Journal ArticleDOI
Modeling tracer kinetics in dynamic Gd-DTPA MR imaging
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TLDR
Three major models for collecting and analyzing dynamic MRI gadolinium‐diethylenetriamine penta‐acetic acid (Gd‐DTPA) data are examined and the ratio kep, the efflux rate constant, is the simplest to measure.Abstract:
Three major models (from Tofts, Larsson, and Brix) for collecting and analyzing dynamic MRI gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) data are examined. All models use compartments representing the blood plasma and the abnormal extravascular extracellular space (EES), and they are intercompatible. All measure combinations of three parameters; (1) kPSp is the influx volume transfer constant (min-1), or permeability surface area product per unit volume of tissue, between plasma and EES; (2) ve is the volume of EES space per unit volume of tissue (0 < ve < 1); and (3) K(ep), the efflux rate constant (min-1), is the ratio of the first two parameters (k(ep) = kPSp/ve). The ratio K(ep) is the simplest to measure, requiring only signal linearity with Gd tracer concentration or, alternatively, a measurement of T1 before injection of Gd (T10). To measure the physiologic parameters kPSp and ve separately requires knowledge of T10 and of the tissue relaxivity R1 (approximately in vitro value).read more
Citations
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Journal ArticleDOI
Estimating kinetic parameters from dynamic contrast-enhanced T(1)-weighted MRI of a diffusable tracer: standardized quantities and symbols.
Paul S. Tofts,Gunnar Brix,David L. Buckley,Jeffrey L. Evelhoch,Elizabeth Henderson,Michael V. Knopp,Henrik Larsson,Ting-Yim Lee,Nina A. Mayr,Geoffrey J. M. Parker,Ruediger E. Port,June S. Taylor,Robert M. Weisskoff +12 more
TL;DR: A standard set of quantity names and symbols related to the estimation of kinetic parameters from dynamic contrast‐enhanced T1‐weighted magnetic resonance imaging data, using diffusable agents such as gadopentetate dimeglumine (Gd‐DTPA), are described.
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Measuring cerebral blood flow using magnetic resonance imaging techniques
TL;DR: Magnetic resonance imaging techniques measuring CBF have developed rapidly in the last decade, resulting in a wide range of available methods and this review discusses their principles, possible pitfalls, and potential for absolute quantification and outlines clinical and neuroscientific applications.
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Prostate Cancer: Multiparametric MR Imaging for Detection, Localization, and Staging
Caroline M. A. Hoeks,Jelle O. Barentsz,Thomas Hambrock,Derya Yakar,Diederik M. Somford,Stijn W.T.P.J. Heijmink,Tom W. J. Scheenen,Pieter C. Vos,Henkjan J. Huisman,Inge M. van Oort,J. Alfred Witjes,Arend Heerschap,Jurgen J. Fütterer +12 more
TL;DR: Suggestions for a general minimal protocol for multiparametric MR imaging of the prostate based on the literature and the authors' experience are presented and support techniques, such as computer-aided diagnosis, are needed to obtain a fast, cost-effective, easy, and more reproducible prostate cancer diagnosis.
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Geoffrey J. M. Parker,Caleb Roberts,Andrew S. MacDonald,Giovanni A Buonaccorsi,Susan Cheung,David L. Buckley,Alan Jackson,Yvonne Watson,Karen Davies,Gordon C Jayson +9 more
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Randomized double-blind placebo-controlled trial of bevacizumab therapy for radiation necrosis of the central nervous system
Victor A. Levin,Luc Bidaut,Ping Hou,Ashok Kumar,Jeffrey S. Wefel,B. Nebiyou Bekele,Sujit S. Prabhu,Monica Loghin,Mark R. Gilbert,Edward F. Jackson +9 more
TL;DR: In this paper, the authors conducted a randomized double-blind study of bevacizumab for the treatment of central nervous system radiation necrosis of the brain, where a total of 14 patients were entered into a placebo-controlled randomized doubleblind study.
References
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Paul S. Tofts,Allan G. Kermode +1 more
TL;DR: Leakage of Gd‐DTPA through a defective blood‐brain barrier is measured quantitatively using dynamic MRI scanning, in which repeated scans are made after a bolus injection, and implies permeability in the range 4‐17 × 10−6 cm s−1, in broad agreement with other physiological methods.
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Journal ArticleDOI
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Journal ArticleDOI
Pharmacokinetic parameters in CNS Gd-DTPA enhanced MR imaging.
TL;DR: A procedure for dynamic MR is presented, which accurately resolves the fast kinetics of tissue response during and after intravenous infusion of the paramagnetic contrast medium Gd-DTPA and yields a linear relationship between the measured MR signal and the Gd -DTPA concentration in the tissue.
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