Reproducibility of planar (123)I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy in patients with heart failure.
OBJECTIVE
Despite its high prognostic value, widespread clinical implementation of (123)I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is hampered by a lack of validation and standardization. The purpose of this study was to assess the reliability of planar (123)I-MIBG myocardial scintigraphy in patients with heart failure (HF).


METHODS
Planar myocardial MIBG images of 70 HF patients were analysed by two experienced and one inexperienced observer. The reproducibility of early and delayed heart-to-mediastinum (H/M) ratios, as well as washout rate (WR) calculated by two different methods, was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman analysis. In addition, a subanalysis in patients with a very low H/M ratio (delayed H/M ratio <1.4) was performed. The delayed H/M ratio was also assessed using fixed-size oval and circular cardiac regions of interest (ROI).


RESULTS
Intra- and interobserver analyses and experienced versus inexperienced observer analysis showed excellent agreement for the measured early and delayed H/M ratios and WR on planar (123)I-MIBG images (the ICCs for the delayed H/M ratios were 0.98, 0.96 and 0.90, respectively). In addition, the WR without background correction resulted in higher reliability than the WR with background correction (the interobserver Bland-Altman 95 % limits of agreement were -2.50 to 2.16 and -10.10 to 10.14, respectively). Furthermore, the delayed H/M ratio measurements remained reliable in a subgroup of patients with a very low delayed H/M ratio (ICC 0.93 for the inter-observer analysis). Moreover, a fixed-size cardiac ROI could be used for the assessment of delayed H/M ratios, with good reliability of the measurement.


CONCLUSIONS
The present study showed a high reliability of planar (123)I-MIBG myocardial scintigraphy in HF patients, confirming that MIBG myocardial scintigraphy can be implemented easily for clinical risk stratification in HF.
Department of Cardiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands. c.e.veltman@lumc.nl
Caroline E
CE
Veltman
Mark J
MJ
Boogers
Joris E
JE
Meinardi
Imad
I
Al Younis
Petra
P
Dibbets-Schneider
Ernst E
EE
Van der Wall
Jeroen J
JJ
Bax
Arthur J H A
AJ
Scholte
D019797:3-Iodobenzylguanidine; D000368:Aged; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000592:standards; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D055414:Myocardial Perfusion Imaging / Q000592:standards*; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results
D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine