Study objectives: Studies on brain iron content in restless legs syndrome (RLS) using magnetic re... more Study objectives: Studies on brain iron content in restless legs syndrome (RLS) using magnetic resonance imaging (MRI) are heterogeneous. In this study, we sought to leverage the availability of a large dataset including a range of iron-sensitive MRI techniques to reassess the association between brain iron content and RLS with added statistical power and to compare these results to previous studies. Methods: The relaxation rates R 2 , R 2’ , and R 2* and quantitative susceptibility are MRI parameters strongly correlated to iron content. In general, these parameters are sensitive to magnetic field variations caused by iron particles. These parameters were quantified within iron-rich brain regions using a fully automatized approach in a cohort of 72 RLS patients and individually age and gender-matched healthy controls identified from an existing dataset acquired at the Sleep Laboratory of the Department of Neurology, Medical University of Innsbruck. 3T-MRI measures were corrected for age and volume of the segmented brain nuclei and results were compared with previous findings in a meta-analysis. Results: In our cohort, RLS patients had increased R 2* signal in the caudate and increased quantitative susceptibility signal in the putamen and the red nucleus compared to controls, suggesting increased iron content in these areas. The meta-analysis revealed no significant pooled effect across all brain regions. Furthermore, potential publication bias was identified for the substantia nigra. Conclusions: Normal and increased iron content of subcortical brain areas detected in this study is not in line with the hypothesis of reduced brain iron storage, but favors CSF investigations and post mortem studies indicating alteration of brain iron mobilization and homeostasis in RLS.
Patients undergoing breast MRI frequently have metallic biopsy clips placed within or adjacent to... more Patients undergoing breast MRI frequently have metallic biopsy clips placed within or adjacent to the lesion, producing metallic artifacts, which could lead to misinterpretation. The aim of our study was to investigate the extent of the artifact of four different clips commonly used in our hospital on diffusion-weighted images obtained with a readout-segmented sequence (RESOLVE) and their influence on ADC maps. It is found that artifacts vary in shape and size between different clips, DWI images and ADC-maps. For the marker with the smallest artifact the minimum size of detectable lesion seems to be approximately 10mm.
We investigated whether multiple SPACE sequences accelerated using CAIPIRINHA and acquired with d... more We investigated whether multiple SPACE sequences accelerated using CAIPIRINHA and acquired with different echo times can be used to obtain high resolution isotropic whole brain T2 maps within a clinical feasible scan time. In a phantom study, we could show that the SPACE based T2 values are comparable with T2 values derived using multiple single spin echo sequences. By reducing the number of echoes we could acquire 1 mm isotropic in vivo whole brain T2 maps in under 3 minutes.
Poster: "ECR 2013 / C-0877 / The value of diffusion tensor imaging (DTI) and tractography in... more Poster: "ECR 2013 / C-0877 / The value of diffusion tensor imaging (DTI) and tractography in patients with intraspinal tumours: a preliminary study" by: "F. Cartes-Zumelzu, S. Ingorokva, H. Kostron, G. Feuchtner, C. Kremser, C. Thome; Innsbruck/AT"
IntroductionGreen tea is associated with decreased risk for cardiovascular disease and stroke. Ma... more IntroductionGreen tea is associated with decreased risk for cardiovascular disease and stroke. Matcha is a special kind of powdered green tea known for its use in the Japanese tea ceremony. Due to its influence on lipoprotein parameters, it has been postulated to exert antiatherogenic effects. This study investigates whether it modulates the high‐density lipoprotein (HDL) function and thereby influences the atherogenic process in an animal model with a strong influence on humans' situation.Methods and ResultsAfter a pretreatment phase based on a standard diet, 10 female New Zealand White (NZW) rabbits are fed a high‐fat diet for 20 weeks. The treatment group is additionally administered 1% matcha during the whole experiment. Long‐term matcha treatment leads to lowered HDL cholesterol, impaired cholesterol transport manifested by reduced in vitro cholesterol efflux capacity, reduced cholesteryl ester transfer protein (CETP)‐mediated cholesterol ester (CE) transfer between HDL and triglyceride‐rich particles, and reduced macrophage‐specific in vivo transfer, where ian increased absorption of cholesterol in the liver but a decreased secretion into bile is observed. Pulse wave velocity, assessed by nuclear magnetic resonance, is increased in matcha‐treated animals, and a similar trend is observed for atherosclerotic lesion formation.ConclusionLong‐term matcha green tea treatment of hypercholesterolemic rabbits cause impaired reverse cholesterol transport and increased vascular stiffness, and susceptibility for atherosclerotic lesion development.
