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Your search keyword '"Friedrich, Klaus M."' showing total 38 results
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38 results on '"Friedrich, Klaus M."'

14. 7T Imaging of the Wrist

Author

Friedrich, Klaus M., Komorowski, Arkadiusz, and Trattnig, Siegfried

Published
2012

21. When an incidental MRI finding becomes a clinical issue

Author

Schwarz-Nemec, Ursula, primary, Friedrich, Klaus M., additional, Arnoldner, Michael A., additional, Schwarz, Felix K., additional, Weber, Michael, additional, Trattnig, Siegfried, additional, Grohs, Josef G., additional, and Nemec, Stefan F., additional

Published
2019
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22. Sodium MR imaging of the lumbar intervertebral disk at 7 T: correlation with T2 mapping and modified Pfirrmann score at 3 T - preliminary results

Author

Noebauer-Huhmann, Iris-Melanie, Juras, Vladimir, Pfirrmann, Christian W A, Szomolanyi, Pavol, Zbyn, Stefan, Messner, Alina, Wimmer, Johannes, Weber, Michael, Friedrich, Klaus M, Stelzeneder, David, Trattnig, Siegfried, and University of Zurich

Subjects
2741 Radiology, Nuclear Medicine and Imaging, 610 Medicine & health, 10046 Balgrist University Hospital, Swiss Spinal Cord Injury Center
Published
2012

23. MRI of the Wrist at 7 Tesla using an 8 Channel Array Coil Combined with Parallel Imaging: Preliminary Results

Author

Chang, Gregory, Friedrich, Klaus M., Wang, Ligong, Vieira, Renata L.R., Schweitzer, Mark E., Recht, Michael P., Wiggins, Graham C., and Regatte, Ravinder R.

Subjects
Adult, Male, Phantoms, Imaging, Transducers, Reproducibility of Results, Pilot Projects, Wrist, Image Enhancement, Magnetic Resonance Imaging, Sensitivity and Specificity, Article, Magnetics, Feasibility Studies, Humans, Female
Abstract

To determine the feasibility of performing MRI of the wrist at 7 Tesla (T) with parallel imaging and to evaluate how acceleration factors (AF) affect signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and image quality.This study had institutional review board approval. A four-transmit eight-receive channel array coil was constructed in-house. Nine healthy subjects were scanned on a 7T whole-body MR scanner. Coronal and axial images of cartilage and trabecular bone micro-architecture (3D-Fast Low Angle Shot (FLASH) with and without fat suppression, repetition time/echo time = 20 ms/4.5 ms, flip angle = 10 degrees , 0.169-0.195 x 0.169-0.195 mm, 0.5-1 mm slice thickness) were obtained with AF 1, 2, 3, 4. T1-weighted fast spin-echo (FSE), proton density-weighted FSE, and multiple-echo data image combination (MEDIC) sequences were also performed. SNR and CNR were measured. Three musculoskeletal radiologists rated image quality. Linear correlation analysis and paired t-tests were performed.At higher AF, SNR and CNR decreased linearly for cartilage, muscle, and trabecular bone (r-0.98). At AF 4, reductions in SNR/CNR were:52%/60% (cartilage), 72%/63% (muscle), 45%/50% (trabecular bone). Radiologists scored images with AF 1 and 2 as near-excellent, AF 3 as good-to-excellent (P = 0.075), and AF 4 as average-to-good (P = 0.11).It is feasible to perform high resolution 7T MRI of the wrist with parallel imaging. SNR and CNR decrease with higher AF, but image quality remains above-average.

Published
2010

25. Sodium MR Imaging of the Lumbar Intervertebral Disk at 7 T: Correlation with T2 Mapping and Modified Pfirrmann Score at 3 T—Preliminary Results

Author

Noebauer-Huhmann, Iris-Melanie, primary, Juras, Vladimir, additional, Pfirrmann, Christian W. A., additional, Szomolanyi, Pavol, additional, Zbyn, Stefan, additional, Messner, Alina, additional, Wimmer, Johannes, additional, Weber, Michael, additional, Friedrich, Klaus M., additional, Stelzeneder, David, additional, and Trattnig, Siegfried, additional

