Fig. 2
From: Paediatric multi-detector row chest CT: what you really need to know
The position of the ascending aorta or pulmonary artery cannot be distinguished on this axial pre-monitoring image (a) in a 1-month-old child with a large thymus and lack of mediastinal body fat, making it difficult to accurately place the ROI for automatic scan triggering. Post contrast enhancement positions of the great vessels are clearly seen in b. Scanning parameters: 80 kV, 10 mAs