Investigative radiology
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Investigative radiology · Mar 2014
Multicenter StudyValue of 3-T multiparametric magnetic resonance imaging and magnetic resonance-guided biopsy for early risk restratification in active surveillance of low-risk prostate cancer: a prospective multicenter cohort study.
The objective of this study was to evaluate the role of 3-T multiparametric magnetic resonance imaging (MP-MRI) and magnetic resonance-guided biopsy (MRGB) in early risk restratification of patients on active surveillance at 3 and 12 months of follow-up. ⋯ Application of MP-MRI and MRGB in active surveillance may contribute in early identification of patients with GGP 4 or 5 containing cancers at 3 months of follow-up. If, during further follow-up, a PI-RADS score of 1 or 2 continues to have a negative predictive value for GGP 4 or 5 containing cancers, a PI-RADS standardized reported MP-MRI may be a promising tool for the selection of prostate cancer patients suitable for active surveillance.
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Investigative radiology · Mar 2014
Feasibility of single-source dual-energy computed tomography for urinary stone characterization and value of iterative reconstructions.
The purposes of this study were to demonstrate the feasibility and accuracy of single-source dual-energy (DE) computed tomography (CT) with sequential data acquisition and a coregistration motion correction algorithm for urinary stone characterization and to evaluate the value of iterative reconstructions (IRs) in DE imaging. ⋯ Our study indicates that single-source dual-energy CT with sequential acquisitions at different energy levels and a coregistration motion correction algorithm is feasible and accurate for characterizing urinary stone composition on the basis of phantom evaluation. As compared with reconstructions with FBP, the use of IR in dual-energy CT reduces noise, improves overall image quality and visibility of stones particularly in large phantoms, and helps to avoid false classifications of urinary stones.
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Investigative radiology · Feb 2014
Comparative StudyComparison of fat saturation techniques for single-shot fast spin echo sequences for 7-T body imaging.
For T2-weighted abdominal images, homogenous fat suppression (FS) is crucial for diagnosis, but inherent B0/B1 inhomogeneities at 7 T lead to inhomogeneous FS and to tissue signal loss for most techniques. Here, 4 different FS techniques for single-shot fast spin echo were compared, whereby the recently proposed time-interleaved acquisition of modes (TIAMO) was used for the imaging portion of the sequence to reduce B1 artifacts. ⋯ Of the compared techniques, the most favorable was SSGR because, here, a homogeneous FS with moderate tissue signal loss of approximately 20% was achieved with no additional preparation pulses being necessary. Using this FS technique combined with TIAMO image acquisition, delineation between fat and bright liquids in single-shot fast spin echo images, which is essential for diagnosis, is possible at 7 T.
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Investigative radiology · Feb 2014
Diffusion-weighted magnetic resonance imaging of the pancreas: diagnostic benefit from an intravoxel incoherent motion model-based 3 b-value analysis.
The objective of this study was to evaluate the diagnostic benefit of an intravoxel incoherent motion (IVIM) model-based characterization of pancreatic masses from diffusion-weighted imaging (DWI) with 3 b values. ⋯ The determination of IVIM-based microcirculation-sensitive parameter maps from DWI with 3 b values significantly improved the discrimination of CAs from NETs, CPs, and the healthy tissue.
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Investigative radiology · Feb 2014
Characterization of the intestinal and hepatic uptake/efflux transport of the magnetic resonance imaging contrast agent gadolinium-ethoxylbenzyl-diethylenetriamine-pentaacetic acid.
The objectives of the study were to measure the pharmacokinetics and liver enhancement of gadoxetate (gadolinium-ethoxylbenzyl-diethylenetriamine-pentaacetic acid [Gd-EOB-DTPA], Eovist, Primovist) after oral and intravenous administration in wild-type and (multidrug resistance-associated protein 2) Mrp2-deficient rats and to evaluate the in vitro transport of the contrast agent via intestinal and hepatic transporter proteins. ⋯ The nonmetabolized Gd-EOB-DTPA may have some potentials to be used as a probe-contrast agent to evaluate transporter-mediated mechanisms along the enterohepatic absorption route for drugs by functional visualization in vivo.