Heterotopic ossifications of the TMJ may be seen in children with JIA and are associated with particularly severe TMJ arthritis, joint destruction, and pannus formation. Pathology from these joints suggests that the heterotopic ossification may result from multiple pathological processes.

Cytomegalovirus (CMV) is a ubiquitous virus that usually results in asymptomatic or clinically benign infection. However, there are two groups of patients whose response to CMV infection is much more severe: those who are infected during fetal development and those who are immunocompromised. Although the manifestations of these types of infection differ, both often result in substantial neurologic sequelae. Imaging plays a key role in the diagnosis of both congenital and acquired CMV infection. Neurologic findings of congenital CMV infection include intracranial calcification, migrational abnormalities, cerebral and cerebellar volume loss, ventriculomegaly, and white matter disease. The presence of these findings in children with neurodevelopmental delays is suggestive of congenital CMV infection, even if the child was asymptomatic at birth. Certain imaging features also may indicate future neurologic deficits in symptomatic infants. Acquired CMV infection is potentially deadly in immunocompromised patients such as those infected with human immunodeficiency virus or with acquired immune deficiency syndrome and those with a history of solid organ or bone marrow transplantation. Imaging findings of acquired CMV infection often are nonspecific; however, they may indicate a need for further serologic analysis to determine if CMV infection is present. Early recognition and treatment of central nervous system CMV infection is vital for effective treatment, and familiarity with the imaging findings of this common infection is important for accurate diagnosis.

These findings identify new US criteria that compare favorably to CT. In children with suspected appendicitis, using US as the initial imaging study will ultimately lead to improved accuracy, lower cost and the elimination of ionizing radiation exposure.