title: Towards the identification of multi-parametric quantitative MRI biomarkers in lupus nephritis.
abstract: OBJECTIVE
  To identify potential biomarkers of the renal impairment in lupus nephritis using a multi-parametric renal quantitative MRI (qMRI) protocol including diffusion weighted imaging (DWI), blood oxygen level dependent (BOLD), arterial spin labeling (ASL) and T1rho MRI between a cohort of healthy volunteers and lupus nephritis (LN) patients.
  
  
  METHODS
  The renal qMRI protocol was performed twice with repositioning in between on 10 LN patients and 10 matched controls at 1.5 T. Navigator-gated and breath-hold acquisitions followed by non-rigid image registration were used to control respiratory motion. The repeatability of the 4 MRI modalities was evaluated with the intra-class correlation coefficient (ICC) and within-subject coefficient of variation (wsCV). Unpaired t-test and stepwise logistic regression were carried out to evaluate qMRI parameters between the LN and control groups.
  
  
  RESULTS
  The reproducibility of the 4 qMRI modalities ranged from moderate to good (ICC=0.4-0.91, wsCV≤12%) with a few exceptions. T1rho MRI and ASL renal blood flow (RBF) demonstrated significant differences between the LN and control groups. Stepwise logistic regression yielded only one significant parameter (medullar T1rho) in differentiating LN from control groups with 95% accuracy.
  
  
  CONCLUSIONS
  A reasonable degree of test-retest repeatability and accuracy of a multi-parametric renal qMRI protocol has been demonstrated in healthy volunteers and LN subjects. T1rho and ASL RBF are promising imaging biomarkers of LN.
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Rapacchi
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Robert X
authors.initials: RX
authors.lastname: Smith
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Lirong
authors.initials: L
authors.lastname: Yan
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Sigalov
authors.affiliation: Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Kate E
authors.initials: KE
authors.lastname: Krasileva
authors.affiliation: Department of Rheumatology, Harbor-UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: George
authors.initials: G
authors.lastname: Karpouzas
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Plotnik
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Sayre
authors.affiliation: Department of Rheumatology, Harbor-UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Hernandez
authors.affiliation: Biogen Idec, Cambridge, MA, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Verma
authors.affiliation: Biogen Idec, Cambridge, MA, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Burkly
authors.affiliation: Biogen Idec, Cambridge, MA, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Wisniacki
authors.affiliation: Biogen Idec, Cambridge, MA, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: Torrington
authors.affiliation: Department of Radiology, State University of New York at Stony Brook, Stony Brook, NY, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: He
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.affiliation: Biogen Idec, Cambridge, MA, USA.
authors.forename: Ping-Chun
authors.initials: PC
authors.lastname: Chiao
authors.affiliation: Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA; Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA. Electronic address: jwang71@gmail.com.
authors.forename: Danny J J
authors.initials: DJJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D015415:Biomarkers; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008181:Lupus Nephritis / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers
keywords: Arterial spin labeling (ASL); Blood oxygen level dependent (BOLD); Lupus nephritis (LN); Multi-parametric quantitative MRI (qMRI); Renal function; T1rho MRI