Dose-area Product Values Research Articles

Artificial Neural Network-based Model for Predicting Cardiologists’ Over-apron Dose in CATHLABs

Abstract Aim: The radiation dose that cardiologists receive in the catheterization laboratory is influenced by various factors. Handling high-stress tasks in interventional cardiology departments may cause physicians to overlook the use of dosimeters. Therefore, it is essential to develop a model for predicting cardiologists’ radiation exposure. Materials and Methods: This study developed an artificial neural network (ANN) model to predict the over-apron radiation dose received by cardiologists during catheterization procedures, using dose area product (DAP) values. Leveraging a validated Monte Carlo simulation program, we generated data from simulations with varying spectra (70, 81, and 90 kVp) and tube orientations, resulting in 125 unique scenarios. We then used these data to train a multilayer perceptron neural network with four input features: DAP, energy spectrum, tube angulation, and the resulting cardiologist’s dose. Results: The model demonstrated high predictive accuracy with a correlation coefficient (R-value) of 0.95 and a root mean square error (RMSE) of 3.68 μSv, outperforming a traditional linear regression model, which had an R-value of 0.48 and an RMSE of 18.15 μSv. This significant improvement highlights the effectiveness of advanced techniques such as ANNs in accurately predicting occupational radiation doses. Conclusion: This study underscores the potential of ANN models for accurate radiation dose prediction, enhancing safety protocols, and providing a reliable tool for real-time exposure assessment in clinical settings. Future research should focus on broader validation and integration into real-time monitoring systems.

Impact of the Endonaut® Angio-Navigation System on Radiation Exposure in Endovascular Aortic Repair Performed with Mobile C-Arms

Fusion imaging systems have proved to reduce radiation exposure mostly in hybrid rooms but reports with mobile C-arms are few. The aim of this study was to analyze the impact of the Endonaut navigation system on radiation exposure in endovascular aneurysm repair (EVAR) performed with mobile C-arms. All patients undergoing EVAR and/or iliac branched devices implantation between January 2016 and August 2022 were included. All procedures were performed with a mobile C-arm (Siemens Avantic or GE Elite until March 2018, Siemens Cios Alpha thereafter). The Endonaut navigation system has been used since January 2021. Two groups were, therefore, compared: before (control group [CGr]) and after the use of Endonaut. Radiation data including Dose Area Product (DAP) values, Air Kerma (AK) and fluoroscopy time (FT) were collected retrospectively. Overall, 153 patients were included: CGr, n=121; Endonaut group (EnGr), n=32. No significant difference was found between the 2 groups regarding demographic data. DAP values were significantly lower in the EnGr (38Gycm2±24) vs. the CGr (76Gycm2±51) (P<0.05) despite a significantly higher number of complex procedures such as iliac branched devices (P<0.05). AK values were not significantly different between the EnGr and the CGr (196mGy±114 vs. 209mGy±138) as well as FT (33minutes±18 vs. 33minutes±16). Technical success was 97% (31/32) in the EnGr vs. 96% (116/121) in the CGr (P=0.79). The volume of contrast media was significantly lower in the EnGr (94cc±41) vs. the CGr (143cc±66) (P<0.05). In this study, the use of the Endonaut angio-navigation system when performing EVAR with mobile C-arms led to a radiation dose reduction without compromising technical success or procedural time.

Radiation dose during transarterial chemoembolization and associated factors.

To provide detailed reports on radiation doses during transarterial chemoembolization (TACE) in the cone-beam computed tomography (CBCT) era and to identify the associated factors. This retrospective study included 385 consecutive patients who underwent initial conventional TACE for hepatocellular carcinoma (HCC) between January 2016 and December 2017. In most cases, CBCT was performed at the common hepatic artery or celiac axis to confirm the location of the tumor and the three-dimensional hepatic artery anatomy. Superselective TACE was performed for all technically feasible cases. Information on total dose area product (DAP), total cumulative air kerma (CAK), fluoroscopy time, and DAP and CAK of each digital subtraction angiography (DSA) and CBCT scan was recorded. Multiple linear regression analysis was performed to identify the factors associated with increased DAP during TACE. The mean values of total DAP and CAK were 165.2 ± 81.2 (Gy·cm²) and 837.1 ± 571.0 (mGy), respectively. The mean fluoroscopy time was 19.1 ± 10.3min. The mean DAP caused by fluoroscopy, DSA, and CBCT was 51.8 ± 43.9, 28.0 ± 24.1, and 83.9 ± 42.1Gy·cm², respectively. Male sex, a high body mass index, largest tumor size > 3cm, presence of aberrant right and left hepatic arteries, and superselective TACE were identified as independent predictors of increased total DAP during TACE. We were able to provide detailed reports on radiation doses during TACE and associated factors.

