Thoracic disorders
The thorax is the most common region to undergo imaging evaluation in children. While a chest radiograph (or chest X-ray) is the most frequently performed procedure, computed tomography (CT), ultra sonography (US) and magnetic resonance (MR) imaging also provide important diagnostic information for paediatric thoracic and intrathoracic abnormalities. Knowledge of the relative advantages and disadvantages of the modalities provides an opportunity for optimal diagnostic imaging strategies for the range of disorders in infants and children. The systematic review of these disorders can be based on the traditional classification scheme, consisting of congenital (including neonatal) abnormalities, infectious/ inflammatory conditions, tumour and tumour-like conditions, traumatic abnormalities or toxic/metabolic disorders, which includes thoracic manifestations of systemic disorders. Alternatively, disorders could be classified based on the presentation, such as fever, mass or wheezing. However, the signs or symptoms of thoracic disorders in children are relatively non-specific and often overlap the individual disorder classifications noted above. For example, wheezing can be caused by infection (viral or bacterial), toxic exposure (inhalation), trauma (aspirated foreign body) or congenital anomalies (such as tracheal compression by a vascular ring such as a double aortic arch). Therefore, the following material will be divided based on the traditional classification scheme, and subclassified by region (chest wall, airway, lung parenchyma, mediastinum, heart and great vessels). Within each category, the role of the various imaging modalities will be addressed (and general technique provided, when pertinent) with more in-depth discussion and illustration of the more common of the disorders. The reader is referred to several other excellent references for a more in-depth discussion [2,3]. © 2008 Springer Medizin Verlag Heidelberg.