REVIEW ARTICLE 21 물콩팥증 의 치료에 서 방사성동위원소검사 Radioisotope Study in the Management of Hydronephrosis

Hydronephrosis is defined as a dilatation of the pelvocalyceal system and has an estimated incidence of 1 in 600 infants. To decide whether neo-natal hydronephrosis can be managed non-operatively or require surgical intervention is still a challenge. Of nuclear medicine tests, diuretic renog-raphy using Tc-99m MAG3 is useful to differentiate progressive hydro-nephrosis requiring surgical intervention from transient hydronephrosis. Diuretics cause increased urinary flow which promotes a prompt washout in non-obstructive hydronephrosis. An obstructed system will not respond to diuretics, so radioactivity will accumulate continuously and in reno-gram the curve will rise constantly or show plateau occasionally. In gen-eral, the T1/2 is used as an indicator of obstruction even though it is not confirmative- greater than 20 minutes means obstruction whereas less than 15 minutes indicates no obstruction. A split renal function of 45-55% is considered to be within normal range and it is decreased abnormally in obstruction. Diuretic renography is noninvasive and can quantify pa-rameters about renal function, such as T1/2 and split renal function, therefore it is very useful clinical tool in the diagnosis and management of hydronephrosis and other pediatric urologic diseases