title: Grading diffuse gliomas without intense contrast enhancement by amide proton transfer MR imaging: comparisons with diffusion- and perfusion-weighted imaging.
abstract: OBJECTIVE
  To investigate whether amide proton transfer (APT) MR imaging can differentiate high-grade gliomas (HGGs) from low-grade gliomas (LGGs) among gliomas without intense contrast enhancement (CE).
  
  
  METHODS
  This retrospective study evaluated 34 patients (22 males, 12 females; age 36.0 ± 11.3 years) including 20 with LGGs and 14 with HGGs, all scanned on a 3T MR scanner. Only tumours without intense CE were included. Two neuroradiologists independently performed histogram analyses to measure the 90th-percentile (APT90) and mean (APTmean) of the tumours' APT signals. The apparent diffusion coefficient (ADC) and relative cerebral blood volume (rCBV) were also measured. The parameters were compared between the groups with Student's t-test. Diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  The APT90(2.80 ± 0.59 % in LGGs, 3.72 ± 0.89 in HGGs, P = 0.001) and APTmean(1.87 ± 0.49 % in LGGs, 2.70 ± 0.58 in HGGs, P = 0.0001) were significantly larger in the HGGs compared to the LGGs. The ADC and rCBV values were not significantly different between the groups. Both the APT90and APTmeanshowed medium diagnostic performance in this discrimination.
  
  
  CONCLUSIONS
  APT imaging is useful in discriminating HGGs from LGGs among diffuse gliomas without intense CE.
  
  
  CONCLUSIONS
  • Amide proton transfer (APT) imaging helps in grading non-enhancing gliomas • High-grade gliomas showed higher APT signal than low-grade gliomas • APT imaging showed better diagnostic performance than diffusion- and perfusion-weighted imaging.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Togao
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan. hiwatasi@radiol.med.kyushu-u.ac.jp.
authors.forename: Akio
authors.initials: A
authors.lastname: Hiwatashi
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamashita
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Philips Research, Röntgenstrasse 24-26, Hamburg, 22335, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Keupp
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yoshimoto
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kuga
authors.affiliation: Philips Electronics Japan, 2-13-37 Konan Minato-ku, Tokyo, 108-8507, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Yoneyama
authors.affiliation: Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Satoshi O
authors.initials: SO
authors.lastname: Suzuki
authors.affiliation: Department of Neuropathology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Iwaki
authors.affiliation: Advanced Imaging Research Center, UT Southwestern Medical Center, 2201 Inwood Rd, Dallas, TX, 75235, USA.
authors.forename: Masaya
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Iihara
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D002648:Child; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D055420:Perfusion Imaging; D011522:Protons; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D000577:Amides; D011522:Protons
keywords: Amide proton transfer imaging; Brain tumour; Chemical exchange saturation transfer; Glioma; MR imaging