Local Diagnostic Reference Levels Research Articles

Establishment of local diagnostic reference levels for computed tomography with cloud-based automated dose-tracking software in Türkiye

The purpose of this study is to establish local diagnostic reference levels (LDRLs) for computed tomography (CT) procedures using cloud-based automated dose-tracking software. The study includes the dose data obtained from a total of 104,272 examinations performed on adult patients (>18 years) using 8 CT scanners over 12 months. The protocols included in our study were as follows: head CT without contrast, cervical spine CT without contrast, neck CT with contrast, chest CT without contrast, abdomen-pelvis CT without contrast, lumbar spine CT without contrast, high-resolution computed tomography (HRCT) of the chest, and coronary CT angiography (CTA). Dose data were collected using cloud-based automatic dose-tracking software. The 75th percentiles of the distributions of the median volume CT dose index (CTDIvol) and dose length product (DLP) values were used to determine the LDRLs for each protocol. The LDRLs were compared with national DRLs (NDRLs) and DRLs set in other countries. Inter-CT scanner variability, which is a measure of how well clinical practices are standardized, was determined for each protocol. Median values for each protocol were compared with the LDRLs for dose optimization in each CT scanner. The LDRLs (for DLP and CTDIvol, respectively) were 839 mGy.cm and 41.2 mGy for head CT without contrast, 530.6 mGy.cm and 19.8 mGy for cervical spine CT without contrast, 431.9 mGy.cm and 15.5 mGy for neck CT with contrast, 364.8 mGy.cm and 9.3 mGy for chest CT without contrast, 588.9 mGy. cm and 11.2 mGy for abdomen-pelvis CT without contrast, 713 mGy.cm and 24.3 mGy for lumbar spine CT without contrast, 326 mGy.cm and 9.5 mGy for HRCT, and 642.3 mGy.cm and 33.4 mGy for coronary CTA. The LDRLs were comparable to or lower than NDRLs and DRLs set in other countries for most protocols. The comparisons revealed the need for immediate initiation of an optimization process for CT protocols with higher dose distributions. Furthermore, protocols with high inter-CT scanner variability revealed the need for standardization. There is a need to update the NDRLs for CT protocols in Turkey. Until new NDRLs are established, local institutions in Turkey can initiate the optimization process by comparing their dose distributions to the LDRLs established in our study. Automated dose-tracking software can play an important role in establishing DRLs by facilitating the collection and analysis of large datasets.

Age-based diagnostic reference levels and achievable doses for paediatric CT: a survey in Shanghai, China

Computed tomography (CT) is extensively utilised in medical diagnostics due to its notable radiographic superiority. However, the cancer risk associated with CT examinations, particularly in children, is of significant concern. The assessment of cancer risk relies on the radiation dose to examinees. Diagnostic reference levels (DRLs) and achievable doses (ADs) were used to assess the level of radiation dose in CT examinations widely. Although the national DRLs of paediatric CT have been explored in China, few local DRLs at the city level have been assessed. To set up the local DRLs and ADs of paediatric CT, we investigated the radiation dose level for paediatric CT in Shanghai. In this survey, a total of 3061 paediatric CT examinations underwent in Shanghai in 2022 were selected by stratified sampling, and the dose levels in terms of volume CT dose index (CTDIvol) and the dose-length product (DLP) were analysed by 4 age groups. The DRLs and ADs were set at the 75th and 50th percentile of the distribution and compared with the previous studies at home and abroad. The survey results revealed that, for head scan, the DRLs of CTDIvol were from 25 to 46 mGy, and the levels of DLP were from 340 to 663 mGy·cm. For chest, the DRLs of CTDIvol were from 2.2 to 8.3 mGy, and the levels of DLP were from 42 to 223 mGy·cm. For abdomen, the DRLs of CTDIvol were from 6.3 to 16 mGy, and the levels of DLP were from 181 to 557 mGy·cm. The ADs were about 60% lower than their corresponding DRLs. The levels of radiation doses in children-based hospitals were higher than those in other medical institutions (P < 0.001). In conclusion, there was still potential for reducing radiation dose of paediatric CT, emphasising the urgent need for optimising paediatric CT dose in Shanghai.

