title: Acoustic radiation force impulse imaging for non-invasive assessment of renal histopathology in chronic kidney disease.
abstract: OBJECTIVE
  To investigate the stiffness values obtained by acoustic radiation force impulse (ARFI) quantification in assessing renal histological fibrosis of chronic kidney disease (CKD).
  
  
  METHODS
  163 patients with CKD and 32 healthy volunteers were enrolled between June 2013 and April 2014. ARFI quantification, given as shear wave velocity (SWV), was performed to measure renal parenchyma stiffness. Diagnostic performance of ARFI imaging and conventional ultrasound (US) were compared with histologic scores at renal biopsy. Intra- and inter-observer reliability of SWV measurement was analyzed.
  
  
  RESULTS
  In CKD patients, SWV measurements correlated significantly with pathological parameters (r = -0.422--0.511, P<0.001), serum creatinine (r = -0.503, P<0.001), and glomerular filtration rate (r = 0.587, P<0.001). The mean SWV in kidneys with severely impaired (histologic score: ≥19 points) was significant lower than that mildly impaired (histologic score: ≤9 points), moderately impaired (histologic score: 10-18 points), and control groups (all P<0.001). Receiver operating characteristic (ROC) curves analyses indicated that the area under the ROC curve for the diagnosis of renal histological fibrosis using ARFI imaging was superior to these conventional US parameters. Using the optimal cut-off value of 2.65 m/s for the diagnosis of mildly impaired kidneys, 2.50 m/s for moderately impaired kidneys, and 2.33 m/s for severely impaired kidneys, the corresponding area under the ROC curves were 0.735, 0.744, and 0.895, respectively. Intra- and intre-observer agreement of SWV measurements were 0.709 (95% CI: 0.390-0.859, P<0.001) and 0.627 (95% CI: 0.233-0.818, P = 0.004), respectively.
  
  
  CONCLUSIONS
  ARFI may be an effective tool for evaluating renal histological fibrosis in CKD patients.
authors.affiliation: Department of Diagnostic Ultrasound, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Department of Diagnostic Ultrasound, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Nephrology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Hong-Guang
authors.initials: HG
authors.lastname: He
authors.affiliation: Department of Pathology, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Hai-Ming
authors.initials: HM
authors.lastname: Wei
authors.affiliation: Department of Diagnostic Ultrasound, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Li-Ke
authors.initials: LK
authors.lastname: Kang
authors.affiliation: Department of Diagnostic Ultrasound, the People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.
authors.forename: Gui-Can
authors.initials: GC
authors.lastname: Qin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000000981:diagnostic imaging* / Q000473:pathology; D012680:Sensitivity and Specificity