Determination of Diagnostic Reference Level in Dose-Area Product (DAP) and Evaluation of Dosimetry in Chest x-ray Examination at Bingerville Mother-Child Hospital, Cote D’Ivoire

X-rays have an undeniable advantage in medicine, especially for diagnosis. However, their use is not without risk. Following numerous studies carried out by the International Atomic Energy Agency and learned societies, it has been recommended to strengthen the principle of optimization in diagnostic radiology by implementing Diagnostic Reference Levels. The purpose of this study is to determine diagnostic reference levels (DRLs) in order to evaluate radiological practices and to reduce doses received by patients for frontal chest examination at the Bingerville Mother-Child Hospital (MCH). The work was carried out on a sample of 110 patients at the Mother and Child Hospital in Bingerville. We used a generator and a tube for the production of X-rays. The dose-area product (DAP) value was obtained using a dose calculator built into the generator. The determination of the DRLs in DAP (cGy.cm²) was made with the 75th percentile statistical method and yielded the following result of 14.32 cGy.cm². Comparing our DRL value with those obtained elsewhere, as well as comparing the median DAP from the present study with the DRLs in Abidjan and at the national level, radiological practices are satisfactory for frontal chest examination. However, after analysis of some radiological parameters used, it appears that efforts need to be made by acting on the kV, mAs, diaphragm and the filtration.

Comparative Analysis of Transpedal and Transfemoral Access During Genicular Artery Embolization for Knee Osteoarthritis.

This retrospective study aimed to compare the efficacy and safety of transpedal access (TPA) with transfemoral access (TFA) in Genicular Artery Embolization (GAE). 60 patients who underwent GAE between January and June 2023, were recruited and outcomes were compared between the TFA (n = 37) and TPA (n = 23) groups. Technical and clinical success rates, complications, and patient-reported outcomes were assessed. All patients attained a 100% technical success rate, which was defined as the successful selective catheterization and embolization of at least one feeding artery to the knee joint, without encountering any major complications. Minor complications, observed in 12/60 patients (20%), were predominantly manifested as a transient skin discoloration. The TPA group had a comparatively higher (p = 0.008) rate of minor complication than the TFA group. Notably, TPA was associated with a longer duration of the procedure (p = 0.013), duration of fluoroscopy (p = 0.004), increased total air kerma (p = 0.037), dose-area product values (p = 0.021), and a greater incidence of vasospasm (p = 0.018) than TFA. However, TPA patients reported shorter recovery times and less post-procedural discomfort, especially reduced back pain due to postinterventional bedrest (p < 0.001). At the 3-month follow-up, the clinical success rate was similar between the two groups (p = 0.905). TFA is the safer and faster method for GAE, offering fewer complications and reduced radiation exposure. For patients with challenging groin anatomies, however, TPA may provide a valuable alternative.

Low-dose CT: A safe and effective imaging modality in post-operative pelvic & acetabular fixation

