Background Atherosclerosis is a common cardiovascular disease in parrots but the antemortem diagnosis is challenging. In human medicine, computed tomography angiography (CTA) has been used widely for the diagnosis of atherosclerosis. By adjusting the injection rate and total dose of contrast medium, the image quality can be improved. To test the effects of different injection conditions on the image quality of major arteries, 10 African grey parrots (Psittacus erithacus) were used. Three injection rates (0.3, 0.4, 0.5 mL/s) and three doses (740, 370, 222 mg of iodine/bird) were tested while the other variables of the studies were fixed. Result A higher injection dose led to a significantly higher attenuation, image noise and diameter, with a lower signal-to-noise ratio and contrast-to-noise ratio of the six major arteries. The 370 mg of iodine/bird group showed significantly better subjective image quality. Furthermore, with increasing injection rates, the prevalence of heterogeneity decreased. However, we found an increased risk of injection failure for the 0.5 mL/s groups. Conclusion We recommend a combination of 370 mg of iodine/bird with 0.4 mL/s for clinical use to achieve better image quality for CTA.

Background Atherosclerosis is a common cardiovascular disease in parrots but the antemortem diagnosis is challenging. In human medicine, computed tomography angiography has been used widely for the diagnosis of atherosclerosis. By adjusting the injection conditions (injection rate and total dose of contrast medium [CM]), the image quality can be improved. To test the effects of different CM injection conditions on the image quality of major arteries, 10 African grey parrots (Psittacus erithacus) were used. Three injection rates (0.3, 0.4, 0.5 mL/s) and three CM doses (740, 370, 222 mg of iodine/bird) were tested while the other variables of the studies were fixed. Results We found no difference of the measured diameter, attenuation, image noise, signal-to-noise ratio, or contrast-to-noise ratio of the six major arteries (p > 0.05) among these three CM injection rates. However, these parameters showed significant differences among the three CM injection doses. Furthermore, with increasing CM injection rates, the prevalence of heterogeneity decreased. Conclusion We recommend a combination of 370 mg of iodine/bird with 0.4 mL/s for clinical use to achieve better image quality for CTA.