Estimation of organ-specific cancer and mortality risks associated with common indication-specific CT examinations of the abdominopelvic region.

Introduction: There is a paucity of large-scale studies reporting organ doses and cancer risks in patients who undergo indication-specific CT examinations. This study estimated organ-specific lifetime attributable risk (LAR) of cancer incidence and mortality among patients who underwent indication-based computed tomography (CT) examinations [(involving abdominopelvic lesion, kidney stones and computed tomography-intravenous urography (CT-IVU)] in about 70% of the functioning CT facilities in Ghana.

Methods: With a total of 1,100 data sets, organ doses were first determined using the National Cancer Institute Dosimetry System for CT (NCICTX) software version 2.

Adult Computed Tomography examinations in Uganda: Towards determining the National Diagnostic Reference Levels.

Introduction: Diagnostic Reference Levels (DRLs), typically set at the 75th percentile of the dose distribution from surveys conducted across a broad user base using a specified dose-measurement protocol, are recommended for radiological examinations. There is a need to develop and implement DRLs as a standardisation and optimisation tool for the radiological protection of patients at Computed Tomography (CT) facilities.

Methods: This was a retrospective cross-sectional study conducted in seven (7) different CT scan facilities in which participants were recruited by systematic random sampling.

Towards the establishment of national imaging practice guidelines: A preliminary study of the basic computed tomography imaging protocols in Ghana.

Background: There is a need to harmonize imaging practices in computed tomography (CT) imaging. This study, therefore, investigated the variability of the basic imaging protocols used for CT imaging of common indications in Ghana in order to generate recommendations for the development of national imaging practice guidelines in CT imaging.

Method: A cross-sectional study, utilizing a structured online questionnaire, was undertaken (between December 2018 to March 2019) to collect indication-based imaging protocol data (scan coverage, scan series, image quality requirement, slice thickness, reconstruction, scan mode and orientation, required window, AEC usage, scan and breath hold techniques etc.

Variability of redundant scan coverages along the Z-axis and dose implications for common computed tomography examinations.

Background: Scan length optimization is a method of optimization which ensures that, imaging is performed to cover just the area of interest without unnecessarily exposing structures that would not add value to answer a given clinical question.

Purpose: This study assessed the variability and degree of redundant scan coverages along the z-axis of CT examinations of common indications and the associated radiation dose implications in CT facilities in Ghana for optimization measures to be recommended.

Methods: On reconstructed acquired CT images, the study measured extra distances covered above and below anatomical targets for common indications with calibrated calipers across 25 CT facilities.

ASSESSMENT OF MEASUREMENT UNCERTAINTY FOR THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP (10) IN PHOTON FIELDS USING THE GUM FRAMEWORK AND THE MONTE CARLO METHODS: APPLICATION TO GABON RESULTS OBTAINED DURING THE 2018 IAEA REGIONAL INTERCOMPARISON EXERCISE.

This paper describes the essential of the "Guide to the expression of Uncertainty in Measurement" Framework (GUMF) Method and Monte Carlo Method (MCM) for propagating uncertainties, with an application to Gabon results obtained during the 2018 International Atomic Energy Agency (IAEA) regional intercomparison exercise. The work has shown that the output quantity Hp (10) follows a lognormal distribution. The study has also shown that although the normal distribution does not best approximate the distribution of the output quantity Hp (10), it has been observed that its estimate, the associated standard uncertainty and the coverage interval determined by GUMF and MCM were close, meaning that the application of the GUMF could still be seen as valid.