Spatial Resolution Analysis of a Variable Resolution X-ray Cone-beam Computed Tomography System

<p>A new cone-beam computed tomography (CBCT) system is designed and implemented that can adaptively provide high resolution CT images for objects of different sizes. The new system, called Variable Resolution X-ray Cone-beam CT (VRX-CBCT) uses a CsI-based amorphous silicon flat panel detector (FPD) that can tilt about its horizontal (<em>u</em>) axis and vertical (<em>v</em>) axis independently. The detector angulation improves the spatial resolution of the CT images by changing the effective size of each detector cell. Two components of spatial resolution of the system, namely the transverse and axial modulation transfer functions (MTF), are analyzed in three different situations: (1) when the FPD is tilted only about its vertical axis (<em>v</em>), (2) when the FPD is tilted only about its horizontal axis (<em>u</em>), and (3) when the FPD is tilted isotropically about both its vertical and horizontal axes. Custom calibration and MTF phantoms were designed and used to calibrate and measure the spatial resolution of the system for each case described above. A new 3D reconstruction algorithm was developed and tested for the VRX-CBCT system, which combined with a novel 3D reconstruction algorithm, has improved the overall resolution of the system compared to an FDK-based algorithm.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biomedical Engineering and Imaging

Year dc:date.available

2009

Author dc:creator

• Dahi, Bahram

Contributors dc:contributor

• Gary S. Keyes, Ph.D.

• CBCT
• CT Reconstruction
• FPD
• MTF
• Spatial Resolution
• VRX-CBCT
• Analytical, Diagnostic and Therapeutic Techniques and Equipment
• Medical Sciences
• Medicine and Health Sciences

Repository record dc:identifier

https://dc.uthsc.edu/dissertations/59

OAI identifier oai:identifier

oai:dc.uthsc.edu:dissertations-1053