The basic principles for achieving population inversion and stimulated emission in the far infrar... more The basic principles for achieving population inversion and stimulated emission in the far infrared from p-Ge is discussed. In the heavy-light hole lasing mode a broad gain region is found resulting in a broad multimode spectrum due to intracavity modes. By attaching external plates of Ge a single mode operation is realized. The obtained powers are in the W range with linewidths of ≈ 0.2 cm−1. A single mode magnetically tunable coherent source is achieved with the light hole cyclotron resonance laser. With external mirrors a tuning range from 20 cm−1 to 120 cm−1 with magnetic fields between 1 and 6 T is achieved. The intensity of the single mode is in the order of mW, the linewidth below 0.2 cm−1.
Diffusion‐weighted imaging(DWI) in MRI has been developed as an important tool for the detection ... more Diffusion‐weighted imaging(DWI) in MRI has been developed as an important tool for the detection of cholesteatoma. Various DWI sequences are available. This study aims to evaluate the importance of the observer's reliance level for the detection of cholesteatoma.
PURPOSE To compare liver stiffness (LS) in patients with suspected diffuse liver disease between ... more PURPOSE To compare liver stiffness (LS) in patients with suspected diffuse liver disease between gradient-recalled-echo magnetic resonance elastography (GRE-MRE) and different spin-echo echo-planar imaging (SE-EPI-MRE) sequences and to investigate confounding factors including fat, iron, age, and sex. METHOD LS was measured at 1.5T using GRE-MRE, SE-EPI-MRE and short-TE-SE-EPI-MRE (hiSE-EPI-MRE) sequences and compared using Bland-Altman-plots together with concordance correlation coefficients (CCC). Success gradings were evaluated considering possible confounding factors. RESULTS 305 patients (225 male, 80 females, mean age 51.12 years) were included. 109/305 showed hepatic iron overload, 183 hepatic steatosis. The mean difference (bias) in stiffness values between GRE-MRE and SE-EPI-MRE/hiSE-EPI-MRE was 0.15/0.2 kPa (LOA: -0.72,0.41 kPa/-0.94,0.55 kPa), between SE-EPI-MRE and hiSE-EPI-MRE 0.04 kPa (LOA: -0.62,0.53 kPa). The CCC for agreement between stiffness values for GRE-MRE and SE-EPI-MRE was 0.94 (0.92-0.95), 0.89 (0.86-0.91) for hiSE-EPI-MRE and GRE-MRE and 0.94 (0.92-0.95) for SE-EPI-MRE and hiSE-EPI-MRE. Using GRE-MRE, 72/305 showed unusable results whereby all these patients had high iron levels (mean R2*=209.7 1/s). For SE-EPI-MRE and hiSE-EPI-MRE only 10/305 and 8/305 were inconclusive respectively, corresponding to a significantly higher iron load (mean R2*= 549.2 1/s for SE-EPI-MRE and 570.7 1/s for hiSE-EPI-MRE). Concerning fat, age or sex no significant influence on success was observed for all sequences. CONCLUSIONS Good agreement of LS values was observed between GRE-MRE and SE-EPI-MRE sequences. The number of successful exams, however, was considerably lower for GRE-MRE, mainly due to iron content. Study reference number: AN5093.