IntroductionPost-operative pelvic & acetabular fixation patients are conventionally imaged using 3-view radiographs (AP, inlet and outlet). The efficacy of such radiographs is inconsistent due to technical difficulties capturing an adequate view, often necessitating repeat radiographs and therefore increasing radiation exposure. Radiographs can be difficult to interpret, limiting the assessment of fracture reduction and fixation, especially with respect to metalwork positioning around articular surfaces. Traditionally, post-operative pelvic & acetabular fixation patients undergo repeat 3-view radiographs post-operatively, at 6 weeks, followed by at 3, 6, 12, 18 and 24 months. We propose a new pathway, in which patients have one low-dose pelvic CT immediately post-operatively, followed by one radiograph (AP pelvis) at the same time points. MethodsA new pelvic CT protocol was created to provide high quality 3D imaging whilst delivering a 5 times lower radiation dose (compared to normal pelvic CT). Data for all pelvic radiographs and CTs between January 2021 and March 2022 was exported. Using dose area product values, effective radiation dose and attributable lifetime cancer risk were calculated. ResultsThere were 42 patients included in the analysis (age range 15 to 87).The average effective dose for the 3-view pelvic X-rays was 0.6mSv (range 0.2 to 2.8mSv), and 1.1mSv (range 0.5 to 2.2mSv) for the low-dose pelvic CT. Traditional 7 × 3-view post-operative radiographs: 7 × 0.6mSv = 4.2mSv (corresponding to 1 in 11,000 cancer risk) Low dose post-operative CT and 6 × 1-view radiographs: 1.1mSv + (6 × 0.6mSv / 3) = 2.3mSv (corresponding to 1 in 20,000 cancer risk) ConclusionLow-dose CT scanning (in conjunction with 1-view radiographs) is an effective and safe imaging modality in the post-operative assessment of pelvic & acetabular fracture fixation, conferring a lower radiation burden, easier logistics, and higher quality images when compared to the traditional pathway of 3-view radiographs.

A simple method for radiation exposure reduction during atrial fibrillation ablation: the lead-apron-free approach.

Radiofrequency catheter ablation (RFCA) is a well-established treatment for atrial fibrillation (AF). Fluoroscopy, a widely used imaging method for RFCA, has significant implications for human health. Although no fluoroscopy or near-zero fluoroscopy strategies have gained popularity, they have limitations, such as long procedure times, additional equipment, and expertise. A simple and cost-effective radiation reduction method is needed for treating AF and is compatible with the daily workflow. We aimed to compare the efficacy and safety of fluoroscopy-free and lead apron-free (LAF) after transseptal puncture AF ablation with conventional ablation (CON). This retrospective study included all patients who underwent RF catheter AF ablation. The lead apron used for protection was removed immediately before 3D reconstruction of the left atrium (LA) after transseptal puncture (TSP), while fluoroscopy was performed on stand-by and locked-in. The pulmonary vein isolation (PVI) was performed using a 3D mapping system, a multielectrode catheter, and a Smart Touch contact force (CF) sensing catheter, via the lead-apron-free (LAF) method, which is similar to the conventional ablation (CON) method. This study enrolled 152 consecutive patients, with 72 and 80 patients in the LAF and CON groups, respectively. The LAF group demonstrated significantly lower values in total fluoroscopy time (6.9 vs. 14 min, P<0.001) and dose area product (DAP) values (15.4±12.1 vs. 31.5±17.4 G/m2, P<0.001) than the CON group. However, there was no significant difference in the total procedure time (83.6±21.1 vs. 77.2±11.4 min, P=0.12) between the two groups. Only four procedures (5.5%) required repositioning of the apron, and no complications were observed with the LAF method. Pulmonary vein isolation was achieved in all patients. The LAF method reduced fluoroscopy use compared with CON, with no change in procedure time or efficacy.

X-ray Doses in Relation to Body Mass, Indication, and Substrate During Pediatric Electrophysiological Procedures on the Heart.

The main goal of this study is to determine typical values of dose area product (DAP) and difference in the effective dose (ED) for pediatric electrophysiological procedures on the heart in relation to patient body mass. This paper also shows DAP and ED in relation to the indication, the arrhythmia substrate determined during the procedure, and in relation to the reason for using radiation. Organ doses are described as well. The subjects were children who have had an electrophysiological study done with a 3D mapping system and X-rays in two healthcare institutions. Children with congenital heart defects were excluded. There were 347 children included. Significant difference was noted between mass groups, while heavier children had higher values of DAP and ED. Median DAP in different mass groups was between 4.00 (IQR 1.00-14.00) to 26.33 (IQR 8.77-140.84) cGycm2. ED median was between 23.18 (IQR 5.21-67.70) to 60.96 (IQR 20.64-394.04) µSv. The highest DAP and ED in relation to indication were noted for premature ventricular contractions and ventricular tachycardia-27.65 (IQR 12.91-75.0) cGycm2 and 100.73 (IQR 53.31-258.10) µSv, respectively. In arrhythmia substrate groups, results were similar, and the highest doses were in ventricular substrates with DAP 29.62 (IQR 13.81-76.0) cGycm2 and ED 103.15 (IQR 60.78-266.99) µSv. Pediatric electrophysiology can be done with very low doses of X-rays when using 3D mapping systems compared to X-rays-based electrophysiology, or when compared to pediatric interventional cardiology or adult electrophysiology.

