title: Subendocardial versus transmural ischaemia in myocardial perfusion SPECT--a Monte Carlo study.
abstract: Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) is useful for the evaluation of patients with known or suspected coronary artery disease. Parameters of interest are the reduction in the blood perfusion (severity) and the lesion volume (extent). The aim of this study was to evaluate these parameters, as calculated by automatic quantification software, for different cases of subendocardial and transmural myocardial lesions.
  
  
  METHODS
  A computer phantom was used to simulate 32 male patients with different defect locations and activity uptakes, which were based on clinical patient studies. The Monte Carlo program SIMIND was used to simulate realistic SPECT projections which were reconstructed to give short-axis images, analysed by the AutoQUANT program using the same procedure as for a real patient.
  
  
  RESULTS
  The results showed a disparity between the quantification of transmural and subendocardial lesions with the same lesion activity uptake reduction and this could be confirmed by visual interpretation. Neither the parameters given by the quantification program nor visual interpretation could distinguish between the transmural lesions and the subendocardial lesions with activity uptake reduction twice as high as in the corresponding transmural lesions.
  
  
  CONCLUSIONS
  Transmural lesions and the corresponding subendocardial lesions with the same activity uptake reduction could be separated by the quantification software for SPECT imaging and visual analysis. The subendocardial lesions with activity uptake reduction twice as high as in the corresponding transmural lesions could not be differentiated neither by the quantification software nor by visual interpretation. Thus these lesions will get the same scoring when analysed by the AutoQUANT program.
authors.affiliation: Department of Clinical Physiology, Helsingborg Hospital, Helsingborg, Sweden. jolanta.bartosik@helsingborgslasarett.se
authors.forename: Jolanta
authors.initials: J
authors.lastname: Bartosik
authors.forename: Henrik Hussein
authors.initials: HH
authors.lastname: El-Ali
authors.forename: Ulf
authors.initials: U
authors.lastname: Nilsson
authors.forename: Jan
authors.initials: J
authors.lastname: Dahlström
authors.forename: Lars
authors.initials: L
authors.lastname: Edenbrandt
authors.forename: Michael
authors.initials: M
authors.lastname: Ljungberg
mesh_terms: D001185:Artificial Intelligence; D003198:Computer Simulation; D004699:Endocardium / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D008297:Male; D009010:Monte Carlo Method; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000473:pathology*; D015425:Myocardial Reperfusion / Q000295:instrumentation; D019047:Phantoms, Imaging; D012107:Research Design; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation