The optimal application of imaging diagnostics in the thorax for premature and newborn infants, as well as toddlers, is comprehensively described in this book. This includes the particularly demanding requirements for equipment and examination techniques, as well as radiation protection, especially for children. The selection of appropriate procedures and typical findings for diseases and malformations in the thoracic area are presented in detail and richly illustrated; in addition to differential diagnoses that should be considered, clinical information is integrated that is important for the choice of procedure and interpretation of findings. Some thoracic diseases in children and adolescents beyond toddler age are also included. Through 14 exemplary cases that encompass the entire spectrum of thoracic diseases in this age group, the assessment can be illustrated.