Evaluation of left ventricular endocardial volumes and ejection fractions computed from gated perfusion SPECT with magnetic resonance imaging: comparison of two methods.
BACKGROUND
Two methods of computing left ventricular volumes and ejection fraction (EF) from 8-frame gated perfusion single photon emission computed tomography (SPECT) were compared with each other and with magnetic resonance (MR) imaging.


RESULTS
Thirty-five subjects underwent 8-frame gated dual-isotope SPECT imaging and 12- to 16-frame gated MR imaging. Endocardial boundaries on short-axis MR images were hand traced by experts blinded to any SPECT results. Volumes and EF were computed with the use of Simpson's rule. SPECT images were analyzed for the same functional variables with the use of 2 automatic programs, Quantitative Gated SPECT (QGS) and the Emory Cardiac Toolbox (ECTb). The mean difference between MR and SPECT EF was 0.008 for ECTb and 0.08 for QGS. QGS showed a slight trend toward higher correlation for EF (r = 0.72, SE of the estimate = 0.08) than ECTb (r = 0.70, SE of the estimate = 0.09). For both SPECT methods, left ventricular volumes were similarly correlated with MR, although SPECT volumes were higher than MR values by approximately 30%.


CONCLUSIONS
QGS and ECTb values of cardiac function computed from 8-frame gated perfusion SPECT correlate very well with each other and correlate well with MR. Averaged over all subjects, ECTb measurements of EF are not significantly different from MR values but QGS significantly underestimates the MR values.
Faber
T L
TL
Department of Radiology, Emory University School of Medicine, Atlanta, GA 30322, USA. Tracy_Faber@emory.org
Vansant
J P
JP
Pettigrew
R I
RI
Galt
J R
JR
Blais
M
M
Chatzimavroudis
G
G
Cooke
C D
CD
Folks
R D
RD
Waldrop
S M
SM
Gurtler-Krawczynska
E
E
Wittry
M D
MD
Garcia
E V
EV
D002306:Cardiac Volume / Q000502:physiology*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D013318:Stroke Volume / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000503:physiopathology