Author/Authors :
Söylemez, Deniz Sitki Koçman University - School of Medicine Training and Research Hospital - Department of Nuclear Medicine, Turkey , Erselcan, Taner Sitki Koçman University - School of Medicine Training and Research Hospital - Department of Nuclear Medicine, Turkey
Abstract :
Objective: We aimed to investigate patient-related factors that might lead to calculation bias in the ejection fraction (EF), obtained by Myocardial Perfusion Scintigraphy (MPS). In this respect, relationships between EF and some biological and morphological parameters such as gender, left ventricular (LV) volumes, LV areas, beat per minute (BPM) were evaluated in 2 groups of patients (EF normal, above normal). Method: Patients with hypertension, diabetes, CAD, MI, cardiomyopathy, heart failure, left bundle branch block, electrocardiogram (ECG) signs or suspicion of MI were excluded. 87 patients (37 male, 50 female, mean of age: 59 ± 12; 57 ± 11 years) who have visually and quantitatively normal MPS were included to the study. One day stress Tc99m-MIBI gated SPECT protocol was performed. A commercial software (QGS) was used for calculations. Patients were divided into two groups according to the average EF: 72.5 ± 10%; Group 1: EF 72% and Group 2: EF 50-72%. Results: Statistically significant correlation (p= 0.001) was noted between EF and end-systolic volume (ESV) (r=-0.89), end-diastolic volume (EDV) (r=-0.75), maximum LV area (LVA max)(r=-0.79) and minimum LV area (LVAmin) (r=0.90) both in two groups; while there was significant a weak correlation with BPM (p 0.03). The ESV was 20 mL in all patients in Group 1. Therefore, patients in Group 2 were divided into two sub-groups, such that Group2a consisted of patients with ESV 20 mL and Group2b with ESV 20 mL. While significant correlation was observed between EF with ESV, EDV, LVAmax and LVAmin. values in 29 patients of Group 2b (p 0.001), there was no correlation in 18 patients of Group 2a (p 0.01). Conclusion: Although, it is known that EF is overestimated in patients with ESV 20 mL, EF values were within normal range, in a group of patients with ESV 20 mL in our study. Therefore, we believe that EF values have some non-systematic bias, probably resulting from the calculation technique and partial volume effect that there is a need for correction parameters to improve the accuracy of the quantitative evaluation in MPS.
NaturalLanguageKeyword :
Myocardial perfusion scintigraphy , ejection fraction , end , systolic volumes