Characterisation of Portuguese radiotherapy departments: Organisation, occupational exposure values and diagnostic reference levels for breast and prostate computed tomography planning

IntroductionPortugal currently hosts 24 active radiotherapy departments, 8 public and 16 privates, presenting potential radiation exposure risks to multidisciplinary teams. Patients in these treatments also face ionising radiation during treatment planning and verification. MethodsAuthorisation and ethical approval were secured for a national online survey, disseminated to radiotherapy departments across Portugal. The survey encompassed three sections: equipment, staff, and radiographer role characterisation; occupational exposure values for one month; and exposure parameters, including computed tomography (CT) dose values [CT dose index (CTDIvol) and dose length product (DLP)] for breast and prostate cancer CT planning. Local Diagnostic Reference Levels (DRLs) derived were based on the 75th percentile of median dose values. ResultsThe study garnered a 50% response rate from public institutions, 12,5% from private and 25% from all active radiotherapy institutions in Portugal. All departments employ Three-Dimensional Conformal Radiation Therapy (3D–CRT) and incorporate Intensity Modulated Radiation Therapy (IMRT) and/or Volumetric Modulated Arc Therapy (VMAT) irradiation techniques. Additionally, half of the departments also perform Brachytherapy (BT). Radiographers demonstrated an occupational dose of zero mSv. CT planning dose values were 13 mGy and 512 mGy cm for breast CT and 16 mGy and 689 mGy cm for prostate CT, pertaining to CTDIvol and DLP, respectively. ConclusionMost aspects of national radiotherapy characterisation align with the established literature. Occupational exposure values exhibited consistency across radiotherapy modalities. An approach to national DRLs was formulated for breast and prostate CT planning, yielding values congruent with recent European studies. Implications for practiceThis study offers vital insights for analysing occupational contexts and risk prevention, serving as the initial characterisation of the national radiotherapy landscape. It also pioneers the calculation of DRLs for CT planning in radiotherapy to optimise procedures.

An audit of patient radiation doses during interventional cardiology procedures in Uttarakhand, India, and establishment of local diagnostic reference levels.

The objective of this study was to investigate patient radiation doses by a dose audit of three common interventional cardiology (IC) procedures: coronary angiography (CA), percutaneous transluminal coronary angioplasty (PTCA) and CA-PTCA procedures performed in IC centres in the Uttarakhand state of India, for the establishment of local diagnostic reference levels (DRLs) and the estimation of average effective dose (Eav) for these procedures. For each procedure, the values of kerma-area product (PKA), reference air kerma (Ka,r), fluoroscopy time (FT) and the number of cine images were recorded from 1233 CA, 458 PTCA and 736 CA-PTCA procedures performed over a 12-month period at 13 IC centres of the state. From the recorded dose data, 0.6%, 1.53% and 7.9% patients were identified to have exceeded the PKA trigger level of 500 Gy cm2 for possible skin injury for CA, PTCA and CA-PTCA procedures, respectively. The 3rd quartile of the distribution of the recorded PKA values for each type of procedure was calculated to estimate local DRL values. The estimated values of DRLs and Eav were 37, 153 and 224 Gy cm2, and 6.72, 23.97 and 34.79 mSv for CA, PTCA and CA-PTCA procedures, respectively. For about 77% of the surveyed centres, the recorded patient doses were in agreement with the international standards. The local DRLs proposed in this study may be used to achieve patient dose optimization during IC procedures and the obtained patient dose data may also be archived into national dose database for the establishment of national DRLs.

Prospective dose monitoring using a manual dose management system: experience in brain computed tomography from a tertiary hospital in Nigeria.

