S. Jaggi et al., ESTIMATION OF DYNAMICALLY EVOLVING ELLIPSOIDS WITH APPLICATIONS TO MEDICAL IMAGING, IEEE transactions on medical imaging, 14(2), 1995, pp. 249-258
Citations number
28
Categorie Soggetti
Engineering, Biomedical","Radiology,Nuclear Medicine & Medical Imaging
The estimation of dynamically evolving ellipsoids from noisy lower-dim
ensional projections is examined, In particular, this work describes a
model-based approach using geometric reconstruction and recursive est
imation techniques to obtain a dynamic estimate of left-ventricular ej
ection fraction from a gated set of planar myocardial perfusion images
, The proposed approach differs from current ejection fraction estimat
ion techniques both in the imaging modality used and in the subsequent
processing which yields a dynamic ejection fraction estimate, For thi
s work, the left ventricle is modeled as a dynamically evolving three-
dimensional (3-D) ellipsoid. The left-ventricular outline observed in
the myocardial perfusion images is then modeled as a dynamic, two-dime
nsional (2-D) ellipsoid, obtained as the projection of the former 3-D
ellipsoid, This data is processed in two ways: first, as a 3-D dynamic
ellipsoid reconstruction problem; second, each view is considered as
a 2-D dynamic ellipse estimation problem and then the 3-D ejection fra
ction is obtained by combining the effective 2-D ejection fractions of
each view, The approximating ellipsoids are reconstructed using a Rau
ch-Tung-Striebel smoothing filter, which produces an ejection fraction
estimate that is more robust to noise since it is based on the entire
data set; in contrast, traditional ejection fraction estimates are ba
sed only on two frames of data, Further, numerical studies of the sens
itivity of this approach to unknown dynamics and projection geometry a
re presented, providing a rational basis for specifying system paramet
ers, This investigation includes estimation of ejection fraction from
both simulated acid real data.