This poster is published under an
open license. Please read the
disclaimer for further details.
Keywords:
Image verification, Computer Applications-3D, CT, Radioprotection / Radiation dose
Authors:
Y. Shimomiya1, T. Shirasaka1, M. Tachibana2, H. Hamasaki1, K. Ogawa1, M. Namekata3, K. Kumagai2, Y. Nakamura1; 1Fukuoka, Fukuoka/JP, 2Hiroshima, Hiroshima/JP, 3Tokyo, Tokyo/JP
DOI:
10.1594/ecr2014/C-0949
Results
Modulation transfer function
The results of the MTF with respect to FBP and FBP images processed using the TV method (three stages of intensity; level 1,
3,
and 5) are displayed in Fig.
4.
We observed no changes in the results of the MTF for FBP and FBP images processed using the TV method.
We obtained the same results regardless of whether there were changes in mAs.
Noise power spectrum
The results of our evaluation of the NPS with respect to FBP and FBP images processed using the TV method is displayed in Fig.
5.
According to the graph,
noise was reduced in the high-frequency regions of FBP images processed using the TV method in comparison with FBP images alone.
As the intensity of the TV filter increased,
the degree of noise reduction increased accordingly.
We obtained the same results regardless of whether there were changes in mAs.
Contrast-to-Noise Ratio
The results of our evaluation of the CNR are displayed in Fig.
6.
For 60 mAs,
the CNR value improved because of the FBP images processed using the TV method.
As the intensity of the TV filter increased,
the CNR improved accordingly (FBP,
TV level 1,
level 3,
and level 5; 1.17,
1.34,
1.92,
and 2.22).
The CNR improved in the same manner regardless of whether there were changes in mAs.
Observer study
The results of the observer study are displayed in Fig.
7.
We observed no significant difference in low-contrast detectability with respect to FBP images processed using the TV method (Steel-Dwass test p>0.05).