title: Feasibility of shutter-speed DCE-MRI for improved prostate cancer detection.
abstract: The feasibility of shutter-speed model dynamic-contrast-enhanced MRI pharmacokinetic analyses for prostate cancer detection was investigated in a prebiopsy patient cohort. Differences of results from the fast-exchange-regime-allowed (FXR-a) shutter-speed model version and the fast-exchange-limit-constrained (FXL-c) standard model are demonstrated. Although the spatial information is more limited, postdynamic-contrast-enhanced MRI biopsy specimens were also examined. The MRI results were correlated with the biopsy pathology findings. Of all the model parameters, region-of-interest-averaged K(trans) difference [ΔK(trans) ≡ K(trans)(FXR-a) - K(trans)(FXL-c)] or two-dimensional K(trans)(FXR-a) vs. k(ep)(FXR-a) values were found to provide the most useful biomarkers for malignant/benign prostate tissue discrimination (at 100% sensitivity for a population of 13, the specificity is 88%) and disease burden determination. (The best specificity for the fast-exchange-limit-constrained analysis is 63%, with the two-dimensional plot.) K(trans) and k(ep) are each measures of passive transcapillary contrast reagent transfer rate constants. Parameter value increases with shutter-speed model (relative to standard model) analysis are larger in malignant foci than in normal-appearing glandular tissue. Pathology analyses verify the shutter-speed model (FXR-a) promise for prostate cancer detection. Parametric mapping may further improve pharmacokinetic biomarker performance.
authors.affiliation: W. M. Keck Foundation High-Field MRI Laboratory, Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon 97239, USA. lxin@ohsu.edu
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Priest
authors.forename: William J
authors.initials: WJ
authors.lastname: Woodward
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Tagge
authors.forename: Faisal
authors.initials: F
authors.lastname: Siddiqui
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: William D
authors.initials: WD
authors.lastname: Rooney
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Beer
authors.forename: Mark G
authors.initials: MG
authors.lastname: Garzotto
authors.forename: Charles S
authors.initials: CS
authors.lastname: Springer
mesh_terms: D000368:Aged; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity