Haziness of the right hemithorax in a newborn

The breadth of the diaphragm: updates in embryogenesis and role of imaging

The diaphragm is an unique skeletal muscle separating the thoracic and abdominal cavities with a primary function of enabling respiration. When abnormal, whether by congenital or acquired means, the consequences for patients can be severe. Abnormalities that affect the diaphragm are often first detected on chest radiographs as an alteration in position or shape. Cross-sectional imaging studies, primarily CT and occasionally MRI, can depict structural defects, intrinsic and adjacent pathology in greater detail. Fluoroscopy is the primary radiologic means of evaluating diaphragmatic motion, though MRI and ultrasound also are capable of this function. This review provides an update on diaphragm embryogenesis and discusses current imaging of various abnormalities, including the emerging role of three-dimensional printing in planning surgical repair of diaphragmatic derangements.

Accessory hemi diaphragm

BACKGROUND/PURPOSE

Accessory hemi diaphragm (AHD) is an uncommon condition. Its clinical features, diagnosis and management have not been clearly defined.

METHODS

We reviewed the world literature and added a case of our own.

RESULTS

There are 40 proven cases in the literature. The lesion occurs almost exclusively in the right hemithorax. Twenty seven cases presented with cardiovascular and/or respiratory symptoms while 3 had symptoms pertaining to other systems. In the remaining 10 patients the diagnosis was either made accidentally or information pertaining to their presentation is missing. Abnormalities of pulmonary and systemic blood vessels often accompany the abnormality. The diagnosis is usually suspected because of an abnormal chest radiograph and confirmed by a variety of tests.

CONCLUSIONS

If the AHD prevents proper aeration of the lung it should be excised. If vascular abnormalities coexist they should be treated along with the AHD. Asymptomatic patients may be observed after confirming the diagnosis.

Retrosternal density: pulmonary underdevelopment or accessory hemidiaphragm

Vertical retrosternal density paralleling the sternum, with haziness of a hemithorax on chest roentgenogram, often challenges the clinical acumen of pediatricians, chest physicians, and pediatric radiologists alike. Its presence has been historically linked to either pulmonary underdevelopment and/or accessory hemidiaphragm. The surgical and radiological pediatric literature has long debated this topic, but unfortunately, it has not received much attention in the general pediatric or in pediatric pulmonology literature. The similar radiologic appearance of these two entities can cause confusion both in diagnostic and the therapeutic approach. Many authors advocate an invasive modality, including thoracotomy, as the only definitive way to differentiate between them. We present two similar cases with retrosternal densities, review the pertinent literature, and propose a rational approach to diagnosis and treatment.