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.

Assessment of diagnostic reference levels for paediatric cardiac computed tomography in accordance with European guidelines

Recently, paediatric cardiac computed tomography (CCT) has caused concerns that diagnostic image quality and dose reduction may require further improvement. Consequently, this study aimed to establish institutional (local) diagnostic reference levels (LDRLs) for CCT for paediatric patients, and assess the impact of tube voltage on proposed DRLs in terms of the volume computed tomography index (CTDIvol) and dose length product (DLP). In addition, effective doses (EDs) of exposure were estimated. A population of 453 infants, whose mass and age were less than 12 kg and 2 years, respectively, were considered from January 2018 to August 2021. Based on previous studies, this number of patients was considered to be sufficient for establishing LDRLs. A group of 245 patients underwent CCT examinations at 70 kVp tube voltage with an average scan range of 23.4 cm. Another set of 208 patients underwent CCT examinations at 100 kVp tube voltage with an average scan range of 15.8 cm. The observed CTDI_vol and DLP values were 2.8 mGy and 54.8 mGy.cm, respectively. The mean effective dose (ED) was 1.2 mSv. It is concluded that provisional establishment and use of DRLs for cardiac computed tomography in children are crucial, and further research is needed to develop regional and international DRLs.

Paediatric effective radiation doses during brain computed tomography angiography procedure

In comparison to adults and paediatric are more sensitive to ionizing radiation exposure. Computed tomography (CT) is now the dominant source of medical radiologic tests for patients, accounting for more than 70% of total doses to the general public. Paediatric CT brain scans (with and without contrast) are routinely performed for a variety of clinical reasons. As a result, this parameter must be calculated in order to determine relative radiation risk. The goal of this study is to assess the radiation risk to children during CT brain diagnostic procedures. Three hundred fifty three child patients' radiation risk doses were assessed over the course of a year. The mean and ranged of the children's radiation doses were 40.6 ± 8.8 (27.8-45.8) CTDIvol (mGy) and 850 ± 230 (568.1-1126.4) DLP (mGy.cm) for the brain with contrast medium. For CT brain without contrast, the patients' doses were 40.9 ± 9.4 (14.27-64.07) CTDIvol (mGy), and 866.1 ± 289.3 (203.6-2484.9) DLP (mGy.cm). The characteristics related to the radiation dose were retrieved from the scan protocol generated by the CT system by the participating physicians after each procedure. Furthermore, optimizing the CT acquisition parameter is critical for increasing the benefit while lowering the procedure's radiogenic risk. The patients' radiation dose is comparable with the most previously published studies and international diagnostic reference levels (DRLs). Radiation dose optimization is recommended due to high sensitivity of the paediatric patients to ionizing radiation.

Paediatric minor head injury applied to Paediatric Emergency Care Applied Research Network CT recommendations: An audit

Background

Traumatic brain injury (TBI) is a common cause of paediatric morbidity and mortality, with higher TBI rates in low- and middle-income countries. Non-contrast brain CT is the gold standard for diagnosing intracranial injuries; however, it exposes patients to ionising radiation. The Paediatric Emergency Care Applied Research Network (PECARN) clinical decision rule (CDR) aids clinicians in their decision-making processes whilst deciding whether a patient at very low risk of a clinically important TBI (ciTBI) requires a CT scan.

Objectives

To establish whether the introduction of the PECARN CDR would affect CT utilisation rates for paediatric patients presenting with minor blunt head injuries to an academic hospital in Gauteng, South Africa.

Method

This was an audit of paediatric patients who presented with minor blunt head injuries and were referred for CT imaging at an academic hospital in Gauteng, compared with PECARN CDR recommendations, over a 1-year period.

Results

A total of 100 patients were referred for CT imaging. Twenty patients were classified as very low risk, none of whom had any CT findings of a TBI or ciTBI (p < 0.01). A total of 61 patients were classified as intermediate risk and 19 as high risk. In all, 23% of the intermediate and 47% of the high-risk patients had CT features of a TBI, whilst 8% and 37% had a ciTBI, respectively.

