MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy
The local magnetic field inside and around an object in a magnetic resonance imaging unit depends on the magnetic susceptibility of the object being magnetized, in combination with its geometry/orientation. Magnetic susceptibility can thus be exploited as a source of tissue contrast, and susceptibil...
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| Format: | Article |
| Language: | English |
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Wiley
2018-01-01
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| Series: | Radiology Research and Practice |
| Online Access: | http://dx.doi.org/10.1155/2018/6709525 |
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| author | Emma Olsson Ronnie Wirestam Emelie Lind |
| author_facet | Emma Olsson Ronnie Wirestam Emelie Lind |
| author_sort | Emma Olsson |
| collection | DOAJ |
| description | The local magnetic field inside and around an object in a magnetic resonance imaging unit depends on the magnetic susceptibility of the object being magnetized, in combination with its geometry/orientation. Magnetic susceptibility can thus be exploited as a source of tissue contrast, and susceptibility imaging may also become a useful tool in contrast agent quantification and for assessment of venous oxygen saturation levels. In this study, the accuracy of an established procedure for quantitative susceptibility mapping (QSM) was investigated. Three gel phantoms were constructed with cylinders of varying susceptibility and geometry. Experimental results were compared with simulated and analytically calculated data. An expected linear relationship between estimated susceptibility and concentration of contrast agent was observed. Less accurate QSM-based susceptibility values were observed for cylindrical objects at angles, relative to the main magnetic field, that were close to or larger than the magic angle. Results generally improved for large objects/high spatial resolution and large volume coverage. For simulated phase maps, accurate susceptibility quantification by QSM was achieved also for more challenging geometries. The investigated QSM algorithm was generally robust to changes in measurement and calculation parameters, but experimental phase data of sufficient quality may be difficult to obtain in certain geometries. |
| format | Article |
| id | doaj-art-16bf8b5465664eb6bdb21df94d3a8b8b |
| institution | Kabale University |
| issn | 2090-1941 2090-195X |
| language | English |
| publishDate | 2018-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Radiology Research and Practice |
| spelling | doaj-art-16bf8b5465664eb6bdb21df94d3a8b8b2025-02-03T01:11:00ZengWileyRadiology Research and Practice2090-19412090-195X2018-01-01201810.1155/2018/67095256709525MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation AccuracyEmma Olsson0Ronnie Wirestam1Emelie Lind2Department of Medical Radiation Physics, Lund University, Skåne University Hospital Lund, 22185 Lund, SwedenDepartment of Medical Radiation Physics, Lund University, Skåne University Hospital Lund, 22185 Lund, SwedenDepartment of Medical Radiation Physics, Lund University, Skåne University Hospital Lund, 22185 Lund, SwedenThe local magnetic field inside and around an object in a magnetic resonance imaging unit depends on the magnetic susceptibility of the object being magnetized, in combination with its geometry/orientation. Magnetic susceptibility can thus be exploited as a source of tissue contrast, and susceptibility imaging may also become a useful tool in contrast agent quantification and for assessment of venous oxygen saturation levels. In this study, the accuracy of an established procedure for quantitative susceptibility mapping (QSM) was investigated. Three gel phantoms were constructed with cylinders of varying susceptibility and geometry. Experimental results were compared with simulated and analytically calculated data. An expected linear relationship between estimated susceptibility and concentration of contrast agent was observed. Less accurate QSM-based susceptibility values were observed for cylindrical objects at angles, relative to the main magnetic field, that were close to or larger than the magic angle. Results generally improved for large objects/high spatial resolution and large volume coverage. For simulated phase maps, accurate susceptibility quantification by QSM was achieved also for more challenging geometries. The investigated QSM algorithm was generally robust to changes in measurement and calculation parameters, but experimental phase data of sufficient quality may be difficult to obtain in certain geometries.http://dx.doi.org/10.1155/2018/6709525 |
| spellingShingle | Emma Olsson Ronnie Wirestam Emelie Lind MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy Radiology Research and Practice |
| title | MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy |
| title_full | MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy |
| title_fullStr | MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy |
| title_full_unstemmed | MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy |
| title_short | MRI-Based Quantification of Magnetic Susceptibility in Gel Phantoms: Assessment of Measurement and Calculation Accuracy |
| title_sort | mri based quantification of magnetic susceptibility in gel phantoms assessment of measurement and calculation accuracy |
| url | http://dx.doi.org/10.1155/2018/6709525 |
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