[The echographic assessment of the size of normal pyelo-calyceal cavities. Accuracy and limits (author's transl)].

The authors studied using two echographies 90 kidneys in 53 patients free of known urinary tract pathology and not suffering from renal colic, the first immediately before intravenous urography (at a stage of relative fluid restriction) and the second before micturition (at a stage of higher urine output and filling of the bladder). Findings were as follows: - normal excretory cavities may be seen by echotomography, this being in contrast to a widely held view; - changes in the echographic appearance of the pyelocalyceal cavities may occur in the absence of any pathology merely as a result of changes in urine output. They draw attention to the possible errors inherent in echotomography performed alone. They emphasise the need, at least in the absence of renal insufficiency, to preceed any echography by intravenous urography.