Study objectives: Studies on brain iron content in restless legs syndrome (RLS) using magnetic re... more Study objectives: Studies on brain iron content in restless legs syndrome (RLS) using magnetic resonance imaging (MRI) are heterogeneous. In this study, we sought to leverage the availability of a large dataset including a range of iron-sensitive MRI techniques to reassess the association between brain iron content and RLS with added statistical power and to compare these results to previous studies. Methods: The relaxation rates R 2 , R 2’ , and R 2* and quantitative susceptibility are MRI parameters strongly correlated to iron content. In general, these parameters are sensitive to magnetic field variations caused by iron particles. These parameters were quantified within iron-rich brain regions using a fully automatized approach in a cohort of 72 RLS patients and individually age and gender-matched healthy controls identified from an existing dataset acquired at the Sleep Laboratory of the Department of Neurology, Medical University of Innsbruck. 3T-MRI measures were corrected for age and volume of the segmented brain nuclei and results were compared with previous findings in a meta-analysis. Results: In our cohort, RLS patients had increased R 2* signal in the caudate and increased quantitative susceptibility signal in the putamen and the red nucleus compared to controls, suggesting increased iron content in these areas. The meta-analysis revealed no significant pooled effect across all brain regions. Furthermore, potential publication bias was identified for the substantia nigra. Conclusions: Normal and increased iron content of subcortical brain areas detected in this study is not in line with the hypothesis of reduced brain iron storage, but favors CSF investigations and post mortem studies indicating alteration of brain iron mobilization and homeostasis in RLS.
Patients undergoing breast MRI frequently have metallic biopsy clips placed within or adjacent to... more Patients undergoing breast MRI frequently have metallic biopsy clips placed within or adjacent to the lesion, producing metallic artifacts, which could lead to misinterpretation. The aim of our study was to investigate the extent of the artifact of four different clips commonly used in our hospital on diffusion-weighted images obtained with a readout-segmented sequence (RESOLVE) and their influence on ADC maps. It is found that artifacts vary in shape and size between different clips, DWI images and ADC-maps. For the marker with the smallest artifact the minimum size of detectable lesion seems to be approximately 10mm.
We investigated whether multiple SPACE sequences accelerated using CAIPIRINHA and acquired with d... more We investigated whether multiple SPACE sequences accelerated using CAIPIRINHA and acquired with different echo times can be used to obtain high resolution isotropic whole brain T2 maps within a clinical feasible scan time. In a phantom study, we could show that the SPACE based T2 values are comparable with T2 values derived using multiple single spin echo sequences. By reducing the number of echoes we could acquire 1 mm isotropic in vivo whole brain T2 maps in under 3 minutes.
Poster: "ECR 2013 / C-0877 / The value of diffusion tensor imaging (DTI) and tractography in... more Poster: "ECR 2013 / C-0877 / The value of diffusion tensor imaging (DTI) and tractography in patients with intraspinal tumours: a preliminary study" by: "F. Cartes-Zumelzu, S. Ingorokva, H. Kostron, G. Feuchtner, C. Kremser, C. Thome; Innsbruck/AT"
IntroductionGreen tea is associated with decreased risk for cardiovascular disease and stroke. Ma... more IntroductionGreen tea is associated with decreased risk for cardiovascular disease and stroke. Matcha is a special kind of powdered green tea known for its use in the Japanese tea ceremony. Due to its influence on lipoprotein parameters, it has been postulated to exert antiatherogenic effects. This study investigates whether it modulates the high‐density lipoprotein (HDL) function and thereby influences the atherogenic process in an animal model with a strong influence on humans' situation.Methods and ResultsAfter a pretreatment phase based on a standard diet, 10 female New Zealand White (NZW) rabbits are fed a high‐fat diet for 20 weeks. The treatment group is additionally administered 1% matcha during the whole experiment. Long‐term matcha treatment leads to lowered HDL cholesterol, impaired cholesterol transport manifested by reduced in vitro cholesterol efflux capacity, reduced cholesteryl ester transfer protein (CETP)‐mediated cholesterol ester (CE) transfer between HDL and triglyceride‐rich particles, and reduced macrophage‐specific in vivo transfer, where ian increased absorption of cholesterol in the liver but a decreased secretion into bile is observed. Pulse wave velocity, assessed by nuclear magnetic resonance, is increased in matcha‐treated animals, and a similar trend is observed for atherosclerotic lesion formation.ConclusionLong‐term matcha green tea treatment of hypercholesterolemic rabbits cause impaired reverse cholesterol transport and increased vascular stiffness, and susceptibility for atherosclerotic lesion development.
