title: Simple, age-based formula for predicting renal length in children.
abstract: OBJECTIVE
  To determine a simple, age based formula for predicting ideal renal length in children. Renal size is a valuable marker in the evaluation of children with urological disorders. Although many authors have described complex nomograms and multivariate formulas for determining renal size, we propose a simple and accurate formula.
  
  
  METHODS
  All renal ultrasound (US) studies performed over a 9-year period in patients <18 years of age were retrospectively evaluated, excluding patients with a history of urinary tract disease or with abnormal renal US findings.
  
  
  RESULTS
  Ultrasounds were performed in 778 children <18 years who met inclusion criteria. Sixty-one percent of the patient population was ≥1 year of age at the time of the US. Forty-four percent of the children were male. In children 1 year of age or older, the formula was length (cm) = age (years) × 0.3 + 6, R(2) = .81. In infants younger than 1 year, renal length was poorly estimated by a simple age-based formula.
  
  
  CONCLUSIONS
  Our proposed formula can be used to predict renal length in children older than 1 year.
authors: Department of Urology, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors: Ardavan
authors: A
authors: Akhavan
authors: Jonathan S
authors: JS
authors: Brajtbord
authors: Daryl J
authors: DJ
authors: McLeod
authors: Abdo E
authors: AE
authors: Kabarriti
authors: Henrietta K
authors: HK
authors: Rosenberg
authors: Jeffrey A
authors: JA
authors: Stock
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D005544:Forecasting; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000033:anatomy & histology*; D008297:Male; D008433:Mathematics; D009929:Organ Size; D012189:Retrospective Studies