Influence of ROI definition on the heart-to-mediastinum ratio in planar123I-MIBG imaging.
Iodine-123-metaiodobenzylguanidine (123I-MIBG) imaging with estimation of the heart-to-mediastinum ratio (HMR) has been established for risk assessment in patients with chronic heart failure. Our aim was to evaluate the effect of different methods of ROI definition on the renderability of HMR to normal or decreased sympathetic innervation.



The results of three different methods of ROI definition (clinical routine (CLI), simple standardization (STA), and semi-automated (AUT) were compared. Ranges of 95% limits of agreement (LoA) of inter-observer variabilities were 0.28 and 0.13 for STA and AUT, respectively. Considering a HMR of 1.60 as the lower limit of normal, 13 of 32 (41%) for method STA and 5 of 32 (16%) for method AUT of all HMR measurements could not be classified to normal or pathologic. Ranges of 95% LoA of inter-method variabilities were 0.72 for CLI vs AUT, 0.65 for CLI vs STA, and 0.31 for STA vs AUT.



Different methods of ROI definition result in different ranges of the LoA of the measured HMR with relevance for rendering the results to normal or pathological innervation. We could demonstrate that standardized protocols can help keep methodological variabilities limited, narrowing the gray zone of renderability.
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany. c.klene@uke.de.
Christiane
C
Klene
Department of Cardiology - Electrophysiology, University Heart Centre, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.|DZHK (German Centre for Cardiovascular Research, partner site Hamburg/Kiel/Lübeck, Germany), Berlin, Germany.
Christiane
C
Jungen
Department of Physics, Kanazawa Medical University, Uchinada, Kahoku, Japan.
Koichi
K
Okuda
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Yuske
Y
Kobayashi
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Annabelle
A
Helberg
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
Janos
J
Mester
Department of Cardiology - Electrophysiology, University Heart Centre, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.|DZHK (German Centre for Cardiovascular Research, partner site Hamburg/Kiel/Lübeck, Germany), Berlin, Germany.
Christian
C
Meyer
Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa, Japan.
Kenichi
K
Nakajima
D019797:3-Iodobenzylguanidine / Q000737:chemistry*; D000368:Aged; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000294:innervation*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008482:Mediastinum / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015588:Observer Variation; D010363:Pattern Recognition, Automated; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System
D019797:3-Iodobenzylguanidine
123I-MIBG; heart-to-mediastinum ratio; standardization