|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Information Science and Technology / Faculty of Information Science and Technology >
Peer-reviewed Journal Articles, etc >
EPR-based oximetric imaging : a combination of single point-based spatial encoding and T1 weighting
| Title: | EPR-based oximetric imaging : a combination of single point-based spatial encoding and T1 weighting |
| Authors: | Matsumoto, Ken-ichiro Browse this author | | Kishimoto, Shun Browse this author | | Devasahayam, Nallathamby Browse this author | | Chandramouli, Gadisetti V. R. Browse this author | | Ogawa, Yukihiro Browse this author | | Matsumoto, Shingo Browse this author →KAKEN DB | | Krishna, Murali C. Browse this author | | Subramanian, Sankaran Browse this author |
| Keywords: | EPR imaging | | EPR oximetry | | in vivo oximetry | | partial oxygen pressure | | single-point imaging | | spin-lattice relaxation time | | triphenylmethyl radical | | tissue oxygen |
| Issue Date: | Nov-2018 |
| Publisher: | Wiley |
| Journal Title: | Magnetic Resonance in Medicine |
| Volume: | 80 |
| Issue: | 5 |
| Start Page: | 2275 |
| End Page: | 2287 |
| Publisher DOI: | 10.1002/mrm.27182 |
| Abstract: | Purpose: Spin-lattice relaxation time (T1)-weighted time-domain EPR oximetry is reported for in vivo applications using a paramagnetic probe, a trityl-based Oxo71.
Methods: The R1 dependence of the trityl probe Oxo71 on pO2 was assessed using single point imaging (SPI) mode of spatial encoding combined with rapid repetition, similar to T1-weighted MRI, where R1 was determined from 22 repetition times ranging from 2.1–40.0 μs at 300 MHz. The pO2 maps of a phantom with three tubes containing 2 mM Oxo71 solutions equilibrated at 0%, 2%, and 5% oxygen were determined by R1 and apparent spin-spin relaxation rate (R2*) simultaneously.
Results: The pO2 maps derived from R1 and R2* agreed with the known pO2 levels in the tubes of Oxo71. However, the histograms of pO2 revealed that R1 offers better pO2 resolution than R2* in low pO2 regions. The standard deviations of pixels at 2% pO2 (15.2 mmHg) were about 5 times lower in R1-based estimation than R2*-based estimation (mean ± SD: 13.9 ± 1.77 mmHg and 18.3 ± 8.70 mmHg, respectively). The in vivo pO2 map obtained from R1-based assessment displayed a homogeneous profile in low pO2 regions in tumor xenografts, consistent with previous reports on R2*-based oximetric imaging. The scan time to obtain the R1 map can be significantly reduced using three repetition times ranging from 4.0‒12.0 μs.
Conclusion: Using the SPI modality, R1-based oximetry imaging with useful spatial and oxygen resolutions for small animals was demonstrated. |
| Rights: | This is the peer reviewed version of the following article: Matsumoto K‐i, Kishimoto S, Devasahayam N, et al. EPR‐based oximetric imaging: a combination of single point‐based spatial encoding and T1 weighting. Magn Reson Med. 2018;80(5):2275-2287. https://doi.org/10.1002/mrm.27182, which has been published in final form at https://doi.org/10.1002/mrm.27182. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/76009 |
| Appears in Collections: | 情報科学院・情報科学研究院 (Graduate School of Information Science and Technology / Faculty of Information Science and Technology) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 松元 慎吾
|