Evaluation of Radiation Exposure and Influential Factors in Cone-Beam Computed Tomography (CBCT) of the Head and Abdomen during Interventional Procedures.

Cone-beam computed tomography (CBCT) is a widely used imaging technique in interventional radiology. Although CBCT offers great advantages in terms of improving comprehension of complex angioarchitectures and guiding therapeutic decisions, its additional degree of radiation exposure has also aroused considerable concern. In this study, we aimed to assess radiation exposure and its influential factors in patients undergoing CBCT scans of the head and abdomen during interventional procedures. A total of 752 patients were included in this retrospective study. Dose area product (DAP) and reference air kerma (RAK) were used as measures of patient dose. The results showed that the median values of DAP were 53.8 (50.5-64.4) Gy⋅cm2 for head CBCT and 47.4 (39.6-54.3) Gy⋅cm2 for that of the abdomen. Male gender and body mass index (BMI) were characterized by increased DAP and RAK values in both head and abdominal CBCT scans. Larger FOV size was associated with a higher DAP but a lower RAK value, especially in head CBCT scans. Exposure parameters under automatic exposure control (AEC) also varied according to patient BMI and gender. In conclusion, the patients received slightly higher radiation doses from head CBCT scans than from those applied to the abdomen. BMI, gender, and FOV size were the key factors that influenced the radiation dose administered to the patients during CBCT scans. Our results may help to define and minimize patients' exposure to radiation.

Proposed Diagnostic Reference Levels in the Missouri/Southern Illinois Region Associated with Cone-beam Computed Tomography Use in Endodontics

IntroductionDiagnostic reference levels (DRLs) are intended to improve patient safety and ensure that patient ionizing radiation doses are as low as reasonably achievable. The purpose of this dosimetry study was to establish regional DRL levels for cone-beam computed tomography (CBCT) imaging for specialty endodontics. Another aim was to compare phantom-measured ionizing radiation dose index 1 (DI1) index doses to the manufacturer-provided dose area product (DAP) radiation output values for each of the CBCT machines studied, to ascertain their degree of correlation. DAP refers to the dose area product, a measure of radiation dose monitoring which represents the dose within the beam times the area within the beam at that position. MethodsA thimble ionization chamber and polymethyl methacrylate phantom were used to obtain DI1 values using the SEDENTEXTCT method from 21 different CBCT units. DRLs were calculated based on the 75th percentile (third quartile) of the median output values. ResultsThe proposed DRL from the CBCT units surveyed has a DAP value of 838 mGy cm2 and a DI1 value of 3.924 mGy. DAP versus DI1 values of 500.6 mGy cm2 versus 2.006 mGy, and 838 mGy cm2 versus 3.906 mGy represented the third quartile of the median values for the 4-cm × 4-cm and 5-cm × 5-cm field of views (FOVs), respectively. ConclusionsThe DI1 and DAP values strongly correlated when 3 outlier CBCT machines (J Morita Veraview X800) using a novel 360° (full rotation) acquisition mode were excluded. The importance of selectable exposure parameters as directly related to ionizing radiation output is illustrated among the CBCT units surveyed. Although the actual FOV that is selected is ultimately dictated by the specific clinical requirements, a 4-cm × 4-cm FOV is recommended for specialist endodontics practice, whenever clinically practical, based on the decreased ionizing radiation output, as compared to that from a 5-cm × 5-cm FOV.

