title: pCEST: Positive contrast using Chemical Exchange Saturation Transfer.
abstract: Chemical Exchange Saturation Transfer (CEST) contrast utilizes selective pre-saturation of a small pool of exchanging protons and subsequent detection of the decrease in bulk water signal. The CEST contrast is negative and requires detection of small signal change in the presence of a strong background signal. Here we develop a Positive CEST (pCEST) detection scheme utilizing the analogous nature of the CEST and off-resonance T(1)(ρ) experiments and exploring increased apparent relaxation rates in the presence of the selective pre-saturation. pCEST leads to the positive contrast, i.e., increased signal intensity as the result of the presence of the agent and RF pre-saturation. Simultaneously substantial background suppression is achieved. The contrast can be switched "ON" and "OFF", similar to the original CEST.
authors.affiliation: Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. elena.vinogradov@utsouthwestern.edu
authors.forename: Elena
authors.initials: E
authors.lastname: Vinogradov
authors.forename: Todd C
authors.initials: TC
authors.lastname: Soesbe
authors.forename: James A
authors.initials: JA
authors.lastname: Balschi
authors.forename: A Dean
authors.initials: AD
authors.lastname: Sherry
authors.forename: Robert E
authors.initials: RE
authors.lastname: Lenkinski
mesh_terms: D000362:Agar; D000465:Algorithms; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy; D007091:Image Processing, Computer-Assisted; D007202:Indicators and Reagents; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging
chemical_list: D007202:Indicators and Reagents; D000362:Agar