Patient Radiation Dose Research Articles

Body-Mass Index-Based Effective Dose Determination in Commonly Performed Computed Tomography Examinations in Adults

Purpose: With the widespread application of ionizing radiation in medical practice, concerns have been increased regarding the hazardous effects of radiation. Studies have demonstrated that some variables such as body dimensions affect the absorbed radiation dose. In this study, the association between Body Mass Index (BMI) and absorbed dose in Computed Tomography (CT) is investigated.
 Materials and Methods: A total of 550 adult patients (age ≥ 15 years) were included in the study. The height and weight of the patients were recorded for BMI calculation. Dosimetry data were acquired from digital imaging and communications in medicine dose reports. The patients were categorized into five groups according to their BMI, the categorized information was then imported into ImPACT Dose software for calculation of Size-Specific Dose Estimate (SSDE) and organ and effective doses. The relationship between patient BMI and the effective dose was also determined.
 Results: A higher BMI contributed to increased radiation dose and SSDE in patients who had undergone chest or abdomen-pelvis CT examination (p < 0.05). 
 Conclusion: The radiation dose is related to a patient’s BMI and rises with an increase in BMI. Accordingly, it is suggested that BMI and other variables, such as the type of scan and other body dimensions, which affect the radiation dose, can be used to estimate the radiation dose before performing CT. This estimation can be considered for the justification and optimization of CT examinations.

Patient Radiation Doses in Interventional Radiology Procedures: Comparison of Fluoroscopy Dose Indices between the American College of Radiology Dose Index Registry-Fluoroscopy Pilot and the Radiation Doses in Interventional Radiology Study

To compare radiation dose index distributions for fluoroscopically guided interventions in interventional radiology from the American College of Radiology (ACR) Fluoroscopy Dose Index Registry (DIR-Fluoro) pilot to those from the Radiation Doses in Interventional Radiology (RAD-IR) study. Individual and grouped ACR Common identification numbers (procedure types) from the DIR-Fluoro pilot were matched to procedure types in the RAD-IR study. Fifteen comparisons were made. Distribution parameters, including the 10th, 25th, 50th, 75th, and 95th percentiles, were compared for fluoroscopy time (FT), cumulative air kerma (Ka,r), and kerma area product (PKA). Two derived indices were computed using median dose indices. The procedure-averaged reference air kerma rate (Ka,r) was computed as Ka,r / FT. The procedure-averaged x-ray field size at the reference point (Ar) was computed as PKA / (Ka,r× 1,000). The median FT was equally likely to be higher or lower in the DIR-Fluoro pilot as it was in the RAD-IR study, whereas the maximum FT was almost twice as likely to be higher in the DIR-Fluoro pilot than it was in the RAD-IR study. The median Ka,r was lower in the DIR-Fluoro pilot for all procedures, as was median PKA. The maximum Ka,r and PKA were more often higher in the DIR-Fluoro pilot than in the RAD-IR study. Ka,r followed the same pattern as Ka,r, whereas Ar was often greater in DIR-Fluoro. The median dose indices have decreased since the RAD-IR study. The typical Ka,r rates are lower, a result of the use of lower default dose rates. However, opportunities for quality improvement exist, including renewed focus on tight collimation of the imaging field of view.

PRECAUTION IN THE USE OF EFFECTIVE DOSE IN CORONARY CT ANGIOGRAPHY

The effective dose is a quantity used in clinical practice for statistical evaluation of the radiation dose of patients undergoing different types of examinations. Coronary computed tomography angiography (CCTA) is a specific examination whose calculated effective dose may be subject to several biases. For this reason, it is important to consider factors (different examination techniques, heart rate and patient habitus) that may influence its resulting value. Another critical factor is the methodological procedure for calculating the effective dose and cardiac-specific coefficient used to estimate effective dose from the dose-length product in computed tomography. Because CCTA is increasingly used in cardiology, it is recommended that the chest coefficient be replaced with a new cardiac coefficient when calculating the effective dose.

THE IMPORTANCE OF FEEDBACK IN MONITORING PATIENTS' RADIATION DOSES IN MAMMOGRAPHY.

