Several multicenter studies and meta-analysis in Europe, the USA and Japan have indicated the value of sympathetic innervation imaging using
123I-
meta-iodobenzylguanidine (MIBG) for patients with heart failure (HF) [
1‐
5]. The Clinical Practice Guidelines of Nuclear Cardiology published by the Japanese Circulation Society included this procedure based on the considerable accumulation of clinical experience with
123I-MIBG in Japan [
6,
7]. The European Association of Nuclear Medicine (EANM) Cardiovascular Committee and the European Council of Nuclear Cardiology have proposed MIBG protocols [
8], and the American Society of Nuclear Cardiology (ASNC) imaging guidelines also summarize the application of
123I-MIBG and its methodology [
9]. In addition to cardiology,
123I-MIBG has been used since the late 1990s with increasing frequency in patients with Parkinson’s disease and dementia with Lewy bodies, in whom cardiac
123I-MIBG uptake characteristically decreases due to neural degeneration [
10,
11]. Thus,
123I-MIBG findings are considered as a biomarker of Lewy-body disease.
Although reproducibility of the heart-to-mediastinum ratio (HMR) is generally believed to be good [
12], a major factor affecting HMR is differences among camera collimators at various hospitals [
13]. For example, average normal values of late HMR are 2.5 with low-energy (LE) collimators and 3.0 for medium-energy (ME) collimators [
14]. In fact, collimator designs are further divided into at least 6–7 collimator groups [
15], and these differences are supposed to be mainly caused by different degrees of septal penetration and scatter in collimators, and the precise specifications of the size and length of holes and septal thickness are variable among vendors. We, therefore, developed a phantom-based correction method to cross-calibrate HMR among all Anger camera collimator systems [
14]. Several phantom experiments have shown that even collimators of the same type, for example, low-energy high resolution (LEHR), have different specifications depending on the designs of vendors [
17]. D-SPECT (Spectrum Dynamics, Israel; Biosensors Japan, Tokyo, Japan) has a cadmium–zinc–telluride (CZT) detector that enables high resolution and high sensitivity in myocardial perfusion imaging [
17]. However, tomographic imaging is the standard output, and planar images commonly used with Anger cameras are not directly used. Differences between the Anger and D-SPECT cameras were investigated in the ADRECARD study, in which virtual anterior planograms were created with D-SPECT, and the HMR between the two methods correlated well [
18].
The present study aimed to create a method of integrating HMR derived from D-SPECT planogram and Anger cameras using the same phantom-based conversion method to generate comparable quantitative parameters in 123I-MIBG study.