A manual radiation dose management system was developed to track the radiation dose and scan parameters of patients for brain computed tomography (CT). Radiation dose in volume computed tomography dose index (CTDIvol) and dose length product (DLP) were monitored to identify procedures that may require optimisation using notification values. The data were analysed and compared with national and international diagnostic reference levels (DRLs). A total of 596 brain CTs were monitored and grouped as <1: 36, 1-<5: 38, 5-<10: 25, 10-<15: 31 and adult: 466. The CTDIvol notification value identified the following number of examinations having high CTDIvol in <1y: 1, 1-<5: 1, 5-<10: 0, 10-<15: 0 and adult (>15): 11. Furthermore, the DLP notification values identified the following examinations with high DLP in <1y: 1, 1-<5:1, 5-<10:1, 10-<15: 1 and adults (>15): 18. The established local paediatric DLP DRLs were 2-3 times higher than the international paediatric DLP DRLs. This calls for a total protocol review and optimisation considering the local CT practices for paediatric imaging.

Optimization of Routine Pediatric Computed Tomography Examinations in Hawassa City, Sidama Regional State, Ethiopia

Computed tomography (CT) has considerable impact in patient care. However, it is the most irradiating medical imaging technique in diagnostic radiology department. Optimization of pediatric CT is not well-practiced in developing countries. Protocols for some age groups were missed, and scan parameters are not adapted to the patient body size and age group. Furthermore, there are no established diagnostic reference levels to enhance dose optimization for pediatric patients at the local, regional, and national levels. Therefore, this study aimed to assess the optimization of routine pediatric CT examinations in Hawassa city, Ethiopia. A total of 360 pediatric dose records were reviewed for routine pediatric CT performed between January 1st, 2021 - May 30th, 2022. The data were analyzed using the statistical package for social science version 25 software. The Local Diagnostic Reference Levels (LDRLs) were established at the 75th percentile of CT dose quantities. The average KVp, mAs, and scan length used for pediatric head, chest, and abdomen CT were (112.8, 260.6, and 19.8), (112.9, 64.7, and 31.5), and (113.3, 79.4, and 32.9) respectively. The range of the established LDRLs in terms of volumetric CT dose index for the head, chest, and abdomen CT were (31.5 to 47, 2.3 to 6.1, 1.7 to 4.7) mGy. Whereas the range in terms of dose length product per scan for the head, chest, and abdomen CT were (723.4 to 1126.7, 55.9 to 258.9, and 38.1 to 242.5) mGy cm respectively. The obtained results show that the LDRLs for volumetric CT does index for head and chest CT were equivalent to the international studies. Whereas the local DRLs in terms of dose length product per scan were higher than the reports other studies except in Japan where the values for chest CT were comparable to the results of this study. Finally, the findings suggested that non-optimized pediatric head and chest CT were performed across all age groups.

Local Diagnostic Reference Levels for Adult Computed Tomography Urography Exams.

A Computed Tomography Urography (CTU) scan is a medical imaging test that examines the urinary tract, including the bladder, kidneys, and ureters. It helps diagnose various urinary tract diseases with precision. However, patients undergoing CTU imaging receive a relatively high dose of radiation, which can be a concern. In our research paper, we analyzed the Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) for 203 adult patients who underwent CTU at one of the most important regional centers in Bosnia and Herzegovina that sees a large number of patients. Our study included the distribution of age and sex, the number of phases within one examination, and different clinical indications. We compared our findings with the results available in the scientific literature, particularly the recently published results from 20 European countries. Furthermore, we established the local diagnostic reference levels (LDRLs) that can help set the national diagnostic reference levels (NDRLs). We believe our research is a significant step towards optimizing the protocols used in different hospitals in our country.

National and local diagnostic reference levels for adult 18F-FDG and CT in Jordanian PET/CT: findings and implications in practice

