ESTABLISHMENT OF LOCAL DIAGNOSTIC REFERENCE LEVEL FOR ROUTINE PAEDIATRIC COMPUTED TOMOGRAPHY EXAMINATIONS IN BAFOUSSAM WEST CAMEROON.

The main purpose of this study was to determine local diagnostic reference level (LDRL) for routine computed tomography (CT) examination in Bafoussam, western Cameroon. The exposure parameters and dose quantities were collected manually. This retrospective, evaluative and comparative study was conducted to determine LDRLs for routine head CT examination in Bafoussam, to optimize these procedures in the region. The 75th percentile values of the calculated volume CT dose index (CTDIvol) and dose length product (DLP) were proposed as LDRL. The sample was classified in four age groups: < 1, 1-5, 5-10 and 10-15 y. The LDRLs obtained for the four age groups were: 24 mGy and 381.32 mGy.cm, 42.5 mGy and 875.55 mGy.cm, 45.85 mGy and 939.62 mGy.cm, 57.12 mGy and 1222.3 mGy.cm, respectively. The 75th percentile CTDIvol and DLP dose values for this study are higher than international values. We propose a coordinating discussions and collaboration about patient's and specific equipment's change information's, between radiologists, medical imaging technicians and medical physicist, which can reduce absorbed doses and improved medical practice in hospitals.

Optimization of pediatric CT scans in a developing country.

BACKGROUND: The purpose of this study was to assess scan parameters and to propose strategies to optimize the examinations of children (from 0 to 15 years old) on adult scanners in developing countries. METHODS: A study was done in 2015 and 2018 on 312 pediatric patients to verify improved practices. The study of 2015 ended with proposed strategies. Dose and scan parameters were available for prospective dose analysis. These strategies were implemented in a study of 2018. RESULTS: Amount the CT examinations study in this paper, the common was head trauma (90 %). For every pediatric CT scan in 2015, a kV of 120 was used in the various hospitals. The mAs ranged from 57.75 to 283.33, slice thicknesses from 1.25 to 2.5 mm and pitch from 0.525 to 1.375 mm. In the study of 2018, implementing the strategy defined in the methodology and proposed in 2015: CTDIVol decreased by 21.27 % for children < 1 year, 31.97 % for children 1-4 years, 17 % for children 5-9 years. DLP also decreased by 25.14 %, 36.29 % and 19.85 % for children < 1 year, 1-4 years and 5-9 years respectively. Children were exposed to ionizing radiation on machines designed for adults, but now the doses received by children are reduced. CONCLUSIONS: The reduction of doses during the pediatric CT examination is possible with the introduction of new optimization protocols or the acquisition of a new machine with a pediatric protocol.