Xin Li1, Ryan A. Priest2, 3, William J. Woodward1, Ian J. Tagge1, Faisal Siddiqui2, 3, Wei Huang1, William D. Rooney1, Tomasz M. Beer4, 5
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States; 2School of Medicine, Oregon Health & Science University, Portland, OR, United States; 3Radiology, Oregon Health & Science University, Portland, OR, United States; 4Hematology/Oncology, Oregon Health & Science University, Portland, OR, United States; 5Knight Cancer Institute, Oregon Health & Science University, Portland, OR, United States; 6Urology, Oregon Health & Science University, Portland, OR, United States; 7Portland VA Medical Center, Portland, OR, United States
Standard Dynamic-Contrast-Enhanced MRI (DCE-MRI) pharmacokinetic modeling assumes inter-compartmental water exchange kinetics to be infinitely fast. Though it is physically impossible that such processes be truly infinitely rapid, in many tissue regions they seem so as far as DCE MRI water signals are concerned: the exchange MR systems remain in their fast-exchange-limit [FXL] conditions. However, there are tissue loci where these systems transiently depart their FXLs during DCE-MRI contrast reagent (CR) bolus passage. Using an exchange-sensitized DCE-MRI acquisition and analytical shutter-speed model, we demonstrate the feasibility of prostate cancer detection with water exchange allowed DCE-MRI pharmacokinetic modeling.