title: Diagnostic performance between contrast enhancement, proton MR spectroscopy, and amide proton transfer imaging in patients with brain tumors.
abstract: To explore the relationship among parameters of magnetic resonance spectroscopy (MRS) and amide proton transfer (APT) imaging, and to assess the diagnostic performance of MRS and APT imaging for grading brain tumors in comparison with contrast enhancement of conventional MRI for preoperative grading in patients with brain tumor.
  
  
  
  Institutional Review Board approval and written informed consent were obtained. Forty-one patients with suspected brain tumors were enrolled in the study. Single-voxel MRS and 2D APT imaging of the same slice level were conducted using a 3T MRI scanner. Positive or negative contrast enhancement on T1-weighted images was assessed by two neuroradiologists. Correlations among metabolite concentrations, metabolite ratios, and calculated histogram parameters, including mean APT (APTmean) and the 90th percentile of APT (APT90) were assessed using Spearman's correlation coefficient. Diagnostic performance was evaluated with receiver operating characteristic (ROC) curve analysis for contrast enhancement and MRS and APT imaging. Values of P < 0.05 were considered statistically significant.
  
  
  
  Positive correlations with statistical significance were found between total concentration of choline (Cho) and APT90(r = 0.49), and between Cho/creatine (Cr) and APTmean(r = 0.65) as well as APT90(r = 0.49). A negative correlation with statistical significance was observed between NAA/Cr and APTmean(r = -0.52). According to ROC curves, Cho/Cr, APTmean, APT90, demonstrated higher area under the curve (AUC) values than that of contrast enhancement in grading gliomas.
  
  
  
  Significant correlations were observed between metabolite concentrations and ratios on MRS and APT values. MRS and APT imaging showed comparable diagnostic capability for grading brain tumors, suggesting that both MRS and APT imaging offer potential for quantitatively assessing similar biological characteristics in brain tumors on noncontrast MRI.
  
  
  
  2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:732-739.
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sakata
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan.
authors.forename: Yasutaka
authors.identifier: 0000-0002-1982-3168
authors.initials: Y
authors.lastname: Fushimi
authors.affiliation: Kyoto University Graduate School of Medicine, Human Brain Research Center, Kyoto, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Okada
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Neurosurgery, Kyoto, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Arakawa
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Neurosurgery, Kyoto, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Kunieda
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Diagnostic Pathology, Kyoto, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Minamiguchi
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Kido
authors.affiliation: Toshiba Medical Systems Corporations, MRI Systems Development Department, Otawara, Japan.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Sakashita
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Neurosurgery, Kyoto, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Miyamoto
authors.affiliation: Kyoto University Graduate School of Medicine, Department of Diagnostic Imaging and Nuclear Medicine, Kyoto, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Togashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: amide proton transfer imaging; chemical exchange saturation transfer; magnetic resonance imaging; magnetic resonance spectroscopy