Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. (a) Cone beam CT breast imaging system. This imaging system’s x-ray tube is the Rad 71SP. Its FPD is PaxScan 4030CB, a FPD that is specifically designed to meet the needs of cone beam x-ray imaging applications. Sedecal USA provides a modified SHF- class high frequency generator with 16-kW power (SHF-1635). (b) The phantom was made with easy to get material. First, a 35-μm tungsten wire was kindly provided by Elmet Technologies from Lewiston, Maine. This wire was placed inside a cylindrical plastic container 125mm in diameter and 200mm in height. One end was attached to the center of the container by Super Glue while the other was passed through a hole on the lid of the container and tied to the outside to strengthen the wire. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Two composite MTFs of the cone beam CT breast imaging system. One was acquired by taking into account scattering, as illustrated by the dashed line, and the other one, as illustrated by a solid line, was taken in a scattering-free environment. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequency values at which the MTF is at 50, 10, 5, and 0.5% as a function of current (mA) as evaluated in a scattering medium. The phantom was scanned with 300 projection images at 49kVp and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequency values at which the MTF is at 50, 10, 5, and 0.5% as a function of current (ms) as evaluated in a scattering-free medium. The phantom was scanned with 300 projection images at 49kVp and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequencies for given MTF values as a function of voltage as evaluated in a scattering-free (lines) and scattering (symbols) media. The phantom was scanned with 300 projection images at 100mA and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequencies for given MTF values as a function of voxel size as evaluated in a scattering medium. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Two composite MTFs as a function of spatial frequency using two pixel sizes, namely 194μm (dashed line) and 388μm (solid line). The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. The MTF in scattering medium as a function of spatial frequency for the various filters used in the back-projection. These filters are the cosine-windowed ramp, the Hamming-windowed ramp, the Hann-windowed ramp, the modified Shepp-Logan, the linear ramp, and Shepp-Logan filters. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. MTF in a scattering medium as a function of spatial frequency for two reconstruction algorithms, the full and half-scan FDK-based reconstruction algorithms. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequencies for given MTF values as a function of starting angle as evaluated in a scattering medium. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms, and a pixel size of 388μm. The reconstruction was made using the ramp filter and a half-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequency as a function of the number of projections used in the reconstruction. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. The composite MTF in x (solid line) and y (dashed line) directions in a scattering media is illustrated here. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full- scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequency values at which the MTF is at 50, 10, and 5% as a function of the radial distance from the center of rotation. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /

Date of download: 5/28/2016 Copyright © 2016 SPIE. All rights reserved. Spatial frequency at which the composite MTF in the x-y plane at r=0mm is at 50, 10, 5, and 0.5% as a function of the z distance. The phantom was scanned with 300 projection images at 49kVp, 100mA, and 8.0ms. The reconstruction was made using the ramp filter and a full-scan FDK-based algorithm with a voxel size of 100μm. Figure Legend: From: Composite modulation transfer function evaluation of a cone beam computed tomography breast imaging system Opt. Eng. 2009;48(11): doi: /