Establishing diagnostic reference levels for CT examinations in the south region of Saudi Arabia

Patient perspectives on ionising radiation exposure from computed tomography in Saudi Arabia: a knowledge and perception study

The objective of this study was to evaluate patient knowledge and understanding of ionising radiation and dosage, as well as the accompanying risks related to computed tomography scans. A total of 412 outpatients who underwent computed tomography (CT) scans were surveyed to assess their understanding of radiation dose and exposure risks. CT was correctly classified as an ionising radiation by 56.8% of the respondents. More than half of the patients reported that a CT scan increases the probability of inducing cancer. Awareness of varying radiation doses in different CT exams was noted in 75.2% of patients, but only 21.4% reported having discussions with their physician about radiation dose. Gender, age and employment were significantly correlated with knowledge levels. The survey findings indicate a limited understanding of the hazards associated with ionising radiation used in CT scans, highlighting a need for increased awareness and education on radiation protection to ensure informed consent.

Knowledge of computed tomography dose optimisation and justification among CT users and referring physicians: A single hospital study

INTRODUCTION

Radiation dose associated with computed tomography (CT) remains a concern, and radiation risk does not receive the needed attention, especially in low and middle-income countries. This because the frequency of this high-dose examination is rapidly growing and systems for protocol optimisation and dose justification are yet to be provided in CT imaging.

OBJECTIVE

To determine radiographers' and radiologists' awareness and knowledge of CT dose optimisation. We also determined knowledge of dose justification and use of the referral guidelines amongst the referring physicians.

METHODS

Radiographers and radiologists were invited to complete a web-based questionnaire whilst the referring physicians completed a self-administered questionnaire. The returned questionnaires were analysed and a significant difference was determined using Yates corrected Chi-square, and a p-value of 0.05 was considered at the 95% confidence interval.

RESULTS

The response rates were 50% (17 out 34) and 35% (16 out 46) for radiographers and radiologists respectively while referring physicians had a response rate of 84% (92 out of 110). Overall, more radiographers (47.1%) than radiologists (18.8%) had good knowledge of CT doses and image quality, however, the difference in knowledge was not found to be significant (p = 0.167). In addition, knowledge of diagnostic reference levels (DRLs) was significantly (p = 0.033) higher amongst radiographers (52.9%) as compared to radiologists (12.5%). Meanwhile, physicians understood the principles of dose justification. However, their knowledge of referral guidelines was limited.

CONCLUSION

The study revealed that radiographers were more knowledgeable on matters relating to radiation dose and image quality as well as DRLs when compared to radiologists. Meanwhile, the concept of dose justification was understood among physicians, however, they had limited awareness and knowledge of referral guidelines.

Reporting Diagnostic Reference Levels for Paediatric Patients Undergoing Brain Computed Tomography

Brain computed tomography (CT) is a diagnostic imaging tool routinely used to assess all paediatric neurologic disorders and other head injuries. Despite the continuous development of paediatric CT imaging, radiation exposure remains a concern. Using diagnostic reference levels (DRLs) helps to manage the radiation dose delivered to patients, allowing one to identify an unusually high dose. In this paper, we propose DRLs for paediatric brain CT examinations in Saudi clinical practices and compare the findings with those of other reported DRL studies. Data including patient and scanning protocols were collected retrospectively from three medical cities for a total of 225 paediatric patients. DRLs were derived for four different age groupings. The resulting DRL values for the dose-length product (DLP) for the age groups of newborns (0-1 year), 1-y-old (1-5 years), 5-y-old (5-10 years) and 10-y-old (10-15 years) were 404 mGy cm, 560 mGy cm, 548 mGy cm, and 742 mGy cm, respectively. The DRLs for paediatric brain CT imaging are comparable to or slightly lower than other DRLs due to the current use of dose optimisation strategies. This study emphasises the need for an international standardisation for the use of weight group categories in DRL establishment for paediatric care in order to provide a more comparable measurement of dose quantities across different hospitals globally.

Size based dependence of patient dose metrics, and image quality metrics for clinical indicator-based imaging protocols in abdominal CT procedures

INTRODUCTION

Diagnostic reference level (DRL) values for computed tomography (CT) based on clinical indication are warranted since imaging protocols are indication-dependent. This study proposes clinical DRL values using the CT dose metrics and five patient size-related parameters while considering image quality.

METHODS

The volumetric CT dose index (CTDIvol), dose-length product (DLP) and five size-related parameters of size-specific dose estimates (SSDE), namely the anterior-posterior (AP) dimension, lateral (LAT) dimension, sum dimension, effective diameter, and the body mass index (BMI), were used to calculate DRL values for CT chest-abdomen-pelvis (CAP) and abdomen-pelvis (AbP) protocols. DRL values of the clinical indications for cancer, urinary system stones and other pathologies were assessed based on the BMI classifications using the median and 75th percentile. An image subtraction algorithm was used to assess the image quality metrics (IQM) of the CT images.

RESULTS

The 75th percentile for SSDEAP dimension for CAP cancer was 19.7, 14.9 and 12.7 mGy at Hospitals A, C and E, respectively. The median DLP for other AbP pathologies was 556.3, 1452.0 and 1960.7 mGy.cm for normal weight, overweight and obese patients, respectively, at Hospital A. The image quality varied among BMI classifications for different clinically indicated examinations. Although the dose increased with BMI, the image quality index was consistent because automatic tube current modulation (ATCM) was used.

CONCLUSION

DRL values are influenced by patient size-related parameters and the clinical indication protocols, while the image quality index is independent of the BMI.

IMPLICATIONS FOR PRACTICE

Size-related clinical DRL values and image quality index can be used to monitor and optimise dose and image quality. Acquisition parameters and image quality indexes should be investigated and adjusted when unusually high DRL values are noted.

Updated National Diagnostic Reference Levels and Achievable Doses for CT Protocols: A National Survey of Korean Hospitals

Background: In 2021, the Korean government proposed a new CT diagnostic reference level. This study performed a nationwide survey and developed new DRLs and AD for 13 common CT examinations. We compared other countries’ DRLs for CT examinations. Methods: This study investigated the CTDI_vol and DLP of the 12 types of CT protocols for adults and brain CT protocol for pediatrics. A total of 7829 CT examinations were performed using 225 scanners. We defined the DRLs values in the distribution of radiation exposure levels to determine the nationwide patient dose and distribution status of the dose. Results: This study showed that the new Korean national CT DRLs are slightly higher or similar to those of previous surveys and are similar or lower than those of other countries. In some protocols, although the DLP value increased, the CTDI_vol decreased; therefore, it can be concluded that the patient’s dose in CT examinations was well managed. Conclusions: The new CT DRLs were slightly higher than or similar to that of the previous survey and were evaluated to be similar or lower than CT DRLs of other countries. These DRLs will be used for radiation optimization and effective dose calculation for an individual.