title: High quality three-dimensional gagCEST imaging of in vivo human knee cartilage at 7 Tesla.
abstract: To develop a new faster and higher quality three-dimensional (3D) gagCEST MRI technique for reliable quantification of glycosaminoglycan (GAG) present in the human knee cartilages.
  
  
  
  A new magnetization-prepared 3D gradient echo-based MRI pulse sequence has been designed to obtain the B0inhomogeneity, B1inhomogeneity, and CEST Z-spectra images.
  
  
  
  The gagCEST values of different compartments of knee cartilage are calculated using a newly developed technique for healthy subjects and a symptomatic knee cartilage degenerated subject. The effect of the acquired CEST saturation frequency offset step-size was investigated to establish the optimal step-size to obtain reproducible gagCEST maps. Our novel 3D gagCEST technique demonstrates markedly higher gagCEST contrast value than the previously reported 3D gagCEST studies. This study demonstrates the need for separate B0and B1inhomogeneity estimation and correction.
  
  
  
  The new technique provided high quality gagCEST maps with clearer visualization of different layers of knee cartilage with reproducible results. Magn Reson Med 77:1866-1873, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands.
authors.forename: Guruprasad
authors.initials: G
authors.lastname: Krishnamoorthy
authors.affiliation: CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Ravi Prakash Reddy
authors.initials: RPR
authors.lastname: Nanga
authors.affiliation: CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Puneet
authors.initials: P
authors.lastname: Bagga
authors.affiliation: CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Hari
authors.initials: H
authors.lastname: Hariharan
authors.affiliation: CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Ravinder
authors.initials: R
authors.lastname: Reddy
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D006025:Glycosaminoglycans / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007717:Knee / Q000000981:diagnostic imaging*; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D008297:Male; D009038:Motion; D051381:Rats; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D006025:Glycosaminoglycans
keywords: 3D gagCEST; B0; B1 calibration; magnetization preparation 3D