Correction of iodine-123-labeled meta-iodobenzylguanidine uptake with multi-window methods for standardization of the heart-to-mediastinum ratio

J Nucl Cardiol. 2007 Nov-Dec;14(6):843-51. doi: 10.1016/j.nuclcard.2007.08.002.

Abstract

Background: To overcome differences in the choice of collimator for an iodine-123 ((123)I)-labeled meta-iodobenzylguanidine (MIBG) heart-to-mediastinum (H/M) ratio, we examined multi-window correction methods with (123)I dual-window (IDW) and triple-energy window (TEW) acquisition.

Methods and results: Standard phantoms, which consisted of the heart, mediastinum, lung, and liver, were generated. Three correction methods were compared: TEW and two IDW methods (IDW(0) and IDW(1)). Low-energy high-resolution (LEHR), medium-energy (ME), and (123)I-specific low-medium-energy high-resolution (LMEHR) collimators were used. Clinical studies were performed in 10 patients. In the phantom study, the H/M ratio was significantly underestimated without correction, with both the LEHR and ME collimators (70% and 88% of the true value). When H/M with the LEHR collimator was divided by uncorrected H/M with the ME collimator, the ratio (mean +/- SD) was 80% +/- 5%, 98% +/- 5%, 104% +/- 7%, and 98% +/- 5% for the no-correction, TEW, IDW(0), and IDW(1) methods, respectively. Clinical studies with the LEHR collimator after TEW and IDW correction (uncorrected average H/M ratio, 1.86 +/- 0.23; TEW, 2.47 +/- 0.46, P = .0015; IDW, 2.46 +/- 0.46, P = .0017) provided comparable values to the uncorrected ME collimator (2.56 +/- 0.46, P = NS vs TEW and IDW).

Conclusions: The H/M ratio with the ME collimator, after application of the TEW or IDW methods, was close to the theoretical value in the phantom study. However, the corrected H/M ratios with the LEHR collimator provided comparable H/M ratios to the uncorrected ME data in phantom and clinical studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Iodobenzylguanidine / pharmacokinetics*
  • Artifacts
  • Calibration
  • Heart / diagnostic imaging
  • Humans
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods*
  • Mediastinum / diagnostic imaging
  • Myocardium / metabolism*
  • Phantoms, Imaging*
  • Positron-Emission Tomography / instrumentation*
  • Positron-Emission Tomography / methods*
  • Radiopharmaceuticals / pharmacokinetics
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • Radiopharmaceuticals
  • 3-Iodobenzylguanidine