title: Repeatability of automatic left ventricular cavity volume measurements from myocardial perfusion SPECT.
abstract: BACKGROUND
  This study sought to assess the repeatability of automatic quantitative measurements of left ventricular (LV) cavity volumes in a large patient population (N = 926), to correlate those measurements to similarly obtained LV ejection fraction (LVEF) measurements, and to investigate the relationship between ungated and gated volumes.
  
  
  METHODS
  All 926 patients underwent ungated single photon emission computed tomography (SPECT) immediately followed by 8-frame gated SPECT. LV cavity volumes were automatically measured from ungated (V), summed gated (SUMV), end-systolic (ESV) and end-diastolic (EDV) images, and LVEFs derived from the latter 2.
  
  
  RESULTS
  Repeatability (SUMV vs V) was very good overall (6.4%+/-6.6%), further improving for volumes >25 mL (5.7%+/-5.5%) and >40 mL (5.2%+/-5.0%). Exponential regression between ESV and LVEF (r = 0.925, SEE = 15.0 mL), EDV and LVEF (r = 0.802, SEE = 24.2 mL), and SUMV and LVEF (r = 0.867, SEE = 19.7 mL) was also very good. Summed gated volumes were closer to ESV than to EDV (43.3%+/-8.8% of EDV-ESV range). SUMV <50 mL and SUMV >110 mL were good substitutes for LVEF >50% and LVEF <40% (93.4% and 97.1%, respectively).
  
  
  CONCLUSIONS
  Automatic quantitative measurements of gated and ungated volumes with our algorithm are repeatable, correlate well with other global myocardial parameters, and may contribute important additional information to that conventionally provided by myocardial perfusion SPECT studies.
authors.affiliation: Cedars-Sinai Research Institute, Cedars-Sinai Medical Center, Department of Radiological Sciences, UCLA School of Medicine, Los Angeles, Calif, USA. germano@nucmed.csmc.edu
authors.forename: G
authors.initials: G
authors.lastname: Germano
authors.forename: P B
authors.initials: PB
authors.lastname: Kavanagh
authors.forename: J T
authors.initials: JT
authors.lastname: Kavanagh
authors.forename: S H
authors.initials: SH
authors.lastname: Wishner
authors.forename: D S
authors.initials: DS
authors.lastname: Berman
authors.forename: G J
authors.initials: GJ
authors.lastname: Kavanagh
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D013318:Stroke Volume; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left