Renal calculi in children: imaging features that lead to diagnoses: a pictorial essay.

Abstract

Renal stones in children are often associated with radiologic findings that lead one to deduce the cause of stone formation. The images presented here show pediatric patients with renal stone disease who have associated imaging findings that should enable one to form an association or atrigger a synapseo between the characteristic associated finding and the cause of the renal stone. It is the elucidation of these associations or imaging features that is the focus of this pictorial essay. Approximately two-thirds of urinary calculi in North American children are located in the kidney at the time of diagnosis. The other third are in the ureter and the bladder. They are rarely in the urethra. Renal stones occur equally in males and females. Previously, there were no disproportionately affected age groups [1]. However, with recent advances in the care of premature infants, an increasing number of patients with hyaline membrane disease treated with furosemide has resulted in an increased incidence of stones in infants [2]. Symptoms of renal stone disease vary with age. The traumatic incapacitating flank, abdominal, or pelvic pain associated with the passage of stones is unusual in children. However, pain does occur in about half of patients with renal stones [1, 3]. Pain is more commonly the presenting problem in adolescence, whereas preschool children more commonly present with infection. Microscopic or macroscopic hematuria has been reported in 33% to 90% of children with urinary calculi [1]. The typical causes of renal stone disease in children include urologic conditions causing urinary stasis, urinary manifestations of myelodysplasia, recurrent urinary tract infection with urea-splitting bacteria, metabolic abnormalities, immobilization, enteric diseases, and iatrogenic causes [4, 5]. Radiolucent stones