The Radiological Diagnosis of Lower Urinary Obstruction in the Early Years

This paper is concerned with obstructions involving the lower urinary tract which cause retention of urine and dilatation of the ureters, because it is in these groups that infants and children present certain special problems and suffer some rather unfamiliar diseases. It is a field in which there is considerable scope not only for technical improvement in radiological methods, but for an increasing contribution from radiology to our knowledge of the pathology, which it must be admitted is at present somewhat meagre. The obstructions for which radiological assistance is required are chronic lesions, since the acute retentions of early childhood are often due to transitory and minor abnormalities which are easy to diagnose and to correct. In adults the causes of chronic retention are comparatively few and they can for the most part be diagnosed by a finger in the rectum or an instrument in the urethra; radiology is useful only in estimating the effects of the obstruction on the upper urinary tract. In infants there is considerably more variety, and the radiological findings are required to give us information about the actual site and nature of the obstructing lesion. The intravenous pyelogram will naturally be the first investigation undertaken in any case of urinary obstruction in which operation is not urgent and in which the renal function is adequate.