Conclusion

Computed tomography brain imaging may be omitted in patients classified as very low risk without missing a clinically important TBI. Implementing the PECARN CDR in appropriate patients would reduce CT utilisation rates.

An Africa point of view on quality and safety in imaging

Africa has seen an upsurge in diagnostic imaging utilization, with benefits of efficient and accurate diagnosis, but these could easily be offset by undesirable effects attributed to unjustified, unoptimized imaging and poor quality examinations. This paper aims to present Africa’s position regarding quality and safety in imaging, give reasons for the rising interest in quality and safety, define quality and safety from an African context, list drivers for quality and safety in Africa, discuss the impact of COVID-19 on quality and safety, and review Africa’s progress using the Bonn Call for Action framework while proposing a way forward for imaging quality and safety in Africa. In spite of a healthcare setting characterized by meagre financial, human and technology resources, a rapidly widening disease-burden spectrum, growing proportion of non-communicable diseases and resurgence of tropical and global infections, Africa has over the last ten years made significant strides in quality and safety for imaging. These include raising radiation-safety awareness, interest and application of evidence-based radiation safety recommendations and guidance tools, establishing facility and national diagnostic reference levels (DRLs) and strengthening end-user education and training. Major challenges are: limited human resource, low prioritization of imaging in relation to other health services, low level of integration of imaging into the entire health service delivery, insufficient awareness for radiation safety awareness, a radiation safety culture which is emerging, insufficient facilities and opportunities for education and training. Solutions to these challenges should target the entire hierarchy of health service delivery from prioritization, policy, planning, processes to procedures.

Estimation of radiation dose and establishment of local diagnostic reference levels for computed tomography of head in pediatric population

BACKGROUND

Pediatric population is more sensitive to the effects of radiation than adults. Establishing diagnostic reference level (DRL) is an efficient dose optimization technique implemented by many countries for reducing radiation dose during Computed Tomography (CT) examinations.

OBJECTIVES

To estimate radiation dose and establish a new local diagnostic reference level for CT head examination in the pediatric population.

MATERIALS AND METHODS

We prospectively recruited 143 pediatric patients referred for CT head examination with age ranging from 0-5 years old. All patients had undergone CT head examination using the standard pediatric head protocol. Volumetric CT dose index (CTDIvol) and dose length product (DLP) were recorded. The effective dose was first calculated. Then, 75th percentile of dose indices was calculated to establish DRLs.

RESULTS

DRLs in terms of CTDIvol and DLP are 23.84 mGy, 555.99 mGy.cm for patients <1 years old and 28.65 mGy, 794.99 mGy.cm for patients from 1-5 years old, respectively. Mean effective doses for <1 years old patients and 1-5 years old patients are 2.91 mSv and 2.78 mSv respectively.

CONCLUSION

The study concludes that DRL in terms of CTDIvol is lower but DRL in terms of DLP and the effective dose is higher compared to a few other studies which necessitate the need for dose optimization.

An audit of published South African diagnostic reference level data

Diagnostic reference levels (DRLs) are accepted as a dose optimisation tool for patients undergoing x-ray imaging and are required by South African (SA) legislation for 26 fluoroscopically guided procedures (FGPs). The aim of this paper is to collate all published SA data on DRLs in preparation for a project to establish national DRLs. Systematic searches were conducted of various applicable databases. All research that proposed DRLs for any imaging procedure in South Africa was included. Twenty-one works met inclusion criteria, the earliest from 2001. Two-thirds of all work reported on FGPs and five studies documented computed tomography DRLs. Three publications focussed exclusively on paediatric imaging DRLs. No studies on mammography or dental radiography were found. For clinical procedures with more than one proposed DRL, the range of proposed DRL varied by up to a factor of five. The highest proposed DRL is 373.1 Gy cm²for endovascular aneurysm/aortic repair procedures. Data were collected in six public hospitals and two private hospital groups. Thirty-six authors contributed to the manuscripts, but only six studies had an inter-disciplinary authorship. This is the first paper to provide a comprehensive review of SA DRL data and thereby advances international radiation protection initiatives. The data suggests there is room for more interdisciplinary work and that there must be rigorous standardization of reported parameters and data collection. This audit also highlights the need for standardized terminology, particularly for FGPs.

