Approach and Analysis

A number of emergent conditions are unique to the pediatric and neonatal age groups, and these are addressed in this chapter. Conditions also seen in adults, such as intussusception and appendicitis, can be found in the corresponding chapters organized by anatomy.

Studies that do not utilize ionizing radiation are preferred in the pediatric age group. Because the lifetime risk of developing a radiation-induced cancer is greater with early exposure, it is prudent to avoid unnecessary X-ray and CT examinations in children and to minimize radiation dose in any necessary study that utilizes ionizing radiation. Fortunately, most practices and equipment manufacturers have protocols and techniques that reduce radiation dose to the minimum needed for accurate diagnosis. Ultrasound and MRI are preferred for cross-sectional imaging, especially in the diagnosis of pediatric abdominal pain and in the often-repeated evaluation of hydro-cephalus in children with ventriculoperitoneal shunts.

In children with suspected appendicitis, ovarian torsion, testicular torsion, intussusception, or pyloric stenosis, ultrasound should be attempted prior to CT. Radio-graphs are the primary imaging modality for acute thoracic disease, ingested foreign bodies, and musculoskeletal injuries, and they can be helpful in evaluating abdominal pain by establishing the diagnosis of severe constipation as well as bowel obstruction. In the emergency setting, CT is generally reserved for significant traumatic injury and for acute abdominal pain that cannot be diagnosed by clinical and laboratory findings, plain radiography, and ultrasound.

Imaging and Anatomy

Salter-Harris Classification of Pediatric Fractures

Salter-Harris classification of pediatric fractures is seen in Fig. 8.1.

Clinical Presentations and Differential Diagnosis

Nonaccidental Trauma

Children who suffer nonaccidental trauma (NAT) are often brought to the emergency department with minor rather than catastrophic injuries. Emergency physicians and radiologists are therefore in a unique position to first identify NAT, and recognition of characteristic injury patterns can potentially avert future abuse or neglect. Common injuries include fractures, intracranial hemorrhage or contusion, and intra-abdominal injuries. Head injury is important to recognize, because it represents a frequent cause of death in abused children below the age of 3.

Suspicious injuries include any fracture in a preambulatory child, any injury incompatible with the clinical history, unusual delay in seeking medical attention, retinal hemorrhage, multiple fractures in the absence of any family history of osteogenesis imperfecta, and subdural hematomas of different ages. A skeletal survey should be performed in cases of suspected abuse to evaluate the location and extent of present and remote osseous injuries.

Certain fractures have been recognized as indicative of NAT: metaphyseal (bucket-handle or corner) fractures, posterior rib fractures, skull fractures, scapular fractures, and sternal fractures. Periosteal reactions and juxtaosseous soft tissue calcifications signify healing fractures and should be carefully documented for medicolegal purposes.

Head CT may identify skull fractures missed by skeletal survey as well as more significant brain injury. Nonparietal skull fractures, diastatic sutures, cross sutures, or depressed fractures should be considered suspicious. MRI can evaluate the brain parenchyma more sensitively and show subdural hematomas of varying ages, hypoxic-ischemic injury, cerebral contusions, and traumatic subarachnoid hemorrhages ( Fig. 8.2 ).

Lung Disease of Prematurity

Lung disease of prematurity, also known as respiratory distress syndrome (RDS), is an acute lung disease seen in children born before the lungs produce adequate surfactant to maintain alveolar expansion. It is seen in neonates younger than 32 weeks gestational age or who weigh less than 1,200 grams. Symptoms, which are usually evident within hours of delivery, include tachypnea, expiratory grunting, nasal flaring, and substernal and intercostal retractions. In addition to prematurity, other risk factors include maternal gestational diabetes, prenatal asphyxia, and multiple gestations.

Radiographs show a bell-shaped thoracic contour. The lung parenchyma has a fine granular, or “ground glass,” appearance, often with air bronchograms.

Complications of RDS are related to ventilation and barotrauma and include pulmonary interstitial emphysema, pneumothorax, and bronchopulmonary dysplasia.

Treatment consists of administration of artificial pulmonary surfactant and supportive ventilation and oxygen therapy. With the increased use of antenatal steroids to accelerate pulmonary maturity, the incidence and severity of hyaline membrane disease has been declining ( Fig. 8.3 ).