Experimental approaches to cardiac imaging with hyperpolarized [1-13c]pyruvate: a feasibility study in rats with a 3T clincal scanner
- Francesca Frijia1,
- Luca Menichetti2,
- Vincenzo Lionetti3,
- Maria Filomena Santarelli2,
- Jan Henrik Ardenkjaer Larsen4,
- Giulio Giovannetti2,
- Vincenzo Positano1,
- Daniele De Marchi1,
- Giovanni Aquaro1,
- Manuela Campan3,
- Valentina Hartwig5,
- Matteo Milanesi1,
- Fabio A Recchia6,
- Luigi Landini1 and
- Massimo Lombardi1
© Positano et al; licensee BioMed Central Ltd. 2010
Published: 21 January 2010
The use of animal models in basic and preclinical sciences offers the possibility of testing new biomarkers, as well as to obtaining predictive model of the compound distribution and profile.
This study was designed to evaluate the performances of a clinical 3T scanner together with a Dynamic Nuclear Polarization for 13C metabolic imaging in rats.
10 healthy rats (350±20g) were examined with 1H MR imaging and hyperpolarized 13C MRS. The rats were sedated with infusion of Zoletil (50 mg/kg/h i.v.) and injected intravenously with 2 mL of 80 mM [1-13C]pyruvate over 5 s; ECG, temperature, respiration and blood pressure from femoral vein catheter was monitored by SA instruments (SAI Inc).
[1-13C]pyruvate hyperpolarization was performed with a Hypersense DNP polarizer (Oxford Inst.Ltd.). The formulation contained 80 mM [1-13C]pyruvate, 40 mM TRIS buffer, 0.27 mM Na2EDTA, 41 mM NaCl, and 5 μM Dotarem (Guerbet). The solution was isotonic (290mOsm) and pH ~ 7.6 at ~ 37 C
The experiments were performed at 3T GE Signa HDx (GE Healthcare) scanner with a 13C dual-tuned rat coil. High resolution anatomical images were acquired in all three planes using a fast-spin echo sequence. 13C dynamic spectra were acquired using elliptic-FIDCSI (GE Healthcare) pulse sequence without phase-encodings (bandwidth 5000Hz, 256 pts, 10° FA). For spatial information the same elliptic-FIDCSI sequence, with a bandwidth= 5000, 256 pts, TR=80msec, FA=10°, 10mm axial slice, 80x80 mm FOV and phase encoding matrix 16x16 was used.
Data processing was performed by using Matlab® and jMRUI software tools. Pyruvate, lactate, and bicarbonate were estimated using the AMARES algorithm of jMRUI and the metabolic curves and maps were generated.
The spatial localization of 13C metabolite in the rat heart can be achieved at 3T clinical scanner with a multiple voxel peak analysis with some limitations (spatial resolution). The feasibility of the same approach can be explored in larger compartments (liver, skeletal muscle) for small animal.
This article is published under license to BioMed Central Ltd.