Reduction of Radiation Risk to Cardiologists and Patients during Coronary Angiography: Effect of Exposure Angulation and Composite Shields

Purpose: This study aimed to design an improved form of a composite shield with different materials and shapes and simultaneously reduce the radiation dose to both the patient and operator.&#x0D; Materials and Methods: A female phantom study was performed with and without bismuth belt-shaped composite shields on the breast region at different beam projections used in coronary angiography. Dose measurements were conducted using GR-200 thermo-luminescence dosimeters, dose area product (DAP), and air kerma (AK) over regular and large breast locations, with and without using bismuth shields. An electronic personal dosimeter was used for operator dose assessment. Patients received doses between 2.27 mSv and 3.38 mSv, depending on the size and strength of beam projections.&#x0D; Results: The use of the developed shields caused a dose reduction of 18%–25% of sensitive breast tissue due to breast size and shield type. During coronary angiography, the mean values of DAP and AK were 2.02 (1.24-2.80) mGy.m2 and 314.1 (202.8-500) mGy, respectively. The highest recorded dose was at the LAO/CRA and LAO/CAU beam projections for both the patient and operator. After applying a belt shield, the operator's radiation dose was decreased by approximately 32%. We found a statistically significant correlation between the radiation dose received by the operator and the patient's breast radiation exposure dose (p&lt;0.001, r2=0.93).&#x0D; Conclusion: The designed belt shield can be a potentially promising protective device for decreasing the radiation risk to the patient's breast and the operator during coronary angiography. However, further studies will be considered before the application of this shield in standard clinical practice.

The effect of optimum, indication-specific imaging fields on the radiation exposure from CBCT examinations of impacted maxillary canines and mandibular third molars

Objective Indication-specific optimum field-of-views (FOVs) have been assessed for CBCT scans of impacted maxillary canines and mandibular third molars, as 40∅ × 35 mm and 35∅ × 35 mm, respectively. The objective was to investigate possible changes in absorbed organs and effective doses, for these two imaging indications, performing CBCT examinations with optimum FOV sizes instead of commonly used FOVs. Additionally, radiation exposure-induced cancer risk was calculated for both imaging indications with optimum FOVs. Methods An adult female head phantom (ATOM 702-D, CIRS, Norfolk, VA, USA) was scanned using Planmeca Viso G7 CBCT-device (Planmeca, Helsinki, Finland). Scanning factors, different FOV sizes, dose-area product (DAP) values and anatomical FOV locations were used for Monte Carlo PCXMC-simulation and ImpactMC software. In the PCXMC- simulation, 10-year-old child and 30-year-old adult phantoms were used to estimating effective and absorbed organ doses. Results The effective dose varied from 58 µSv to 284 µSv for impacted maxillary canines, and from 38 µSv to 122 µSv for mandibular third molars, the lowest dose value for each corresponding to optimum FOV. Effective dose reduction between the optimum FOV and the smallest common FOV of 50∅ × 50 mm, maintaining other scanning factors constant, was 33% for impacted maxillary canines, and 45% for mandibular third molars. At all examinations, the highest absorbed organ doses were in salivary glands or in oral mucosa. Conclusions Optimum FOVs, 40∅ × 35 mm for impacted maxillary canine and 35∅ × 35 mm for mandibular third molar, could decrease effective doses received by young patients, and improve radiation safety in these common CBCT imaging procedures.

Novel Deep Learning Denoising Enhances Image Quality and Lowers Radiation Exposure in Interventional Bronchial Artery Embolization Cone Beam CT

In interventional bronchial artery embolization (BAE), periprocedural cone beam CT (CBCT) improves guiding and localization. However, a trade-off exists between 6-second runs (high radiation dose and motion artifacts, but low noise) and 3-second runs (vice versa). This study aimed to determine the efficacy of an advanced deep learning denoising (DLD) technique in mitigating the trade-offs related to radiation dose and image quality during interventional BAE CBCT. This study included BMI-matched patients undergoing 6-second and 3-second BAE CBCT scans. The dose-area product values (DAP) were obtained. All datasets were reconstructed using standard weighted filtered back projection (OR) and a novel DLD software. Objective image metrics were derived from place-consistent regions of interest, including CT numbers of the Aorta and lung, noise, and contrast-to-noise ratio. Three blinded radiologists performed subjective assessments regarding image quality, sharpness, contrast, and motion artifacts on all dataset combinations in a forced-choice setup (-1=inferior, 0=equal; 1=superior). The points were averaged per item for a total score. Statistical analysis ensued using a properly corrected mixed-effects model with post hoc pairwise comparisons. Sixty patients were assessed in 30 matched pairs (age 64±15 years; 10 female). The mean DAP for the 6s and 3s runs was 2199±185 µGym² and 1227±90 µGym², respectively. Neither low-dose imaging nor the reconstruction method introduced a significant HU shift (p≥0.127). The 3s-DLD presented the least noise and superior contrast-to-noise ratio (CNR) (p<0.001). While subjective evaluation revealed no noticeable distinction between 6s-DLD and 3s-DLD in terms of quality (p≥0.996), both outperformed the OR variants (p<0.001). The 3s datasets exhibited fewer motion artifacts than the 6s datasets (p<0.001). DLD effectively mitigates the trade-off between radiation dose, image noise, and motion artifact burden in regular reconstructed BAE CBCT by enabling diagnostic scans with low radiation exposure and inherently low motion artifact burden at short examination times.

