Three-dimensional reconstruction and demarcation of dobutamine induced regional wall thinning

Dobutamine stress echo (DSE) is a well established clinical useful tool and is rapidly gaining popularity. However, it is limited by the subjective image interpretation skill. No current methods are available to objectively measure DSE induced wall motion abnormality. We therefore developed a computer-based 3D reconstruction and display of wall thickening in a 16-segment model based on three apical views (0, 90 and 135 degrees) with B-spline interpolation and mid-line thickness calculation. 12 patients with known coronary artery disease underwent coronary angiography and DSE were studied. The acquired digital cineloops were directly transferred to the computer with preserved high image quality and frame rate. The endocardial and epicardial borders were traced at end-diastole and end-systole. Average wall thickness and systolic thickening of each segment were automatically calculated with a color-tiled reconstruction. RESULTS: The LV endocardial and epicardial surfaces and segmental wall thickness were successfully reconstructed in all 24 stages of the 12 patients. The location and distribution of regional wall thinning were automatically demarcated by the color-tiled display and corresponded well with the coronary artery lesions (stenosis >/= 70%). At baseline, the average wall thickening was 41.0 ± 13.5%. At peak dobutamine stress, the thickening increased to 48.4 ± 17.2% in non-ischemic region, but decreased to -1.6 ± 9.7% in ischemic region (p < .0001). CONCLUSIONS: Dobutamine induced regional wall thinning can be successfully reconstructed and automatically demarcated in a 16 segmental model in three dimensions. Application of this technique may therefore provide an objective quantitative measurement of wall thickening or thinning with dobutamine stress echocardiography.