Fig. 4. Subjective image quality grading of pediatric cardiothoracic CT.
Axial (A) and coronal (B) CT images show excellent image quality (grade 1) without substantial artifacts in 6 months-old female infant whose arm were raised up during CT scanning. Axial CT image (A) at same slice position, where CTDIvol value was calculated, was used to measure CT densities in aorta (1), spinal muscles (2), and air (3) by placing rectangular regions of interest in areas showing homogeneous attenuation as much as possible. Axial (C) and coronal (D) CT images show severely degrade subjective image quality (grade 3) in posterior thoracic inlet and left shoulder regions due to horizontal position of left arm during CT scanning. Metal artifacts from electrocardiography electrode located at right upper chest are also noted on axial CT image (C).