This study aims to report the findings of Jordanian national diagnostic reference level (NDRL) survey for fluorodeoxyglucose (18F-FDG) and local diagnostic reference level (LDRL) of computed tomography (CT) used for attenuation correction and anatomical localisation (AC-AL); and AC and diagnostic CT (AC-DX) within the context of whole-body WB and half-body HB adult oncology PET/CT scanning. Two-structured questionnaires were prepared to gather the necessary information: dosimetry data, patient demographics, equipment specification, and acquisition protocols for identified 18F-FDG PET/CT procedures. The NDRL and achievable dose were reported based on the 75th and 50th percentiles for 18F-FDG administered activity (AA), respectively. The LDRL was reported based on the 50th percentile for (CTDIvol) and (DLP). Data from 562 patients from four Jordanian PET/CT centres were collected. The survey revealed that Jordanian NDRL for AA (303 MBq) was within the acceptable range compared to the published-peer NDRL data (240–590 MBq). However, the 18F-FDG AA varied across the participated PET/CT centres. The reported LDRL CTDIvol and DLP of CT used for (AC-AL) was 4.3 mGy and 459.3 mGy.cm for HB CT scan range, and 4.1 mGy and 659.9 mGy.cm for WB CT scans. The reported LDRL for CTDIvol and DLP for HB CT was higher when compared with the United Kingdom (3.2 mGy and 310 mGy.cm). Concurrently, in the context of WB CT, the reported values (i.e. CTDIvol and DLP) were also higher than both Kuwait (3.6 mGy and 659 mGy.cm) and Slovenia (3.6 mGy and 676 mGy.cm). The reported HB CT(AC-DX) was higher than Nordic, New Zealand and Swiss NDRLs and for WB (AC-DX) CT it was higher than Swiss NDRLs. This study reported the first Jordanian NDRL for 18F-FDG and LDRL for HB and WB CT associated with 18F-FDG PET/CT scans. This data is useful for Jordanian PET/CT centres to compare their LDRL to the suggested DRLs and utilise it in the process of optimising CT radiation doses.

Enhancing Nuclear Medicine Practice in Saudi Arabia: Advocating for Comprehensive Guidelines and Local Diagnostic Reference Levels.

Diagnostic reference levels(DRLs) were initially introducedbythe International Commission on Radiation Protection (ICRP). It refers to the measured quantity ofadministered activity (MBq) in nuclear medicine imaging studies and is a type of investigation level. DRL is recommended to prevent excessive radiation exposure to patients while maintaining adequate image quality. It should not be implemented as a dose constraint or dose limit.The Saudi Food and Drug Authority (SFDA) is the primary government body responsible for reporting national diagnostic reference levels (NDRLs) for diagnostic medical imaging technologies in Saudi Arabia. Only NDRLs for computed tomography, general X-ray, and mammography have been published and enforced locally.This study aims to establish local DRLs for nuclear medicine imaging procedures at King Abdulaziz University Hospital, Saudi Arabia, preparing for compliance proof once required by local authorities. Data were collected from all machines, and sixcommon protocols were studied, with datafrom 50 patientsof standard body size for each identified protocol. The study was conducted retrospectively, and the 50thpercentile was then calculated for each scan. Both protocols for renal scansadministered the lowest doses to patients (130 MBq and 148 MBq), respectively. The highest dose administered to patients was found to be in bone scans (1110 MBq). The study establishes local DRLs for nuclear medicine imaging in our institution. Median activity dosages in renal, thyroid, and parathyroid imaging were comparable to locally and internationally published DRLs. However, they are higher in cardiac and bone imaging comparedto local Saudi DRL and DRL in the European Union and the USA, likely due to the adopted protocols. These highlight the need for modifying the protocols to fulfill optimization efforts. These findings serve as a foundation for compliance with future regulatory requirements, ensuring patient safety and maintaining imaging quality in Saudi healthcare.

Establishment of local diagnostic reference levels for radiation dose in paediatric interventional cardiology procedures in Brazil

