Investigative radiology
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Investigative radiology · Feb 2016
Meta Analysis Comparative StudyIntravoxel Incoherent Motion Protocol Evaluation and Data Quality in Normal and Malignant Liver Tissue and Comparison to the Literature.
Although intravoxel incoherent motion (IVIM) becomes more and more popular, there is currently no clear consensus on the number and distribution of b-values to use. In this work, we (1) tested and evaluated the data quality of a 25-b-value IVIM protocol in patients with malignant liver lesions and normal liver tissue as a standard of reference, (2) calculated an optimal b-value distribution and compared with the standard of reference, and (3) compared the 25-b-value protocol with other proposed protocols in the literature. ⋯ Including more b-values and applying an optimized b-value distribution significantly reduces errors in the IVIM parameter estimates, thereby increasing its accuracy.This effect is even more pronounced in inhomogeneous tumor compared with that in normal liver tissue. However, when restrictions in acquisition time or patient-related factors apply, a minimum of 16 b-values should be considered for reliable results.
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Investigative radiology · Feb 2016
Optimized Fast Dynamic Contrast-Enhanced Magnetic Resonance Imaging of the Prostate: Effect of Sampling Duration on Pharmacokinetic Parameters.
The aim of this study was to evaluate the effect of sampling duration on pharmacokinetic parameters from dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and their diagnostic accuracy regarding the detection of potentially malignant prostate lesions. ⋯ Using fast optimized DCE-MRI of the prostate, a minimum sampling duration of 150 seconds is required for sufficient pharmacokinetic parameter estimates, providing a high diagnostic accuracy regarding the discrimination between benign and potentially malignant lesions.
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Investigative radiology · Feb 2016
Dual-Energy Computed Tomography Angiography of the Lower Extremity Runoff: Impact of Noise-Optimized Virtual Monochromatic Imaging on Image Quality and Diagnostic Accuracy.
The aim of this study was to evaluate the impact of a noise-optimized virtual monochromatic imaging algorithm (VMI+) on image quality and diagnostic accuracy at dual-energy computed tomography angiography (CTA) of the lower extremity runoff. ⋯ Image reconstruction using low-kiloelectron volt VMI+ improves image quality and diagnostic accuracy compared with traditional VMI technique and standard linear blending for evaluation of the lower extremity runoff using dual-energy CTA.
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Investigative radiology · Feb 2016
Signal Increase on Unenhanced T1-Weighted Images in the Rat Brain After Repeated, Extended Doses of Gadolinium-Based Contrast Agents: Comparison of Linear and Macrocyclic Agents.
In this prospective preclinical study, we evaluated T1-weighted signal intensity in the deep cerebellar nuclei (CN) and globus pallidus (GP) up to 24 days after repeated administration of linear and macrocyclic gadolinium-based contrast agents (GBCAs) using homologous imaging and evaluation methods as in the recently published retrospective clinical studies. In a second part of the study, cerebrospinal fluid (CSF) spaces were evaluated for contrast enhancement by fluid-attenuated magnetic resonance imaging (MRI). ⋯ In this animal study in rats, increased signal intensity in the CN was found up to 24 days after multiple, extended doses of linear GBCAs. However, in contrast to clinical reports, the signal enhancement in the GP was not reproduced, demonstrating the limitations of this animal experiment. The elevated signal intensities remained persistent over the entire observation period. In contrast, no changes of signal intensities in either the CN or the GP were observed for macrocyclic GBCAs. However, all GBCAs investigated were able to pass the blood-CSF barrier in rats to a certain, not yet quantified extent.