Table 1 demonstrate that the demographics of participants consider their age and gender, the knowledge of radiation protection in 4 levels (excellent, good, sufficient, and insufficient) and relative trainings. All 180 participants completed the questionnaire. The average age for radiology residents, and radiography staff reported 22.5, 35.6 years old, respectively (t-test p<0.05). Radiology students and radiography staff constitute 45.5% and 34.6% of males participants and 55.5% and 65.5% of females respectively in this survey (chi-square test, p > 0.05). The questionnaire have acceptable internal reliability (α= 0.780; CI95 0.762 - 0.852). The quantity of consistency in the internal reliability of the questionnaire was also investigated amongst participants. Cronbach’s α coefficients were 0.760 (CI95 0.746 - 0.796), 0.727 (CI95 0.688 - 0.744) and 0.797 (CI95 0.696 - 0.835), respectively. Regarding perceived knowledge in participants, it has shown that radiology staff had the most information in good level ( 40.5% ) compared to radiology students ( 36.1% ); moreover, their knowledge in the excellent level was by far the lowest amount 6.6% for radiology students and 10.3% for radiology staff. Fact, 41% of radiology residents had sufficient information (Fisher’s exact test, p < 0.05).
Fig1 indicates the total questionnaire scores in different charts. All there tables give information for radiology students and radiology staff. Chart A illustrates the scores of radiation protection knowledge. In which radiology students got the score between 3 to 4 out of 5 while radiology staff got the score, approximately between1.8 to 2.8 out of 4 (Kruskal-Wallis test p < 0.001). Chart B shows the amount of dose level assessment. The count of dose level assessment reported around 4.5 out of 8.5 for radiology staff while for radiology students. It was approximately 2.5 out of the maximum of 8. (Kruskal-Wallis test, p < 0.001). Regarding chart C, the overall knowledge among both groups was as followed: about 7.7 out of more than 12.5 and 5.7 out of 11.7 for radiology staff and radiology students respectively, (Kruskal-Wallis test, p < 0.001).
3.1. Radiation protection knowledge:
Fig 2 gives a describes of the statistics of radiology staff and radiology students' education to survey questions about general radiation protection issues. Considering to chart 1, shows that the majority numbers of both radiology students (79.1%) and radiology staff (about 87%) were aware of the necessity to inform patients about the dangers of radiation exposure. As can be seen, the highest percentage about the responses to the question of “which patients have the most sensitivity to ionizing radiation?” was reported for radiology students (slightly less than 50%) as one-year-old girl while around 45% of radiology staff answered that the risk of radiation damage does not depend on age or sex.
A high rate of radiology students and radiology staff have correctly answer that all items in the bar chart 3 are responsible for unnecessary patient exposure and lack of optimization.
Considerably about 6% of both groups (lowest percent) responded that only radiological staffs are responsible for this matter (Chi-square test, p < 0.05).
Interventional radiologists and cardiologists accounted for the second-highest amount of exposed professionals, at the same time, nuclear medicine has answered as the most exposed category with the percentage of approximately 38 and just above 50 for radiology students and radiology staff, respectively. About 64% of radiology students and 40% of radiology staff considered breast as the most sensitive tissue.
Regarding the question about ” which of the following disease may be a result of stochastic radiation damage? ” the percentages of those who answered all times ( dermatitis, leukemia, alopecia, and cataract ) were the highest ratio slightly more than 40% and around 50% for radiology students and staff respectively. The final question, which is described in bar chart number 7, is about the meaning of dose optimization. As can be seen, the above rates of answers were reported for radiology staff (around 60%). All the same, the percentage for radiology students who answered all mentioned items in the chart were the same as their answer that was said, in radiological tests (Fisher’s exact test, p < 0.05).
3.2. Knowledge of recommended radiation dose levels for the main imaging procedures:
Table 2 gives a breakdown of the percentage of answers to the questions about the dose of natural background, commonly performed imaging examinations given by radiology students and staff.
The two exanimated groups estimated the average dose for a PA chest radiograph, 0.01 – 0.1 mSv in this way: 29 % and 49.5 % of radiology students and radiology staff, respectively (Fisher’s exact test, p < 0.05).
6.6 % of radiography students and significantly less than that, 2.9 % of radiology staff in Iran answer the average dose of the natural background radiation correctly.
Regarding the average dose due to a lumbar X-Ray examination, 9.8 % of radiography students and around three times more than that, 27.7% of radiology staff gave the correct dose value.
The average dose due to mammography was known by 19.7% of radiography students and 17.8% of radiology staff; all the same 10.1 in total consider mammography as a radiation-free procedure should be a matter of concern (8.1 % of radiography students and 2% of radiology staff).
The next figure shows the average dose because of the non-contrast chest CT examinations in which it was correctly estimated by 45.9% and slightly less 45.1% for radiography students and radiology residents, respectively. Considerably for radiography students and radiology staff, those who answered that CT involves no radiation exposure, the ratio is 0% for the former survey respondents and 1% for the later. The MRI examination was correctly identified as radiation-free by 62.3% of radiography students and significantly 88.5% of radiology staff. As for nuclear medicine procedures, the correct estimation ratio for the radiation dose of PET-CT examinations was 20% of radiography students and 36.7% of radiology staff ; ( Fisher’s exact test, p < 0.05 ); however the average dose due to myocardial scintigraphy has estimated by 16.7 % of the former respondents and 55.7% for the later; ( Fisher’s exact test, p < 0.05 ). Furthermore, as can be seen, 3.4% of radiology students about PET-CT examinations and exactly half of that (1.7%) for myocardial scintigraphy thought that these examinations are not associated with radiation exposure, this ratio for radiology staff was 2% for the former analysis and 0% for the later.
Table 2 overall distributions of answers to questions about the dose of natural background radiation and commonly performed imaging examinations given by Radiology staff and radiography students. Values are expressed in terms of equivalent number of chest radiographs. Correct answers are highlighted in shaded bold.