title: Amide proton transfer imaging of 9L gliosarcoma and human glioblastoma xenografts.
abstract: Amide proton transfer (APT) imaging is a variant of magnetization transfer (MT) imaging, in which the contrast is determined by a change in water intensity due to chemical exchange with saturated amide protons of endogenous mobile proteins and peptides. In this study, eight Fisher 344 rats implanted with 9L gliosarcoma cells and six nude rats implanted with human glioblastoma cells were imaged at 4.7 T. There were increased signal intensities in tumors in the APT-weighted images. The contrast of APT imaging between the tumor and contralateral brain tissue was about 3.9% in water intensity (1.49 +/- 0.66% vs -2.36 +/- 0.19%) for the more uniformly hypercellular 9L brain tumors, and it was reduced to 1.6% (-1.18 +/- 0.60% vs -2.77 +/- 0.42%) for the human glioblastoma xenografts that contained hypocellular zones of necrosis. The preliminary results show that the APT technique at the protein level may provide a unique MRI contrast for the characterization of brain tumors.
authors.affiliation: Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Amandeep
authors.initials: A
authors.lastname: Salhotra
authors.forename: Bachchu
authors.initials: B
authors.lastname: Lal
authors.forename: John
authors.initials: J
authors.lastname: Laterra
authors.forename: Phillip Zhe
authors.initials: PZ
authors.lastname: Sun
authors.forename: Peter C M
authors.initials: PC
authors.lastname: van Zijl
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000577:Amides / Q000737:chemistry*; D000818:Animals; D001834:Body Water / Q000737:chemistry; D001921:Brain / Q000166:cytology / Q000473:pathology; D001932:Brain Neoplasms / Q000737:chemistry / Q000648:ultrastructure; D045744:Cell Line, Tumor; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods; D019471:Elementary Particle Interactions; D004735:Energy Transfer; D005909:Glioblastoma / Q000737:chemistry* / Q000648:ultrastructure; D018316:Gliosarcoma / Q000737:chemistry* / Q000648:ultrastructure; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009368:Neoplasm Transplantation; D011522:Protons; D051381:Rats; D011916:Rats, Inbred F344; D011923:Rats, Nude; D014183:Transplantation, Heterologous
chemical_list: D000577:Amides; D003287:Contrast Media; D011522:Protons