Browsing by Author "Joseph, Dlama Z."

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    Assessment of Dose to Patients Undergoing Computed Tomography Procedures at Selected Diagnostic Centers in Kano, Nigeria
    (Department of Physics, Nasarawa State University Keffi, 2020-09-10) Hassan, Abdullahi A.; Umar, Ibrahim; Ige, Taofeeq A.; Joseph, Dlama Z.; Aisha, A.; Rilwan, Usman
    Radiation dose levels for adult most common Computed Tomography (CT) examinations namely brain, chest and abdomen CT scans were studied. Radiation dose reports, scan parameters and demographic information were surveyed for a period of three - months. Ethical approvals were obtained from the research ethics committee of Ministry of Health and the studied centers. Data were randomly collected using a simple random technique from 131 adult patients with weights 70 ± 3kg. The General Electric 8 and 16-slice and 160-slice Toshiba CT scanners were used in the study. The data were analyzed using SPSS (version 20.0 Chicago) statistical software. The results indicated that the CTDIw and DLP values were (62.5 mGy and 2946mGy*cm), (9.9mGy and 663.3 mGy*cm) and (13.5 mGy and 1397 mGy*cm) for brain CT, chest CT and abdominal CT scans respectively. The study shows that the CTDIw values are relatively similar to those reported in established work by the European Commission. However, the DLP values are comparably higher than those of the European Commission. This revealed that there is need for robust and sustained optimization program so as to reduce patient doses without affecting diagnostic image quality.
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    Comparison of Calculated Percentage Depth Doses at Extended Source-to-Surface Distance for 6 MV And 15 MV Photon Beam of a Linear Accelerator
    (Department of Physics, Nasarawa State University Keffi, 2018-04-19) Umar, Ibrahim; Idris, Mustapha M.; Mundi, Abdullahi A.; Joseph, Dlama Z.
    Background: Research findings from percentage depth dose (PDD) are crucial in evaluating patient doses received in radiation therapy. Objective: To compare calculated percentage depth doses at an extended source-to-surface distance (SSD) for 6 MV and 15 MV photon beams of a linear accelerator. Methodology: Measured PDD values of the 100 cm source to surface distance (SSD) and calculated values at extended SSDs for 6 MV and 15 MV photon beams of an Elekta NHA SLi 1998 linear accelerator were analyzed. The PDD data was collected by placing ionization chamber inside water phantom for depths ranging from z = 0 - 30 cm in a water phantom and using a square field sizes of 10 x 10 cm2. Photon energies of 6 MV and 15 MV were used for the measurement, with both gantry and collimator angles fixed at zero degree. PDD was calculated at extended SSD of 110 cm, 120 cm, 130 cm, and 140 cm from the measured PDD values of 100 cm SSD for both 6 MV and 15 MV photon energies using Mayneord factor. Results: The depth dose maximum (Dmax) for field size 10 x 10 cm2 for 6 MV and 15 MV photon energies were 1.62 cm and 2.65 cm, respectively and the PDD at 10 cm (D10) were 67.9% and 75.9%, respectively. The mean deviation of the calculated PDD at extended SSDs was found to be between 0.2% and 1%. Conclusion: The calculated PDD values at extended SSDs are considered suitable for clinical use at all clinically relevant depths and field sizes.