Phantom-Based Standardization Method for <sup>123</sup>I-meta-iodobenzylguanidine Heart-to-Mediastinum Ratio Validated by D-SPECT Versus Anger Camera

Background: The 123I-metaiodobenzylguanidine heart-to-mediastinum ratios (HMRs) have been standardized between D-SPECT and Anger cameras in a small patient cohort using phantom-based conversion method. This study aimed to determine the validity of this method compare diagnostic performance two larger cohort.Methods: We retrospectively calculated HMRs from early late anterior-planar equivalent planar images acquired 173 patients 177 studies cameras, respectively. were cross-calibrated an camera coefficients based on previous phantom findings, then medium-energy general-purpose collimator conditions. Relationships before after corrections investigated. Late classified into four cardiac mortality risk groups divided threshold 2.2 verify concordance.Results: Correction improved linear regression lines differences among groups. overall perfect concordance (134 [75.7%] 177), higher with very low (49 [80.3%] 61) high (51 [86.4%] 59) when HMR was according risk. That systems highest (164 [92.7%] 177) by value 2.2.Conclusions: Phantom-based can standardize because provided comparable performance. Our findings indicated that could be applied multicenter include both cameras.