Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys
Purpose: The sensitivity and accuracy of chemical exchange saturation transfer (CEST) and nuclear Overhauser enhancement (NOE) effects for assessing injury-associated changes in cervical spinal cords were evaluated in squirrel monkeys. Multiple interacting pools of protons, including one identified...
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| Format: | Article |
| Language: | English |
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Elsevier
2021-01-01
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| Series: | NeuroImage: Clinical |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2213158221000772 |
| _version_ | 1819002535024787456 |
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| author | Feng Wang Zhongliang Zu Tung-Lin Wu Xinqiang Yan Ming Lu Pai-Feng Yang Nellie E. Byun Jamie L. Reed John C. Gore Li Min Chen |
| author_facet | Feng Wang Zhongliang Zu Tung-Lin Wu Xinqiang Yan Ming Lu Pai-Feng Yang Nellie E. Byun Jamie L. Reed John C. Gore Li Min Chen |
| author_sort | Feng Wang |
| collection | DOAJ |
| description | Purpose: The sensitivity and accuracy of chemical exchange saturation transfer (CEST) and nuclear Overhauser enhancement (NOE) effects for assessing injury-associated changes in cervical spinal cords were evaluated in squirrel monkeys. Multiple interacting pools of protons, including one identified by an NOE at −1.6 ppm relative to water (NOE(-1.6)), were derived and quantified from fitting proton Z-spectra. The effects of down-sampled data acquisitions and corrections for non-specific factors including T1, semi-solid magnetization transfer, and direct saturation of free water (DS), were investigated. The overall goal is to develop a protocol for rapid data acquisition for assessing the molecular signatures of the injured spinal cord and its surrounding regions. Methods: MRI scans were recorded of anesthetized squirrel monkeys at 9.4 T, before and after a unilateral dorsal column sectioning of the cervical spinal cord. Z-spectral images at 51 different RF offsets were acquired. The amplitudes of CEST and NOE effects from multiple proton pools were quantified using a six-pool Lorenzian fitting of each Z-spectrum (MTRmfit). In addition, down-sampled data using reduced selections of RF offsets were analyzed and compared. An apparent exchange-dependent relaxation (AREXmfit) method was also used to correct for non-specific factors in quantifying regional spectra around lesion sites. Results: The parametric maps from multi-pool fitting using the complete sampling data (P51e) detected unilateral changes at and around the injury. The maps derived from selected twofold down-sampled data with appropriate interpolation (P26sI51) revealed quite similar spatial distributions of different pools as those obtained using P51e at each resonance shift. Across 10 subjects, both data acquisition schemes detected significant decreases in NOE(-3.5) and NOE(-1.6) and increases in DS(0.0) and CEST(3.5) at the lesion site relative to measures of the normal tissues before injury. AREXmfit of cysts and other abnormal tissues at and around the lesion site also exhibited significant changes, especially at 3.5, −1.6 and −3.5 ppm RF offsets. Conclusion: These results confirm that a reduced set of RF offsets and down sampling are adequate for CEST imaging of injured spinal cord and allow shorter imaging times and/or permit additional signal averaging. AREXmfit correction improved the accuracy of CEST and NOE measures. The results provide a rapid (~13 mins), sensitive, and accurate protocol for deriving multiple NOE and CEST effects simultaneously in spinal cord imaging at high field. |
| first_indexed | 2024-12-20T23:06:39Z |
| format | Article |
| id | doaj.art-518442a5ba43469c941e3352d8fc40a5 |
| institution | Directory Open Access Journal |
| issn | 2213-1582 |
| language | English |
| last_indexed | 2024-12-20T23:06:39Z |
| publishDate | 2021-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | NeuroImage: Clinical |
