Evaluation of the spatial resolution characteristics of a cone‐beam breast CT scanner

Kwan, Alexander L. C.; Boone, John M.; Yang, Kai; Huang, Shih‐Yu

doi:10.1118/1.2400830

Cited by 123 publications

(127 citation statements)

References 42 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…Breast CT images were reconstructed by filtered backprojection with a Shepp-Logan filter. 28,29 The resulting CT images, reconstructed in the coronal plane, encompassed 512 pixelsϫ 512 pixels, with a section thickness of 0.21 mm. The pixel dimensions for these images varied from patient to patient ͑range: 0.23-0.41 mm; average: 0.34 mm͒ as did the number of section images in a volume, which depended on the size of the breast.…”

Section: Iiib Bct Scansmentioning

confidence: 99%

Characterizing anatomical variability in breast CT images

et al. 2008

Self Cite

View full text Add to dashboard Cite

Previous work ͓Burgess et al., Med. Phys. 28, 419-437 ͑2001͔͒ has shown that anatomical noise in projection mammography results in a power spectrum well modeled over a range of frequencies by a power law, and the exponent ͑␤͒ of this power law plays a critical role in determining the size at which a growing lesion reaches the threshold for detection. In this study, the authors evaluated the power-law model for breast computed tomography ͑bCT͒ images, which can be thought of as thin sections through a three-dimensional ͑3D͒ volume. Under the assumption of a 3D power law describing the distribution of attenuation coefficients in the breast parenchyma, the authors derived the relationship between the power-law exponents of bCT and projection images and found it to be ␤ section = ␤ proj − 1. They evaluated this relationship on clinical images by comparing bCT images from a set of 43 patients to Burgess' findings in mammography. They were able to make a direct comparison for 6 of these patients who had both a bCT exam and a digitized film-screen mammogram. They also evaluated segmented bCT images to investigate the extent to which the bCT power-law exponent can be explained by a binary model of attenuation coefficients based on the different attenuation of glandular and adipose tissue. The power-law model was found to be a good fit for bCT data over frequencies from 0.07 to 0.45 cyc/ mm, where anatomical variability dominates the spectrum. The average exponent for bCT images was 1.86. This value is close to the theoretical prediction using Burgess' published data for projection mammography and for the limited set of mammography data available from the authors' patient sample. Exponents from the segmented bCT images ͑average value: 2.06͒ were systematically slightly higher than bCT images, with substantial correlation between the two ͑r = 0.84͒.

show abstract

Section: Iiib Bct Scansmentioning

confidence: 99%

Characterizing anatomical variability in breast CT images

et al. 2008

Self Cite

View full text Add to dashboard Cite

show abstract

“…This property has a practical consequence because it allows us to measure the system's LSF and thus the MTF, by integrating the system's PSF image along an arbitrary direction. In CT, it is easy to realize a physical measurement of the 2D PSF on a given plane by scanning an object with negligible crosssectional size (e.g., a tungsten wire) placed perpendicularly to the plane of interest (Kwan et al, 2007;Mettivier and Russo, 2011). A drawback of this method is that the cross-sectional diameter of the wire must be negligible with respect to the width of the system's PSF; if the diameter of the wire cannot be neglected, the measured PSF must be deconvolved for the finite aperture of the object.…”

Section: High-contrast Spatial Resolutionmentioning

confidence: 99%

High-Resolution CT for Small-Animal Imaging Research

Badea

Panetta²

2014

Comprehensive Biomedical Physics

View full text Add to dashboard Cite

“…23 CT images were reconstructed as an 8192 × 8192 matrix with a pixel size of 19 µm. Since the effect of reconstruction filter kernel on image resolution has been well studied, 8 only the ramp filter was used in this work. The measured detector MTF was multiplied by the ramp filter in the frequency domain before the reconstruction to simulate the actual detector response.…”

Section: F Image Reconstructionmentioning

confidence: 99%

“…These four positions were chosen to match the experimental settings in the physical measurement. 8 Due to the circularly symmetric nature of CT images, the one-dimensional MTFs in both radial and azimuthal directions (ρ, θ) were calculated, instead of along a Cartesian based coordinate system. The two-dimensional PSF was integrated along the radial (ρ) direction (from isocenter outward) to compute the azimuthal MTFs, and the PSF was integrated along the angular (θ) direction to compute the radial MTF, as illustrated in Fig.…”

Section: G Mtf Calculationmentioning

confidence: 99%

“…8 The breast CT system uses a CsI based a-Si:H flat panel detector (PaxScan 4030CB, Varian Medical Systems, Salt Lake City, UT), with a detector element dimension of 388 µm × 388 µm when working in the 2 × 2 pixel binning mode, corresponding to a 1024 × 768 image matrix. An x-ray generator (HF160, Pantak, East Haven, CT) was coupled with an x-ray tube (MXR-160/ 20, COMET, Flamatt, Switzerland) with a nominal 0.4 mm focal spot (IEC 336 standard).…”

Section: Physical Measurement Of the Breast Ct Scanner Mtfmentioning

confidence: 99%

See 1 more Smart Citation

Computer modeling of the spatial resolution properties of a dedicated breast CT system

2007

Self Cite

View full text Add to dashboard Cite

Computer simulation methods were used to evaluate the spatial resolution properties of a dedicated cone-beam breast CT system. x-ray projection data of a 70 µm nickel-chromium wire were simulated. The modulation transfer function (MTF) was calculated from the reconstructed axial images at different radial positions from the isocenter to study the spatial dependency of the spatial resolution of the breast CT scanner. The MTF was also calculated in both the radial and azimuthal directions. Subcomponents of the cone beam CT system that affect the MTF were modeled in the computer simulation in a serial manner, including the x-ray focal spot distribution, gantry rotation under the condition of continuous fluoroscopy, detector lag, and detector spatial resolution. Comparison between the computer simulated and physically measured MTF values demonstrates reasonable accuracy in the simulation process, with a small systematic difference (~9.5±6.4% difference, due to unavoidable uncertainties from physical measurement and system calibration). The intrinsic resolution in the radial direction determined by simulation was about 2.0 mm −1 uniformly through the field of view. The intrinsic resolution in the azimuthal direction degrades from 2.0 mm −1 at the isocenter to 1.0 mm −1 at the periphery with 76.9 mm from the isocenter. The results elucidate the intrinsic spatial resolution properties of the prototype breast CT system, and suggest ways in which spatial resolution can be improved with system modification.

show abstract

Evaluation of the spatial resolution characteristics of a cone‐beam breast CT scanner

Cited by 123 publications

References 42 publications

Characterizing anatomical variability in breast CT images

Characterizing anatomical variability in breast CT images

High-Resolution CT for Small-Animal Imaging Research

Computer modeling of the spatial resolution properties of a dedicated breast CT system

Contact Info

Product

Resources

About