Purpose or Case Report: Computed tomography with its excellent spatial and temporal resolution remains valuable diagnostic modality in pediatrics. On the other hand there has been increasing attention placed on the radiation risks associated with CT imaging, especially in children.
In recent years many advances in CT hardware and software, for example automatic exposure control tools and iterative reconstruction techniques allowed for the reduction of applied radiation dose while maintaining image quality.

The aim of our educational exhibit is:

- to present optimal protocols for chest CT in the youngest age group of children, scanned according to body weight protocols (0-10kg; 10-30kg) with assesement of image quality and dose indices (CTDIvol and DLP; SSDE)
- to present pictorial review of the pediatric chest pathologies in low dose chest CT
Methods & Materials: We reviewed our database for chest CT performed in youngest group of children (aged 0-5 years), according to body weight protocols (0-10kg and 10-30kg), examined with iterative reconstruction technique iDose; 64-slice scanner Philips Brillance. Scans were performed to confirm or exclude suspected congenital malformations of lungs, heart and great vessels, chest wall and diaphragm and in patients with acquired pulmonary conditions, such as infections and BPD.
CTDIvol and DLP for 16-cm phantom were obtained to estimate radiation dose and SSDE was calculated.
Evaluation of image quality in lowest dose exams were performed addressing to the most important factors which influence the quality. Potential space for further optimization was established.
Results: Spectrum of pathologies examined with the lowest dose included:
- congenital pulmonary airway malformation (Fig.2)
- pulmonary hypoplasia in patients with congenital diaphragmatic hernia
- congenital bronchial abnormalities (Fig.1)
- pulmonary sequestration (Fig.2)
- pulmonary infections; BPD as a complications of RDS (Fig.2)
- abnormalities of the aortic arch: right-sided aortic arch, vascular rings, coartaction of aorta (Fig.3)

Dose indices for the lowest dose scans ranged: CTDIvol 1,88 – 3,9mGy; DLP 29,4 – 62.1mGyxcm; SSDE 2,18 – 3,95 mGy.
Lowest dose indices were obtained in examination performed in children in pre-operative evaluation of heart and great vessels with no adverse influence on image quality.
Conclusions: Chest pathologies can be properly visualized in small children using iterative CT reconstruction technique with appropriate quality of scans at a reduced dose with no influence on observer performance.
Our experience in chest CT in the youngest group of patients enhances the need for futher optimalization of CT protocols.