| spelling | doaj.art-518442a5ba43469c941e3352d8fc40a52022-12-21T19:23:50ZengElsevierNeuroImage: Clinical2213-15822021-01-0130102633Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeysFeng Wang0Zhongliang Zu1Tung-Lin Wu2Xinqiang Yan3Ming Lu4Pai-Feng Yang5Nellie E. Byun6Jamie L. Reed7John C. Gore8Li Min Chen9Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Biomedical Engineering, Vanderbilt University, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USA; Department of Biomedical Engineering, Vanderbilt University, TN, USAVanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, TN, USA; Corresponding author at: Department of Radiology and Radiological Sciences, Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. S, Nashville, TN 37232, USA.Purpose: The sensitivity and accuracy of chemical exchange saturation transfer (CEST) and nuclear Overhauser enhancement (NOE) effects for assessing injury-associated changes in cervical spinal cords were evaluated in squirrel monkeys. Multiple interacting pools of protons, including one identified by an NOE at −1.6 ppm relative to water (NOE(-1.6)), were derived and quantified from fitting proton Z-spectra. The effects of down-sampled data acquisitions and corrections for non-specific factors including T1, semi-solid magnetization transfer, and direct saturation of free water (DS), were investigated. The overall goal is to develop a protocol for rapid data acquisition for assessing the molecular signatures of the injured spinal cord and its surrounding regions. Methods: MRI scans were recorded of anesthetized squirrel monkeys at 9.4 T, before and after a unilateral dorsal column sectioning of the cervical spinal cord. Z-spectral images at 51 different RF offsets were acquired. The amplitudes of CEST and NOE effects from multiple proton pools were quantified using a six-pool Lorenzian fitting of each Z-spectrum (MTRmfit). In addition, down-sampled data using reduced selections of RF offsets were analyzed and compared. An apparent exchange-dependent relaxation (AREXmfit) method was also used to correct for non-specific factors in quantifying regional spectra around lesion sites. Results: The parametric maps from multi-pool fitting using the complete sampling data (P51e) detected unilateral changes at and around the injury. The maps derived from selected twofold down-sampled data with appropriate interpolation (P26sI51) revealed quite similar spatial distributions of different pools as those obtained using P51e at each resonance shift. Across 10 subjects, both data acquisition schemes detected significant decreases in NOE(-3.5) and NOE(-1.6) and increases in DS(0.0) and CEST(3.5) at the lesion site relative to measures of the normal tissues before injury. AREXmfit of cysts and other abnormal tissues at and around the lesion site also exhibited significant changes, especially at 3.5, −1.6 and −3.5 ppm RF offsets. Conclusion: These results confirm that a reduced set of RF offsets and down sampling are adequate for CEST imaging of injured spinal cord and allow shorter imaging times and/or permit additional signal averaging. AREXmfit correction improved the accuracy of CEST and NOE measures. The results provide a rapid (~13 mins), sensitive, and accurate protocol for deriving multiple NOE and CEST effects simultaneously in spinal cord imaging at high field.http://www.sciencedirect.com/science/article/pii/S2213158221000772MRIChemical exchange saturation transfer (CEST)Nuclear Overhauser enhancement (NOE)Spinal cord injury (SCI)Non-human primates (NHP) |
| spellingShingle | Feng Wang Zhongliang Zu Tung-Lin Wu Xinqiang Yan Ming Lu Pai-Feng Yang Nellie E. Byun Jamie L. Reed John C. Gore Li Min Chen Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys NeuroImage: Clinical MRI Chemical exchange saturation transfer (CEST) Nuclear Overhauser enhancement (NOE) Spinal cord injury (SCI) Non-human primates (NHP) |
| title | Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys |
| title_full | Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys |
| title_fullStr | Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys |
| title_full_unstemmed | Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys |
| title_short | Sensitivity and specificity of CEST and NOE MRI in injured spinal cord in monkeys |
| title_sort | sensitivity and specificity of cest and noe mri in injured spinal cord in monkeys |
| topic | MRI Chemical exchange saturation transfer (CEST) Nuclear Overhauser enhancement (NOE) Spinal cord injury (SCI) Non-human primates (NHP) |
| url | http://www.sciencedirect.com/science/article/pii/S2213158221000772 |
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