Image quality of thoracic 64-MDCT angiography: imaging of infants and young children with or without general anesthesia.

Objective: The purpose of this study was to compare the image quality of thoracic CT angiography (CTA) studies performed with two techniques--with general anesthesia and without general anesthesia--for infants and for children younger than 5 years.

Materials And Methods: All consecutively registered infants and young children (age, ≤ 5 years) who underwent contrast-enhanced thoracic CTA from November 2005 to October 2010 were categorized into two groups: general anesthesia and awake (i.e., no general anesthesia). Two radiologists independently evaluated image quality by quantifying the degree of motion artifact at three anatomic levels (upper, middle, and lower lung zones). Motion artifacts were graded on an ordinal scale (0, no motion; 1, mild; 2, moderate; 3, severe), and the Pearson chi-square test was used to assess whether the degree of motion artifact differed between the general anesthesia and awake groups in the upper, middle, and lower lung zones. Logistic regression analysis was performed to determine whether image quality based on the presence or absence of motion artifact in any lobe was related to general anesthesia versus the awake state; age and sex were covariates. Interobserver agreement between two reviewers was evaluated with kappa statistics.

Results: There were a total of 135 patients (mean age 1.0 year), 95 in the awake group (70%) and 40 in the general anesthesia group (30%). No significant difference was found between the two groups in percentage of studies with motion artifact detected in each lung zone and the total motion artifact score. Results of multivariable logistic regression analysis indicated that image quality was not influenced by age (p = 0.52) or sex (p = 0.20). There was excellent interobserver kappa agreement between reviewers for detecting motion artifact in the upper, middle, and lower lung zones (all κ > 0.90, p < 0.001).

Conclusion: There is no significant difference in image quality of thoracic CTA with 64-MDCT assessed by degree of motion artifact with and without general anesthesia. The results of this study support use of thoracic CTA without general anesthesia in the care of young pediatric patients who meet screening criteria for awake imaging studies.