOM) were calculated. Results: Images obtained from the study group were sharper and contained less noise and fewer streak artifacts (all, p < 0.05) compared to those obtained from the control group. However, the texture of images from the study group was worse (p < 0.05). Although the CT attenuation values were comparable between the study and control groups, the image noise was considerably lower for the study group than that for the corresponding control group (all, p < 0.05). Thus, the SNR, CNR, and FOM were higher in the study group (all, p < 0.05) than in the control group. Conclusion: The use of the IR technique and a small volume of contrast material yielded CT images with better qualities compared to those obtained using the FBP technique and conventional contrast volume in a rabbit model.

Keywords

• computed tomography
• x-ray
• animals
• control groups
• image reconstruction
• contrast material