Quality Control Monitoring of Medical Diagnostic X-Ray Units in Southern Tanzania

Document Type : Original Paper


1 Southern Zone, Tanzania Atomic Energy Commission (TAEC), MTWARA, United Republic of Tanzania

2 Eastern Zone, Tanzania Atomic Energy Commission (TAEC), Dar Es Salaam, United Republic of Tanzania

3 Zanzibar Office, Tanzania Atomic Energy Commission (TAEC), Zanzibar, United Republic of Tanzania

4 Southern Zone, Tanzania Atomic Energy Commission (TAEC), Dar es Salaam, United Republic of Tanzania.

5 Zanzibar Office, Tanzania Atomic Energy Commission (TAEC), Zanzibar, United Republic of Tanzania.

6 Tanzania Atomic Energy Commission (TAEC), Head Quarter, Arusha, United Republic of Tanzania.


Regular conduction of diagnostic QC program in X-ray units is significant for optimization of image quality and reduction of patient radiation dose. The study focused on assessment of QC tests in X-ray units from the Southern regions of Tanzania to produce data required to formulate and implement quality control policies and strategies.

QC measurements were conducted on twenty-six diagnostic X-ray units in private and government hospital at southern regions of Tanzania during 2020 – 2021. The measurements were done in accordance with the QC guidelines and the values of the measured parameters were compared with the tolerance limits. In this study, the QC measurements on kVp, time reproducibility, the accuracy of accelerating tube potential and half-value layer, collimation and beam alignment were carried out by using Unfors non-invasive X-ray test device, RMI collimation and beam alignment tools.

Of all X-ray units evaluated, 92.31% had kVp accuracy within tolerance limit of 5% and 92% of the X-ray units had acceptable HVL ≥ 2.3 mm Al at 80 kVp. Moreover, results have shown that 86.96% and 82.61% of X-ray units had acceptable beam collimation (≤ ±2 cm) and beam alignment (≤3% of the focus to image distance), respectively.

Comprehensive regulatory inspections and equipment maintenance plans at Southern zone is significantly required due to high patient’s workload which attribute frequent breakdown of X-ray units. Moreover, radiographers need to be trained on how to minimize and detect beam misalignment and collimation failure since most unacceptable results were observed from these tests.


Main Subjects

Articles in Press, Accepted Manuscript
Available Online from 14 May 2022
  • Receive Date: 28 December 2021
  • Revise Date: 08 May 2022
  • Accept Date: 14 May 2022
  • First Publish Date: 14 May 2022