Published
2012
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28. Feasibility of Texture Analysis for the Assessment of Biochemical Changes in Meniscal Tissue on T1 Maps Calculated From Delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage Data

Author

Mayerhoefer, Marius E., primary, Welsch, Goetz H., additional, Riegler, Georg, additional, Mamisch, Tallal C., additional, Materka, Andrzej, additional, Weber, Michael, additional, El-Rabadi, Karem, additional, Friedrich, Klaus M., additional, Dirisamer, Albert, additional, and Trattnig, Siegfried, additional

Published
2010
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34. Diffusion Weighted Imaging in Osteoradiology

Author

Herneth, Andreas M., primary, Ringl, Helmut, additional, Memarsadeghi, Mazda, additional, Fueger, Barbara, additional, Friedrich, Klaus M., additional, Krestan, Christian, additional, and Imhof, Herwig, additional

Published
2007
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37. Diffusion-weighted magnetic resonance imaging of head and neck squamous cell carcinomas

Author

Friedrich, Klaus M., Matzek, Wolfgang, Gentzsch, Stephan, Sulzbacher, Irene, Czerny, Christian, and Herneth, Andreas M.

Subjects
*SQUAMOUS cell carcinoma, *HEAD & neck cancer diagnosis, *DIFFUSION, *MEDICAL imaging systems, *IMAGE quality in imaging systems, *MAGNETIC resonance imaging
Abstract

Abstract: Objective: To evaluate whether diffusion-weighted imaging (DWI) is a reliable technique to quantify microstructural differences between head and neck squamous cell carcinomas (SCC) and tumour-free soft tissue. Materials and methods: DWI was obtained from 20 patients with histologically proven, untreated head and neck SCC. DWI was acquired using a diffusion-weighted, navigated echo-planar imaging sequence with a maximum b-value of 800s/mm2. For an objective assessment of image quality, the signal-to-noise ratio (SNR) was calculated. Microstructural differences between vital tumour tissue and tumour-free soft tissue were quantified by calculating the apparent-diffusion-coefficients (ADC) on a pixel by pixel method. Results: Echo-planar DWI provided good image quality in all patients (mean SNR 18.4). The mean ADC of SCC, (0.64±0.28×10−3 mm2/s), was significantly (P <0.0001) lower than that of the tumour-free soft tissue, (2.51±0.82×10−3 mm2/s). Conclusion: DWI is a reliable diagnostic tool to quantify the microstructural differences between vital tumour tissue and tumour-free soft tissue in patients with head and neck SCC. [Copyright &y& Elsevier]

Published
2008
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38. T2 measurements of cartilage in osteoarthritis patients with meniscal tears.

Author

Friedrich KM, Shepard T, de Oliveira VS, Wang L, Babb JS, Schweitzer M, and Regatte R

Subjects
Aged, Analysis of Variance, Body Mass Index, Female, Humans, Image Interpretation, Computer-Assisted, Male, Middle Aged, Prospective Studies, Magnetic Resonance Imaging methods, Menisci, Tibial pathology, Osteoarthritis, Knee pathology
Abstract

Objective: The objective of this study was to quantitatively assess cartilage degeneration via T2 mapping to compare patients with and those without meniscal tears., Subjects and Methods: Thirty-seven patients (18 men, mean age +/- SD, 65.7 +/- 7.8 years; 19 women, mean age, 63.8 +/- 12.0 years) with clinical symptoms of osteoarthritis were studied on 3-T MRI using a 2D multiecho spin-echo sequence for T2 mapping. Meniscal signal and morphology were qualitatively graded and correlated to the T2 values of cartilage. Analysis of covariance, Bonferroni multiple comparison correction, and Spearman's correlation coefficients were used for statistical analysis., Results: Patients with meniscal tears (median +/- interquartile range, 50.1 +/- 6.1 milliseconds) had significantly (p = 0.021) higher T2 values of cartilage than those without meniscal tears (45.7 +/- 4.8 milliseconds). T2 values of cartilage were significantly higher in the medial compartment than in the lateral compartment in patients with medial meniscal tears (p = 0.018)., Conclusion: T2 measurements are increased in patients with meniscal tears; this finding adds support to the theory of an association of osteoarthritis with damage to both the menisci and hyaline cartilage.

Published
2009
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