RT Journal Article SR Electronic T1 Value of Supranormal Function and Renogram Patterns on 99mTc-Mercaptoacetyltriglycine Scintigraphy in Relation to the Extent of Hydronephrosis for Predicting Ureteropelvic Junction Obstruction in the Newborn JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 725 OP 731 VO 44 IS 5 A1 Moon, Dae Hyuk A1 Park, Young Seo A1 Jun, Nu-Lee A1 Lee, So Young A1 Kim, Kun Suk A1 Kim, Jin Hee A1 Yoon, Chong Hyun A1 Kang, Weechang A1 Lee, Hee Kyung YR 2003 UL http://jnm.snmjournals.org/content/44/5/725.abstract AB We investigated the value of supranormal function and renogram patterns on 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction (UPJ) obstruction in the newborn. Methods: We studied 48 patients with prenatally diagnosed unilateral hydronephrosis that was confirmed on postnatal ultrasonography. The anteroposterior pelvic diameter (APPD) and the Society for Fetal Urology (SFU) grade were measured on 1-mo ultrasonography to assess the extent of hydronephrosis. Neonates with an APPD of ≤10 mm or a differential renal function of ≤40% were excluded. Supranormal function (≥55%) and renogram grades (1, not obstructive; 2, indeterminate; 3, obstructive; and 4, prolonged parenchymal transit) were determined on 1-mo 99mTc-MAG3 renography. Multivariate logistic regression analysis was performed to predict the presence of obstruction. Results: Of the 48 kidneys with hydronephrosis, 19 were diagnosed as having UPJ obstruction. Twenty-nine kidneys were classified as having nonobstructive hydronephrosis. The APPD of the 19 kidneys with obstruction (24.3 ± 9.2 mm) was significantly larger than that of the 29 kidneys without obstruction (17.5 ± 11.2 mm; P < 0.05). The SFU grades of UPJ obstruction (2 with grade 3, 17 with grade 4) were also significantly higher than those without UPJ obstruction (grades 1–4 in 1, 6, 10, and 12 kidneys, respectively; P < 0.01). Supranormal function was present in 4 kidneys with UPJ obstruction but in none without obstruction (P < 0.001). 99mTc-MAG3 renography of the 19 obstructions showed grades 2, 3, and 4 renograms in 4, 8, and 7 patients, respectively. The 29 without obstruction revealed significantly lower grades (grades 1–4 in 10, 13, 5, and 1 patient, respectively; P < 0.001). Multivariate logistic regression analysis revealed that the addition of supranormal function or renogram grade in the model significantly increased the likelihood ratio in comparison with that of the SFU grade only (χ2 = 7.73 and 9.99, respectively; P < 0.01). Of the 29 neonates with SFU grade 4, supranormal function or renogram ≥ grade 4 had a positive predictive value of 90% (9/10). Conclusion: 99mTc-MAG3 renography at 1 mo after birth has a significant additive value in relation to the degree of hydronephrosis in predicting UPJ obstruction in patients with prenatally diagnosed unilateral hydronephrosis with normal function.