The primary emphasis of this project is to develop and validate a highly automated, clinically feasible system for accurate qualitative (morphology) and quantitative (volumetry) assessment of the heart by 3 dimensional echocardiography (3DE). The specific hypothesis of this research is; 3DE images of the human heart can provide more accurate qualitative and quantitative information than current 2-dimensional echocardiography.
The aims are to test the hypothesis in the following areas: 1) Image Acquisition; Using a transesophageal approach and acquisition in two cylindrical geometries (pyramidal and conical), find optimal number of incremental scans required for detailed morphological studies and for accurate left ventricular (LV) volume evaluation. 2) Image Segmentation: Develop a two step algorithm for LV extraction in 3DE. The first step includes automated identification of the LV cavity and determination of a global threshold suitable for initial segmentation of the LV and cardiac structures. In the second step, an advanced algorithm for cavity boundary detection is used to create a 3D computer representation of the LV chamber. The algorithm simulates autonomous growth of a natural cell which adapts its shape to the surroundings. The software controlled growth and elastic properties of the """"""""cell membrane"""""""" should reproduce the spatial distribution of the LV endocardial surface. The resulting 3D object will be used for qualitative and quantitative evaluation of the LV. 3) Clinical Validation and Application: Accuracy of LV volumetry by 3DE will be validated through the comparison of this method to volumetry by computed tomography. Patients with normal and symmetrically or asymmetrically enlarged LV will be selected. The validated 3DE algorithm will be subsequently applied to studies in patients with ischemic, valvular and congenital heart diseases examined in the Clinical Echocardiographic Laboratory. The significance of the project is that comprehensible 3DE images of cardiac anatomy and accurate LV volumetry will improve the quality of the diagnosis, treatment, and follow-up of patients with cardiovascular diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29HL052494-01A1
Application #
2229889
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1995-04-01
Project End
1999-02-28
Budget Start
1995-04-01
Budget End
1996-02-29
Support Year
1
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
City
Rochester
State
MN
Country
United States
Zip Code
55905
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Bae, R Y; Belohlavek, M; Greenleaf, J F et al. (2001) Myocardial contrast echocardiography: texture analysis for identification of nonperfused versus perfused myocardium. Echocardiography 18:665-72
Belohlavek, M; Tanabe, K; Jakrapanichakul, D et al. (2001) Rapid three-dimensional echocardiography : clinically feasible alternative for precise and accurate measurement of left ventricular volumes. Circulation 103:2882-4
Belohlavek, M; Tanabe, K; Mulvagh, S L et al. (1998) Image enhancement by noncontrast harmonic echocardiography. Part II. Quantitative assessment with use of contrast-to-speckle ratio. Mayo Clin Proc 73:1066-70
Belohlavek, M; MacLellan-Tobert, S G; Seward, J B et al. (1997) Toroidal geometry: novel three-dimensional intracardiac imaging with a phased-array transducer. J Am Soc Echocardiogr 10:493-8
Belohlavek, M; Greenleaf, J F (1997) Detection of cardiac boundaries in echocardiographic images using a customized order statistics filter. Ultrason Imaging 19:127-37