Diagnostic and therapeutic interventional cardiology procedures are essential tools for evaluating congenital pathologies in paediatric patients. However, these procedures may expose patients to high levels of ionizing radiation. In this paper, we present the results of the radiation doses received by patients undergoing interventional cardiac procedures at a paediatric hospital in Brazil, aiming to establish local Diagnostic Reference Levels (DRL). The data were collected over a period of three years (2019–2022), and 148 procedures were analyzed, comprising 53% male (78) and 47% female (70) patients. These procedures included both diagnostic (59%) and therapeutic (41%) cardiac catheterization interventions. The average patient weight was 21.4 ± 1.7 kg (2.0–112.0 kg), with an average age of 5.3 ± 0.4 years (0.0–17.1 years). Comprehensive data for each procedure were extracted from Radiation Dose Structure Reports generated by the equipment. The results showed significant differences between diagnostic and therapeutic procedures, and the DRL values were estimated considering the age and weight of the patients. The DRL values correspond to the 3rd quartile of the dose distribution for each group. The following local DRL values were estimated, considering the patient's ages. For diagnostic procedures, the PKA defined according to the age groups <1, 1–5, 5–10, 10–15, and >15 years were respectively: 1.4, 2.8, 3.1, 4.3 and 12.0 Gy cm2. For therapeutic procedures, the DRL values for patients with the same ages were: 2.0, 3.7, 5.4, 7.4, and 30.9 Gy cm2. For the total procedures, the PKA values were 1.7, 3.2, 4.9, 6.6, and 24.5 Gy cm2, respectively. The suggested local DRL values for weight groups (<5, 5–15, 15–30, 30–50, and 50–80 kg) for PKA in diagnostic procedures were: 1.3, 2.2, 3.2, 4.1, and 7.9 Gy cm2, respectively. For therapeutic procedures, the PKA values were 1.1, 2.7, 5.4, 5.5, and 30.9 Gy cm2, respectively. For the total procedures, the PKA values were 1.25, 2.5, 4.6, 4.2, and 18.3 Gy cm2, respectively. For establishing PKA DRL, patient weight was found to be preferable over age, whereas for Ka,r, both approaches yielded nearly identical results.

Ionizing radiation exposure in complex percutaneous coronary intervention: Defining local diagnostic reference levels in the catheterization laboratory

Introduction and objectivesConcerns regarding the consequences of ionizing radiation (IR) have been increasing in the field of interventional cardiology (IC). There is little information on reported national and local radiation diagnostic reference levels (DRLs) in catheterization laboratories in Portugal. This study was designed to assess the IR dose exposure during complex percutaneous coronary intervention (PCI), and to set the respective DRLs and future achievable doses (ADs). MethodsThis was a retrospective cohort study which took place between 2019 and 2020, including patients who underwent complex PCI. Complex PCI was defined as all procedures that encompass treatment of chronic total occlusions (CTO) or left main coronary artery. DRLs were defined as the 75th percentile of the distribution of the median values of air kerma area product (PKA) and cumulative air kerma (Ka,r). ADs were set at the 50th percentile of the study dose distribution. Multivariate analysis was performed using linear regression to identify predictors significantly associated with radiation dose (Ka,r). ResultsA total of 242 patients were included in the analysis. Most patients underwent a CTO procedure (146, 60.3%). Patients were aged 67.9±11.2 years and mostly male (81.4%). DRLs were set in Ka,r (3012 mGy) and PKA (162 Gy cm2) for complex PCI. ADs were also set in Ka,r (1917 mGy) and PKA (101 Gy cm2). Independent predictors of Ka,r with a positive correlation were PKA (0.893, p<0.001), fluoroscopy time (0.520, p<0.001) and PCI time (0.521, p<0.001). ConclusionsThis study reports the results of IR in complex PCI. DRLs were set for IR dose exposure measured in Ka,r (3012 mGy) and PKA (162 Gy cm2). ADs, values to be achieved in future assessment, were set to Ka,r (1917 mGy) and PKA (101 Gy cm2).

Establishment of local diagnostic reference levels for CT colonography at a tertiary hospital.

Diagnostic reference levels (DRLs) are an important metric in identifying abnormally high radiation doses in diagnostic examinations. National DRLs for CT colonography do not currently exist in South Africa, but there are efforts to collect data for a national DRL project. This study investigated radiation doses for CT colonography in adult patients at a large tertiary hospital in South Africa with the aim of setting local DRLs. Patient data from two CT scanners (Philips Ingenuity and Siemens Somatom go.Top) in the period March 2020 - March 2023 were obtained from the hospital's picture archiving and communication system (PACS) (n = 115). Analysis involved determining the median computed tomography dose index-volume (CTDIvol) and dose-length product (DLP) values. The findings were compared with DRLs established internationally. Ingenuity median CTDIvol was 20 mGy and DLP was 2169 mGy*cm; Somatom median CTDIvol was 6 mGy and DLP was 557 mGy*cm. Ingenuity exceeded the United Kingdom's (UK) recommended DRLs by 82% and 214%, respectively. Somatom median CTDIvol and DLP were 45% and 19% lower than UK NDRLs. Somatom's tin filter and other dose reduction features provided significant dose reduction. These data were used to set DRLs for CT colonography at the hospital; CTDIvol: 6 mGy and DLP: 557 mGy*cm. In addition to informing radiation protection practices at the level of the institution, the established local DRLs contribute towards implementing regional and national DRLs.