An audit of radiation doses received by paediatric patients undergoing computed tomography investigations at academic hospitals in South Africa

Background

Diagnostic reference levels (DRLs) are a crucial element of auditing radiation doses in paediatric computed tomography (CT). Currently, there are no national paediatric CT DRLs in South Africa.

Objectives

The aim of this article was to establish local paediatric DRLs for CT examinations at two academic hospitals and to compare paediatric CT radiation output levels with established DRLs in the developed and developing world.

Method

Computed Tomography Dose Index_volume (CTDI_vol) and dose length product (DLP) values were collected from CT examinations performed at two university hospitals for patients aged 0–15 years, during 01 November 2016–30 April 2017. The 75th percentile of the data distribution was calculated for each CT examination type and age group, further categorised into routine working hours and after-hours for both hospitals and statistically compared.

Results

Of the 1031 CT examinations performed, CT brain examination was the most common (755/1031; 72.23%). DLP values were increased in the after-hours categories compared to regular working hours at both hospitals. The largest increase was in the 0–1 year age group (150.56%). With the exception of CT Chest and CT abdomen in the 0–1 year age group, the CTDI_vol and DLP values compared favourably to international standards.

Conclusion

Most of the calculated DRLs are acceptable and internationally comparable. This likely indicates effective reduction techniques and protocols. Computed tomography body examination protocols for 0–1 year patients should be reviewed. Strategies should be implemented to limit higher doses in after-hours examinations.

Diagnostic reference levels for paediatric CT in Jordan

This study aimed to investigate the current status of Diagnostic Reference Levels (DRLs) in paediatric CT across Jordan. The dose data for four main CT examinations (brain, chest, abdominopelvic, and chest, abdomen and pelvis (CAP)) in hospitals and imaging centres (n = 4) were measured. The volume CT dose index (CTDIvol) and Dose Length Product (DLP) values were compared within the different hospitals and age groups (<1 year, 1-4 years, 5-10 years and 11-18 years). DRLs in Jordan were compared to international DRLs. The paediatric population consisted of 1818 children; 61.4% of them were male. There were significant variations between the DRLs for each CT scanner with an up to four-fold difference in dose between hospitals. There were apparent significant differences between Jordan and other countries with the DLPs in Jordan being relatively high. However, for CTDIvol, the values in Jordan were close to those of other countries. This study confirmed variations in the CTDIvol and DLP values of paediatric CT scans in Jordan. These variations were attributed to the different protocols and equipment used. There is a need to optimise paediatric CT examinations doses in Jordan.

Diagnostic reference levels in low- and middle-income countries: early "ALARAm" bells?

Background In 1996 the International Commission on Radiological Protection (ICRP) introduced diagnostic reference levels (DRLs) as a quality assurance tool for radiation dose optimization. While many countries have published DRLs, available data are largely from high-income countries. There is arguably a greater need for DRLs in low- and middle-income-countries (LMICs), where imaging equipment may be older and trained imaging technicians are scarce. To date, there has been no critical analysis of the published work on DRLs in LMICs. Such work is important to evaluate data deficiencies and stimulate future quality assurance initiatives. Purpose To review the published work on DRLs in LMICs and to critically analyze the comprehensiveness of available data. Material and Methods Medline, Scopus, and Web of Science database searches were conducted for English-language articles published between 1996 and 2015 documenting DRLs for diagnostic imaging in LMICs. Retrieved articles were analyzed and classified by geographical region, country of origin, contributing author, year of publication, imaging modality, body part, and patient age. Results Fifty-three articles reported DRLs for 28 of 135 LMICs (21%), reflecting data from 26/104 (25%) middle-income countries and 2/31 (6%) low-income countries. General radiography (n = 26, 49%) and computerized tomography (n = 17, 32%) data were most commonly reported. Pediatric DRLs (n = 14, 26%) constituted approximately one-quarter of published work. Conclusion Published DRL data are deficient in the majority of LMICs, with the paucity most striking in low-income countries. DRL initiatives are required in LMICs to enhance dose optimization.