Proton electron double resonance imaging (PEDRI) of the isolated beating rat heart

Thibaut Liebgott, Haihong Li, Yuanmu Deng, Jay L. Zweier

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Proton electron double resonance imaging (PEDRI) is a double resonance technique where proton MRI is performed with irradiation of a paramagnetic solute. A low-field PEDRI system was developed at 20.1 mT suitable for imaging free radicals in biological samples. With a new small dual resonator, PEDRI was applied to image nitroxide free radicals in isolated beating rat hearts. Experiments with phantoms showed maximum image enhancement factors (IEF) of 42 or 28 with TEMPONE radical concentrations of 2-3 mM at EPR irradiation powers of 12W or 6W, respectively. In the latter case, image resolution better than 0.5 mm and radical sensitivity of 5 μM was obtained. For isolated heart studies, EPR irradiation power of 6W provided optimal compromise of modest sample heating with good SNR. Only a small increase in temperature of about 1°C was observed, while cardiac function remained within 10% of control values. With infusion of 3 mM TEMPONE an IEF of 15 was observed enabling 2D or 3D images to be obtained in 27 sec or 4.5 min, respectively. These images visualized the change in radical distribution within the heart during infusion and clearance. Thus, PEDRI enables rapid and high-quality imaging of free radical uptake and clearance in perfused hearts and provides a useful technique for studying cardiac radical metabolism.

Original languageEnglish (US)
Pages (from-to)391-399
Number of pages9
JournalMagnetic Resonance in Medicine
Issue number2
StatePublished - Aug 1 2003
Externally publishedYes


  • EPR imaging
  • Free radicals
  • Nitroxide
  • Overhauser imaging
  • Rat heart
  • Redox state

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology


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