Investigative radiology
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Investigative radiology · Jan 2015
A clinically feasible treatment protocol for magnetic resonance-guided high-intensity focused ultrasound ablation in the liver.
Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) allows for noninvasive thermal ablation under real-time temperature imaging guidance. The purpose of this study was to assess the feasibility and safety of MR-HIFU ablation of liver tissue in a clinically acceptable setting. The experimental protocol was designed with a clinical ablation procedure of a small malignant tumor in mind; the procedures were performed within a clinically feasible time frame and care was taken to avoid adverse events. The main outcome was the size and quality of the ablated liver tissue volume on imaging and histology. Secondary outcomes were safety and treatment time. ⋯ Our results demonstrate the feasibility and safety of MR-HIFU ablation of liver tissue volumes. The imaging data and cell viability histology show, for the first time, that confluent ablation volumes can be achieved with motion-gated ablation and MR guidance. These results were obtained using a readily available MR-HIFU system with only minor modifications, within a clinically acceptable time frame, and with only minor adverse events. This shows that this technique is sufficiently reliable and safe to initiate a clinical trial.
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Investigative radiology · Dec 2014
Comparative StudySimultaneous positron emission tomography/magnetic resonance imaging for whole-body staging in patients with recurrent gynecological malignancies of the pelvis: a comparison to whole-body magnetic resonance imaging alone.
The objective of this study was to assess the diagnostic value of integrated positron emission tomography/magnetic resonance imaging (PET/MRI) for whole-body staging of patients with recurrent gynecological pelvic malignancies, in comparison to whole-body MRI alone. ⋯ These first results demonstrate the high diagnostic potential of integrated PET/MRI for the assessment of recurrence of female pelvic malignancies compared with MRI alone.
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Investigative radiology · Dec 2014
Whole-body diffusion kurtosis imaging: initial experience on non-Gaussian diffusion in various organs.
Diffusion kurtosis imaging (DKI) is based on a non-Gaussian diffusion model that should inherently better account for restricted water diffusion within the complex microstructure of most tissues than the conventional diffusion-weighted imaging (DWI), which presumes Gaussian distributed water molecule displacement probability. The aim of this investigation was to test the technical feasibility of in vivo whole-body DKI, probe for organ-specific differences, and compare whole-body DKI and DWI results. ⋯ Whole-body DKI is technically feasible and may reflect tissue microstructure more meaningfully than whole-body DWI.
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Investigative radiology · Nov 2014
Seven-tesla magnetic resonance imaging of atherosclerotic plaque in the significantly stenosed carotid artery: a feasibility study.
The objective of this study was to assess the feasibility of carotid vessel wall imaging at 7.0 for T magnetic resonance imaging (MRI) in a series of patients with a symptomatic greater than 70% stenosis of the internal carotid artery. ⋯ This first series of patients with carotid atherosclerotic plaque who were scanned at 7.0 T MRI shows that 7.0 T MRI enables to adequately determine lumen and vessel wall areas. Signal hyperintensity in these 7.0 T magnetic resonance images was inversely proportional to calcification. However, at this stage, no other correlations between histologic findings and vessel wall contrast were found. Implementation of in vivo high-resolution 7.0 T MRI of plaque components for risk stratification remains challenging. Future development of hardware and software is still needed to attain a more robust setup and to enable complete plaque characterization, similar to what is currently possible with multiple MRI sequences at 1.5 T and 3.0 T MRI.
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Investigative radiology · Nov 2014
Virtual monoenergetic dual-energy computed tomography: optimization of kiloelectron volt settings in head and neck cancer.
The aim of this study was to evaluate the effects on objective and subjective image quality of virtual monoenergetic reconstructions at various energy levels of dual-energy computed tomography (DECT) in patients with head and neck cancer. ⋯ Compared with linearly blended images, virtual monoenergetic reconstructions of DECT data at 60 keV significantly improve lesion enhancement and CNR, subjective overall image quality, and tumor delineation of head and neck squamous cell carcinoma.