A Novel Method Based on Monte Carlo for Simulation of Variable Resolution X-ray CT Scanner: Measurement of System Presampling MTF
The purpose of this work is measurement of the
system presampling MTF of a variable resolution x-ray (VRX) CT
scanner. In this paper, we used the parameters of an actual VRX CT
scanner for simulation and study of effect of different focal spot sizes
on system presampling MTF by Monte Carlo method (GATE
simulation software). Focal spot size of 0.6 mm limited the spatial
resolution of the system to 5.5 cy/mm at incident angles of below 17º
for cell#1. By focal spot size of 0.3 mm the spatial resolution
increased up to 11 cy/mm and the limiting effect of focal spot size
appeared at incident angles of below 9º. The focal spot size of 0.3
mm could improve the spatial resolution to some extent but because
of magnification non-uniformity, there is a 10 cy/mm difference
between spatial resolution of cell#1 and cell#256. The focal spot size
of 0.1 mm acted as an ideal point source for this system. The spatial
resolution increased to more than 35 cy/mm and at all incident angles
the spatial resolution was a function of incident angle. By the way
focal spot size of 0.1 mm minimized the effect of magnification nonuniformity.
[1] J. Beutel, H. L. Kundel, and R. L. van Metter, Handbook of Medical
Imaging. Physics and Psychophysics 1. SPIE Press Bellingham, 2000.
[2] G. Wang, S. Zhao, H. Yu, C. Miller, P. Abbas, B. Gantz, S. Lee, and J.
Rubinstein, "Design, analysis and simulation for development of the first
clinical micro-CT scanner," Acad. Radiol., vol. 12, pp. 511-525, 2005.
[3] A. Sasov and D. van Dyck, "Desktop x-ray microscopy and
microtomography," J Microsc, vol. 191, pp. 151-158, 1998.
[4] F. A. DiBianca, V. Gupta, and H. D. Zeman, "A variable resolution xray
detector for computed tomography: I. Theoretical basis and
experimental verification," Med Phys, vol. 27:8, pp. 1865-1874, 2000.
[5] F. A. DiBianca, P. Zou, L. M. Jordan, J. S. Laughter, H. D. Zeman, and
J. Sebes, "A variable resolution x-ray detector for computed
tomography: II. Imaging theory and performance," Med Phys, vol. 27:8,
pp. 1875-1880, 2000.
[6] F. A. DiBianca, R. Melnyk, C. N. Duckworth, S. Russ, L. M. Jordan,
and J. S. Laughter, "Comparison of VRX CT scanners geometries,"
Proc. SPIE,vol. 4320, pp. 627-635, 2001.
[7] K. Rossmann, "Point spread-function, line spread-function, and
modulation transfer function. Tools for the study of imaging systems,"
Radiology, vol. 93, pp. 257-272, 1969.
[8] J. L. Lancaster, "Physics of Medical X-Ray Imaging."
http://ric.uthscsa.edu/personalpages/lancaste/DI II.html. Accessed 20
jan 2008.
[9] M. L. Giger and K. Doi, "Investigation of basic imaging properties in
digital radiography. I. Modulation transfer function," Med. Phys, vol. 11,
pp. 287-295 1984.
[10] H. Fujita, K. Doi, and M. L. Giger, "Investigation of basic imaging
properties in digital radiography. 6. MTFs of II-TV digital imaging
systems," Med Phys, vol. 12, (), pp. 713- 720 1985.
[11] J. T. Dobbins, "Effects of undersampling on the proper interpretation of
modulation transfer function, noise power spectra, and noise equivalent
quanta of digital imaging systems," Med Phys, vol. 22, pp. 171-181,
1995.
[12] H. Fujita, D. Y. Tsai, T. Itoh, K. Doi, J. Morishita, K. Ueda, and A.
Ohtsuka, "A simple method for determining the modulation transfer
function in digital radiography," IEEE Trans Med Imaging, vol. 11, pp.
34-39 1992.
[13] J. T. Dobbins, D. L. Ergun, L. Rutz, D. A. Hinshaw, H. Blume, and D.
C. Clark, "DQE(f) of four generations of computed radiography
acquisition devices," Med Phys, vol. 22, pp. 1581-1593, 1995.
[14] E. Samei, N. T. Ranger, J. T. I. Dobbins, and Y. Chen, "Intercomparison
of methods for image quality characterization. I. Modulation transfer
function," Med Phys, vol. 33, pp. 1454-1465, 2006.
[15] R. Melnyk and F. A. DiBianca, "Modeling and measurement of the
detector presampling MTF of a variable resolution x-ray CT scanner,"
Med Phys, vol. 34:3, pp. 1062-1075, 2007.
[16] S. Jan, G. Santin, D. Strul, S. Staelens, K. Assie, D. Autret et al "GATE:
a simulation toolkit for PET and SPECT," Physics in medicine and
biology, vol. 49:19, pp. 4543-4561, 2004.
[17] J. H. Siewerdsen, A. M. Waese, D. J. Moseley, S. Richard, and D. A.
Jaffray, "Spektr: a computational tool for x-ray spectral analysis and
imaging system optimization," Med Phys, vol. 31:11, pp. 3057-3067,
2004.
[18] H. Arabi, A. R. Kamali Asl, S. M. R. Aghamiri "The Effect of focal spot
size on the spatial resolution of variable resolution x-ray CT scanner,"
Iranian Journal of Radiation Research, To be published.
[1] J. Beutel, H. L. Kundel, and R. L. van Metter, Handbook of Medical
Imaging. Physics and Psychophysics 1. SPIE Press Bellingham, 2000.
