MRS Shimming: An Important Point Which Should not be Ignored
Introduction: Proton magnetic resonance spectroscopy (MRS) is a well-known device for analyzing the biological fluids metabolically. Obtaining accurate and reliable information via MRS needs a homogeneous magnetic field in order to provide well-defined peaks and uniform water suppression. There are...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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Shiraz University of Medical Sciences
2018-09-01
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| Series: | Journal of Biomedical Physics and Engineering |
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| Online Access: | http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/845 |
| _version_ | 1818081432374870016 |
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| author | B Zeinali-Rafsanjani R Faghihi M A Mosleh-Shirazi M Saeedi-Moghadam M Lotfi R Jalli S Sina L Mina |
| author_facet | B Zeinali-Rafsanjani R Faghihi M A Mosleh-Shirazi M Saeedi-Moghadam M Lotfi R Jalli S Sina L Mina |
| author_sort | B Zeinali-Rafsanjani |
| collection | DOAJ |
| description | Introduction: Proton magnetic resonance spectroscopy (MRS) is a well-known device for analyzing the biological fluids metabolically. Obtaining accurate and reliable information via MRS needs a homogeneous magnetic field in order to provide well-defined peaks and uniform water suppression. There are lots of reasons which can disturb the magnetic field homogeneity which can be corrected by a process known as shimming. This study is intended to recall the importance of shimming and also the significant role of quality control (QC) in achieving an accurate quantification.
Material and Method: An acrylic cylindrical quality control phantom was designed as an analog of brain MRS test phantoms in order to control the accuracy of the obtained signal of a 1.5 T Siemens MRI system which belonged to one of Shiraz hospitals. The signal of NAA, Cho, Cr, the combination of these metabolites and also the distilled water, which was used in this study, was evaluated using separate phantoms. A QC test was performed using Siemens QC phantom and a standard test phantom.
Results: The spectrum of our home- made phantom had a significant difference with the expected spectrum. The results of checking the spectrum of metabolites separately also confirmed that there was a systemic problem that affects all the signals originated from all metabolites and even the pure distilled water. The MRS system could not pass QC tests, and peak broadening was common in all spectra. The complex spectrum of standard test phantom was not produced successfully by the MRS system.
Discussion: By a simple check of the water peak characteristics, lots of information can be obtained, one of which is the status of shimming that has a considerable effect on the accuracy of the spectrum. Thus, performing an automatic or manual shimming is not a criterion of the spectrum accuracy, and performing a periodic quality control using a test phantom by a specialist is necessary.
Conclusion: Briefly, the quality control of MRS and all the other clinical device must be taken seriously. Sometimes QC can be the boundary of a right or a wrong decision for the patient. |
| first_indexed | 2024-12-10T19:06:07Z |
| format | Article |
| id | doaj.art-ec216b0a5eef4ee78ce52fe5c16c1a66 |
| institution | Directory Open Access Journal |
| issn | 2251-7200 2251-7200 |
| language | English |
| last_indexed | 2024-12-10T19:06:07Z |
| publishDate | 2018-09-01 |
| publisher | Shiraz University of Medical Sciences |
| record_format | Article |
| series | Journal of Biomedical Physics and Engineering |
| spelling | doaj.art-ec216b0a5eef4ee78ce52fe5c16c1a662022-12-22T01:36:53ZengShiraz University of Medical SciencesJournal of Biomedical Physics and Engineering2251-72002251-72002018-09-0183261270MRS Shimming: An Important Point Which Should not be IgnoredB Zeinali-Rafsanjani0R Faghihi1M A Mosleh-Shirazi2M Saeedi-Moghadam3M Lotfi4R Jalli5S Sina6L Mina7Department of Nuclear Engineering, School of Mechanical Engineering, Shiraz University, Shiraz, IranDepartment of Nuclear Engineering, School of Mechanical Engineering, Shiraz University, Shiraz, IranMedical imaging research center, Shiraz University of medical sciences, Shiraz, IranMedical imaging research center, Shiraz University of medical sciences, Shiraz, IranMedical imaging research center, Shiraz University of medical sciences, Shiraz, IranMedical imaging research center, Shiraz University of medical sciences, Shiraz, IranRadiation research center, School of Mechanical Engineering, Shiraz University, Shiraz, IranRadiology department, Faghihi hospital, Shiraz University of medical sciences, Shiraz, IranIntroduction: Proton magnetic resonance spectroscopy (MRS) is a well-known device for analyzing the biological fluids metabolically. Obtaining accurate and reliable information via MRS needs a homogeneous magnetic field in order to provide well-defined peaks and uniform water suppression. There are lots of reasons which can disturb the magnetic field homogeneity which can be corrected by a process known as shimming. This study is intended to recall the importance of shimming and also the significant role of quality control (QC) in achieving an accurate quantification. Material and Method: An acrylic cylindrical quality control phantom was designed as an analog of brain MRS test phantoms in order to control the accuracy of the obtained signal of a 1.5 T Siemens MRI system which belonged to one of Shiraz hospitals. The signal of NAA, Cho, Cr, the combination of these metabolites and also the distilled water, which was used in this study, was evaluated using separate phantoms. A QC test was performed using Siemens QC phantom and a standard test phantom. Results: The spectrum of our home- made phantom had a significant difference with the expected spectrum. The results of checking the spectrum of metabolites separately also confirmed that there was a systemic problem that affects all the signals originated from all metabolites and even the pure distilled water. The MRS system could not pass QC tests, and peak broadening was common in all spectra. The complex spectrum of standard test phantom was not produced successfully by the MRS system. Discussion: By a simple check of the water peak characteristics, lots of information can be obtained, one of which is the status of shimming that has a considerable effect on the accuracy of the spectrum. Thus, performing an automatic or manual shimming is not a criterion of the spectrum accuracy, and performing a periodic quality control using a test phantom by a specialist is necessary. Conclusion: Briefly, the quality control of MRS and all the other clinical device must be taken seriously. Sometimes QC can be the boundary of a right or a wrong decision for the patient.http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/845Magnetic resonance spectroscopyShimmingQuality controlQuality assurance |
| spellingShingle | B Zeinali-Rafsanjani R Faghihi M A Mosleh-Shirazi M Saeedi-Moghadam M Lotfi R Jalli S Sina L Mina MRS Shimming: An Important Point Which Should not be Ignored Journal of Biomedical Physics and Engineering Magnetic resonance spectroscopy Shimming Quality control Quality assurance |
| title | MRS Shimming: An Important Point Which Should not be Ignored |
| title_full | MRS Shimming: An Important Point Which Should not be Ignored |
| title_fullStr | MRS Shimming: An Important Point Which Should not be Ignored |
| title_full_unstemmed | MRS Shimming: An Important Point Which Should not be Ignored |
| title_short | MRS Shimming: An Important Point Which Should not be Ignored |
| title_sort | mrs shimming an important point which should not be ignored |
| topic | Magnetic resonance spectroscopy Shimming Quality control Quality assurance |
| url | http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/845 |
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