The majority of medical facilities in the Slovak Republic archive diagnostic images of their patients in a picture archiving and communicating system (PACS). Data from the PACS system can be used to analyse patient radiation dose and perform internal and external quality control through dose monitoring software systems. However, appropriate use of such systems requires the provision of feedback and the ability of staff to identify causes of diagnostic reference level exceedances. The present pilot study evaluated the use of a Dose quality control system (DQC) for monitoring the radiation dose of the patients in the ongoing mammography screening, with subsequent identification of alerts triggered by the system.

First Clinical Experience with a Novel 3D C-Arm-Based System for Navigated Percutaneous Thoracolumbar Pedicle Screw Placement

Background and Objectives: Navigated pedicle screw placement is becoming increasingly popular, as it has been shown to reduce the rate of screw misplacement. We present our intraoperative workflow and initial experience in terms of safety, efficiency, and clinical feasibility with a novel system for a 3D C-arm cone beam computed-tomography-based navigation of thoracolumbar pedicle screws. Materials and Methods: The first 20 consecutive cases of C-arm cone beam computed-tomography-based percutaneous pedicle screw placement using a novel navigation system were included in this study. Procedural data including screw placement time and patient radiation dose were prospectively collected. Final pedicle screw accuracy was assessed using the Gertzbein–Robbins grading system. Results: In total, 156 screws were placed. The screw accuracy was 94.9%. All the pedicle breaches occurred on the lateral pedicle wall, and none caused clinical complications. On average, a time of 2:42 min was required to place a screw. The mean intraoperative patient radiation exposure was 7.46 mSv. Conclusions: In summary, the investigated combination of C-arm CBCT-based navigation proved to be easy to implement and highly reliable. It facilitates the accurate and efficient percutaneous placement of pedicle screws in the thoracolumbar spine. The careful use of intraoperative imaging maintains the intraoperative radiation exposure to the patient at a moderate level.

Overview of cone beam CT patient radiation dose levels in a dental institution regarding patient age, clinical indications, and CBCT scanners

<h3>Objective</h3> To present an overview of typical cone beam CT patient radiation dose levels in a dental institution for different age groups, clinical indications, and CBCT scanners. <h3>Study Design</h3> The patient dose database for CBCT exams performed in 2019, using the 3D Accuitomo 170 (Morita, Kyoto, Japan) and NewTom VGi evo (QR, Verona, Italy) CBCT systems in a dental education institution was assessed and extracted through an automated dose quality management system DOSE (Qaelum NV, Leuven, Belgium). Data regarding age, gender, and clinical indications related to patients, and the type of CBCT scanner, FOV size (small, medium, and large), and dose-area product (DAP) value related to imaging were recorded for each CBCT imaging procedure. A descriptive data analysis was performed, and the average DAP, an average of effective dose, and frequency of examinations were calculated. <h3>Results</h3> A total of 5,166 CBCT examinations were screened. Surgical planning and follow-up were the most frequent clinical indication being the majority indication in medium (35.7%) and large (27.6%) FOVs. In general, DAP and effective dose increased with FOV size. The effective dose ranged from 42.9 to 188.1 µSv for Accuitomo 170 to 46.7 to 140.1 µSv for NewTom VGi evo. <h3>Conclusion</h3> DAP values and effective doses were heterogeneously distributed amongst age groups and mostly influenced by clinical indications of the related FOV size selection. While patient-specific imaging remains advocated, the fact that two-thirds of the indications are surgically oriented makes the medium and large field of views predominant. Developers of CBCT systems could be advised to move towards patient-specific collimation and dynamic field-of-view selection, preferably via an automated algorithm to facilitate clinical implementation of the optimal patient-specific and indication-oriented dose (ALADAIP). <b>Statement of Ethical Review</b> Ethical review was sought and study was exempted from ethical review

Assessment of patient radiation dose during skull X-ray examinations in King Khalid Hospital in Majmaah

This study aimed to measure entrance surface air kerma (ESAK, in mGy) during routine skull X-ray examinations of adult patients and to establish a local diagnostic reference level (LDRL) in the diagnostic radiology department of King Khalid Hospital in Majmaah. The patient's ESAK, mGy and effective dose (ED, in mSv) at the 75th percentile were calculated based on the output of the X-ray tube and the exposure parameters, as well as the use of suitable conversion coefficients, respectively. To calculate the ED and patient's ESAK, the output and exposure characteristics of the X-ray tube and relevant conversion coefficients were considered (ESAK). Additionally, the 75th percentile distributions for the ESAK and KAP distributions were calculated. A wide range of ESAK was observed, which might be due to the difference in the exposure factors applied for each examination. The mean values of ESAK and KAP together with 75th percentiles for Anteroposterior (AP) and lateral skull projection were 0.22 (0.10–0.30) mGy, 0.24 (0.0.18–0.25) mGy and 0.21 (0.19–0.26) Gy.cm2, 0.29 (0.17–0.32) Gy.cm2, respectively. The findings were significantly lower than national reference levels, the most reported European DRL values, and other previously reported dose values. The measured ESAK and KAP were within the recommended and acceptable dose limits. The best radiation protection can be achieved by optimizing the radiation dose while preserving image quality.

Oligometastatic Head and Neck Cancer: Challenges and Perspectives.

Simple SummaryOligometastasis represents a disease state and an opportunity for cure when metastases emerge. Emerging evidence supports that most head and neck cancer patients with oligometastatic disease are likely to benefit from curative intent local ablative therapy if appropriate selection criteria are applied. Biomarkers to predict development of oligometastasis, as well as to identify which patients could benefit from a radical intent approach, are under investigation. This review summarizes recent knowledge about the characteristics, investigational efforts, and evidence for local ablation regarding oligometastasis in head and neck cancer. We also describe the challenges and opportunities in patient selection and discuss the role of radiotherapy and immunotherapy combinations to enhance anti-tumor immunity.A minority of patients with metastatic head and neck squamous cell carcinoma (HNSCC) present with oligometastatic disease. Oligometastasis not only reflects a disease state, but might also present an opportunity for cure in the metastatic setting. Radical ablation of all oligometastatic sites may confer prolonged survival and possibly achieve cure in some patients. However, substantial debate remains about whether patients with oligometastatic disease could benefit from curative intent therapy or whether aggressive treatments expose some patients to futile toxicity. Optimal selection of patients, carefully balancing the currently known prognostic factors against the risks of toxicity is critical. Emerging evidence suggests that patients with a limited burden of disease, viral-related pharyngeal cancer, metachronous metastasis and lung-only metastasis may benefit most from this approach. Efforts are underway to identify biomarkers that can detect oligometastasis and better select patients who would derive the maximum benefit from an aggressive radical approach. The combination of radiotherapy and immunotherapy promises to enhance the anti-tumoral immune response and help overcome resistance. However, optimization of management algorithms, including patient selection, radiation dose and sequencing, will be critical in upcoming clinical trials. This review summarizes recent knowledge about the characteristics and investigational efforts regarding oligometastasis in HNSCC.

The Actual Role of Iterative Reconstruction Algorithm Methods in Several Saudi Hospitals As A Tool For Radiation Dose Minimization of Ct Scan Examinations.

BackgroundIterative reconstruction algorithm (IR) techniques were developed to maintain a lower radiation dose for patients as much as possible while achieving the required image quality and medical benefits. The main purpose of the current research was to assess the level and usage extent of IR techniques in computed tomographic (CT) scan exams. Also, the obligation of practitioners in several hospitals in Saudi Arabia to implement IR in CT exams was assessed.Material and MethodologyThe recent research was based on two studies: data collection and a survey study. Data on the CT scan examinations were retrospectively collected from CT scanners. The survey was conducted using a questionnaire to evaluate radiographers’ and radiologists’ perceptions about IR and their practices with IR techniques. The statistical analysis results were performed to measure the usage strength level of IR methods.Results and DiscussionsThe IR strength level of 50% was selected for nearly 80% of different CT examinations and patients of different ages and weights. About 46% of the participants had not learned about IR methods during their college studies, and 54% had not received formal training in applying IR techniques. Only 32% of the participants had adequate experience with IR. Half of the participants were not involved in the updating process of the CT protocol.ConclusionThe results indicate that the majority of radiographer and radiologist at four different hospitals in Saudi Arabia have no explicit or understandable knowledge of selecting IR strength levels during the CT examination of patients. There is a need for more training in IR applications for both radiologists and radiographers. Training sessions were suggested to support radiographers and radiologists to efficiently utilize IR techniques to optimize image quality. Further studies are required to adjust CT exam protocols effectively to utilize the IR technique.

Patient Radiation Doses in Interventional Cardiology Procedure

Interventional cardiology is a minimally-invasive imaging procedure that allows medical doctor to evaluate and treat structural heart diseases. Due to its main advantages of avoidance of the scars and pain, as well as long post-operative recovery, interventional cardiology procedures have rapidly been growing. However, the increasingly complex and time-consuming procedures in interventional cardiology may increase the radiation exposure received by patients. This paper describes a study to measure patient radiation doses in terms of air kerma and kerma air-product (KAP) for various types of interventional cardiology procedures conducted in Indonesia. The measurements were performed at the interventional cardiology or cardiac catheterization facilities in sixteen hospitals in ten cities in Indonesia during the years of 2015 to 2019. A total of 147 procedures conducted on adult patients were used in this study. The type of procedure, total KAP, and air kerma were recorded after each procedure was completed. The demographic data of the patients were also recorded. The results showed that the mean air kerma and KAP measured for CA (coronary angiography) procedure were 680.73 ± 57.85 mGy and 12.52 ± 5.86 Gy cm 2 , respectively, while the values for PCI (percutaneous coronary intervention) procedure were 890.66 ± 38.76 mGy and 20.18 ± 9.37 Gy cm 2 , respectively. These results are well within the ranges reported by other previous studies. The results are somewhat affected by the body mass index of patients, while the fatal cancer risks among patients of CA and PCI procedures are comparable with those among interventional radiology procedures patients.

Anthropometric parameters and radiation doses during percutaneous coronary procedures

PurposeBody size is a major determinant of patient’s dose during percutaneous coronary interventions (PCI). Body mass index, body surface area (BSA), lean body mass and weight are commonly used estimates for body size. We aim to identify which of these measures and which procedural/clinical characteristics can better predict received dose. MethodsDose area product (DAP, Gycm2), fluoroscopy DAP rate (Gycm2/min), fluoroscopy DAP (Gycm2), cine-angiography DAP (Gycm2), Air Kerma (mGy) were selected as indices of patient radiation dose. Different clinical/procedural variables were analysed in multiple linear regression models with previously mentioned patient radiation dose parameters as end points. The best model for each of them was identified. ResultsOverall 6623 PCI were analysed, median fluoroscopy DAP rate was 35 [IQR 2.7,4.4] Gycm2, median total DAP was 62.7 [IQR 38.1,107] Gycm2. Among all anthropometric variables, BSA showed the best correlation with all radiation dose parameters considered. Every 1 m2 increment in BSA added 4.861 Gycm2/min (95% CI [4.656, 5.067]) to fluoroscopy DAP rate and 164 Gycm2 (95% CI [145.3, 182.8]) to total DAP. Height and female sex were significantly associated to a reduction in fluoroscopy DAP rate and total DAP. Coronary angioplasty, diabetes, basal creatinine and the number of treated vessels were associated to higher values. ConclusionsMain determinants of patient radiation dose are: BSA, female sex, height and number of treated vessels. In an era of increasing PCI complexity and obesity prevalence, these results can help clinicians tailoring X-ray administration to patient’s size.

