First determination of the heart-to-mediastinum ratio using cardiac dual isotope (¹²³I-MIBG/⁹⁹mTc-tetrofosmin) CZT imaging in patients with heart failure: the ADRECARD study

Eur J Nucl Med Mol Imaging. 2015 Nov;42(12):1912-9. doi: 10.1007/s00259-015-3141-3. Epub 2015 Jul 31.

Abstract

Purpose: Cardiac innervation is assessed using the heart-to-mediastinum ratio (HMR) of metaiodobenzylguanidine (MIBG) on planar imaging using Anger single photon emission computed tomography (A-SPECT). The aim of the study was to determine the HMR of MIBG obtained using a CZT-based camera (D-SPECT; Spectrum Dynamics, Israel) in comparison with that obtained using conventional planar imaging.

Methods: The ADRECARD study prospectively evaluated 44 patients with heart failure. They underwent planar acquisition using the A-SPECT camera 4 h after (123)I-MIBG injection (236.4 ± 39.7 MBq). To localize the heart using D-SPECT, (99m)Tc-tetrofosmin (753 ± 133 MBq) was administered and dual isotope acquisition was performed using the D-SPECT system. HMR was calculated using both planar A-SPECT imaging and front view D-SPECT cine data. In a phantom study, we estimated a model fitting the A-SPECT and the D-SPECT data that was further applied to correct for differences between the cameras.

Results: A total of 44 patients (39 men and 5 women, aged 60 ± 11 years) with ischaemic (31 patients) and nonischaemic (13 patients) cardiomyopathy completed the study. Most patients (28 of 44) were NYHA class II, and the mean left ventricular ejection fraction was 33 ± 7 %. The mean HMR values were 1.34 ± 0.15 and 1.45 ± 0.27 from A-SPECT and D-SPECT, respectively (p < 0.0001). After correction, Lin's concordance correlation showed an almost perfect concordance between corrected D-SPECT HMR and A-SPECT HMR, and Bland-Altman analysis demonstrated a high agreement between the two measurements.

Conclusion: The ADRECARD study demonstrated that determination of late HMR during cardiac MIBG imaging using dual isotope ((123)I and (99m)Tc) acquisition on a CZT camera (D-SPECT) is feasible in patients with heart failure. A linear correction based on the phantom study yielded a high agreement between (123)I MIBG HMR obtained using a CZT camera and that from conventional planar imaging.

Keywords: CZT; D-SPECT; Dual isotope; Heart failure; Heart-to-mediastinum ratio; MIBG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Iodobenzylguanidine*
  • Adult
  • Aged
  • Female
  • Gamma Cameras*
  • Heart / diagnostic imaging*
  • Heart Failure / diagnostic imaging*
  • Humans
  • Male
  • Mediastinum / diagnostic imaging*
  • Middle Aged
  • Organophosphorus Compounds*
  • Organotechnetium Compounds*
  • Phantoms, Imaging
  • Tomography, Emission-Computed, Single-Photon / instrumentation*

Substances

  • Organophosphorus Compounds
  • Organotechnetium Compounds
  • 3-Iodobenzylguanidine
  • technetium tc-99m tetrofosmin