title: Assessment of kidney volume in polycystic kidney disease using magnetic resonance imaging without contrast medium.
abstract: OBJECTIVE
  Total renal volume (TRV) is an important index to evaluate the progression of autosomal-dominant polycystic kidney disease (ADPKD). TRV has been assessed by manually tracing renal contours from CT or MR scans, often employing contrast medium (CM). We developed a fast and nearly automated technique based on the analysis of MR images acquired without CM injection for TRV quantification.
  
  
  METHODS
  30 ADPKD patients underwent MRI. After the selection of one point inside each kidney for the entire volume, the automatic extraction of kidney contours was performed on each acquired slice; the segmentation procedure was based on region growing and on the application of morphological operators and curvature-based motion. The area inside each contour was calculated and TRV was derived. Volume measurements were validated by comparison with measurements obtained by stereology.
  
  
  RESULTS
  TRV estimated in patients was 768 ± 545 ml (range 161-3,111 ml). The automatic measurements were in excellent correlation with the manual ones (r = 0.99, y = x - 0.7), with a small bias and narrow limits of agreement in both absolute (-5 ± 37 ml) and percentage (-0.6 ± 9.6%) terms.
  
  
  CONCLUSIONS
  This preliminary study showed the feasibility of a fast and nearly automated method for determining TRV; importantly it does not require the use of potentially nephrotoxic CM.
authors.affiliation: Nephrology and Dialysis Unit, Infermi Hospital, Rimini, Italy. rmignani@auslrn.net
authors.forename: Renzo
authors.initials: R
authors.lastname: Mignani
authors.forename: Cristiana
authors.initials: C
authors.lastname: Corsi
authors.forename: Mariangela
authors.initials: M
authors.lastname: De Marco
authors.forename: Enrico G
authors.initials: EG
authors.lastname: Caiani
authors.forename: Gioele
authors.initials: G
authors.lastname: Santucci
authors.forename: Enrico
authors.initials: E
authors.lastname: Cavagna
authors.forename: Stefano
authors.initials: S
authors.lastname: Severi
authors.forename: Leonardo
authors.initials: L
authors.lastname: Cagnoli
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D007690:Polycystic Kidney Diseases / Q000473:pathology*; D016891:Polycystic Kidney, Autosomal Dominant / Q000473:pathology; D012044:Regression Analysis
chemical_list: D003287:Contrast Media