PT - JOURNAL ARTICLE AU - Imperiale, Alessio AU - Olianti, Catia AU - Sestini, Stelvio AU - Materassi, Marco AU - Daniela, Seracini AU - Ienuso, Rita AU - La Cava, Giuseppe TI - <sup>123</sup>I-Hippuran Renal Scintigraphy with Evaluation of Single-Kidney Clearance for Predicting Renal Scarring After Acute Urinary Tract Infection: Comparison with <sup>99m</sup>Tc-DMSA Scanning DP - 2003 Nov 01 TA - Journal of Nuclear Medicine PG - 1755--1760 VI - 44 IP - 11 4099 - http://jnm.snmjournals.org/content/44/11/1755.short 4100 - http://jnm.snmjournals.org/content/44/11/1755.full SO - J Nucl Med2003 Nov 01; 44 AB - The value of 123I-hippuran (OIH) renal sequential scintigraphy (RSS) in predicting the evolution of defects detected by 99mTc-dimercaptosuccinic acid (DMSA) scanning during a first episode of acute pyelonephritis (APN) was assessed. Methods: Fifty-eight children with APN underwent 99mTc-DMSA planar scanning and 123I-OIH RSS during acute infection and at least 5 mo later. Renal lesions found by 99mTc-DMSA scanning were classified according to the following 99mTc-DMSA grading system: 0 = normal, 1 = 1 lesion, 2 = 2 lesions, and 3 = diffuse damage with renal parenchymal subversion. Renal scarring was diagnosed whenever a renal cortical defect detected at the first 99mTc-DMSA examination persisted on the follow-up 99mTc-DMSA examination. Single-kidney clearance rate (Cl) was evaluated by a method that was previously validated at our institution and is based on time–activity curves measured on the heart and kidney areas by the region-of-interest technique. Results: 99mTc-DMSA scanning showed renal damage in 76 kidneys and had negative findings for the remaining 40 kidneys (2 patients had bilaterally negative findings). 99mTc-DMSA scanning determined 40 kidneys to be grade 0, 49 to be grade 1, 21 to be grade 2, and 6 to be grade 3. For 99mTc-DMSA grades of 0–3, the corresponding Cl mean values (in mL/min/1.73 m2 of body surface area [BSA]) were 292 ± 33, 237 ± 39, 210 ± 54, and 140 ± 53, respectively. The Spearman regression coefficient (R) demonstrated a significant correlation between 99mTc-DMSA grade and Cl (R = 0.69, P &lt; 0.0001). Thirty-six of the lesions detected by staging 99mTc-DMSA were shown to have recovered on follow-up renal scans, whereas 40 developed scars. A significant difference in Cl was found between the 2 groups (P &lt; 0.0002). The Cl cutoff value was determined by univariate discriminant analysis; a Cl value of 232 mL/min/1.73 m2 of BSA discriminated best between scarred and nonscarred kidneys, with a specificity, sensitivity, positive predictive value, negative predictive value, and overall accuracy of 95%, 95%, 90%, 97%, and 95%, respectively. Conclusion: Cl evaluation, in the course of acute urinary tract infection, is highly valuable in predicting the fibrotic evolution of renal damage detected on acute 99mTc-DMSA scanning. Also, our data show close agreement between Cl and the grade determined by staging 99mTc-DMSA.