Mpumelelo Nyathi
Department of Medical Physics Sefako Makgatho Health Sciences University SouthAfrica
[ 1 ] - Determination of Optimum Planar Imaging Parameters for Small Structures with Diameters Less Than the Resolution of the Gamma Camera
Introduction: The limited spatial resolution of the gamma camera hinders the absolute quantification of planar images of small structures. The imaged structures are affected by partial volume effects (PVEs), which can spread activity and lead to underestimation of the regional distribution. The use of optimum planar parameters reduces the impact of the limited spatial resolution of the gamma c...
[ 2 ] - Quantification of partial volume effects in planar imaging
Introduction: The limited resolution of the imaging system causes partial volume effects (PVEs). These results in spreading of image counts to the neighboring pixels. This phenomenon is called spill-out effect. This study aimed at quantifying PVEs using ImageJ. Methods:Technetium-99m solution of concentration of 74 kBq/ml was filled into spheres A, B<...
[ 3 ] - Impact of Silicone gel breast prosthesis on photon beam therapy of recurrence carcinoma post mastectomy
AbstractIntroduction Silicone gel breast implants are used for breast reconstruction post mastectomy. In the event of cancer recurrence, the radiation oncologists are forced to irradiate through the prosthesis device. Due to prosthesis higher atomic number dose perturbations occur during treatment. This study determined the influence of silicone gel thickness on the photon beam distribution. Ma...
[ 4 ] - Local Diagnostic Reference Levels for Common Computed Tomography Procedures at a Tertiary Hospital in South Africa
Introduction: An operational computed tomography (CT) scanner is a major source of human exposure to ionizing radiation. Exposure increases the risk of cancer and aplastic anaemia. All radiation exposures should be justified and optimized to meet the clinical objective. In order to avoid the administration of excessive radiation dose to patients, diagnostic reference l...
[ 5 ] - Utilization of an optimum low-pass filter during filtered back-projection in the reconstruction of single photon emission computed tomography images of small structures
Introduction:Low-pass filters eliminate noise, and accordingly improve the quality of filtered back-projection (FBP) in the reconstruction of single photon emission computed tomography (SPECT) images. This study aimed at selection of an optimum low-pass filter for FBP reconstruction of SPECT images of small structures. Material and Methods:Sp...
[ 6 ] - Quantification of Partial Volume Effects in Salivary Glands SPECT Images after Radiation Therapy of Head and Neck Tumors
Introduction: Radical radiation therapy of head and neck cancers may injure the salivary glands and reduce their function. Single-photon emission computed tomography (SPECT) images maybe used to evaluate function post-therapy. However, accurate quantification is hindered by the partial volume effects (PVEs). The present study involved the introduction of a PVEs quantif...
[ 7 ] - Establishment of Diagnostic Reference Levels and Estimation of Effective Dose from Computed Tomography Head Scans at a Tertiary Hospital in South Africa
Introduction: Head scans are the most frequently performed computed tomography (CT) examinations worldwide. However, there is growing concern over the probability of increased cancer risks among the exposed populations. Diagnostic reference levels (DRLs) identify radiation dose that is not commensurate with clinical objectives. The aim of this study was to establish DR...
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