Korean Journal of Nephrology 1989;8(3):473-480.

소아 요로질환 평가에 있어서의 99mTc - DMSA Scan 의 의의

이현수 , 김병길 , 오기근 , 최승강

Abstract

99m Technetium dimercaptosuccinic acid (DMSA) is a new renal scanning agent provides a good quality of renal image as a result of preferential cortical accumu- lation. The presence of scarring is the important determinant in the selection of those at risk of progressive damage. Traditionally the IVP has been the preferred study to evaluate pyelonephritic scarring. However the IVP has some limitations, including the short nephrographic phase, the need for adequate perirenal fat for resolution of renal outlines and most importantly, interfere from bowel gas. These problems are particularly important in children, in whom poor cooperation, limited bowel pre- partation and abnormal kidneys are more common. Also Tc-DMSA scan may replace the conditional split renal function study in which traumatic proce- dures, such as cystoscopy and ureteral catheteriation. Therefore the author has performed this study to evaluate the lesions for performing the scan as the initial examination in children with urinary tract infec- tion and validity of "Tc-DMSA uptake for an assess- ment of uropathy. Tc-DMSA scan was performed in 39 patients among 171 patients diagnosed UTI at pediatric depart- ment of Severance Hospital, Yonsei University, College of Medicine form March 1986 to July 1988 The results were as follows: 1) The average value of " Tc-DMSA uptake of each kidney in healthy control group was 38.4±3.4% for the right kidney and 41.8±3.4% for the left kidney. The average value of total " Tc-DMSA uptake was 39.2± 8.2. 2) In cases of unilateral uropathy with a contralateral healthy kidndey, the ""Tc-DMSA uptake from the healthy side increased when compared to the normal healthy control group but the pathologic " Tc-DMSA uptake decreased when compared to the normal healthy control group. 3) In cases of bilateral uropathies, the "Tc-DMSA uptake of each kidney was decreased compared to the normal healthy control group. 4) In 20 simple UTI cases, cases of abnormal findings including renal scar or focal defects on IVP and sono- gram was 5 (25%.) and 4 (20%) respectively. But those in "Tc-DMSA scan was 12 (60%). 5) A sensitivity of 0.53 and specificity of 0.42 for IVP, compared with a specificity of 0.88 and sensitivity of 0. 83 for "Tc-DMSA scan in 20 simple UTI cases. 6) In cases of UTI with obstructive uropathy, " Tc -DMSA scan was an ideal method in detection of renal scarring and evaluation of renal function, compared to IVP, sonogram and VCUG and this increased sensitvity and specificity may affect clinical management. 7) " Tc-DMSA scan was an reliable method in an assessment of postoperative renal function compared to IVP. 8) Preoperative uptake of "Tc-DMSA was compar- ed to early postoperative unilateral Ccr, measured 2 & 3 days postoperatively by urine collection from the ne-phrostomy tube and expressed as a percentage of the total Ccr (Urine from the contralateral kidney was obtained normally). An excellent correlation was found, the correlation coefficient being 0.79 (y=0.70 x+4.58). We concluded that " Tc-DMSA made a feasible quantitation assessment of separate kidney function and had a higher sensitivity and specificity in the detection of pyelonephritic scarring compared to IVP, therefore this increased sensitivity and spnsificity may affect clinical management.