ESTIMASI DAN AUDIT DOSIS RADIASI PASIEN PADA PEMERIKSAAN RADIOGRAFI KONVENSIONAL TORAKS PA DENGAN TEKNIK HIGH KVP

Research about estimation and dose audit of patients' radiation on examination about thorax PA conventional radiography with high kV technique has been conducted in MRCCC Siloam Hospitals Semanggi. The research has been done on 305 patients aged around 15 years old who got thorax examinations. They consist of 129 male patients and 176 female patients. The characteristics of patients' age are between 18-86 years old, and their average age is 44.2 years old. Their weight range is between 38-120 kg, and their average weight is 66.8 kg. The thorax PA conventional radiography examination uses kVp 125, and the content of mAs is 0.5-1.4 mAs, with an average of 0.8 mAs. The dosage of patients with INAK and ESAK are counted from the outcome similarity graph of the radiation from the X-ray craft. Data analysis shows a linear increase of INAK and ESAK with a linear correlation consecutive of 0.9969 and 1 toward the rise in mAs. The higher the mAs, the higher the patient's dose of radiation also becomes bigger because mAs represent the quantity of radiation so that the amount of photons produced by the X-ray tube becomes bigger. The research result shows that the average increase of INAK and ESAK consecutive is 0.11 mGy and 0.15 mGy, with a typical value of INAK at 0.1 mGy and ESAK at 0.14 mGy. The average ESAK on the research is compared with some reference data, and the result of ESAK in MRCCC Siloam Hospitals Semanggi is under some reference data. The dose audit is the establishment of typical value, and it is compared with national DRL based on the regulation of the head of BAPETEN about stipulation of Indonesia Diagnostic Reference Level Value no. 1211/K/V/2021 on thorax PA examination. The examination of thorax PA about INAK and ESAK national DRL consecutive is 0.3 mGy and 0.4 mGy. Therefore, the result of the dose audit about establishing typical value on the study about thorax PA conventional radiography in MRCCCC Siloam Hospitals Semanggi is under national DRL. The follow-up of the dose audit is to keep the examination protocol and evaluate typical values periodically. The high kVp technique on the conventional radiography examination can reduce the patient's radiation dose. Keywords: Radiation Dose, Conventional Radiography, Thorax PA. High kVp Technique, Diagnostic Reference Levels

Positron Emission Tomography and Computed Tomography Contributions to Patient Dose and Personnel Exposure to Radiation during PET/CT-Guided Tumor Ablations

This study sought to quantify the positron emission tomography (PET) and computed tomography (CT) components of patient radiation doses and personnel exposure to radiations during PET/CT-guided tumor ablations and assess the utility of a rolling lead shield for operator protection. Two operators performed 21 PET/CT-guided ablations behind a customized, 25-mm-thick lead shield with midchest-to-midthigh coverage. The mean patient radiation dose per procedure was 3.90 mSv ± 1.13 (11.3%) from PET and 30.51 mSv ± 19.05 (88.7%) from CT. The mean primary and secondary operator exposure outside neck-level thyroid shields was 0.05 and 0.02 mSv per procedure, respectively. The radiation exposure levels behind the rolling lead shield, inside the primary operator’s thyroid shield, and on the other personnel were below the measurable threshold cumulatively over 21 procedures. The mean PET exposure level at continuous close proximity to patients was 0.02 mSv per procedure. The PET radiation doses to the patients and personnel were small. Thus, the rolling lead shield provided limited benefit.

A STUDY OF URINARY TRACT ABNORMALITIES: ROLE OF LOW DOSE MDCT UROGRAPHY

Introduction: Computed Tomography (CT) urography is more accurate in detection of renal masses, urinary tract tumors, inflammatory lesion, calculi and other causes of urinary tract obstruction compared with intravenous urography. The standard single bolus MDCT Urography protocol comprises three to four phases, consists of non-contrast, corticomedullary, nephrographic and excretory phases. A major disadvantage is a high radiation dose, which is 8-10 times higher than an IVP examination. In comparison, an split-bolus, dual-phase technique scans the urinary system in the non-contrast and combined nephrographic-excretory phases. This study aimed to compare the total CT radiation dose of patient and image quality in standard MDCTU protocol and low dose MDCTU protocol. Methodology: In this hospital based prospective study total 100 patients (50 tests and 50 controls) were compared for radiation dose and subjective image quality assessment between standard dose MDCTU protocol [non contrast scan at 120kvp , followed by contrast enhanced corticomedullary phase and excretory phase] and low dose MDCTU protocol (non contrast scan (at 80 kvp), followed by contrast enhanced synchronus corticomedullary phase and excretory phase acquisition by using split bolus contrast administration technique) . Result: In the standard dose MDCTU protocol in unenhanced and enhanced phase, patients received mean net effective dose of 18.83 mSv and in the low dose protocol, patients received mean net effective dose of 9.06 mSv with significant 52% dose reduction (P value &lt;0.001). In Standard dose protocol in unenhanced phase, optimal resolution in 82% patients, moderately grainy/poor resolution in 14% and significantly grainy/very poor resolution in 4% patients. In low dose protocol, optimal resolution in 64% patients, mild to moderately grainy/poor resolution in 22% and significantly grainy/very poor resolution in 14% patients with no significant difference in image quality in both protocol (P value&gt;0.05). In low dose protocol, mild to moderately grainy/poor resolution images (22%) of unenhanced phase reviewed together with normal dose good qualitysynchronus corticomedullary and excretory phase images to diagnosis the almost same spectrum of pathology like standard dose protocol. Conclusion: In low dose MDCT Urography radiation dose reduction of approx 50% is possible with no significant difference in image quality in line to ALARA principle (As low as reasonably achievable), facilitating diagnosis of urological pathologies.

