To evaluate the mean skill level of radiology residents in chest X-ray (CXR) reading, with regard to cognitive mechanisms involved in this task and to investigate for potential factors influencing residents’ skill.

Eighty-one residents were evaluated through a test set including CXR expected to mobilize detection skills (n=10), CXR expected to mobilize interpretation skills (n=10) and normal CXR (n=4). For each radiograph, residents were asked to answer three questions: Does this radiograph show normal or abnormal findings? Does it require complementary computed tomography study? What is your diagnosis? Residents’ answers were evaluated against an experts’ consensus and analyzed according to year of residency, attendance at CXR training course during residency and the average number of CXR read per week.

Residents’ mean success rate was 90.4%, 76.6% and 52.7% for the three questions, respectively. Year of residency was associated with better diagnostic performances in the detection CXR category (P=0.025), while attendance at CXR training course was associated with better performances in the interpretation CXR category (P=0.031). There was no influence of the number of CXR read per week.

These results may suggest promoting systematic CXR theoretical training course in the curriculum of radiology residents.