objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

introduction: attenuation correction is a useful process for improving myocardial perfusion spect and is dependent on activity and distribution of attenuation coefficients in the body (attenuation map). attenuation artifacts are a common problem in myocardial perfusion spect. the aim of this study was to compare the effect of attenuation correction using different attenuation maps and different...

  Introduction: Attenuation correction is a useful process for improving myocardial perfusion SPECT and is dependent on activity and distribution of attenuation coefficients in the body (attenuation map). Attenuation artifacts are a common problem in myocardial perfusion SPECT. The aim of this study was to compare the effect of attenuation correction using different a...

The diagnostic accuracy of single photon emission computed tomography (SPECT) is profoundly influenced by attenuation phenomenon. Soft tissue attenuation degrades cardiac SPECT image quality, thereby decreasing the possibility of the detection of the lesions. A variety of correction techniques based on different assumptions have been used to reduce the impact of attenuation. Several types of sy...

the diagnostic accuracy of single photon emission computed tomography (spect) is profoundly influenced by attenuation phenomenon. soft tissue attenuation degrades cardiac spect image quality, thereby decreasing the possibility of the detection of the lesions. a variety of correction techniques based on different assumptions have been used to reduce the impact of attenuation. several types of sy...

spect detects γ-rays from administered radiopharmaceutical within the patient body. γ-rays pass through different tissues before reaching detectors and are attenuated. attenuation can cause artifacts; therefore different methods are used to minimize attenuation effects. in our study efficacy of chang method was evaluated for attenuation purpose, using a custom made heart phantom. due to differe...

objective(s): the aim of this study was to determine the optimal reconstruction parameters for iterative reconstruction in different devices and collimators for dopamine transporter (dat) single-photon emission computed tomography (spect). the results were compared between filtered back projection (fbp) and different attenuation correction (ac) methods.methods: an anthropomorphic striatal phant...

in present pet/ct scanners, pet attenuation correction is performed by relying on the information given by ct scan. in the ct-based attenuation correction methods, dual-energy technique (dect) is the most accurate approach, which has been limited due to the increasing patient dose. in this feasibility study, we have introduced a new method that can implement dual-energy technique with only a si...

introduction: photon attenuation in tissues is the primary physical degrading factor limiting both visual qualitative interpretation and quantitative analysis capabilities of reconstructed single photon emission computed tomography (spect) images. the aim of present study was to investigate the effect of attenuation correction on the detection of activation foci following statistical analysis w...

background: in this study, quantitative 32p bremsstrahlung planar and spect imaging and consequent dose assessment were carried out as a comprehensive phantom study to define an appropriate method for accurate dosimetry in clinical practice. materials and methods: ct, planar and spect bremsstrahlung images of jaszczak phantom containing a known activity of 32p were acquired. in addition, phanto...