title: Assessment of myocardial adrenergic innervation with a solid-state dedicated cardiac cadmium-zinc-telluride camera: first clinical experience.
abstract: OBJECTIVE
  To investigate the relationships between regional adrenergic innervation heterogeneity, myocardial perfusion, and contractile function obtained by means of a low-dose imaging protocol with a cadmium-zinc-telluride (CZT) dedicated camera.
  
  
  METHODS
  Twenty-eight patients with or without ischaemic heart disease underwent (123)I-metaiodobenzylguanidine (MIBG) planar scintigraphic and CZT early and delayed evaluations followed by (99m)Tc-tetrofosmin rest gated CZT with a single-day protocol. The heart-to-mediastinum ratio and the washout rate were computed from planar (123)I-MIBG images. The summed (123)I-MIBG defect scores (SS-MIBG) were semi-quantitatively assessed from CZT images. The summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were quantitated from (99m)Tc-tetrofosmin images.
  
  
  RESULTS
  Sixteen patients showed a depressed left ventricular systolic function [ejection fraction (EF)<50%]. They presented higher SRS (P = 0.007), SMS (P < 0.001), STS (P < 0.001), and early SS-MIBG (P = 0.007) values than those with normal contractile function. Interestingly, higher early SS-MIBG values, index of regional sympathetic innervation heterogeneity, clustered with more elevated SRS (P = 0.023), and more impaired measures of regional and global left ventricle systolic function, i.e. SMS (P = 0.046), STS (P = 0.014), and EF (P = 0.027). At multivariate analysis, a higher SRS (P = 0.039) remained the only independent predictor of more elevated early SS-MIBG values. In the 20 of 28 ischaemic patients, the correlations between early SS-MIBG and SMS (P = 0.017) and also STS (P = 0.036) were further confirmed. The effective dose of the investigation was 4.2 ± 0.72 mSv.
  
  
  CONCLUSIONS
  An altered early SS-MIBG, assessed with a low-dose imaging protocol and a CZT cardiac camera, identifies patients with more impaired myocardial perfusion and contractile function.
authors.affiliation: Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1, 56124 Pisa, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Gimelli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Liga
authors.forename: Assuero
authors.initials: A
authors.lastname: Giorgetti
authors.forename: Dario
authors.initials: D
authors.lastname: Genovesi
authors.forename: Paolo
authors.initials: P
authors.lastname: Marzullo
mesh_terms: D019797:3-Iodobenzylguanidine; D059331:Adrenergic Neurons; D000368:Aged; D002104:Cadmium; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011857:Radiographic Image Interpretation, Computer-Assisted; D019275:Radiopharmaceuticals; D013691:Tellurium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D015032:Zinc
chemical_list: C474490:CdZnTe; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D002104:Cadmium; D019797:3-Iodobenzylguanidine; C078700:technetium tc-99m tetrofosmin; D015032:Zinc; D013691:Tellurium
keywords: 123I-MIBG; CZT camera; Cardiac innervation; Heart-to-mediastinum ratio