title: [(99m)Tc-MAG3 diuretic renography in assessment of obstructive uropathy. The new test F+10SP: a step ahead in the differential diagnosis].
abstract: BACKGROUND
  Dilation of the renal pelvis is a problem Urologists have often to deal with. One of the key aspects is to clear if the dilation is the consequence of an obstruction to the outflow or a simple anatomic variant. Aim of this study was to compare two diuretic renographic procedures, F-15 vs the new procedure F+10SP (Seated Position) in a group of hydronephrotic patients, in order to increase the accuracy in the differential diagnosis between non-obstructive and obstructive dilation.
  
  
  METHODS
  34 Patients (14 male, 20 female, 18-71 yrs range), 27 pts having an unilateral hydronephrosis and 7 pts a bilateral hydronephrosis diagnosed by ultrasound, were enclosed in the study. They were subjected to two 99mTc-MAG3 diuretic renography with furosemide consecutively, with different modalities: 1) 40 mg of furosemide were administered IV to patient in supine position 15 minutes before tracer injection (Test F-15, by English); 2) the new procedure: 20 mg of furosemide were administered IV to patient in Seated Position (SP), 10 minutes after tracer injection during dynamic acquisition (Test F+10 SP). The average interval between the two tests was 7 days. Two different physicians analyzed all the tests. The results were classified as: non-obstruction (only F+10SP can distinguish between normal and dilated without obstruction), obstruction, equivocal and not applicable.
  
  
  RESULTS
  Among the 68 renal units (RU) included in the analysis, the F+10SP test showed normal findings in 21 RU (30,8%), dilation without obstruction in 21 RU (30,8%), obstruction in 25 RU (36.8%) and equivocal result in 1 RU. The F-15 renography showed non-obstructive results in 35 RU (51.5%), obstruction in 20 RU (29.4%) and equivocal findings in 11 RU (16.1%); the test was not applicable in 2 RU (2.9%) due to insufficient renal function. Side effects reported for the F-15 renogram were hypotension in 1 patient, renal colic in 3 patients, bladder filling in 13 patients, disruption because of voiding in 4 patients. No complications were observed during or after the F+10SP renography. The 20 RU diagnosed with obstruction at the F-15 test were considered obstructed also at the F+10SP test.
  
  
  CONCLUSIONS
  The "equivocal" test rate lowered from 16% for the F-15 test to less than 1.5% for the new F+10 SP test. The F+10SP procedure is easy, well tolerated, time saving and seems to be a more reliable tool in assessment of obstructive uropathy in adults.
authors.affiliation: Department of Urology, Catholic University Medical School, Roma, Italy. matteovittori@inwind.it
authors.forename: Matteo
authors.initials: M
authors.lastname: Vittori
authors.forename: Alessandro
authors.initials: A
authors.lastname: D'Addessi
authors.forename: Francesco
authors.initials: F
authors.lastname: Pinto
authors.forename: Girolamo
authors.initials: G
authors.lastname: Tartaglione
authors.forename: PierFrancesco
authors.initials: P
authors.lastname: Bassi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004232:Diuretics; D005260:Female; D005665:Furosemide; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000209:etiology; D007682:Kidney Pelvis; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011866:Radioisotope Renography / Q000379:methods; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D014517:Ureteral Obstruction / Q000150:complications / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D004232:Diuretics; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D005665:Furosemide