PURPOSE One of the main factors contributing to the accuracy of attenuation correction for SPECT imaging using transmission computed tomography (TCT) with an external gamma-ray source is the radionuclide count. To reduce deterioration of TCT images due to inadequate radionuclide counts, a correction method, segmented attenuation correction (SAC), in which TCT data are transformed into several c...

Although is not a major error source at C-band, attenuation may degrade the radar measurement to a considerable degree in situations like a precipitation event in the radar shadow of a strong convective cell, or may affect precipitation accumulation estimates at distances far from the radar site. For C-band radars, attenuation can be corrected using different methods depending on the type of me...

We describe a hybrid measured/calculated method for attenuation correction in positron emission tomography (PET). This unified reconstruction/segmentation method is based on a penalized weighted least-squares (PWLS) objective function that is minimized using iterative coordinate-descent (ICD). Two penalty functions are compared; one for a discrete object parameterization, the other for a contin...

Network properties can be estimated using functional connectivity MRI (fcMRI). However, regional variation of the fMRI signal causes systematic biases in network estimates including correlation attenuation in regions of low measurement reliability. Here we computed the spatial distribution of fcMRI reliability using longitudinal fcMRI datasets and demonstrated how pre-estimated reliability maps...

For activity quantification based on planar scintillation camera measurements, photon attenuation is an important factor that needs to be corrected for in a patientand organ-specific manner. One possibility for obtaining attenuation correction maps is to use X-ray CT scout images. Since the intensity of scout images is in relative numbers, their image values need to be multiplied by a factor to...

UNLABELLED This study investigates the ability of artificial neural networks (ANN) to simultaneously correct for attenuation and Compton scattering in scintigraphic imaging. METHODS Three sets of experiments are conducted using images of radioactive sources with various shapes and distributions in a homogeneous medium. Numerical Monte Carlo simulations and physical phantom acquisitions of rad...

For activity quantification based on planar scintillation camera measurements, photon attenuation is an important factor that needs to be corrected for in a patient- and organ-specific manner. One possibility for obtaining attenuation correction maps is to use X-ray CT scout images. Since the intensity of scout images is in relative numbers, their image values need to be multiplied by a factor ...

Erratum Unfortunately, the original version of this article [1] contained an error. The author list was included incorrectly. This can be found correctly listed above. Submit your manuscript to a journal and benefi t from: 7 Convenient online submission 7 Rigorous peer review 7 Immediate publication on acceptance 7 Open access: articles freely available online 7 High visibility within the fi el...

We introduced [1] a Bayesian method for transmission tomography that used a novel pointwise prior in the form of a mixture of gamma distributions. Here, we compare the performance our pointwise prior with that of a smoothing prior in the context of a weak tumor detection task for emission PET. The reprojected attenuation maps from each method are used for attenuation correction of 2D PET emissi...