[2] G. Wang, S. Zhao, H. Yu, C. Miller, P. Abbas, B. Gantz, S. Lee, and J.
Rubinstein, "Design, analysis and simulation for development of the first
clinical micro-CT scanner," Acad. Radiol., vol. 12, pp. 511-525, 2005.
[3] A. Sasov and D. van Dyck, "Desktop x-ray microscopy and
microtomography," J Microsc, vol. 191, pp. 151-158, 1998.
[4] F. A. DiBianca, V. Gupta, and H. D. Zeman, "A variable resolution xray
detector for computed tomography: I. Theoretical basis and
experimental verification," Med Phys, vol. 27:8, pp. 1865-1874, 2000.
[5] F. A. DiBianca, P. Zou, L. M. Jordan, J. S. Laughter, H. D. Zeman, and
J. Sebes, "A variable resolution x-ray detector for computed
tomography: II. Imaging theory and performance," Med Phys, vol. 27:8,
pp. 1875-1880, 2000.
[6] F. A. DiBianca, R. Melnyk, C. N. Duckworth, S. Russ, L. M. Jordan,
and J. S. Laughter, "Comparison of VRX CT scanners geometries,"
Proc. SPIE,vol. 4320, pp. 627-635, 2001.
[7] K. Rossmann, "Point spread-function, line spread-function, and
modulation transfer function. Tools for the study of imaging systems,"
Radiology, vol. 93, pp. 257-272, 1969.
[8] J. L. Lancaster, "Physics of Medical X-Ray Imaging."
http://ric.uthscsa.edu/personalpages/lancaste/DI II.html. Accessed 20
jan 2008.
[9] M. L. Giger and K. Doi, "Investigation of basic imaging properties in
digital radiography. I. Modulation transfer function," Med. Phys, vol. 11,
pp. 287-295 1984.
[10] H. Fujita, K. Doi, and M. L. Giger, "Investigation of basic imaging
properties in digital radiography. 6. MTFs of II-TV digital imaging
systems," Med Phys, vol. 12, (), pp. 713- 720 1985.
[11] J. T. Dobbins, "Effects of undersampling on the proper interpretation of
modulation transfer function, noise power spectra, and noise equivalent
quanta of digital imaging systems," Med Phys, vol. 22, pp. 171-181,
1995.
[12] H. Fujita, D. Y. Tsai, T. Itoh, K. Doi, J. Morishita, K. Ueda, and A.
Ohtsuka, "A simple method for determining the modulation transfer
function in digital radiography," IEEE Trans Med Imaging, vol. 11, pp.
34-39 1992.
[13] J. T. Dobbins, D. L. Ergun, L. Rutz, D. A. Hinshaw, H. Blume, and D.
C. Clark, "DQE(f) of four generations of computed radiography
acquisition devices," Med Phys, vol. 22, pp. 1581-1593, 1995.
[14] E. Samei, N. T. Ranger, J. T. I. Dobbins, and Y. Chen, "Intercomparison
of methods for image quality characterization. I. Modulation transfer
function," Med Phys, vol. 33, pp. 1454-1465, 2006.
[15] R. Melnyk and F. A. DiBianca, "Modeling and measurement of the
detector presampling MTF of a variable resolution x-ray CT scanner,"
Med Phys, vol. 34:3, pp. 1062-1075, 2007.
[16] S. Jan, G. Santin, D. Strul, S. Staelens, K. Assie, D. Autret et al "GATE:
a simulation toolkit for PET and SPECT," Physics in medicine and
biology, vol. 49:19, pp. 4543-4561, 2004.
[17] J. H. Siewerdsen, A. M. Waese, D. J. Moseley, S. Richard, and D. A.
Jaffray, "Spektr: a computational tool for x-ray spectral analysis and
imaging system optimization," Med Phys, vol. 31:11, pp. 3057-3067,
2004.
[18] H. Arabi, A. R. Kamali Asl, S. M. R. Aghamiri "The Effect of focal spot
size on the spatial resolution of variable resolution x-ray CT scanner,"
Iranian Journal of Radiation Research, To be published.
@article{"International Journal of Medical, Medicine and Health Sciences:57529", author = "H. Arabi and A.R. Kamali Asl", title = "A Novel Method Based on Monte Carlo for Simulation of Variable Resolution X-ray CT Scanner: Measurement of System Presampling MTF", abstract = "The purpose of this work is measurement of the
system presampling MTF of a variable resolution x-ray (VRX) CT
scanner. In this paper, we used the parameters of an actual VRX CT
scanner for simulation and study of effect of different focal spot sizes
on system presampling MTF by Monte Carlo method (GATE
simulation software). Focal spot size of 0.6 mm limited the spatial
resolution of the system to 5.5 cy/mm at incident angles of below 17º
for cell#1. By focal spot size of 0.3 mm the spatial resolution
increased up to 11 cy/mm and the limiting effect of focal spot size
appeared at incident angles of below 9º. The focal spot size of 0.3
mm could improve the spatial resolution to some extent but because
of magnification non-uniformity, there is a 10 cy/mm difference
between spatial resolution of cell#1 and cell#256. The focal spot size
of 0.1 mm acted as an ideal point source for this system. The spatial
resolution increased to more than 35 cy/mm and at all incident angles
the spatial resolution was a function of incident angle. By the way
focal spot size of 0.1 mm minimized the effect of magnification nonuniformity.", keywords = "Focal spot, Spatial resolution, Monte Carlosimulation, Variable resolution x-ray (VRX) CT.", volume = "4", number = "8", pages = "328-5", }
