PURPOSE: CatalyCEST MRI compares the detection of an enzyme-responsive chemical exchange saturation transfer (CEST) agent with the detection of an unresponsive "control" CEST agent that accounts for other conditions that influence CEST. The purpose of this study was to investigate the feasibility of in vivo catalyCEST MRI. METHODS: CEST agents that were responsive and unresponsive to the activity of urokinase plasminogen activator were shown to have negligible interaction with each other. A CEST-fast imaging with steady state precession (FISP) MRI protocol was used to acquire MR CEST spectroscopic images with a Capan-2 pancreatic tumor model after intravenous injection of the CEST agents. A function of (super)-Lorentzian line shapes was fit to CEST spectra of a region-of-interest that represented the tumor. RESULTS: The CEST effects from each agent showed the same initial uptake into tumor tissues, indicating that both agents had the same pharmacokinetic transport rates. Starting 5 min after injection, CEST from the enzyme-responsive agent disappeared more quickly than CEST from the unresponsive agent, indicating that the enzyme responsive agent was being catalyzed by urokinase plasminogen activator, while both agents also experienced net pharmacokinetic washout from the tumor. CONCLUSION: CatalyCEST MRI demonstrates that dynamic tracking of enzyme-responsive and unresponsive CEST agents during the same in vivo MRI study is feasible.
PURPOSE: CatalyCEST MRI compares the detection of an enzyme-responsive chemical exchange saturation transfer (CEST) agent with the detection of an unresponsive "control" CEST agent that accounts for other conditions that influence CEST. The purpose of this study was to investigate the feasibility of in vivo catalyCEST MRI. METHODS: CEST agents that were responsive and unresponsive to the activity of urokinase plasminogen activator were shown to have negligible interaction with each other. A CEST-fast imaging with steady state precession (FISP) MRI protocol was used to acquire MR CEST spectroscopic images with a Capan-2pancreatic tumor model after intravenous injection of the CEST agents. A function of (super)-Lorentzian line shapes was fit to CEST spectra of a region-of-interest that represented the tumor. RESULTS: The CEST effects from each agent showed the same initial uptake into tumor tissues, indicating that both agents had the same pharmacokinetic transport rates. Starting 5 min after injection, CEST from the enzyme-responsive agent disappeared more quickly than CEST from the unresponsive agent, indicating that the enzyme responsive agent was being catalyzed by urokinase plasminogen activator, while both agents also experienced net pharmacokinetic washout from the tumor. CONCLUSION: CatalyCEST MRI demonstrates that dynamic tracking of enzyme-responsive and unresponsive CEST agents during the same in vivo MRI study is feasible.
Authors: Louke J Delrue; Veerle Casneuf; Nancy Van Damme; Peter Blanckaert; Marc Peeters; Wim P Ceelen; Philippe C O Duyck Journal: MAGMA Date: 2011-05-13 Impact factor: 2.310
Authors: Guanshu Liu; Yajie Liang; Amnon Bar-Shir; Kannie W Y Chan; Chulani S Galpoththawela; Segun M Bernard; Terence Tse; Nirbhay N Yadav; Piotr Walczak; Michael T McMahon; Jeff W M Bulte; Peter C M van Zijl; Assaf A Gilad Journal: J Am Chem Soc Date: 2011-09-23 Impact factor: 15.419
Authors: Nevin McVicar; Alex X Li; Mojmír Suchý; Robert H E Hudson; Ravi S Menon; Robert Bartha Journal: Magn Reson Med Date: 2012-11-19 Impact factor: 4.668
Authors: Vipul R Sheth; Yuguo Li; Liu Qi Chen; Christine M Howison; Chris A Flask; Mark D Pagel Journal: Magn Reson Med Date: 2011-10-25 Impact factor: 4.668
Authors: Kannie W Y Chan; Michael T McMahon; Yoshinori Kato; Guanshu Liu; Jeff W M Bulte; Zaver M Bhujwalla; Dmitri Artemov; Peter C M van Zijl Journal: Magn Reson Med Date: 2012-10-16 Impact factor: 4.668
Authors: Guanshu Liu; M Meser Ali; Byunghee Yoo; Mark A Griswold; Jean A Tkach; Mark D Pagel Journal: Magn Reson Med Date: 2009-02 Impact factor: 4.668
Authors: Zheng Liu; Ivan E Dimitrov; Robert E Lenkinski; Asghar Hajibeigi; Elena Vinogradov Journal: Magn Reson Med Date: 2015-05-29 Impact factor: 4.668
Authors: Gabriela Fernández-Cuervo; Kirsten A Tucker; Scott W Malm; Kyle M Jones; Mark D Pagel Journal: Bioconjug Chem Date: 2016-10-06 Impact factor: 4.774