Modeling respiratory mechanics in the MCAT and spline-based MCAT phantoms

Abstract

Respiratory motion can cause artifacts in myocardial SPECT. We incorporate respiratory mechanics into the current 4D MCAT and into the next generation spline-based MCAT phantoms. In order to simulate respiratory motion in the current MCAT phantom, the geometric solids for the diaphragm, heart, ribs, and lungs were altered through manipulation of parameters defining them. Affine transformations were applied to the control points defining the same respiratory structures in the spline-based MCAT phantom to simulate respiratory motion. The NURBS surfaces for the lungs and body outline were constructed in such a way as to be linked to the surrounding ribs. Expansion and contraction of the thoracic cage then coincided with expansion and contraction of the lungs and body. The changes both phantoms underwent were splined over time to create time continuous 4D respiratory models. We conclude that both respiratory models are effective tools for researching effects of respiratory motion.

Finite element studies of the mechanical behaviour of the diaphragm in normal and pathological cases

“…The results obtained for the tidal volume (TV) as well as for the maximum axial displacement (MAD) of the diaphragm are shown in Figure 8. The values given in the literature (Segars et al 2001;Gaillard 2003) and the results obtained suggest that the best interval for u max , to characterise the excitation in a normal quiet breathing, is between 20 and 30%.…”

Computationally efficient nonlinear edge preserving smoothing of n-D medical images via scale-space fingerprint analysis

“…We are working to implement the edge preserving LBNL-46941 smoothing in 4-D, as well as to compose 4-D edge detection operators using the analytic expressions for the directional derivatives of the nonlinearly smoothed images. The University of North Carolina Mathematical Cardiac Torso (MCAT) phantom [9] will be used to validate the accuracy of the resulting spatiotemporal segmentations. …”

Real-Time Simulation and Visualization of Subject-Specific 3D Lung Dynamics

“…[17] A non-physically-based method to lung deformations was also proposed using NURBS surfaces based on imaging data from CT scans of actual patients. [18] The usage of a high-resolution model for lung deformations and its real-time visualization were not addressed in these efforts. From a modeling and simulation perspective, the physically-based deformation methods are suitable for simulating lung dynamics since they allow the inclusion of different breathing parameters.…”