Background: Photon attenuation as an
inevitable physical phenomenon influences on the
diagnostic information of SPECT images and results
to errors in accuracy of quantitative measurements.
This can be corrected via different physical or
mathematical approaches. As the correction
equation in mathematical approaches is nonlinear, in
this study a new method of linearization called ‘Piece
Wise Linearization’ (PWL) is introduced and to
substantiate its validity for SPECT image
reconstructions, a phantom study is performed.
Material and Methods: A SPECT scan of a homemade
heart phantom filled with 2 mCi 99mTc was acquired
by dual head Siemens E.Cam gamma camera
equipped with LEHR collimator. Row data of the scan
were transferred in DICOM format to a pc computer
for reconstruction of the images using MLEM
iterative algorithm in Matlab software. Results:
Attenuation map of the phantom µ(x) were derived
using PWL with linear optimization approach. Based
on that, the attenuation corrected SPECT image of
the phantom were reconstructed and compared with
non-corrected image, using MLEM iterative algorithm.
Comparison of the corrected and non-corrected
images confirmed with CT attenuation correction
method. Conclusion: Attenuation correction in SPECT
image can be achieved successfully, using emission
data and piecewise linearization with linear
optimization approach. The corrected image of f(x)
and attenuation map µ(x) of the heart phantom
using this approach promise acceptable image
quality for diagnostic clinical use. Iran. J. Radiat. Res.,
2010 8 (2): 111-116
Vahidian Kamyad A, Noori Eskandari M, Naji Midani M, Hajizadeh Saffar M. New approach for attenuation correction in SPECT images, using linear optimization. Int J Radiat Res 2010; 8 (2) :111-116 URL: http://ijrr.com/article-1-624-en.html