Abstract No. 369 Facilitating lower dose quantitative DSA: a technique for simultaneous acquisition of blood velocity and vessel morphology during angiographic imaging

An interleaved x-ray imaging technique was developed to capture diagnostic quality angiographic images and contrast media kinetics in a single scan, while reducing patient radiation and contrast dose. This study assessed the accuracy of arterial velocity calculations using quantitative DSA (qDSA) and the interleaved technique.

Evaluating the use of anti-scatter grids in adult knee radiography

IntroductionAnti-scatter grids efficiently reduce scatter radiation from reaching the imaging receptor, enhancing image quality; however, the patient radiation dose increases in the process. There is disagreement regarding the thickness thresholds for which anti-scatter grids are beneficial. This study aims to establish a thickness threshold for the use of anti-scatter grids to optimise adult knee radiography. MethodsThe study consisted of two phases. In Phase 1 phantom knee radiographs were acquired at varying thicknesses (10–16 cm) and tube voltages (60–80 kV). For each thickness and tube voltage, images with and without an anti-scatter grid were obtained. In Phase 2, two radiologists and three radiographers, evaluated the image quality of these images. Visual Grading Analysis (VGA) scores were analysed using Visual Grading Characteristics (VGC) based on the visualisation of five anatomic criteria. ResultsThe average DAP decreased by 72.1% and mAs by 73.1% when removing the anti-scatter grid. The VGC revealed that overall images taken with an anti-scatter grid have better image quality (AUC ≥0.5 for all comparisons). However, the anti-scatter grids could be removed for thicknesses 10, 12 and 14 cm in conjunction with using 80 kVp,. ConclusionAnti-scatter grids can be removed when imaging adult knees between 10 and 12 cm using any kVp setting since the radiation dose is reduced without significantly affecting image quality. For thicknesses >12 cm, the use of anti-scatter grids significantly improves image quality; however, the radiation dose to the patient is increased. The exception is at 14 cm used with 80 kVp, where changes in image quality were insignificant. Implications for practiceOptimisation by removing anti-scatter grids in adult knee radiography seems beneficial below 12 cm thickness with any kVp value. Since the average knee thickness ranges between 10 and 13 cm, anti-scatter grid can be removed for most patients. Nevertheless, further studies are recommended to test if this phantom-based threshold applies to human subjects.

Long-term follow-up after the use of the as low as reasonably achievable radiation protocol in patients with symptomatic supraventricular tachycardia

IntroductionCatheter ablation is an effective treatment modality for patients with symptomatic supraventricular tachycardia (SVT), such as atrioventricular nodal re-entrant tachycardia (AVNRT) and typical atrial flutter (TAF). With increasingly invasive electrophysiological procedures and continuous development of ablation techniques, the aim is to reduce radiation doses for patients and the electrophysiological team. Modern methods that combine the “as low as reasonably achievable” (ALARA) protocol and three-dimensional mapping systems are now state-of-the-art procedures in the treatment of arrhythmia. This study aimed to compare the effectiveness and long-term success of the ALARA approach compared to those of conventional therapy, without using modern mapping systems. MethodsSixty-one patients with symptomatic SVT (37 with AVNRT, 19 with isthmus-dependent counter-clockwise TAF, and five with other SVTs) were randomised into two groups: the ALARA and conventional groups. All patients underwent successful SVT ablation. Clinical and remote follow-up was available for 59 patients after a mean period of 3.2 years. ResultsThe mean fluoroscopy time was significantly shorter in the ALARA group (1.1 min vs. 8.4 min, p < 0.01). Regarding complications and recurrences, during a median follow-up period of 3.2 years, eight patients (13.5%) had recurrences, all of which occurred in the conventional group. ConclusionThis study confirmed a significantly lower radiation burden for patients and the entire electrophysiological team with the ALARA approach and a significantly increased risk of recurrence and complications with the conventional approach. The reduction in radiation time and high long-term success indicate the utility of the ALARA protocol in daily practice.

