title: Simultaneous quantification of perfusion and permeability in the prostate using dynamic contrast-enhanced magnetic resonance imaging with an inversion-prepared dual-contrast sequence.
abstract: The aim of the present study was to quantify both perfusion and extravasation in the prostate to discriminate tumor from healthy tissue, which might be achieved by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a nonspecific low-molecular-weight contrast medium (CM). To determine extravasation as well as tissue perfusion an inversion-prepared dual-contrast sequence employing a parallel acquisition technique (PAT) was designed for interleaved acquisition of T(1)-weighted images for extravasation measurement and T(2)*-weighted images for determination of the highly concentrated bolus with a sufficiently high temporal and spatial resolution at an acceptable signal-to-noise ratio. Thirteen patients with proven prostate cancer were examined with the sequence using a combined body-array prostate coil. Before pharmacokinetic evaluation the images were intensity-corrected and, if required, motion-corrected. The pharmacokinetic model used to calculate perfusion, permeability, blood volume, interstitial volume, transit time, and vessel size index included two compartments and a correction of delay and dispersion of the arterial input function. The information provided by the dual-contrast sequence allowed application of a more elaborate model for evaluation and enabled quantification of all parameters. Peripheral prostate tumors were found to differ from peripheral healthy prostate tissue in perfusion (1.38 mL/(min cm(3)) vs. 0.23 mL/(min cm(3)), p=0.004), mean transit time (2.88 vs. 4.88 s, p=0.039), and blood volume (1.9 vs. 0.7%, p=0.019). A inversion-prepared dual-contrast sequence acquiring T(1)- and T*(2)-weighted images with sufficient temporal resolution and signal-to-noise ratio was successfully applied in patients with prostate cancer to quantify all pharmacokinetic parameters of inflow and extravasation of a low-molecular-weight inert tracer.
authors.affiliation: Department of Radiotherapy, Charité-Universitätsmedizin Berlin, Charité Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany. lutz.luedemann@charite.de
authors.forename: Lutz
authors.initials: L
authors.lastname: Lüdemann
authors.forename: Daniel
authors.initials: D
authors.lastname: Prochnow
authors.forename: Torsten
authors.initials: T
authors.lastname: Rohlfing
authors.forename: Tobias
authors.initials: T
authors.lastname: Franiel
authors.forename: Carsten
authors.initials: C
authors.lastname: Warmuth
authors.forename: Matthias
authors.initials: M
authors.lastname: Taupitz
authors.forename: Hagen
authors.initials: H
authors.lastname: Rehbein
authors.forename: Dirk
authors.initials: D
authors.lastname: Beyersdorff
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000493:pharmacokinetics*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D010477:Perfusion / Q000379:methods*; D010539:Permeability; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*
chemical_list: D003287:Contrast Media