Radiation doses in endovascular revascularisation of lower-extremity arterial diseases.

The use of percutaneous endovascular intervention in lower-extremity arterial diseases is increasing daily. With the growing technical experience of vascular surgeons, this is preferred to open surgery in more complex lesions. The dose area product (DAP) and fluoro (FL) time values of 150 patients who underwent successful peripheral endovascular arterial intervention were analysed retrospectively. These values were evaluated by grouping according to the anatomical region and complexity of the lesion, type of procedure and arterial access. While the mean DAP was 18 ± 27 Gy cm2 in patients who underwent only angioplasty, it was 21 ± 17 Gy cm2 in patients who underwent stent implantation after angioplasty ( p = 0.069). The DAP value was statistically significantly higher in patients who had intervention in the pelvic region, both in the angioplasty (23 ± 22 Gy cm2) group and in the stenting (29 ± 18 Gy cm2) group, than in patients who had intervention in the femoropopliteal region (18 ± 27 and 15 ± 12 Gy cm2, respectively) (p < 0.05). When the correlation between body mass index (BMI) of the patients and DAP was examined, a moderate positive correlation was found both in the pelvic region (r = 0.601, p = 0.00) and in the femoropopliteal region (r = 0.512, p = 0.00). Out of 78 patients in whom the ipsilateral popliteal retrograde approach was preferred, only two developed arteriovenous fistulae after the procedure, and only two of 77 patients in whom the femoral approach was preferred developed no major or minor complications, except femoral pseudo-aneurysm. The most important factors affecting the radiation doses of the patients were the anatomical region and the patient's BMI. Radiation doses were higher in pelvic interventions compared to the femoropopliteal region. This may encourage the choice of arterial approaches that can minimise visualisation of the pelvic region in particular. Therefore, attention should be paid to pre-operative planning, especially in patients undergoing multiple diagnostic and therapeutic imaging. The ipsilateral popliteal retrograde approach can be safely chosen in combined iliofemoral, common femoral and superficial femoral total occlusions in the hands of surgeons with good Doppler ultrasonography experience.

Evaluation of radiation dose and image quality for dental cone-beam computed tomography in pediatric patients

Children are sensitive to radiation; therefore, it is necessary to reduce radiation dose as much as possible in pediatric patients. In addition, it is crucial to investigate the optimal imaging conditions as they considerably affect the radiation dose. In this study, we investigated the effect of different imaging conditions on image quality and optimized the imaging conditions for dental cone-beam computed tomography (CBCT) examinations to diagnose ectopic eruptions and impacted teeth in children. To achieve our aims, we evaluated radiation doses and subjective and objective image quality. The CBCT scans were performed using 3D Accuitomo F17. All combinations of a tube voltage (90 kV), tube currents (1, 2, 3 mA), fields of view (FOVs) (4 × 4, 6 × 6 cm), and rotation angles (360°, 180°) were used. Dose-area product values were measured. SedentexCT IQ cylindrical phantom was used to physically evaluate the image quality. We used the modulation transfer function as an index of resolution, the noise power spectrum as an index of noise characteristics, and the system performance function as an overall evaluation index of the image. Five dentists visually evaluated the images from the head-neck phantom. The results showed that the image quality tended to worsen, and scores for visual evaluation decreased as tube currents, FOVs and rotation angles decreased. In particular, image noise negatively affected the delineation of the periodontal ligament space. The optimal imaging conditions were 90 kV, 2 mA, 4 × 4 cm FOV and 180° rotation. These results suggest that CBCT radiation doses can be significantly reduced by optimizing the imaging conditions.

Assessment of radiation doses and DNA damage in pediatric patients undergoing interventional procedures for vascular anomalies.

