Analysis of factors correlating with medical radiological examination frequencies

Gender Differences in the Impact of Recommendations on Diagnostic Imaging Tests: A Retrospective Study 2007-2021

(1) Background: The frequency of imaging tests grew exponentially in recent years. This increase may differ according to a patient's sex, age, or socioeconomic status. We aim to analyze the impact of the Council Directive 2013/59/Euratom to control exposure to radiation for men and women and explore the impact of patients' age and socioeconomic status; (2) Methods: The retrospective observational study that includes a catchment population of 234,424. We included data of CT, mammography, radiography (conventional radiography and fluoroscopy) and nuclear medicine between 2007-2021. We estimated the associated radiation effective dose per test according using previously published evidence. We calculated a deprivation index according to the postcode of their residence. We divided the study in 2007-2013, 2014-2019 and 2020-2021 (the pandemic period). (3) Results: There was an increase in the number of imaging tests received by men and women after 2013 (p < 0.001), and this increase was higher in women than in men. The frequency of imaging tests decreased during the pandemic period (2020-2021), but the frequency of CT and nuclear medicine tests increased even during these years (p < 0.001) and thus, the overall effective mean dose. Women and men living in the least deprived areas had a higher frequency of imaging test than those living in the most deprived areas. (4) Conclusions: The largest increase in the number of imaging tests is due to CTs, which account for the higher amount of effective dose. The difference in the increase of imaging tests carried out in men and women and according to the socioeconomic status could reflect different management strategies and barriers to access in clinical practice. Given the low impact of the available recommendations on the population exposure to radiation and the performance of high-dose procedures such as CT, deserve special attention when it comes to justification and optimization, especially in women.

THE FREQUENCIES OF X-RAY EXAMINATIONS AND CT SCANS: FINDINGS FROM A SAMPLE INVESTIGATION IN JIANGSU, CHINA

OBJECTIVE

The present study was performed to evaluate the frequencies of two kinds of examinations using a proportional sample of 262 medical institutions and to observe the factors affecting the amount of examination-related exposure. The other aim of the present study was to observe the relationship between X-ray and CT frequency with GDP per capita, which could indicate the connection between medical exposure practice and economy.

METHODS

A random sample was taken from a pool of 316 medical institutions, and correlation analyses were performed to identify the factors affecting the amount of examination-related exposure. A representative sample of 262 medical institutions, proportional to the distribution of hospitals across grades, was used, and a multiple linear regression model was constructed.

RESULTS

The frequencies of X-ray examinations and CT scans were 523 per 1000 people and 223 per 1000 people, respectively. The two kinds of radio-diagnostic examinations showed different patterns in their relationships with GDP per capita. The factors correlated with the amounts of exposure due to the two kinds of examinations and the outpatient and equipment numbers showed distinctive patterns in the group of grade three institutions.

CONCLUSIONS

The improvement in the economy has caused a rapid increase in the use of radio-diagnostic examinations. The differences in factors correlated with the two types of examinations may stem from the workload statuses of CT scans and X-ray examinations in grade three hospitals.

Radiation Dose from Whole-Body F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Nationwide Survey in Korea

The purpose of this study was to estimate average radiation exposure from (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examinations and to analyze possible factors affecting the radiation dose. A nation-wide questionnaire survey was conducted involving all institutions that operate PET/CT scanners in Korea. From the response, radiation doses from injected FDG and CT examination were calculated. A total of 105 PET/CT scanners in 73 institutions were included in the analysis (response rate of 62.4%). The average FDG injected activity was 310 ± 77 MBq and 5.11 ± 1.19 MBq/kg. The average effective dose from FDG was estimated to be 5.89 ± 1.46 mSv. The average CT dose index and dose-length product were 4.60 ± 2.47 mGy and 429.2 ± 227.6 mGy∙cm, which corresponded to 6.26 ± 3.06 mSv. The radiation doses from FDG and CT were significantly lower in case of newer scanners than older ones (P < 0.001). Advanced PET technologies such as time-of-flight acquisition and point-spread function recovery were also related to low radiation dose (P < 0.001). In conclusion, the average radiation dose from FDG PET/CT is estimated to be 12.2 mSv. The radiation dose from FDG PET/CT is reduced with more recent scanners equipped with image-enhancing algorithms.