Primary ilio-psoas abscess extending to the thigh in a neonate: US, CT and MR findings.

Psoas abscess in children, and especially in neonates, is an uncommon condition which is difficult to diagnose clinically. The US, CT and MR findings of a psoas abscess in a neonate, which extended to the thigh, are reported. Imaging was helpful in revealing the abnormality, in demonstrating its extension and in determining its nature. The child was treated conservatively and the abscess resolved, leaving atrophy of the psoas muscle.