Amide proton transfer (APT) contrast for imaging of brain tumors.
In this work we demonstrate that specific MR image contrast can be produced in the water signal that reflects endogenous cellular protein and peptide content in intracranial rat 9L gliosarcomas. Although the concentration of these mobile proteins and peptides is only in the millimolar range, a detection sensitivity of several percent on the water signal (molar concentration) was achieved. This was accomplished with detection sensitivity enhancement by selective radiofrequency (RF) labeling of the amide protons, and by utilizing the effective transfer of this label to water via hydrogen exchange. Brain tumors were also assessed by conventional T(1)-weighted, T(2)-weighted, and diffusion-weighted imaging. Whereas these commonly-used approaches yielded heterogeneous images, the new amide proton transfer (APT) technique showed a single well-defined region of hyperintensity that was assigned to brain tumor tissue.
Zhou
Jinyuan
J
Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. jzhou@mri.jhu.edu
Lal
Bachchu
B
Wilson
David A
DA
Laterra
John
J
van Zijl
Peter C M
PC
D000577:Amides / Q000032:analysis*; D000818:Animals; D001932:Brain Neoplasms / Q000737:chemistry / Q000175:diagnosis*; D045744:Cell Line, Tumor; D038524:Diffusion Magnetic Resonance Imaging; D018316:Gliosarcoma / Q000737:chemistry / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009368:Neoplasm Transplantation; D011522:Protons; D051381:Rats; D011916:Rats, Inbred F344; D012680:Sensitivity and Specificity
D000577:Amides; D011522:Protons