Interventional procedures (IPs) have been widely used to treat vascular anomalies (VA) in recent years. However, patients are exposed to low-dose X-ray ionizing radiation (IR) during these fluoroscopy-guided IPs. We collected clinical information and IR doses during IPs and measured biomarkers including γ-H2AX, chromosome aberrations (CA), and micronuclei (MN), which underpin radiation-induced DNA damage, from 74 pediatric patients before and after IPs. For the 74 children, the range of dose-area product (DAP) values was from 1.2 to 1754.6Gy∙cm2, with a median value of 27.1Gy∙cm2. DAP values were significantly higher in children with lesions in the head and neck than in the limbs and trunk; the age and weight of children revealed a strong positive correlation with DAP values. The treated patients as a group demonstrated an increase in all three endpoints relative to baseline following IPs. Children with vascular tumors have a higher risk of dicentric chromosome +centric ring (dic+r) and cytokinesis-block micronucleus (CBMN) after IPs than children with vascular malformations. The younger the patient, the greater the risk of CA after IPs. Moreover, rogue cells (RCs) were found in five children (approximately 10%) after IPs, and the rates of dic+r and CBMN were significantly higher than those of other children (Z=-3.576, p<0.001). These results suggest that there may be some children with VA who are particularly sensitive to IR, but more data and more in-depth experiments will be needed to verify this in the future.

Patients’ Radiation Exposure During Endovascular Abdominal Aortic Aneurysm Repair

To investigate associations between patient characteristics, intraprocedural complexity factors, and radiation exposure to patients during endovascular abdominal aortic aneurysm repair (EVAR). Elective standard EVAR procedures between January 2015 and December 2020 were retrospectively analyzed. Patient characteristics and intraprocedural data (i.e., type of device, endograft configuration, additional procedures, and contralateral gate cannulation time [CGCT]) were collected. Dose area product (DAP) and fluoroscopy time were considered as measurements of radiation exposure. Furthermore, effective dose (ED) and doses to internal organs were calculated using PCXMC 2.0 software. Descriptive statistics, univariable, and multivariable linear regression were applied to investigate predictors of increased radiation exposure. The 99 patients were mostly male (90.9%) with a mean age of 74±7years. EVAR indications were most frequently abdominal aortic aneurysm (93.9%), penetrating aortic ulceration (2.0%), focal dissection (2.0%), or subacute rupture of infrarenal abdominal aortic aneurysm (2.0%). Median fluoroscopy time was 19.6minutes (interquartile range [IQR], 14.1-29.4) and median DAP was 86,311 mGycm2 (IQR, 60,160-130,385). Median ED was 23.2 mSv (IQR, 17.0-34.8) for 93 patients (93.9%). DAP and ED were positively correlated with body mass index (BMI) and CGCT. Kidneys, small intestine, active bone marrow, colon, and stomach were the organs that received the highest equivalent doses during EVAR. Higher DAP and ED values were observed using the Excluder endograft, other bi- and tri-modular endografts, and EVAR with ≥2 additional procedures. Multivariable linear regression analysis revealed that BMI, ≥2 additional procedures during EVAR, and CGCT were independent positive predictors of DAP and ED levels after accounting for endograft type. Patient-related and procedure-related factors such as BMI, ≥2 additional procedures during EVAR, and CGCT resulted predictors of radiation exposure for patients undergoing EVAR, as quantified by higher DAP and ED levels. The main intraprocedural factor that increased radiation exposure was CGCT. These data can be of importance for better managing radiation exposure during EVAR.

