title: The impact of hydration on renal measurements and on cortical echogenicity in children.
abstract: BACKGROUND
  Kidney ultrasonography is frequently performed in children; to date there are no specific guidelines regarding hydration before the examination.
  
  
  OBJECTIVE
  Because certain renal measurements can be indicative of pathology, we used sequential US images to investigate the effect of standardised hydration in children relative to renal size, echogenicity and pelvic expansion.
  
  
  METHODS
  Thirty-one children (7 years to 14 years old) underwent US examinations before hydration (T0) and at 30 min (T30) and 60 min (T60) after ingesting water. We measured bladder volume, inter-polar kidney size, renal volume and anterior-posterior diameter of the pelvis. Cortical echogenicity was compared to that of the liver and spleen.
  
  
  RESULTS
  On the right side the increase in average inter-polar renal size was 2.5% at T30 and 2.6% at T60 (P < 0.05) compared to T0. On the left the increase was 3.8% at T30 and 4.3% at T60 (P < 0.05). Volume expansion for the right kidney was 16.8% at T30 and 14.0% at T60 (P < 0.05). On the left it was 12.9% at T30 and 10.2% at T60 (P < 0.05). Cortical echogenicity progressed from hypoechogenicity to isoechogenicity (P < 0.05). The percentage of expanded pelves increased with hydration (T0: 3.2%, T30: 9.7%, T60: 22.6%).
  
  
  CONCLUSIONS
  Oral hydration influences renal length, volume and echogenicity in children. Hydration results in expansion of the pelvis. We recommend standardisation of hydration before US examination.
authors.affiliation: Radiology Department, Hôpital Universitaire des Enfants, Reine Fabiola, Avenue J.J Crocq, 1020, Brussels, Belgium, bpeerboc@ulb.ac.be.
authors.forename: Mooneera
authors.initials: M
authors.lastname: Peerboccus
authors.forename: Nasroolla
authors.initials: N
authors.lastname: Damry
authors.forename: Sanjiva
authors.initials: S
authors.lastname: Pather
authors.forename: Arnaud
authors.initials: A
authors.lastname: Devriendt
authors.forename: Freddy
authors.initials: F
authors.lastname: Avni
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007672:Kidney Cortex / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009929:Organ Size / Q000187:drug effects / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000187:drug effects* / Q000379:methods*; D014867:Water / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D014867:Water
references.citation: Pediatr Radiol. 2008 Feb;38(2):138-45
references.pmid: 18071685
references.citation: Australas Radiol. 2007 Dec;51(6):555-9
references.pmid: 17958691
references.citation: Pediatrics. 1983 Dec;72(6):840-6
references.pmid: 6646928
references.citation: Radiographics. 1990 Nov;10(6):1009-18
references.pmid: 2259758
references.citation: Arch Pediatr. 2009 Aug;16(8):1103-10
references.pmid: 19541461
references.citation: Pediatr Radiol. 2009 Aug;39(8):891-8
references.pmid: 19565235
references.citation: Ultrasound Med Biol. 1977;2(4):287-90
references.pmid: 867562
references.citation: Clin Auton Res. 2002 Aug;12(4):250-5
references.pmid: 12357278
references.citation: J Clin Ultrasound. 2006 Mar-Apr;34(3):128-33
references.pmid: 16547994
references.citation: AJR Am J Roentgenol. 2010 Feb;194(2):W218-20
references.pmid: 20093577
references.citation: Br J Radiol. 1987 Jun;60(714):525-9
references.pmid: 3304502
references.citation: Am J Kidney Dis. 2001 Apr;37(4):706-11
references.pmid: 11273869
references.citation: Radiology. 1999 Jun;211(3):623-8
references.pmid: 10352583
references.citation: AJR Am J Roentgenol. 1985 Sep;145(3):611-6
references.pmid: 3895872
references.citation: Pediatr Nephrol. 2004 Sep;19(9):992-1003
references.pmid: 15206038
references.citation: Scand J Urol Nephrol. 1999 Dec;33(6):386-91
references.pmid: 10636578
references.citation: AJR Am J Roentgenol. 2010 Feb;194(2):509-15
references.pmid: 20093617
references.citation: Eur Radiol. 2002 Aug;12(8):2006-20
references.pmid: 12136319
references.citation: AJR Am J Roentgenol. 2008 Jan;190(1):240-3
references.pmid: 18094318
references.citation: Pediatr Nephrol. 2008 Aug;23(8):1371-2
references.pmid: 18256854
references.citation: AJR Am J Roentgenol. 1993 Jan;160(1):83-6
references.pmid: 8416654