Evaluation of tilted cone-beam CT orbits in the development of a dedicated hybrid mammotomograph
| Autor: | Randolph L. McKinley, Priti Madhav, Martin P. Tornai, Dominic J. Crotty |
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| Rok vydání: | 2009 |
| Předmět: |
Cone beam computed tomography
Physics::Medical Physics Rotation Sensitivity and Specificity Article Optics Sampling (signal processing) Distortion Radiology Nuclear Medicine and imaging Computer vision Mathematics Tomography Emission-Computed Single-Photon Radiological and Ultrasound Technology Phantoms Imaging business.industry Detector Reproducibility of Results Equipment Design Cone-Beam Computed Tomography Equipment Failure Analysis Systems Integration Subtraction Technique Line (geometry) Trajectory Development (differential geometry) Artificial intelligence business Mammography |
| Zdroj: | Physics in Medicine and Biology. 54:3659-3676 |
| ISSN: | 1361-6560 0031-9155 |
| Popis: | A compact dedicated 3D breast SPECT-CT (mammotomography) system is currently under development. In its initial prototype, the cone-beam CT sub-system is restricted to a fixed-tilt circular rotation around the patient's pendant breast. This study evaluated stationary-tilt angles for the CT sub-system that will enable maximal volumetric sampling and viewing of the breast and chest wall. Images of geometric/anthropomorphic phantoms were acquired using various fixed-tilt circular and 3D sinusoidal trajectories. The iteratively reconstructed images showed more distortion and attenuation coefficient inaccuracy from tilted cone-beam orbits than from the complex trajectory. Additionally, line profiles illustrated cupping artifacts in planes distal to the central plane of the tilted cone-beam, otherwise not apparent for images acquired with complex trajectories. This indicates that undersampled cone-beam data may be an additional cause of cupping artifacts. High-frequency objects could be distinguished for all trajectories, but their shapes and locations were corrupted by out-of-plane frequency information. Although more acrylic balls were visualized with a fixed-tilt and nearly flat cone-beam at the posterior of the breast, 3D complex trajectories have less distortion and more complete sampling throughout the reconstruction volume. While complex trajectories would ideally be preferred, negatively fixed-tilt source-detector configuration demonstrates minimally distorted patient images. |
| Databáze: | OpenAIRE |
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