PURPOSE The purpose of this work was to determine the optimal imaging parameters for minimization of metallic susceptibility artifacts during gradient echo (GRE) imaging. METHOD We performed GRE imaging of titanium screws in a nickel-doped agarose gel phantom, systematically varying several parameters to characterize and quantify susceptibility artifacts. RESULTS The greatest reduction in a...

lipomatosis of the nerve, also known as fibrolipomatous hamartoma, is characterized by the infiltration of the nerve by fibro-fatty tissue. the affected nerve becomes thicker, and it simulates a mass lesion. lipomatosis usually affects the median nerve and lipomatosis of the sciatic nerve is extremely rare. magnetic resonance imaging (mri) is the key to diagnosis, and it is usually pathognomoni...

conclusion these data indicate that while ce-mri will depict more positive results, there are cases in which dwi will show a positive result while ce-mri is negative. we suggest that the combination of these two imaging modalities might yield more positive results in diagnosing acute ms attack giving rise to a more accurate diagnosis. results ce-mri yielded positive results for 61 (87%) patient...

PURPOSE We aimed to investigate the effect of key imaging parameters on the accuracy of apparent diffusion coefficient (ADC) maps using a phantom model combined with ADC calculation simulation and propose strategies to improve the accuracy of ADC quantification. METHODS Diffusion-weighted imaging (DWI) sequences were acquired on a phantom model using single-shot echo-planar imaging DWI at 1.5...

Precision of nano-metric operations is an important issue in nano-engineering studies. Several operative parameters might affect the quality of results. The parameters of the nano world are significant but not entirely controllable. However, the geometrical and mechanical properties of micro cantilevers are completely controllable. So, controlling the sensitivity of resulting image through t la...

Myocardial perfusion imaging sequences and analysis techniques continue to improve. We review the state-of-the-art in cardiovascular magnetic resonance first pass perfusion pulse sequences including the application of parallel imaging. There are a wide range of sequence designs and parameters to consider when optimizing an acquisition protocol. The interdependence of these parameters forces the...

Medical ultrasound contrast imaging is a powerful modality undergoing successive developments in the last decade to date. Lately, pulse inversion has been used in both ultrasound tissue harmonic and contrast imaging. However, there was a tradeoff between resolution and penetration. Chirp excitations partially solved the tradeoff, but the chirp setting parameters were not optimized. The present ...

background hepatic fibrosis is a typical complication of chronic liver diseases resulting in cirrhosis that remains a major public health problem worldwide. liver biopsy is currently the gold standard for diagnosing and staging hepatic fibrosis. percutaneous liver biopsy; however, is an invasive procedure with risks of complications. therefore, there is need for alternative non-invasive techniq...

introduction: despite widespread use of 67gallium for lymphoma evaluation, timing of imaging after injection is a matter of controversy and to the extent of our knowledge no direct comparison has been made between early and delayed gallium images. we aimed to compare 24 and 48 hours post injection planar gallium imaging for evaluation of lymphoma recurrence. methods: 255 patients suspicious of...

In this paper, we compute the scattering matrix for the Hilbert modular group over any number field K. We then express the determinant of the scattering matrix as a ratio of completed Dedekind zeta functions associated to the Hilbert class field of K. This generalizes work of Efrat and Sarnak [ES] in the imaginary quadratic case.