PET and NMR dual acquisition (PANDA): applications to isolated, perfused rat hearts

TLDR

Positron emission tomography and nuclear magnetic resonance spectroscopy are non‑invasive techniques that enable serial metabolic measurements in a single subject. The study aims to combine these modalities on a single machine to gain significant advantages. A compact PET scanner was built to fit within a 9.4 T NMR magnet, and simultaneous 31P NMR spectra and PET images were acquired from isolated perfused rat hearts using a custom NMR probe. The PET scanner’s sensitivity and spatial resolution were unaffected by the high magnetic field, though field homogeneity decreased slightly, and the resulting images clearly resolved cardiac structures, demonstrating the feasibility and potential of simultaneous PET/NMR acquisition in perfused rat hearts. © 1997 John Wiley & Sons, Ltd.

Abstract

Positron emission tomography and nuclear magnetic resonance spectroscopy are non-invasive techniques that allow serial metabolic measurements to be obtained in a single subject. Significant advantages could be obtained if both types of scans could be acquired with a single machine. A small-scale PET scanner, designed to operate in a high magnetic field, was therefore constructed and inserted into the top half of a 7.3 cm bore, 9.4 T NMR magnet and its performance characterized. The magnetic field did not significantly affect either the sensitivity (∼ 3 kcps/MBq) or the spatial resolution (2.0 mm full width at half maximum, measured using a 0.25 mm diameter line source) of the scanner. However, the presence of the PET scanner resulted in a small decrease in field homogeneity. The first, simultaneous 31P NMR spectra (200, 80° pulses collected at 6 s intervals) and PET images (transverse, mid-ventricular slices at the level of the mitral value) from isolated, perfused rat hearts were acquired using a specially designed NMR probe inserted into the bottom half of the magnet. The PET images were of excellent quality, enabling the left ventricular wall and interventricular septum to be clearly seen. In conclusion, we have demonstrated the simultaneous acquisition of PET and NMR data from perfused rat hearts; we believe that the combination of these two powerful techniques has tremendous potential in both the laboratory and the clinic. © 1997 John Wiley & Sons, Ltd.