although, most of the abnormal structures of human brain do not alter the shape of outer envelope of brain (surface), some abnormalities can deform the surface extensively. however, this may be a major problem in a surface-based registration technique, since two nearly identical surfaces are required for surface fitting process. a type of verification known as the circularity check for the shap...

background motion artifacts that degrade image quality of coronary ct angiography (ccta) in patients with high heart rates may be reduced with specific automatic motion correction algorithms (amc). conclusions ccta image quality improves significantly with amc in patients with high heart rates and reduces the proportion of non-diagnostic examinations. results mean heart rate during ccta was 61 ...

Introduction: Motion of the patient during myocardial perfusion SPECT could potentially results in false perfusion defects. The effect of different reconstruction methods on these artifacts is not studied. Clarification of the relation between the extent, severity and duration of motion with the resultant artifacts may be helpful in designing special soft wares for motion correction. This...

introduction: filtering can greatly affect the quality of clinical images. determining the best filter and the proper degree of smoothing can help to ensure the most accurate diagnosis. methods: forty five patient’s data aquired during brain phantom spect studies were reconstructed using filtered back-projection technique. the ramp, shepp-logan, cosine, hamming, hanning, butterworth, metz and w...

  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 Maximiz...

Resolution recovery (RR) techniques in PET imaging aim to mitigate spatial resolution losses and related inaccuracies quantification by using a model of the systems point spread function (PSF) during reconstruction or post processing. However, including PSF modelling fully 3D image is far from trivial as access scanner-specific forward back-projectors required, along with sinogram data. Hence p...

Introduction: While the necessity of replacing voxels with blobs in conventional tomographic reconstruction based upon line-integrals is clear, it is not however well-investigated in plane- integral-based reconstruction. The problem is more challenging in convergent-plane projection reconstruction. In this work, we are aiming at utilizing blobs as alternative to voxels. <stron...