Establishing weight-based diagnostic reference levels for neonatal chest X-rays

IntroductionAs weights among neonates can vary from <900 g to >2.5 kg, weight-based Diagnostic Reference Levels (DRLs) specific to the neonatal intensive care unit (NICU) are essential. Repeated radiation exposure to this sensitive patient group raises concerns regarding high cumulative radiation doses and the potential for long-term health detriment. This study aimed to establish weight-based DRLs for neonates undergoing mobile chest radiography (CXR) in the NICU. MethodsNeonates were classified into three discrete groups; <1000, 1000–2500 and >2500 g. Data were collected prospectively over three months; 95 DAP values were collected, and five were excluded due to poor technique, leaving 90 patients that met the inclusion criteria for mobile CXR in the NICU. Dose-area-product (DAP) in mGycm2, the peak kilovoltage (kVp) and the product of tube current and exposure time (mAs) were retrieved from the Picture Archiving and Communication System (PACS). Images and radiological reports were also analysed to confirm diagnostic image quality (IQ). Local DRLs (LDRLs) were derived using the median DAP, and national DRLs were suggested using the 3rd quartile value. ResultsThe proposed LDRLs for neonates weighing <1000 g was 2.7 mGycm2, for neonates weighing between 1000 g and 2500 g, it was 3.7 mGycm2, and for neonates weighing >2500 g it was 6.6 mGycm2. The radiation dose received by the 90 (100%) neonates included in the study fell below 11.4 mGycm2; of these, 82% of the DAP values fell below the study institution's existing LDRL of 7.25 mGycm2. ConclusionWeight-based DRLs provide crucial information on doses to this specific radiation-sensitive group. This work recommends using weight-based categories for DRLs and serves as a benchmark for neonatal CXR standardisation and optimisation. Implications for practiceThe proposed weight-based DRLs can be adopted for neonates’ locally, nationally and internationally.

ESTABLISHMENT OF TYPICAL DOSE VALUE FOR INTERVENTIONAL RADIOLOGY EXAMINATION IN RADIOLOGY DEPARTMENT, HOSPITAL PENGAJAR UPM

Angiography is commonly used as a diagnostic imaging tool for diagnosing and treating the patient from simple to complex examination. Despite the advancement in imaging technologies, the radiation dose to the patient remains a concern when using this procedure. Diagnostic Reference Levels (DRLs) are used to identify the amount of dose exposed to the patient and monitor the high dose received by an individual in a specified radiological procedure. The aim of this study is to establish Institutional Diagnostic Reference Levels (DRLs) based on median data dose distribution for cerebral examination (cerebral angiography and stroke thrombectomy) and compared with established Malaysian National Diagnostic Reference Levels (NDRLs). The Dose Area Product (DAP) and fluoroscopy time were recorded using clinical data from the participating modality from 1 January 2022 until 31 December 2022 at Teaching Hospital Universiti Putra Malaysia (HPUPM). The data collected for each procedure with a minimum recommended number of patients (at least 30) required to propose a DRL for each examination type within the data collection period. The mean value, standard deviation, median value, and 3rd quartile were calculated using Microsoft Excel Version 2013. The Typical Dose Value for the interventional procedure was defined as the median of the distribution of DRL quantities and required further optimization. The distribution of DAP values for the cerebral angiogram and stroke thrombectomy ranged between 5.05 mGy.m2 to 31.80 mGy.m2 and 7.03 mGy.m² to 43.23 mGy.m² respectively. The institutional DRLs for cerebral angiogram (10.60 mGy.m2) and stroke thrombectomy (21.80 mGy.m2) were higher than the established Malaysian National DRL. From the findings, stroke thrombectomy examinations recorded the highest Typical Dose value follow by cerebral angiogram examination. Generally, the factors that can affect DRL values are a patient-related factor, equipment-related factor, the complexity of the procedures, operator’s experience in handling the machine and interventional radiologist experience that can contribute to various results.

DIAGNOSTIC REFERENCE LEVELS AND COMPLEXITY INDICES IN INTERVENTIONAL RADIOLOGY.

The establishment of typical diagnostic reference levels (DRLs) values according to the complexity indices (CIs) for hepatic chemoembolisation (HC), iliac stent placement (ISP) and femoropopliteal revascularisation (FR) is reported in this study. To estimate patients' stochastic effects, effective dose was calculated through dose area product (DAP) values of this study and E/DAP conversion factors derived from the literature. Data for DAP, Reference Air Kerma (Ka,r) and fluoroscopy time (FT) were collected for 218 patients and CIs were assigned to each procedure to extract DRLs. To estimate effective dose, conversion factors and DAP values were used for seven IR procedures. DRL values for DAP were 141, 130 and 28Gy*cm2 for HC, ISP, and FR, respectively. The corresponding DRL values for Ka,r were 634.6, 300.1 and 112.0mGy, and for FT were 15.3, 12.4 and 17.9min, respectively. CIs in interventional radiology are a useful tool for the optimisation of DRLs since they contribute to patient's doses.