introduction:  the  purpose  of  this  study  is  to  define  the  optimal  parameters  for  the  tomographic  reconstruction procedure in a routine single photon emission tomography. the hoffman brain phantom  is modified to evaluate the reconstruction method. the phantom was imaged in a 3 and 2-dimensional  conformation and the results were compared.   materials  and  methods:  the  2d  phant...

The aim of this study is to optimise the acquisition and reconstruction for SPECT with 111 In-pentetrotide with the iterative reconstruction software OSEMS. For 111 In-pentetrotide SPECT, the uptake in the tumour is usually high compared to uptake in normal tissue. It may, however, be difficult to detect small tumours with the SPECT method because of high noise levels and the low spatial resolu...

UNLABELLED Gated SPECT recorded with 16 intervals determines left ventricular (LV) ejection fraction more accurately than does gated SPECT recorded with 8 intervals but produces higher image noise. This study aimed to assess the results from sestamibi and (201)Tl 16-interval gated SPECT when both signal-to-noise ratio and spatial resolution were enhanced with an original method of reconstructio...

In this study, use of a helical orbit in performing a long object SPECT scan with parallel, cone, fan, rotated fan, varying focal-length cone, divergent, and astigmatic collimators is proposed. Sufficient-data scanning helical orbits for these collimation geometries are developed. Both singledetector system and multi-detector system are considered. In order to verify our orbit design requiremen...

SPECT imaging suffers from low spatial resolution and statistical noise. Consequently, the contrast of small structures is reduced, visual detection of defects is limited and exact quantification is difficult. To improve the contrast, it is possible to incorporate a blurring model into the iterative reconstruction process such as OSEM3D. This approach is well known to be effective, but time con...

The dynamic expectation maximization algorithm (dEM) has been developed to determine the kinetic information of various metabolic processes from SPECT projection data acquired with a single slow camera rotation. Depth-dependent detector response compensation (DRC) has been tested as a means to improve the accuracy of these reconstructions. As well, by limiting the number of temporal frames in a...

Quantitative SPECT imaging of In is of growing importance in nuclear medicine applications like patient-specific radionuclide dosimetry. In this study, the quality of a Monte-Carlo based model of the imaging chain from nuclear decay to detection in a gamma camera is investigated. Important characteristics like the camera point spread function (PSF), the phantom attenuation and scatter effects a...

Respiratory motion leads to blur and artifacts in single-photon emission computed tomography (SPECT) images. This may be an issue some treatments such as liver radioembolization. The purpose of this work was reconstruct 4-D respiration-gated SPECT images using a data-driven approach. A respiratory signal extracted from list-mode data Laplacian eigenmaps used for retrospective phase gating. meth...