Investigative radiology
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Investigative radiology · May 2010
Comparative StudyDiffusion tensor imaging (DTI) of the kidney at 3 tesla-feasibility, protocol evaluation and comparison to 1.5 Tesla.
The purpose of this study was to evaluate the feasibility of diffusion tensor imaging of the kidney at a field strength of 3T. We assessed fractional anisotropy (FA) and apparent diffusion coefficients (ADC) of various acquisition protocols and determined the reproducibility of these measurements. FA, ADC, signal-to-noise ratios (SNR), and contrast-to-noise ratios (CNR) were compared with those acquired at 1.5T. ⋯ Diffusion tensor imaging of the kidney at 3T is feasible and yields significantly higher SNR and CNR. FA and ADCs do not significantly differ from 1.5T. Number of b-values influences ADC-values. Acquisitions in 12 directions provide lower cortical FA-values. We recommend a respiratory-triggered protocol because of improved image quality and reproducibility.
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Investigative radiology · May 2010
Intraindividual in vivo comparison of gadolinium contrast agents for pharmacokinetic analysis using dynamic contrast enhanced magnetic resonance imaging.
To compare the intraindividual differences of dynamic signal characteristics for 3 gadolinium chelates (gadopentetate dimeglumine [Gd-DTPA], gadodiamide [Gd-DTPA-BMA], and gadobenate dimeglumine [Gd-BOPTA]) using dynamic contrast enhanced magnetic resonance (MR) imaging (DCE-MRI) with a preclinical beagle model at 7 Tesla. ⋯ Gd chelate containing MR contrast agents can be used at 7T for DCEMRI. Gd-BOPTA demonstrates stronger signal enhancement than standard Gd chelates, in concordance with the results of studies at lower fields. The observed enhancement characteristics for the 3 contrast agents demonstrate that the pharmacokinetic parameter kep is more robust in various models using DCE-MRI than the other pharmacokinetic parameters. This information is important relative to multisite clinical trials and long-term clinical studies that often use several different contrast agents and different models.