title: Diagnostic accuracy of cadmium-zinc-telluride-based myocardial perfusion SPECT: impact of attenuation correction using a co-registered external computed tomography.
abstract: BACKGROUND
  Computed tomography (CT)-based attenuation correction (AC) improves the accuracy of standard myocardial perfusion SPECT. Most dedicated cadmium-zinc-telluride (CZT) SPECT cameras are not equipped with an integrated CT component. We aimed to determine the impact of AC on diagnostic performance of CZT SPECT using co-registration with an external low-dose CT.
  
  
  METHODS
  Sixty patients underwent CZT SPECT (GE Discovery 530c) with (99m)Tc-sestamibi at rest and following regadenoson stress. Using commercial software, SPECT images were co-registered with a low-dose CT acquired on a separate system (GE Discovery 670NMCT). Attenuation corrected and non-corrected (NC) images were reconstructed using an iterative algorithm. Accuracy was measured in 44 patients who had undergone invasive angiography within 6 months. Normalcy was compared in the remaining 16 patients who had a low pre-test likelihood (<5%) of coronary artery disease (CAD).
  
  
  RESULTS
  Summed stress and rest scores were significantly lower in AC images (9 ± 8 vs. 13 ± 9 and 6 ± 7 vs. 10 ± 9, P = 0.01), while summed difference score did not differ. According to angiography, 38 patients had significant CAD in 71 vascular territories. Attenuation correction improved accuracy globally (P = 0.03) and in RCA territory (P = 0.008). Specificity improved both globally (100 vs. 40%, P < 0.05) and in each individual territory (LAD: 63 vs. 36%, LCX: 70 vs. 33%, RCA: 81 vs. 19%, P < 0.01). Normalcy was 100% for AC and 62.5% for NC images (P < 0.05).
  
  
  CONCLUSIONS
  Attenuation correction with a co-registered external CT is feasible using CZT cameras and improves diagnostic accuracy mostly by improving specificity over uncorrected images.
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany caobelli.federico@mh-hannover.de.
authors.forename: Federico
authors.initials: F
authors.lastname: Caobelli
authors.affiliation: Department of Clinical Cardiology, Hannover Medical School, Hannover, Germany.
authors.forename: Muharrem
authors.initials: M
authors.lastname: Akin
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany.
authors.forename: James T
authors.initials: JT
authors.lastname: Thackeray
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Brunkhorst
authors.affiliation: Department of Clinical Cardiology, Hannover Medical School, Hannover, Germany.
authors.forename: Julian
authors.initials: J
authors.lastname: Widder
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Berding
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Burchert
authors.affiliation: Department of Clinical Cardiology, Hannover Medical School, Hannover, Germany.
authors.forename: Johann
authors.initials: J
authors.lastname: Bauersachs
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl Neuberg Strasse, 1, 30625 Hannover, Germany.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Bengel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002104:Cadmium; D016022:Case-Control Studies; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013691:Tellurium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D015032:Zinc
chemical_list: C474490:CdZnTe; D002104:Cadmium; D015032:Zinc; D013691:Tellurium
keywords: Attenuation correction; CZT SPECT; Coronary artery disease; Myocardial perfusion imaging