Monitoring of precipitation using higher frequency radar systems such as X-band is becoming popular. At X-band frequency, weather radar signals are attenuated along their paths due to precipitation. A network-based reflectivity retrieval technique has been developed for the Adaptive Sensing of the Atmosphere (CASA) system, which is a radar network that can observe a weather event simultaneously...

In order to improve the performance of X-band dual-polarization radars, it is necessary to conduct attenuation correction before using the X-band radar data. This study analyzes a variety of attenuation correction methods for the X-band radar reflectivity, and proposes a high-resolution slide self-consistency correction (SSCC) method, which is an improvement of Kim et al.’s method based on Brin...

Optical-computed tomography (CT) and optical-emission computed tomography (ECT) are recent techniques with potential for high-resolution multi-faceted 3D imaging of the structure and function in unsectioned tissue samples up to 1-4 cc. Quantitative imaging of 3D fluorophore distribution (e.g. GFP) using optical-ECT is challenging due to attenuation present within the sample. Uncorrected reconst...

The aim of this study was to evaluate the effect of the CT-derived attenuation correction on (99m)Tc-MIBI normal myocardial perfusion scintigrams. Rest perfusion scintigrams of patients in whom coronary artery disease was suspected, without a history or any signs in ECG of a myocardial infarction, were analysed. Patients were included in the material if their rest perfusion scintigrams were nor...

Planar g-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simulations. This st...

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...

UNLABELLED Planar gamma-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simul...

Soft tissue attenuation artefacts are more likely to occur in patients with high body mass index (BMI) undergoing myocardial perfusion imaging (MPI) and therefore it is routine practice in our department to perform attenuation correction in this group of patients. However, we suspected that attenuation artefacts may also occur in patients with normal BMI. We collected data prospectively on 5...

In PET activation studies, linear changes in regional cerebral blood flow may be caused by subject interscan displacements rather than by changes in cognitive state. The aim of this study was to investigate the impact of these artifacts and to assess whether they can be removed by applying a scan-specific calculated attenuation correction (CAC) instead of the default measured attenuation correc...

This paper presents the results of evaluating the use of X-ray CT data for attenuation correction of PET data. This method of attenuation correction is intended for use with a combined volume-imaging PET/CT scanner for oncology. We discuss four possible methods of scaling the attenuation map from the CT energies to the required PET attenuation map at 511 keV. Results are presented on the testin...