title: The impacts of severe perfusion defects, akinetic/dyskinetic segments, and viable myocardium on the accuracy of volumes and LVEF measured by gated ⁹⁹mTc-MIBI SPECT and gated ¹⁸F-FDG PET in patients with left ventricular aneurysm: cardiac magnetic resonance imaging as the reference.
abstract: BACKGROUND
  To compare the accuracy of end-diastolic and end-systolic volumes (EDV, ESV) and LV ejection fraction (LVEF) measured by both GSPECT and GPET, using cardiac magnetic resonance imaging (CMR) as a reference. Furthermore, the impacts of severe perfusion defects, akinetic/dyskinetic segments, and residual viable myocardium on the accuracy of LV functional parameters were investigated.
  
  
  METHODS
  Ninety-six consecutive patients with LV aneurysm and LV dysfunction (LVEF 32 ± 9%) diagnosed by CMR were studied with GSPECT and GPET. EDV, ESV, and LVEF were calculated using QGS software.
  
  
  RESULTS
  Correlations of volumes were excellent (r 0.81-0.86) and correlation of LVEF was moderate (r 0.65-0.76) between GSPECT vs CMR and between GPET vs CMR. Compared with CMR, ESV was overestimated by GSPECT (P < .01) and underestimated by GPET (P < .0001); EDV was underestimated by GPET (P < .001); LVEF was underestimated by GSPECT but overestimated by GPET (both P < .001). Multivariate regression analysis revealed that the number of segments with severe perfusion defects (P < .001) was the only independent factor which was correlated to the EDV difference between GSPECT and CMR, the number of akinetic/dyskinetic segments with absent wall thickening (WT) was the only independent factor which was significantly correlated to the differences of ESV and LVEF measurements between GSPECT vs CMR and between GPET vs CMR (P < .0001), respectively. Neither the mismatch score nor the segments with viable myocardium were correlated to the differences of LV volumes and LVEF measurements between different imaging modalities.
  
  
  CONCLUSIONS
  In LV aneurysm patients, LV volumes and LVEF measured by both GSPECT and GPET imaging correlated well with those determined by CMR, but should not be interchangeable in individual patients. The accuracy of LVEF measured by GSPECT and GPET was affected by the akinetic/dyskinetic segments with absent WT.
authors.affiliation: Department of Nuclear Medicine, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 10037, People's Republic of China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Wei
authors.forename: Congna
authors.initials: C
authors.lastname: Tian
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Schindler
authors.forename: Mei
authors.initials: M
authors.lastname: Qiu
authors.forename: Minjie
authors.initials: M
authors.lastname: Lu
authors.forename: Rui
authors.initials: R
authors.lastname: Shen
authors.forename: Yueqin
authors.initials: Y
authors.lastname: Tian
authors.forename: Shi-hua
authors.initials: SH
authors.lastname: Zhao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
mesh_terms: D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging; D005260:Female; D019788:Fluorodeoxyglucose F18; D006322:Heart Aneurysm / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods / Q000592:standards; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D017256:Technetium Tc 99m Sestamibi; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D017256:Technetium Tc 99m Sestamibi