Exposure frequency and radiation dose from CT examinations in Huaian.

This study quantified the exposure frequency and established the local diagnostic reference levels (DRLs) for the most common computed tomography (CT) examinations. A combined method census and sampling survey was used to quantify both frequency and radiation dose of CT examinations. Data were acquired through Picture Archiving and Communication System (PACS) or Radiology Information System (RIS). The annual frequency of CT examinations was 239.8 per 1000 inhabitants. The P75 of volume CT dose index (CTDIvol) to adult patients from CT scanning for head, chest, abdomen and lumbar spine examinations were 63.0, 12.4, 20.0 and 24.0mGy, respectively. The P75 of dose-length product were 858.6, 416.0, 620.7 and 559.2mGy·cm, respectively. This dose audit of CT practice can act as a starting point for establishing Huaian local DRLs and could be a reference for dose optimisation in China. This study compared DRLs in different countries and analysed some reasons for the rapid growth of CT examination frequency in Huaian.

Evaluation of radiation dose and establishment of local DRLs for adult during abdominopelvic CT scan imaging for university hospital centers, Morocco

Objective: In this study, we have planned to establish the local Diagnostic Reference Levels (DRLs) for the five University Hospital Centers in Morocco and to propose a national DRL for abdominopelvic CT examinations for adult patients. Materials and methods: Data were collected using a specially designed form, which included patient demographics, exposure parameters and dosimetric indicators such as dose-length product (DLP) and CT volume dose index (CTDIvol). The establishment of local and national DRL in terms of CTDIvol and DLP was carried out in accordance with the methodology described in Report 135 of the International Commission on Radiological Protection (ICRP). The effective dose was assessed using the DLP and the dose conversion factor appropriate for this location. Results: A total of 300 patients undergoing abdominopelvic examinations at the five Moroccan university hospitals were collected for this study. Patients' mean age, weight and BMI were (50.97 ± 15.05) years (67.94 ± 11.41) Kg and (25.71 ± 3.03) Kg/m2 respectively. The local DRL, in terms of DLP were 551.56, 2293.33, 709.02, 843.52 and 1059.62 mGy-cm and in terms of CTDIvol were 11,05, 46,40, 13,14, 12,01, 9,88 mGy respectively for UHC-1, UHC-2, UHC-3, UHC-4 and UHC-5 hospitals. The proposed National DRL, defined as a single value for the 75th percentile on the aggregation of data from the five centers, for abdominopelvic scan CT was 773.20 mGy.cm and 12.05 mGy for DLP and CTDIvol, respectively. Conclusion: The Moroccan DRL was comparable to those of other countries, ranking 10th among 21 countries. However, we are still seeking to reduce and optimize radiation dose while maintaining good image quality for reliable diagnosis, and this can be achieved by enhancing radiographers' and radiologists' knowledge of radiation protection, protocol justification, and optimization through rigorous hospital radiation audits at national level.

Establishment of local diagnostic reference levels for breast cancer CT protocols in radiotherapy in a single Moroccan center

The objective of this study was to establish local diagnostic reference levels (LDRLs) for breast cancer computed tomography imaging in radiotherapy (CT-RT) at a single hospital in Morocco. Data were collected from 106 adult breast cancer patients aged between 33 and 78 yr during five months. Data were obtained using a Hitachi Supria 16-slice CT simulator at a regional oncology center in Morocco. CT-RT images are intended for 3D conformal radiotherapy treatment planning. Dose length product (DLP) and volumetric computed tomography dose index (CTDIvol) were evaluated by determining the 75th percentile as diagnostic reference levels for CT-RT breast cancer. LDRLs for CT-RT breast cancer have been determined in terms of DLP and CTDIvol, and they were 330.4 mGy.cm and 6.8 mGy, respectively. The DRLs were compared with other Europeans study. DRLs for this study were lower than those for the United Kingdom (UK), Croatia and Slovenia. The results of this study can be a reference for the establishment of local and national DRLs in Morocco and the optimization of CT-RT breast cancer procedures.

