Assessment of left ventricular volume and function by integration of simplified 3D echocardiography, tissue harmonic imaging and automated extraction of endocardial borders.
BACKGROUND
Quantitative three-dimensional echocardiography (3DEcho) of left ventricle (LV) is still limited because of the need for manually tracing endocardial borders: this can increase observer variability depending on the quality of fundamental (FUND) 2D images. We tested the combination of a simplified 3DEcho technique for LV reconstruction with automated endocardial border detection (Digital Echo Quantification, DEQ) and tissue harmonic imaging (THI) for enhancement of endocardium-cavity interface.


METHODS
Twenty-five consecutive patients with ischaemic heart disease and dilated or distorted LV underwent 3DEcho and gated-SPECT nuclear examinations evaluating: (a) end-diastolic and end-systolic volumes (EDV, ESV); (b) ejection fraction (EF); (c) volume/time curve (VTC). Thereafter, 3DEcho was applied to 47 patients with acute myocardial infarction (AMI) at pre-discharge and 6 months to evaluate remodelling.


RESULTS
Integrated 3DEcho values in THI modality were obtained in 84% of patients and correlated well with nuclear data for EDV (r = 0.95, mean difference = -2.2 +/- 15.8 ml), ESV (r = 0.98, mean difference = -3.5 +/- 10.2 ml), and EF (r = 0.82, mean difference = 0.6 +/- 6.4%; all mean differences NS vs. 0), with an interobserver variability of 4.9, 5.7 and 8.2% for EDV, ESV and EF respectively. Automated VTC by 3DEcho in THI modality reproduced well that obtained by nuclear technique (r = 0.96) and allowed recognition of LV remodelling in 36% of patients at 6 months. Integrated 3DEcho values in FUND modality were obtained only in 52% of patients and showed much higher errors and interobserver variability.


CONCLUSIONS
THI permits accurate 3D reconstruction of LV borders detected by DEQ, allowing automated VTC throughout the cardiac cycle as well as study of LV remodelling.
Mele
Donato
D
Institute of Cardiology, Azienda Ospedaliera Universitaria, Ferrara, Italy. donatomele@libero.it
Teoli
Roberta
R
Cittanti
Corrado
C
Pasanisi
Giovanni
G
Guardigli
Gabriele
G
Levine
Robert A
RA
Ferrari
Roberto
R
D000465:Algorithms; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology