[Cardiac metabolism and perfusion evaluation in a rat model using 18F- FDG, 1-11C-acetate, 13NH3 and micro-positron emission tomography (microPET)].

OBJECTIVE

To standardize an acquisition protocol for the study of myocardial glucolitic and oxidative metabolism and perfusion in a rat model.

METHODS

Studies were carried out with the three main radiopharmaceuticals used to assess heart function:[18F]-FDG for glucolitic metabolism; [1-11C]-acetate for oxidative metabolism and [13N]-NH3for myocardial perfusion.[18F]-FDG -Five Wistar adult male rats were studied in three different protocols: non-fasting group, fasting group,8 h before the study with water provided ad libitum, and a fasting group by the same time receiving an oral 50%-glucose solution. Thirty-minute scans were performed with a microPET Focus 120, 30 and 60 min after the administration of 370 - 555 MBq 18F-FDG. [1-11C]-Acetate -Eight rats were studied. Four static and four dynamic 30 min acquisitions after a 370 - 555 MBq of [1-11C]-acetate caudal vein administration.[13N]-NH3-Ten static studies were acquired 15 min post-administration of 370- 555 MBq of 13NH3 isofluorane anesthesia. Comparative and visual analyses wy performer by two experts in the field. A semi-quantitative analysis was performa using 3D reconstructions and ROI selections with AMIDE software.

RESULTS

The best images were those obtained from the non-fasting group, especially those taken at 60 min after the [18F]-FDG administration. High quality myocardial, static images were obtained with [1-11C]-acetate, and the dynamic adquisitions allowed the identification of myocardial perfusion. The 13NH3images showed a homogeneous distribution of the radiotracer in different segments of the short, long and horizontal axes in the left ventricle.

CONCLUSIONS

It is possible to standardize the microPET acquisition protocols for the three main radiopharmaceuticals to evaluate the heart function in a rat model. It is feasible to establish a valid protocol for measuring glucolitic and oxidative myocardial metabolism and perfusion for gene, drug or surgical therapy assessment.