title: Practical data acquisition method for human brain tumor amide proton transfer (APT) imaging.
abstract: Amide proton transfer (APT) imaging is a type of chemical exchange-dependent saturation transfer (CEST) magnetic resonance imaging (MRI) in which amide protons of endogenous mobile proteins and peptides in tissue are detected. Initial studies have shown promising results for distinguishing tumor from surrounding brain in patients, but these data were hampered by magnetic field inhomogeneity and a low signal-to-noise ratio (SNR). Here a practical six-offset APT data acquisition scheme is presented that, together with a separately acquired CEST spectrum, can provide B(0)-inhomogeneity corrected human brain APT images of sufficient SNR within a clinically relevant time frame. Data from nine brain tumor patients at 3T shows that APT intensities were significantly higher in the tumor core, as assigned by gadolinium-enhancement, than in contralateral normal-appearing white matter (CNAWM) in patients with high-grade tumors. Conversely, APT intensities in tumor were indistinguishable from CNAWM in patients with low-grade tumors. In high-grade tumors, regions of increased APT extended outside of the core into peripheral zones, indicating the potential of this technique for more accurate delineation of the heterogeneous areas of brain cancers.
authors.affiliation: Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. jzhou@mri.jhu.edu
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Zhou
authors.forename: Jaishri O
authors.initials: JO
authors.lastname: Blakeley
authors.forename: Jun
authors.initials: J
authors.lastname: Hua
authors.forename: Mina
authors.initials: M
authors.lastname: Kim
authors.forename: John
authors.initials: J
authors.lastname: Laterra
authors.forename: Martin G
authors.initials: MG
authors.lastname: Pomper
authors.forename: Peter C M
authors.initials: PC
authors.lastname: van Zijl
mesh_terms: D000577:Amides / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D005910:Glioma / Q000175:diagnosis* / Q000378:metabolism*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000577:Amides; D014408:Biomarkers, Tumor; D011522:Protons