title: Detection of intrarenal microstructural changes with supersonic shear wave elastography in rats.
abstract: OBJECTIVE
  To evaluate, in a rat model of glomerulosclerosis, whether ultrasonic shear wave elastography detects kidney cortex stiffness changes and predicts histopathological development of fibrosis.
  
  
  METHODS
  Three groups were studied transversally: a control group (n = 8), a group after 4 weeks of L-NAME administration (H4, n = 8), and a group after 6 weeks (H6, n = 15). A fourth group was studied longitudinally (n = 8) before, after 4 weeks and after 7 weeks of L-NAME administration. Shear modulus of renal cortex was quantified using supersonic shear imaging technique. Urine was analysed for dosage of protein/creatinine ratio. Kidneys were removed for histological quantification of fibrosis.
  
  
  RESULTS
  Diseased rats showed an increased urinary protein/creatinine ratio. Cortical stiffness expressed as median (interquartile range) was 4.0 kPa (3.3-4.5) in control kidneys. It increased in all but one pathological groups: H4: 7.7 kPa (5.5-8.6) (p < 0.01); H6: 4.8 kPa (3.9-5.9) (not significant); in the longitudinal cohort, from 4.5 kPa (3.1-5.9) to 7.7 kPa (5.9-8.3) at week 4 (p < 0.05) and to 6.9 kPa (6.1-7.8) at week 7 (p < 0.05). Stiffness values were correlated with the proteinuria/creatininuria ratio (r = 0.639, p < 0.001).
  
  
  CONCLUSIONS
  Increased cortical stiffness is correlated with the degree of renal dysfunction. More experience in other models is necessary to understand its relationship with microstructural changes.
authors.affiliation: Laboratory for Molecular and Functional Imaging, from Physiology to Therapy, FRE 3313 CNRS & University Bordeaux Segalen, Bordeaux, France. marc.derieppe@gmail.com
authors.forename: Marc
authors.initials: M
authors.lastname: Derieppe
authors.forename: Yahsou
authors.initials: Y
authors.lastname: Delmas
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Gennisson
authors.forename: Colette
authors.initials: C
authors.lastname: Deminière
authors.forename: Sandrine
authors.initials: S
authors.lastname: Placier
authors.forename: Mickaël
authors.initials: M
authors.lastname: Tanter
authors.forename: Christian
authors.initials: C
authors.lastname: Combe
authors.forename: Nicolas
authors.initials: N
authors.lastname: Grenier
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004548:Elasticity; D054459:Elasticity Imaging Techniques / Q000379:methods; D005355:Fibrosis / Q000175:diagnosis; D005923:Glomerulosclerosis, Focal Segmental / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D007668:Kidney / Q000473:pathology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019331:NG-Nitroarginine Methyl Ester