PURPOSE The wavelet transform is a newly developed signal-processing tool that decomposes a signal into various levels of resolution. The wavelet transform based noise reduction has the characteristics of optimally separating signal from noise, preserving the rapid rises and falls of a signal, and reconstructing a smooth signal from noise-imposed observations. The aim of this study was to evalu...

in nuclear medicine, there are two methods of imaging, planar and tomography. single photon emission computerized tomography (spect) shows better image details and therefore is influenced more by image parameters such as resolution, uniformity, sensitivity, etc. manufacturers provide customers with data which are obtained by complicated and sometimes secret methods. marketing companies test and...

UNLABELLED The accuracy of clinical SPECT is highly dependent on the acquisition and processing parameters, which are selected according to the clinical task. These parameters are usually set within protocols in order to allow for standardization from one study to another and to speed up the clinical routine. METHODS In the first part of this work, tomographic images of a Jaszczak phantom wer...

Filter backprojection is an important method of image reconstruction technique in clinical nuclear medicine imaging. Because of noisy images due to less available photon statistics and different factors associated with imaging system in nuclear medicine tomography, using optimal filter to suppress the noise with keeping the proper signal is one of the significant steps in image reconstruction s...

Quantitative SPECT as well as simultaneous acquisition of multiple isotopes with SPECT in the clinical field, although clinically interesting, are still limited by reconstruction artifacts and computing power. As a considerable step in this direction, we have implemented an efficient reconstructor with variance reduced Monte-Carlo-simulation in the forward and/or backward projection of an OS-EM...

This paper intends to compare the abilities of the two major imaging modalities in nuclear medicine imaging: Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT). The motivations are many-fold: (i) To gain a better understanding of the strengths and limitations of the two imaging modalities in the context of recent and ongoing developments in hardware ...

We investigated the accuracy of a single photon emission computed tomography (SPECT) system in quantifying a wide range of radioactivity concentrations using different scan times in both phantom and animal models. A phantom containing various amounts of In-111 or Tc-99m was imaged until the activity had decayed close to background levels. Scans were acquired for different durations, employing d...

BACKGROUND The reverse distribution pattern (RDP), in which resting perfusion imaging demonstrates a de novo or more marked regional defect than that present in stress images, is observed frequently in patients with a low likelihood of coronary artery disease. METHODS AND RESULTS To determine whether this scan pattern is artifactual and to investigate its causes, we retrospectively evaluated ...

The motion of the beating heart is complex and creates artifacts in SPECT and x-ray CT images. Phantoms such as the Jaszczak Dynamic Cardiac Phantom are used to simulate cardiac motion for evaluation of acquisition and data processing protocols used for cardiac imaging. Two concentric elastic membranes filled with water are connected to tubing and pump apparatus for creating fluid flow in and o...