Optimising whole body computed tomography doses for paediatric trauma patients: a Swiss retrospective analysis

We aimed to evaluate the impact of a low-dose whole-body computed tomography (WBCT) protocol on radiation doses in paediatric major trauma patients. Retrospective cohort study of paediatric trauma patients (<16 years) at a national level 1 paediatric trauma centre (PTC) over a 6 year period prior and post introduction of a low-dose WBCT protocol (2014–2019). Demographic data, patient characteristics, CT device, and exposure information including scan range, dose-length product, and volume CT dose index were collected. Effective dose (ED) and exposure parameters were compared before and after protocol introduction. Forty-eight patients underwent WBCT during the study period. Prior to introduction of the low-dose protocol (n = 18), the ED was 20.6 mSv (median 20.1 ± 5.3 mSv [range 12.5–30.7]). After introduction of the low-dose WBCT protocol (n = 30), mean ED was 4.8 mSv (median 2.6 ± 5.0 [range: 0.8–19.1]). This resulted in a reduction of 77% in mean ED (p value <0.001). Significant radiation dose reduction of 77% can be achieved with low-dose WBCT protocols in PTCs.

Radiation dose reduction during adrenal vein sampling using a new angiographic imaging technology

To compare the patient radiation doses during angiographic selective adrenal vein sampling (AVS) before and after an imaging technology upgrade. In this retrospective single-center-study, cumulative air kerma (AK), cumulative dose area product (DAP), fluoroscopy time and contrast agent dosage were recorded from 70 patients during AVS. 35 procedures were performed before and 35 after an imaging processing technology upgrade. Mean values were calculated and compared using an unpaired student’s t-test. DSA image quality was assessed independently by two blinded readers using a four-point Likert scale (1 = poor; 4 = excellent) and compared using Wilcoxon signed-rank test. After the technology upgrade we observed a significant reduction of 35% in AK (1.7 ± 0.7 vs. 1.1 ± 0.7 Gy, p = 0.01) and a significant reduction of 28% in DAP (235.1 ± 113 vs. 170.1 ± 94 Gy*cm2, p = 0.01) in comparison to procedures before the upgrade. There were no significant differences between the number of exposure frames (143 ± 86 vs. 132 ± 61 frames, p = 0.53), fluoroscopy time (42 ± 23 vs. 36 ± 18 min, p = 0.22), or the amount of contrast medium used (179.5 ± 84 vs. 198.1 ± 109 ml, p = 0.41). There was also no significant difference regarding image quality (3 (2–4) vs. 3 (2–4), p = 0.67). The angiographic imaging technology upgrade significantly decreases the radiation dose during adrenal vein sampling without increasing time of fluoroscopy or contrast volume and without compromising image quality.

Patient radiation dose and lifetime attributable risk of cancer due to ionizing radiation in cardiovascular interventional radiological procedures

The aim of this study is to calculate the patient radiation dose and Lifetime Attributable Risk (LAR) in Cardiovascular Interventional Radiological (CVIR) procedures. The patient population included 327 patients who underwent Coronary Angiography (CA) and Percutaneous Coronary Interventions (PCI). Exposure data were reported for every examination such as Kerma-Area Product (KAP), fluoroscopy time and number of exposures. Organ dose and effective dose were assessed by PCXMC software. LAR values were determined according to BEIR VII report. The mean effective dose per examination in CA is 12.6 mSv for males and 10.25 mSv for females. In PCI, the mean effective dose is 18.06 mSv for males and 22.73 mSv for females. Organs with highest dose are thymus, heart, breast, and lung. The mean of LAR value in CA is 62 and 60 for males and females, respectively. In PCI, the mean of LAR value is 89 and 132 for males and females, respectively. Also, the KAP to effective dose conversion factors (CFKAP-ED) were calculated. CFKAP-ED for CA is 0.249 in males and 0.228 in females, and for PCI is 0.2446 and 0.2316 for males and females, respectively. This study will help better understand the concept of ionizing radiation dose in the CVIR procedures and how the individual patient’s effective dose and LAR can evaluate the cancer risk.