The basic principles for achieving population inversion and stimulated emission in the far infrar... more The basic principles for achieving population inversion and stimulated emission in the far infrared from p-Ge is discussed. In the heavy-light hole lasing mode a broad gain region is found resulting in a broad multimode spectrum due to intracavity modes. By attaching external plates of Ge a single mode operation is realized. The obtained powers are in the W range with linewidths of ≈ 0.2 cm−1. A single mode magnetically tunable coherent source is achieved with the light hole cyclotron resonance laser. With external mirrors a tuning range from 20 cm−1 to 120 cm−1 with magnetic fields between 1 and 6 T is achieved. The intensity of the single mode is in the order of mW, the linewidth below 0.2 cm−1.
Diffusion‐weighted imaging(DWI) in MRI has been developed as an important tool for the detection ... more Diffusion‐weighted imaging(DWI) in MRI has been developed as an important tool for the detection of cholesteatoma. Various DWI sequences are available. This study aims to evaluate the importance of the observer's reliance level for the detection of cholesteatoma.
PURPOSE To compare liver stiffness (LS) in patients with suspected diffuse liver disease between ... more PURPOSE To compare liver stiffness (LS) in patients with suspected diffuse liver disease between gradient-recalled-echo magnetic resonance elastography (GRE-MRE) and different spin-echo echo-planar imaging (SE-EPI-MRE) sequences and to investigate confounding factors including fat, iron, age, and sex. METHOD LS was measured at 1.5T using GRE-MRE, SE-EPI-MRE and short-TE-SE-EPI-MRE (hiSE-EPI-MRE) sequences and compared using Bland-Altman-plots together with concordance correlation coefficients (CCC). Success gradings were evaluated considering possible confounding factors. RESULTS 305 patients (225 male, 80 females, mean age 51.12 years) were included. 109/305 showed hepatic iron overload, 183 hepatic steatosis. The mean difference (bias) in stiffness values between GRE-MRE and SE-EPI-MRE/hiSE-EPI-MRE was 0.15/0.2 kPa (LOA: -0.72,0.41 kPa/-0.94,0.55 kPa), between SE-EPI-MRE and hiSE-EPI-MRE 0.04 kPa (LOA: -0.62,0.53 kPa). The CCC for agreement between stiffness values for GRE-MRE and SE-EPI-MRE was 0.94 (0.92-0.95), 0.89 (0.86-0.91) for hiSE-EPI-MRE and GRE-MRE and 0.94 (0.92-0.95) for SE-EPI-MRE and hiSE-EPI-MRE. Using GRE-MRE, 72/305 showed unusable results whereby all these patients had high iron levels (mean R2*=209.7 1/s). For SE-EPI-MRE and hiSE-EPI-MRE only 10/305 and 8/305 were inconclusive respectively, corresponding to a significantly higher iron load (mean R2*= 549.2 1/s for SE-EPI-MRE and 570.7 1/s for hiSE-EPI-MRE). Concerning fat, age or sex no significant influence on success was observed for all sequences. CONCLUSIONS Good agreement of LS values was observed between GRE-MRE and SE-EPI-MRE sequences. The number of successful exams, however, was considerably lower for GRE-MRE, mainly due to iron content. Study reference number: AN5093.
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