Investigative radiology
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Investigative radiology · Mar 2009
Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.
To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. ⋯ DCE-MRI using a blood pool contrast agent allows absolute quantification of total kidney perfusion as well as separate determination of cortical and medullary flow. The results show that our technique has sufficient accuracy and reproducibility to be transferred to the clinical setting.
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Investigative radiology · Feb 2009
Comparative Study Controlled Clinical TrialLow dose gadobenate dimeglumine for imaging of chronic myocardial infarction in comparison with standard dose gadopentetate dimeglumine.
Gadobenate dimeglumine has a 2-fold higher T1 relaxivity compared with gadopentetate dimeglumine and can be used for imaging delayed enhancement in the assessment of myocardial infarction. The purpose of this study was to compare 0.1 mmoL/kg gadobenate dimeglumine (Gd-BOPTA, MultiHance, Bracco Imaging SpA, Milan, Italy) with 0.2 mmoL/kg gadopentetate dimeglumine (Gd-DTPA, Magnevist, Bayer-Schering Pharma AG, Berlin, Germany) in cardiac magnetic resonance imaging. ⋯ Low dose Gd-BOPTA resulted in significantly higher CNRinf-myo compared with standard dose Gd-DTPA in imaging of myocardial infarction with IR SSFP and IR GRE sequences. Demarcation of infarcted myocardium from the left ventricular cavity assessed by CNR showed no significant difference after application of either contrast media in both imaging techniques.
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Investigative radiology · Feb 2009
Image subtraction facilitates assessment of volume and density change in ground-glass opacities in chest CT.
To study the impact of image subtraction of registered images on the detection of change in pulmonary ground-glass nodules identified on chest CT. ⋯ Image subtraction improves the evaluation of subtle changes in pulmonary ground-glass opacities and decreases interobserver variability.
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Investigative radiology · Feb 2009
Brain tumor enhancement in magnetic resonance imaging: dependency on the level of protein binding of applied contrast agents.
To evaluate the dependency of tumor contrast enhancement (CE) in regard to protein-binding properties of contrast agents, using 4 different agents with a wide range of protein-binding capacities in a standardized rat brain glioma model. ⋯ The protein-binding capacity of gadolinium chelates shows a significant impact on CE and CNR in brain tumors with disrupted blood-brain barrier. In comparison with currently approved agents, high albumin-binding agents show further improved brain tumor CE. However, the time course of enhancement and optimal time frame for scanning after injection of agents with higher protein-binding capacities (approximately 50%-90%) has yet to be evaluated.
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Investigative radiology · Jan 2009
Rapid whole-brain magnetic resonance imaging with isotropic resolution at 3 Tesla.
Isotropic imaging offers the potential of improving lesion detection and imaging efficiency by enabling orthogonal image reformations without loss of spatial resolution. However, lengthy scan times for T1-weighted isotropic data acquisitions have been an impediment to the routine clinical application of this approach. We tested the feasibility of using the improved signal-to-noise ratio at 3 Tesla to perform rapid, whole-brain T1-weighted imaging with isotropic 0.8 mm x 0.8 mm x 0.8 mm (0.51 mm3) voxels. ⋯ Artifacts were minimal, especially compared with 2D SE, whereas CNR was 2-fold better than SPGR-IR. The capability for creating reformatted images in orthogonal orientations from a single isotropic acquisition greatly improves efficiency compared with 2D acquisitions acquired in multiple planes. Although further clinical study is needed in a larger patient cohort, these initial results suggest substantial clinical promise for the technique.