Simultaneous imaging of hyperpolarized [1,4 ‐13C2]fumarate, [1‐13C]pyruvate and 18F–FDG in a rat model of necrosis in a clinical PET/MR scanner

A co‐polarization scheme for [1,4‐13C2]fumarate and [1‐13C]pyruvate is presented to simultaneously assess necrosis and metabolism in rats with hyperpolarized 13C 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 [1,4‐13C2]fumarate and [1‐13C]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, 13C metabolic maps were obtained with a chemical shift imaging sequence (16 × 16) with a resolution of 3.1 × 5.0 × 25.0 mm3. The 13C spectroscopic images were acquired in 12 s, followed by an 8‐min 18F‐2‐fluoro‐2‐deoxy‐d‐glucose (18F–FDG) PET acquisition with a resolution of 3.5 mm. [1,4‐13C2]Malate was observed from the tissue injected with turpentine indicating necrosis. Normal [1‐13C]pyruvate metabolism and 18F–FDG uptake were o...
Source: NMR in Biomedicine - Category: Radiology Authors: Tags: RESEARCH ARTICLE Source Type: research