title: Sonographic assessment of the severity and progression of autosomal dominant polycystic kidney disease: the Consortium of Renal Imaging Studies in Polycystic Kidney Disease (CRISP).
abstract: BACKGROUND
  The accuracy and precision of ultrasonography (US) in assessing the severity of autosomal dominant polycystic kidney disease (ADPKD) is unknown.
  
  
  METHODS
  US and magnetic resonance imaging (MRI) were performed at baseline and 1 year on 230 subjects with ADPKD. Ellipsoid volume was calculated from US length, width, and depth, and sequential transverse images were used to measure total and cystic volume directly. These were compared with MRI measurements of kidney volume and cystic volume.
  
  
  RESULTS
  Variability between different sonographers ranged from 18% to 42%. Correlations between US and MRI volume were 0.88 and 0.89. The SD of the discrepancy from MRI ranged from 21% to 33% and was unrelated to kidney size or body mass. Kidney length was the most reproducible measurement, and its correlation with MRI volume was 0.84. All patients with an US volume less than 700 cm3 had an MRI volume less than 1,000 cm3, and all patients with an US volume greater than 1,700 cm3 had an MRI volume greater than 1,000 cm3. Increases in volume after 1 year were 12% +/- 36% for the ellipsoid method, 6% +/- 29% for the direct method, and 4.2% +/- 7.2% for MRI. Correlation between US and MRI measurement of fractional cyst volume was 0.80.
  
  
  CONCLUSIONS
  Sonographic measurement of kidney volume in patients with ADPKD is inaccurate and lacks the precision necessary to measure short-term disease progression. However, sonography can provide an estimate of kidney volume that reflects severity and prognosis in individual patients.
authors.affiliation: Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA. woneill@emory.edu
authors.forename: W Charles
authors.initials: WC
authors.lastname: O'Neill
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Robbin
authors.forename: Kyongtae T
authors.initials: KT
authors.lastname: Bae
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Grantham
authors.forename: Arlene B
authors.initials: AB
authors.lastname: Chapman
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Guay-Woodford
authors.forename: Vicente E
authors.initials: VE
authors.lastname: Torres
authors.forename: Bernard F
authors.initials: BF
authors.lastname: King
authors.forename: Louis H
authors.initials: LH
authors.lastname: Wetzel
authors.forename: Paul A
authors.initials: PA
authors.lastname: Thompson
authors.forename: J Philip
authors.initials: JP
authors.lastname: Miller
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D001835:Body Weight; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D016891:Polycystic Kidney, Autosomal Dominant / Q000000981:diagnostic imaging* / Q000473:pathology; D011379:Prognosis; D015203:Reproducibility of Results; D014463:Ultrasonography