title: Novel application of chemical shift gradient echo in- and opposed-phase sequences in 3 T MRI for the detection of H-MRS visible lipids and grading of glioma.
abstract: OBJECTIVE
  We evaluated the feasibility of using chemical shift gradient-echo (GE) in- and opposed-phase (IOP) imaging to grade glioma.
  
  
  METHODS
  A phantom study was performed to investigate the correlation of (1)H MRS-visible lipids with the signal loss ratio (SLR) obtained using IOP imaging. A cross-sectional study approved by the institutional review board was carried out in 22 patients with different glioma grades. The patients underwent scanning using IOP imaging and single-voxel spectroscopy (SVS) using 3T MRI. The brain spectra acquisitions from solid and cystic components were obtained and correlated with the SLR for different grades.
  
  
  RESULTS
  The phantom study showed a positive linear correlation between lipid quantification at 0.9 parts per million (ppm) and 1.3 ppm with SLR (r = 0.79-0.99, p < 0.05). In the clinical study, we found that SLR at the solid portions was the best measure for differentiating glioma grades using optimal cut-points of 0.064 and 0.086 with classification probabilities for grade II (SII = 1), grade III (SIII = 0.50) and grade IV (SIV = 0.89).
  
  
  CONCLUSIONS
  The results underscore the lipid quantification differences in grades of glioma and provide a more comprehensive characterization by using SLR in chemical shift GE IOP imaging. SLR in IOP sequence demonstrates good performance in glioma grading.
  
  
  CONCLUSIONS
  • Strong correlation was seen between lipid concentration and SLR obtained using IOP • IOP sequence demonstrates significant differences in signal loss within the glioma grades • SLR at solid tumour portions was the best measure for differentiation • This sequence is applicable in a research capacity for glioma staging armamentarium.
authors.affiliation: Department of Biomedical Imaging, University Malaya Research Imaging Centre, University of Malaya, 59100, Kuala Lumpur, Malaysia. norlisahramli@gmail.com.
authors.forename: Norlisah
authors.initials: N
authors.lastname: Ramli
authors.affiliation: Department of Radiology, Sultan Ismail Hospital, Jalan Persiaran Mutiara Emas Utama, Taman Mount Austin, 81100, Johor Bahru, Malaysia.
authors.forename: Azua Mohd
authors.initials: AM
authors.lastname: Khairy
authors.affiliation: Department of Biomedical Imaging, University Malaya Research Imaging Centre, University of Malaya, 59100, Kuala Lumpur, Malaysia.
authors.forename: Pohchoo
authors.initials: P
authors.lastname: Seow
authors.affiliation: Department of Biomedical Imaging, University Malaya Research Imaging Centre, University of Malaya, 59100, Kuala Lumpur, Malaysia.
authors.forename: Li Kuo
authors.initials: LK
authors.lastname: Tan
authors.affiliation: Department of Biomedical Imaging, University Malaya Research Imaging Centre, University of Malaya, 59100, Kuala Lumpur, Malaysia.
authors.forename: Jeannie Hsiu Ding
authors.initials: JH
authors.lastname: Wong
authors.affiliation: Division of Neurosurgery, Department of Surgery, University of Malaya, 59100, Kuala Lumpur, Malaysia.
authors.forename: Dharmendra
authors.initials: D
authors.lastname: Ganesan
authors.affiliation: Department of Biomedical Imaging, University Malaya Research Imaging Centre, University of Malaya, 59100, Kuala Lumpur, Malaysia.
authors.forename: Kartini
authors.initials: K
authors.lastname: Rahmat
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D003430:Cross-Sectional Studies; D005240:Feasibility Studies; D005260:Female; D005910:Glioma / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008055:Lipids / Q000008:administration & dosage*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D055815:Young Adult
chemical_list: D008055:Lipids
keywords: Glioma classification; In- and opposed-phase imaging; Lipid phantom; Magnetic resonance spectroscopy; Volume under the receiver operating curve surface