title: An automatic method for quantification of myocardium at risk from myocardial perfusion SPECT in patients with acute coronary occlusion.
abstract: BACKGROUND
  In order to determine myocardial salvage, accurate quantification of myocardium at risk (MaR) is necessary. We present a validated novel automatic segmentation algorithm for quantification of MaR by myocardial perfusion SPECT (MPS) in patients with acute coronary occlusion.
  
  
  RESULTS
  Twenty-nine patients with coronary occlusion were injected with a perfusion tracer before reperfusion, and underwent rest MPS within 4 hours. The MaR was quantified using the proposed algorithm (Segment software), the software Quantitative Perfusion SPECT (QPS) and by manual segmentation. The Segment MaR algorithm used a threshold of 55% of maximal counts and an a priori model based on normal coronary artery perfusion territories. The MaR was 30 ± 10% left ventricular mass (%LVM) by manual segmentation, 31 ± 12%LVM by Segment, and 36 ± 14%LVM by QPS. There was a good agreement between automatic and manual segmentation for both of the algorithms with a lower bias for Segment (.8 ± 4.0%LVM) than for QPS (5.8 ± 5.8%LVM) when compared to manual segmentation.
  
  
  CONCLUSIONS
  The Segment MaR algorithm can be used to correctly assess MaR from MPS images in patients with acute coronary occlusion without access to tracer-specific normal database. The MaR in relation to final infarct size enables determination of myocardial salvage.
authors.affiliation: Department of Clinical Physiology, Skåne University Hospital, Lund University, 221 85 Lund, Sweden.
authors.forename: Helen
authors.initials: H
authors.lastname: Soneson
authors.forename: Henrik
authors.initials: H
authors.lastname: Engblom
authors.forename: Erik
authors.initials: E
authors.lastname: Hedström
authors.forename: Frederic
authors.initials: F
authors.lastname: Bouvier
authors.forename: Peder
authors.initials: P
authors.lastname: Sörensson
authors.forename: John
authors.initials: J
authors.lastname: Pernow
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
authors.forename: Einar
authors.initials: E
authors.lastname: Heiberg
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D054059:Coronary Occlusion / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D018570:Risk Assessment; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*