Influence of collimator choice and simulated clinical conditions on 123I-MIBG heart/mediastinum ratios: a phantom study

Abstract

For straightforward implementation of semi-quantitative (123)I-MIBG myocardial studies, we recommend the use of ME collimators without scatter correction.

How to use myocardial 123I-MIBG scintigraphy in chronic heart failure

“…These high-energy photons lead to penetration of the collimator septa and cause scatter detected in the 159-keV energy window. Septal penetration affects estimation of the H/M ratio in 123 I-MIBG imaging with a low-energy (LE) collimator [17]. Nevertheless, LE collimators are frequently used for imaging 123 I-MIBG [12,18].…”

“…Nevertheless, LE collimators are frequently used for imaging 123 I-MIBG [12,18]. Medium-energy (ME) collimators have been shown to provide better quantitative accuracy in 123 I studies [17][18][19]. Therefore, in order to minimize the effects of septal penetration the ME collimator is preferred.…”

“…The triple energy window (TEW) scatter correction method estimates the scatter component in the prime photopeak from counts in a window just below and above the prime photopeak window [21]. Data on the effect of this TEW scatter correction method in 123 I studies on semiquantitative cardiac analysis are limited [17,19]. Although TEW scatter correction increases all planar ME collimated H/M ratios, TEW scatter correction does not improve the contrast between the ME collimated H/M ratios.…”

Standardization of metaiodobenzylguanidine heart to mediastinum ratio using a calibration phantom: effects of correction on normal databases and a multicentre study

“…Inter-institutional differences in MIBG quantification using the heart-tomediastinum ratio (H/M) have hampered multi-center comparison of the H/M ratio, and single-center results could not easily be extrapolated to other hospitals [8]. Since the difference in collimator type has been investigated and found to be one of the major confounders of the results, a practical standardization method for quantification has been sought [9][10][11][12].In neurological studies, patients with Parkinson disease and dementia with Lewy bodies (DLB), which is categorized as Lewy-body disease demonstrated significantly lower H/ M ratios both in early and late imaging [4][5][6][7]. Since the patients with Lewy-body disease showed lower H/M values compared with those of normal populations, we used this patient group for a pilot study of the procedure for correction of H/M ratios.…”

Cardiac autonomic imaging with SPECT tracers

“…However, because of septal penetration by higher energy ([400 keV) 123 I photons, mostly a 529-keV emission, some have recommended using a medium energy collimator that has been shown to provide superior quantitative accuracy. 36,43,44 To compensate for the resulting corruption of image quantitation related to LEHR collimator penetration by higher energy photons, Chen et al 45,46 have developed a mathematical technique (iterative reconstruction with deconvolution of septal penetration) that appears to improve quantitative accuracy of cardiac 123 I-mIBG uptake in reference to a phantom standard. Clinical applications have yet to be determined.…”