IQ Research Journal-Open Access-ISSN:2790-4296

Influence De La Qualité De L'image Sur L'optimisation De La Dose En Radiologie Conventionnelle



Authors: Lingbe Seconde 1, Ekobena Fouda Henri P 2, Mbo Amvene Jérémie 3. Paper Title: Influence De La Qualité De L’image

Sur L’optimisation De La Dose En Radiologie Conventionnelle

IQ Research Journal of IQ res. j. (2022)1(5): pp 01-11. Vol. 001, Issue 005, 05-2022, pp. 01129-01140


The dose entering the skin (De) is the main parameter used to determine the irradiation that a patient receives during a radiodiagnostic examination. The dose entering the skin depends on parameters such as the charge (mAs), the tube voltage (kV), the focus-film distance (DFF), the focus-skin distance (DFP). Thus the objective of our work is to reduce as much as possible the dose at the entrance of the skin while taking into account the quality of the resulting image. This was done through the
determination of the De of four (4) anatomical regions explored, the comparison of these doses obtained with the international diagnostic reference levels (NRD) adopted in Cameroon, then the comparison of the images obtained according to the dose at the entrance of the skin used. We conducted a prospective study over a period of five (5) months from May 24 to September 15, 2017 in the imaging department of the Garoua Regional Hospital (HRG). The data used come from 459 adult patients with a mass between 50 and 90 kg. The evaluation of the dose at the entrance to the skin of
the patients was done through the Davies model and the determination of the quality  of the image using the Michelson process and the Davies model, then the calculations of the 75th percentiles of the dose at the entrance and the analysis and processing of the data was done by Excel 2010 and Sphinx version 4.0. The doses at the entrance to the skin obtained in mGy were respectively 5.05 ± 0.4 for the thorax, 13.84 ± 0.5 for the pelvis, 21.00 ± 5.1 and 149.18 ±9.9 for AP and lateral views of the lumbar spine, 17.85 ± 2.5 for AP views / 10.52 ± 0.9 for skull profile. This study led us to understand that the 75ths the dose at the entrance to the skin varies very little with the DFF / DFP ratio (the value 1 which translates the absence of blur) and rather we obtain a maximum contrast with the values elevated by 75ths of the dose on the surface of the skin. The maximum contrast represents the visibility of each pixel in black and white, whereas with a small value of 75ths of the dose to the skin, the contrast is zero. The result of all these variations is that the quality of the image remains clinically
diagnostic according to the values considered in our study.