Radiation dose assessment: Establishment of local diagnostic reference levels for selected radiography examinations across three prominent hospitals in Sudan

Due to variation among radiographers’ practice, and the importance of unifying practice during radiography for optimizing radiation level and image quality, the current manuscript aims to assess the radiation dose level and propose local diagnostic reference levels (LDRL) for posterior-anterior (PA) chest, antero-posterior (AP) abdomen, and pelvis examinations in two hospitals in Khartoum (‘K’) and one hospital in Wad-Medani (‘M’) cities, Sudan. Along with patient demographics like height and weight, the radiation exposure parameters including tube potential, current, and radiation duration were documented. This included 732 patients whose tests were conducted at one of three departments located in two different cities. The entrane surface air kerma (ESAK) was calculated using DosCal software and an Unfors -Xi-meter. The average ESAK for an X-ray of the chest was 0.18 mGy in M, 0.19 mGy in K (averaged over two hospitals in the K), for the abdomen it was 1.1 and 1.23 mGy, and for the pelvis it was 1.8 and 01.9 mGy respectively. The proposed DRL was achieved from the third quartile of radiation dosage of data, and it was 0.21, 1.7 and 1.9 mGy for the chest, abdomen and pelvis respectively. There was a wide variation in dosage levels among the three hospitals. The current proposed DRL was lower than most literature for the chest, abdomen and pelvis. More studies are recommended for other examinations such as skull and contrast media studies.

Estimating Local Diagnostic Reference Levels for Mammography in Dubai.

As the total volume of mammograms in Dubai is increasing consistently, it is crucial to focus on the process of dose optimization by determining dose reference levels for such sensitive radiographic examinations as mammography. This work aimed to determine local diagnostic reference levels (DRLs) for mammography procedures in Dubai at different ranges of breast thickness. A total of 2599 anonymized mammograms were randomly retrieved from a central dose survey database. Mammographic cases for screening women aged from 40 to 69 years were included, while cases of breast implants and breast thickness outside the range of 20-100 mm were excluded. Mean, median, and 75 percentiles were obtained for the mean glandular dose (MGD) distribution of each mammography projection for all compressed breast thickness (CBT) ranges. The local DRLs for mammography in Dubai were found to be between 0.80 mGy and 0.82 mGy for the craniocaudal (CC) projection and between 0.89 mGy and 0.971.8 mGy for the mediolateral oblique (MLO) projection. Local DRLs were proposed according to different breast thicknesses, starting from 20 to 100 mm. All groups of CBT showed a slight difference in MGD values, with higher values in MLO views rather than CC views. The local DRLs in this study were lower than some other Middle Eastern countries and lower than the standard reference levels reported by the International Atomic Energy Agency (IAEA) at 3 mGy/view.

Establishment of a local diagnostic reference level for computed tomography chest and abdomen in two different cities in Saudi Arabia

