title: Quantification of glomerular number and size distribution in normal rat kidneys using magnetic resonance imaging.
abstract: BACKGROUND
  Glomerular number and size are important risk factors for chronic kidney disease (CKD) and cardiovascular disease and have traditionally been estimated using invasive techniques. Here, we report a novel technique to count and size every glomerulus in the rat kidney using magnetic resonance imaging (MRI).
  
  
  METHODS
  The ferromagnetic nature of cationized ferritin allowed visualization of single glomeruli in high-resolution susceptibility-weighted MRI. A segmentation algorithm was used to identify and count all glomeruli within the whole kidney. To prove our concept, we estimated total glomerular number and mean glomerular volume of each kidney using design-based stereology.
  
  
  RESULTS
  The glomerular counts obtained with MRI agreed well with estimates obtained using traditional methods [MRI, 32 785 (3117); stereology, 35 132 (3123)]. For the first time, the glomerular volume distribution for the entire kidney is shown. Additionally, the method is substantially faster than the current methods.
  
  
  CONCLUSIONS
  MRI provides a new method for measuring these important microanatomical markers of disease risk and leads the way to in vivo analysis of these parameters, including longitudinal studies of animal models of CKD.
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Heilmann
authors.forename: Sabine
authors.initials: S
authors.lastname: Neudecker
authors.forename: Ivo
authors.initials: I
authors.lastname: Wolf
authors.forename: Lina
authors.initials: L
authors.lastname: Gubhaju
authors.forename: Carsten
authors.initials: C
authors.lastname: Sticht
authors.forename: Daniel
authors.initials: D
authors.lastname: Schock-Kusch
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kriz
authors.forename: John F
authors.initials: JF
authors.lastname: Bertram
authors.forename: Lothar R
authors.initials: LR
authors.lastname: Schad
authors.forename: Norbert
authors.initials: N
authors.lastname: Gretz
mesh_terms: D000818:Animals; D002452:Cell Count; D005293:Ferritins; D007678:Kidney Glomerulus / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005293:Ferritins