Abstract
A co-polarization scheme for [1,4-(13) C2 ]fumarate and [1-(13) C]pyruvate is presented to simultaneously assess necrosis and metabolism in rats with hyperpolarized (13) C magnetic resonance (MR). The co-polarization was performed in a SPINlab polarizer. In addition, the feasibility of simultaneous positron emission tomography (PET) and MR of small animals with a clinical PET/MR scanner is demonstrated. The hyperpolarized metabolic MR and PET was demonstrated in a rat model of necrosis. The polarization and T1 of the co-polarized [1,4-(13) C2 ]fumarate and [1-(13) C]pyruvate substrates were measured in vitro and compared with those obtained when the substrates were polarized individually. A polarization of 36 ± 4% for fumarate and 37 ± 6% for pyruvate was obtained. We found no significant difference in the polarization and T1 values between the dual and single substrate polarization. Rats weighing about 400 g were injected intramuscularly in one of the hind legs with 200 μL of turpentine to induce necrosis. Two hours later, (13) C metabolic maps were obtained with a chemical shift imaging sequence (16 × 16) with a resolution of 3.1 × 5.0 × 25.0 mm(3) . The (13) C spectroscopic images were acquired in 12 s, followed by an 8-min (18) F-2-fluoro-2-deoxy-d-glucose ((18) F-FDG) PET acquisition with a resolution of 3.5 mm. [1,4-(13) C2 ]Malate was observed from the tissue injected with turpentine indicating necrosis. Normal [1-(13) C]pyruvate metabolism and (18) F-FDG uptake were observed from the same tissue. The proposed co-polarization scheme provides a means to utilize multiple imaging agents simultaneously, and thus to probe various metabolic pathways in a single examination. Moreover, it demonstrates the feasibility of small animal research on a clinical PET/MR scanner for combined PET and hyperpolarized metabolic MR.
Originalsprog | Engelsk |
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Artikelnummer | e3803 |
Tidsskrift | N M R in Biomedicine |
Vol/bind | 30 |
Udgave nummer | 12 |
Sider (fra-til) | 1-9 |
Antal sider | 9 |
ISSN | 0952-3480 |
DOI | |
Status | Udgivet - 18 okt. 2017 |