title: The Utility of Segmental Analysis in Cardiac I-123 MIBG SPECT in Parkinson's Disease.
abstract: OBJECTIVE
  Cardiac images using I-123 metaiodobenzylguanidine (MIBG) are widely used to evaluate cardiac sympathetic denervation in Parkinson's disease (PD). The aim of this study was to evaluate the utility of segmental analysis on cardiac MIBG SPECT in PD patients.
  
  
  METHODS
  In total, 36 patients with PD (n = 26) or essential tremor (ET, n = 10) who underwent MIBG cardiac SPECT were enrolled. The heart-to-mediastinum (H/M) ratios of MIBG uptake were acquired on planar images. For the segmental analysis of SPECT images, we evaluated the summed defect score (SDS) using a 17-segment model. The diagnostic abilities of H/M ratios and segmental parameters on MIBG SPECT were assessed by ROC curve analysis.
  
  
  RESULTS
  The H/M ratios were significantly lower in PD than in ET patients (p < 0.05). On segmental analysis, SDS was significantly higher in PD patients than in the ET group (7.04 ± 4.09 vs. 2.90 ± 2.80; p = 0.006). The defect score of the anteroseptal region showed a significant difference between the groups (p = 0.002). The ROC analysis suggested only SDS (AUC = 0.785, p = 0.0003) and defect scores in the anteroseptal (AUC = 0.800, p < 0.0001) and inferior (AUC = 0.667, p = 0.013) regions showed significant diagnostic ability to differentiate PD from ET.
  
  
  CONCLUSIONS
  Segmental parameters from cardiac MIBG SPECT images can provide additional information to differentiate PD from ET patients. Beyond H/M ratios from planar images, we recommend an MIBG SPECT study to evaluate sympathetic denervation in PD.
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Kwon
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Joon-Kee
authors.initials: JK
authors.lastname: Yoon
authors.affiliation: Department of Neurology, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Jung Han
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Kyung Sook
authors.initials: KS
authors.lastname: Jo
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Ajou University School of Medicine, 164, World cup-ro, Yeongtong-gu, Suwon, 443-380 Republic of Korea.
authors.forename: Young-Sil
authors.initials: YS
authors.lastname: An
keywords: Heart; I-123 MIBG; Parkinson’s disease; SPECT; Segmental analysis