Ultrasonography (US) is well suited to the study of pathologic conditions of the scrotum in children. US provides excellent anatomic detail; when color Doppler and power Doppler imaging are added, testicular perfusion can be assessed. Gray-scale, color Doppler, and power Doppler US were used to study a spectrum of scrotal disorders in 750 boys aged 1 day to 17 years. The entities studied included processus vaginalis-related disorders (cryptorchidism, inguinal-scrotal hernia, and hydrocele); varicocele; acute scrotum (epididymo-orchitis, torsion of the testicular appendages, and testicular torsion); scrotal tumors; testicular microlithiasis; scrotal trauma; and systemic diseases with scrotal involvement. When combined with the results of clinical and physical examination, the information obtained with US is sufficient to enable diagnosis in most cases of scrotal disease. Moreover, color Doppler imaging is essential for differentiation between processes such as epididymo-orchitis or torsion of the testicular appendages and testicular torsion, which have similar clinical manifestations (pain, swelling, and redness) but are managed differently.

Clinical evidence questions the use of surgery for asymptomatic complex ovarian cysts. Histologic analysis suggests gonad maldevelopment as the origin of complex neonatal ovarian cysts.

Neck lesions are common findings in pediatric patients and can be clas-Index terms: Aneurysm.

This pictorial review describes in detail the examination technique used to study the neonatal brain via the mastoid fontanelle and offers a panoramic view of the anatomical structures that can be identified in each US slice. The brain lesions are grouped as congenital malformations, haemorrhage, cerebellar lesions and sinus venous thrombosis. In each section, the additional information obtained through the mastoid fontanelle is provided.

Misleading images seen on US examination of the neonatal brain that could be misinterpreted as pathology are presented, with clues to their differentiation from true lesions.