ABSTRACT
Plain radiography is often the first imaging undertaken to aid in the diagnosis of a sick child. A chest radiograph may reveal consolidation in a lower lobe as a cause of abdominal pain or the presence of pleural effusion complicating pneumonia. In the abdomen, free gas or intestinal obstruction may be demonstrated, as may diagnostic features, such as intramural and portal gas in necrotizing enterocolitis (Figure 6.1). Plain films, however, are two-dimensional representations of three-dimensional structures, with only limited soft-tissue discrimination, and their limitations should be recognized. A normal abdominal radiograph would not exclude intussusception or malrotation but could exclude obstruction or toxic dilation in the presence of active ulcerative colitis (Figure 6.2).
