PT  - JOURNAL ARTICLE
AU  - Christian Vanhove
AU  - Philippe R. Franken
AU  - Michel Defrise
AU  - Afsana Momen
AU  - Hendrik Everaert
AU  - Axel Bossuyt
TI  - Automatic Determination of Left Ventricular Ejection Fraction from Gated Blood-Pool Tomography
DP  - 2001 Mar 01
TA  - Journal of Nuclear Medicine
PG  - 401--407
VI  - 42
IP  - 3
4099  - http://jnm.snmjournals.org/content/42/3/401.short
4100  - http://jnm.snmjournals.org/content/42/3/401.full
SO  - J Nucl Med2001 Mar 01; 42
AB  - The aim of this study was to develop and validate a new algorithm to automatically compute left ventricular ejection fraction (LVEF) from gated blood-pool tomography (GBPT). The results were compared with those of conventional planar radionuclide angiocardiography (PRNA). Methods: Fifty-three consecutive patients received an injection of 740 MBq 99mTc-labeled human serum albumin. PRNA and GBPT were performed consecutively in a random sequence. PRNA served as the reference, and GBPT images were processed using a new edge detection algorithm. The algorithm is fast (<45 s), fully automatic, and works in three-dimensional space. The method includes identification of the valve plane and the septum. The left ventricular cavity at end-diastole is delineated by segmentation using an iterative threshold technique. An optimal threshold is reached when the corresponding isocontour best fits the first derivative of the end-diastolic count distribution in three dimensions. This optimal threshold is then applied to delineate the left ventricular cavity on the other time bins. The data are corrected for the partial-volume effect. Left ventricular volumes are determined using a geometry-based method and are used to calculate the ejection fraction. Results: The success rate of the new algorithm was 94%. LVEFs calculated from GBPT agreed well with those calculated from PRNA (r = 0.78; GBPT = 0.94 PRNA + 6.33). The systematic error was 2.8%, and the random error was 8.8%. Excellent inter- and intraobserver reproducibility was found, with average differences of 1.1% ± 4.6% and 1.1% ± 5.0%, respectively, between the two measurements. Conclusion: This new algorithm provides a fast, automated, and objective method to calculate LVEF from GBPT.