Assessment of infective urinary tract disorders

Urinary tract infection (UTI) is common in children, particularly in the youngest age groups. There is a risk for progressive deterioration of renal function in these children if aggravating factors such as gross reflux and/or outflow obstruction of the urinary tract are present. In this review the pros and cons of available scintigraphic and radiological imaging techniques for the work-up of these children are presented. Ultrasound can be used in the acute phase to exclude obstruction but can not reliably show transient or permanent parenchymal lesions. The presence of reflux can be established with X-ray or direct nuclide cystography. The X-ray technique gives good morphological information and has a grading system with prognostic relevance. Both techniques are invasive and great care must be taken to keep the radiation burden down with the X-ray technique. Indirect nuclide cystography following a renographic study is non-invasive but has a lower sensitivity than direct techniques. More experience is needed with the indirect technique to evaluate the consequences of its apparently low sensitivity. Urography has a limited place in the acute work-up of urinary tract infection but can be used to look for renal scarring 1-2 years after an acute pyelonephritis. The 99mTc dimercaptosuccinic acid (DMSA) scan can be used during the acute UTI to show pyelonephritic lesions with good accuracy and/or during the follow-up after six months to show permanent lesions. The acute DMSA scan can be omitted. An early treatment is more important than an early scan!