Imaging in pediatric urolithiasis—what’s the best choice?
The incidence of urolithiasis increased dramatically during the last decades in adults as well as in children. Today, when a urinary stone is suspected, the imaging modality used most frequently is non-contrast enhanced computed tomography (NCCT). Due to the high sensitivity and specifity, NCCT is regarded as the gold standard. Its major drawback is the high dose of radiation administered with this examination. This is of special concern in children. Children with urinary stones are at high risk for multiple recurrences during their life. NCCT increases the risk for abdominal and pelvic cancer in children significantly. With respect to therapeutic success, however, conventional imaging modalities like ultrasound are not inferior and are without any harm. Therefore, ultrasound is recommended as the primary imaging technique in children by several guidelines. Nevertheless, as could be shown by Tasian et al., ultrasound was the first imaging study in only 24% of children with urolithiasis. NCCT was the modality used most frequently (63%) in the USA between 2003 and 2011. There was a wide regional variation within the USA with highest CT use in the Northwestern and Southern and lowest in the New England states. It is hypothesized that engrained practice patterns and specific local medical resources as well as a lower confidence in ultrasound with its operator dependence are potential reasons. Regarding the fact that ultrasonography is highly reliable in the diagnosis of urolithiasis and is without any harm, it is essential to make all efforts to increase the adherence to the guidelines.