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Volume 7
OMICS Journal of Radiology
Radiology and Oncology 2018
July 16-17, 2018
July 16-17, 2018 Dubai, UAE
Radiology and Oncology
2
nd
World Congress on
Breast tumor imaging using coded aperture: Monte-Carlo simulation study
Mohammed A Alnafea and A M Alenezi
King Saud University, Saudi Arabia
Background:
Scintimammography (SM) is a promising functional radionuclide imaging technique that is generally undertaken
using high resolution parallel-hole collimators with Gamma Cameras. The main clinical limitation of this technique is
inaccuracy in detecting small lesions less than 1 cm diameter. This limitation is due to resolution-efficiency trade-off that
is inherent in the use of collimation. As an alternative approach this study proposes using a simple Coded Aperture (CA)
mask, instead of a collimator, coupled to a standard clinical gamma camera for breast tumor imaging. This imaging technique
successfully predicts the overall form of artefacts arising from the near-field imaging geometries.
Aim & Methods:
To investigate the applications of CA technique a Monte Carlo Simulation (MCS) is used using MCNPX
package. To emulate SM, 3D pseudo-anthropomorphic phantoms have been developed and verified and used along with a
realistic model of a clinical gamma camera. This study examines a moderately compressed breast phantom in a cranio-caudal-
projection. The performance of such an imaging system is modeled by the MCS method and images are reconstructed by
correlation analysis. This imaging system was quantitatively evaluated using variable parameters: The detected photon from
tumor, spatial resolution, photon statistics and lesion visibility of the system at several tumor-background activity ratios. The
effectiveness and the performance of the CA-SM system was assessed and compared with low energy high resolution parallel-
hole collimator and ultra-high resolution parallel-hole collimator image formation systems.
Results:
The predicted background can be used to correct the near-field effect of 3D sources, as might be found in SM using
CA. The simulated planar images from these collimator-based image formation systems suggest tumors of 1 cm diameter may
be observable with a tumor-background-ratio of 5:1. However, when the tumor diameter is ≤0.8 cm these become less reliable
detecting small (less than 1 cm in diameter) lesion unless a tumor-background-ratio of more than 10:1 is used.
Conclusion:
The results of the simulations demonstrate that with near-field artefacts corrections the CA-SM approach shows
good performance in lesion detection for all lesions (located 3 cm deep in a 6 cm thick breast phantom) and for a tumor-
background ratio as low as 3:1. This level of performance is highly competitive, in some cases, superior to conventional
collimator based image formation methods.
Biography
M AAlnafea is presently working as an Assistant professor in
King Saud University, Saudi Arabia.
He attended several International and National conferences. He
published several article in different journals as well.
alnafea@ksu.edu.saMohammed A Alnafea et al., OMICS J Radiol 2018, Volume 7
DOI: 10.4172/2167-7964-C1-021