occurs more commonly than other fungal infections, such as Candida [24]. Chest radiographs or chest CT typically demonstrate lymphadenopathy, recurrent pneumonia, and pleural thickening (Fig. 5) [25]. The radiographic manifestations of Aspergillus vary but segmental or lobar infiltrates, nodular opacities, and cavitation are typical [24]. Although recurrent pneumonias and pulmonary abscesses are common, other thoracic manifestations include lymphadenitis, osteomyelitis, and chest wall abscesses. Esophageal strictures can also be a complication of chronic granulomatous disease. Leukocyte adhesion deficiency results from a defect in the gene encoding CD18, a component of three different types of leukocyte adhesion mole- cules required for effective cell adhesion and migra- tion [2]. This defect results in faulty phagocyte migration and ultimately increased host susceptibility to pyogenic infections. Severity of symptoms varies greatly, but these patients typically present with recurrent bacterial pneumonias and other severe and repetitive bacterial infections. Other primary immunodeficiencies Hyperimmunoglobulinemia E syndrome typically is associated with widespread staphylococcal ab- scesses of the skin, lungs, viscera, and other sites. Onset of symptoms characteristically occurs in in- fancy in association with markedly elevated serum IgE levels [26]. Pulmonary sequellae include recur- rent staphylococcal pneumonias, which typically result in pneumatocele formation (Fig. 6). The most striking radiographic manifestation of this disease is persistent single or multiple, often large, pneumato- celes. These pulmonary air cysts may persist, expand, or become superinfected. Not infrequently, surgical Fig. 5. An 8-month-old boy with chronic granulomatous disease. (A) The initial frontal and lateral chest radiographs demonstrates pulmonary hyperinflation with diffuse nodular opacities and lymphadenopathy. Axial images from an intravenous contrast-enhanced chest scan better delineate the extensive adenopathy (B) and pulmonary nodules (C) from an unusual species of gram-negative bacteria. thoracic disorders: immunocompromised child 439 Imaging Evaluation of Chest Wall Disorders in Children Nancy R. Fefferman, MD * , Lynne P. Pinkney, MD Division of Pediatric Radiology, Department of Radiology, New York University School of Medicine, 560 First Avenue, RIRM 234, New York, NY 10016, USA The chest wall encases and protects the vital structures within the thoracic cavity. The chest wall comprises multiple layers, including skin, subcuta- neous fat, muscle, bone, cartilage, and pleura. Chest wall disorders may be congenital, developmental, or acquired and typically involve one or more of these layers. Acquired pathologic processes may be infec- tious, neoplastic, or traumatic. Imaging often plays an integral role in the evaluation of symptomatic and asymptomatic chest wall abnormalities. Symptomatic chest wall pathology usually requires imaging evalua- tion to assist in localization and characterization of lesions. Although asymptomatic palpable chest wall lesions tend to be benign or reflect normal developmental variations, imaging is still often re- quested [1,2]. Imaging modalities and techniques Radiography Conventional radiography of the chest or osseous structures is often the primary screening modality for palpable, symptomatic, or asymptomatic chest wall disorders as well as for symptomatic nonpalpa- ble processes. Palpable but otherwise asymptomatic osseous abnormalities, including congenital and developmental variants involving the ribs and ster- num, can sometimes be recognized on chest radio- graphs or on dedicated radiographs, avoiding further imaging evaluation. Chest or rib radiographs may be the only imaging study necessary for definitive diagnosis of benign osseous lesions. Additionally, chest radiography can be useful in the preliminary assessment of suspected malignant osseous lesions and can help direct the imaging work-up. Cross-sectional imaging CT CT has a pivotal role in the evaluation of chest wall pathology. Recent technological advances in CT allowing improved spatial resolution, multiplanar ca- pabilities, and faster examination times minimizing respiratory artifact have increased the appeal of this imaging modality in children. Additionally, the rapid scan time with multidetector helical CT (MDCT) has helped to overcome the need for sedation in younger children [3]. Concerns regarding the radiation dose associated with CT in children and the potential car- cinogenic effects [4,5] remain important considera- tions when using CT. CT may be indicated for further evaluation when plain radiographs are normal or in- conclusive. In particular, CT is excellent for defin- ing lesion extent, including involvement of adjacent structures, for providing information that can be im- portant for determining the nature of the disorder, or for narrowing the range of differential considerations. Examinations for chest wall pathology can be performed using single-detector or multidetector CT. The smallest possible field of view should be used to maximize spatial resolution. When diagnostic 0033-8389/05/$ – see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.rcl.2004.11.002 radiologic.theclinics.com * Corresponding author. E-mail address: nancy.fefferman@nyumc.org (N.R. Fefferman). Radiol Clin N Am 43 (2005) 355 – 370 . ribs and ster- num, can sometimes be recognized on chest radio- graphs or on dedicated radiographs, avoiding further imaging evaluation. Chest or rib radiographs may be the only imaging study. gram-negative bacteria. thoracic disorders: immunocompromised child 4 39 Imaging Evaluation of Chest Wall Disorders in Children Nancy R. Fefferman, MD * , Lynne P. Pinkney, MD Division of Pediatric. lesions. Additionally, chest radiography can be useful in the preliminary assessment of suspected malignant osseous lesions and can help direct the imaging work-up. Cross-sectional imaging CT CT has