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...

In this paper, precipitation rate retrieval algorithms for the Global Precipitation Measurement mission's Dual-frequency Radar (DPR) are developed. The DPR consists of a Ku-band radar (KuPR; 13.6 GHz) and Ka-band (KaPR; 35.5 GHz). For KuPR, an algorithm similar to Tropical Rainfall Measuring Mission's is developed, with relation between R massweighted mean diameter Dm (R?Dm relation) replacing ...

In recent years the use of small inexpensive Xband radars for meteorological and hydrological purposes has increased significantly. Compared to the traditional C-band and S-band radars the X-band weather radar has the advantage of high temporal and spatial resolution and low financial cost; however, the trade off is attenuation due to X-band technology and short range due to the higher spatial ...

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...

This study proposes investigation of new attenuation correction and microphysical retrieval methods for X-band polarimetric radar (XPOL). It will concentrate on exploring the dependence of the retrieval on raindrop size distribution variability, and its sensitivity with respect to the selection of oblateness-size relation (or axial ratio) and maximum diameter limit. Variations in the assumed fo...

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...

The most commonly used polarimetric radar measurements in rainfall estimation are the reflectivity factor, usually at horizontal polarization (Zh), differential reflectivity (Zdr) and specific differential propagation phase (Kdp). Based on the above three measurements, a number of algorithms have been derived in the literature to estimate rainfall (see Bringi and Chandrasekar, 2001 for a summar...