Shortly after birth, the sclerae and skin may acquire a yellow appearance secondary to the accumulation of bilirubin in these tissues. This is called neonatal jaundice.
There are two types of jaundice, physiologic and pathologic. Physiologic jaundice is a common condition that can be observed in 80% of pre-term newborns and in 60% of normal newborns. It is a benign condition with increased levels of bilirubin at the end of the first week of life. Patients are active and no signs of sepsis or anemia should be present (Gubernick et al. 2000).
On the other hand, pathologic bilirubinemia will be characterized by jaundice presenting within the first day of life or persistent after 1 week in term newborns and 2 weeks in pre-term infants. It is characterized by an increase of bilirubin levels greater than 5 mg/dl in one day, with levels of direct bilirubin greater than 2 mg/dl and total bilirubin greater than 15 mg/dl. The child is often lethargic and quiet. The differential diagnosis includes infectious etiologies such as hepatitis (caused by the TORCH entities toxoplasmosis, rubella, cytomegalovirus, Herpes simplex), syphilis, and metabolic diseases such as
Fig. 4.1. a Longitudinal US image shows the normal texture and a normal gallbladder. b Transverse US image reveals normal echo texture and a normal portal vein/common bile duct alpha 1 antitrypsin deficiency and cystic fibrosis (Gubernick et al. 2000).
Once these causes of jaundice have been excluded, neonatal hepatitis, biliary atresia (BA) or duct paucity syndromes will account for more than two thirds of the remaining cases of conjugated hyperbilirubi-nemia in the neonate. In conjunction with nuclear medicine, US is the primary imaging modality for differentiating among these diseases and differentiation is important, as surgery is the treatment for BA but not for the other entities (Kelly 1999; Mortele et al. 2006; Gazelle et al. 1998).
Was this article helpful?