Three-dimensional echocardiography: rational mode of component images for left ventricular volume quantitation.
Three-dimensional echocardiography (3DE) improves the accuracy of left ventricle (LV) volumetry compared with the two-dimensional echocardiography (2DE) approach because geometric assumptions in the algorithms may be eliminated. The relationship between accuracy of mode (short- versus long-axis planimetry) and the number of component images versus time required for analysis remains to be determined. Sixteen latex models simulating heterogeneously distorted (aneurysmatic) human LVs (56-303 ml; mean 182+/-82 ml) were scanned from an 'apical' position (simultaneous 2DE and 3DE). For 3DE volumetry, the slice thickness was varied for the short (C-scan) and long axes (B-scan) in 5-mm steps between 1 and 25 mm. The mean differences (true-echocardiographic volumes) were 16.5+/-44.3 ml in the 2DE approach (95% confidence intervals -27.8 to +60.8) and 0.6+/-4.0 ml (short axis; 95% confidence intervals -3.4 to +4.6) as well as 2.1+/-9.9 ml (long axis; 95% confidence intervals -7.8 to +12.0) in the 3DE approach (in both cases, the slice thickness was 1 mm). Above a slice thickness of 15 mm, the 95% confidence intervals increased steeply; in the short versus long axes, these were -6.5 to +8.5 versus -7.0 to +10.6 at 15 mm and -10.1 to +15.7 versus -11.3 to +10.9 at 20 mm. The intra-observer variance differed significantly (p<0.001) only above 15 mm (short axis). Time required for analysis derived by measuring short-axis slice thicknesses of 1, 15, and 25 mm was 58+/-16, 7+/-2 and 3+/-1 min, respectively. The most rational component image analysis for 3DE volumetry in the in vitro model uses short-axis slices with a thickness of 15 mm.
Nixdorff
Uwe
U
2nd Medical Clinic, University of Erlangen-Nuremberg, Erlangen, Germany. uwe.nixdorff@rzmail.uni-erlangen.de
Feddersen
Isa
I
Voigt
Jens-Uwe
JU
Flachskampf
Frank A
FA
D002306:Cardiac Volume / Q000502:physiology*; D004452:Echocardiography; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006322:Heart Aneurysm / Q000000981:diagnostic imaging*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging*; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D009203:Myocardial Infarction / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D012680:Sensitivity and Specificity; D013673:Technology Assessment, Biomedical