Background and aimSpiral computed tomography (CT) scans, which are considered a high-contrast resolution, quick and cross-sectional imaging technique, have grown in popularity as a result of technological advancements. However, these advancements have brought with them the potential for significantly increased radiation doses to the patient. Consequently, many organizations recommended optimization and establishing diagnostic reference levels. The aim of the current study was to assess CT radiation dose and propose a local diagnostic reference level (LDRL) for the adult trunk [chest and abdomen] using CT dose parameters such as CT dose index volume (CTDIvol) and dose length product (DLP) as well as to compare the practices for aforementioned examinations between two hospitals in Taif and Abha cities in Saudi Arabia. Materials and methodsData from 428 patients (216 for abdomen and 212 for chest) who were examined in two hospitals in Taif and Abha City in Saudi Arabia from December 2022 to March 2023, are used in this study. The data for hospitals in Taif and Abha are presented as ‘T’ and ‘A’ throughout this manuscript. The parameters of exposure and slice thickness were recorded in a specially designed data sheet together with the gender, age and patients morphometric. Microsoft Excel version 2010 was used to analyze results and plot the figures. The LDRL was achieved from the third quartile of CTDIvol and DLP for each hospital and examination. ResultsThe average DLP (mGy-cm) and CTDIvol (mGy) for the chest and abdomen were 243 mGy cm, 5.8 mGy and 549 mGy cm, 8.6 mGy respectively. The average effective dose (ED) for chest and abdomen were 5.10 and 21.10 mSv, respectively. The proposed LDRL for the chest and abdomen were 6.9 mGy (CTDIvol), 375 mGy-cm (DLP), 7.8 mGy (CTDIvol), and 747 (DLP) mGy-cm, respectively. ConclusionHospital ‘A’ irradiated patients with a higher dose for the abdomen exam than Hospital ‘T’, but both hospitals agreed on the amount of radiation dose received by patients for chest imaging. The proposed LDRL for two examinations was less than the DRL obtained from the literature.

Estimation of diagnostic reference levels for pediatric head computed tomography in Yaoundé.

The diagnostic reference levels (DRLs) are determined from dosimetry studies to compare and manage patient doses in medical imaging procedures. The aim of this work was to establish the first DRLs for pediatric patients during the most common computed tomography (CT) procedures in Yaoundé, Cameroon during routine head CT examinations to know how to improve our clinical practice tomorrow. The sample was classified per age group: ≤ 1-, 1-5-, 5-10- and 10-15-y-old. The retrospective study was used. The proposed DRLs were defined as 75th percentile of the median values of the distributions. In terms of Volume CT Dose Index (CTDIvol) and dose length product (DLP), the DRLs obtained for the ages groups were: 28.6mGy and 545.8mGy.cm, 32.6mGy and 735mGy.cm, 37.1mGy and 761.6mGy.cm and 44.2mGy and 1081.2mGy.cm, respectively. DRLs in Yaoundé for DLP were higher than those of comparison literatures. The Yaoundé CTDIvol was higher than the comparison literatures except for the IAEA (2015) values for the three older age groups. The DRLs reported in Yaoundé were compared to Morocco 2020, Switzerland 2018, IAEA 2015 and Iran 2020 values. The estimation of this first DRL for pediatric head CT scan in Yaoundé must be a starting point to spread this investigation towards other examinations and imaging modalities across the country. Therefore, optimization of the CT scan procedures and orderly updates of local DRLs are necessary to improve radioprotection.

Establishment of local diagnostic reference levels for abdomen and chest radiographies in the region of Algarve, Portugal

PurposeTo assess doses variabilities in the same abdomen and chest RX exams for adults, to check the need for dose harmonization. To calculate Diagnostic Reference Levels (DRL), mandatory in the European Union, for the Algarve district in Portugal. Our results can be a valuable reference for the Portuguese official determination of DRLs, still in progress. MethodWe considered 4,936 abdomen and 41,320 chest radiographs of adults, covering 7 health centres and 35 radiographers in Algarve. Entrance skin dose (ESD) was calculated for each radiograph and the corresponding uncertainty estimated. Mean doses per centre and per technician, and their uncertainties, were calculated to access dose variabilities. DRLs, set at the 3rd quartile of the total ESD distribution, were determined for a standard patient and for intervals of body mass index (BMI) to study their correlation with patient anatomical variations. Standard quartile errors were estimated. ResultsOur results suggest significant dispersion in applied ESDs among different centres and radiographers. Estimates of DRLs also show small fluctuations across years and an important dependence on BMI intervals. For a standard patient, they are 8.7 ± 0.1 (abdomen) and 0.44 ± 0.01 (chest), while the European DRLs are, respectively, 5.1 and 0.2 (all in mGy). ConclusionsResults suggest that there is room for dose optimization and harmonization with European DRLs, urging a national dose survey and the establishment of official national DRLs. Official DRLs in intervals of BMI would be quite beneficial, to avoid unnecessary dose exposures.