Dose Area Product Research Articles

Next-generation atrial fibrillation ablation: clinical performance of pulsed-field ablation and very high-power short-duration radiofrequency.

Pulsed-field energy (PFA) and very high-power short-duration radiofrequency (vHPSD-RF) are two novel ablation methods for pulmonary vein isolation (PVI). Both PFA and vHPSD-RF show promise for improving efficacy, safety, and reducing procedure durations. However, direct comparisons between these two techniques are scarce. Retrospective analysis of 82 patients with symptomatic AF. Of these, 52 patients received PFA and 30 received vHPSD-RF (90 W, 4s) as index procedure. At the 6-month follow-up, AF recurrence occurred in 4 patients following PFA and 5 patients following vHPSD-RF (p-value = 0.138). Significant improvements in the EHRA and NYHA stages were evident in both PFA (p < 0.001 and p = 0.047, respectively) and vHPSD-RF groups (p = 0.007 and p = 0.012, respectively). The total procedure duration and the left atrial dwell time were significantly shorter in the PFA group (64 ± 19min vs. 99 ± 32min, p < 0.001 and 41 ± 12min vs. 62 ± 29min, p < 0.001, respectively). The fluoroscopy time and dose area product were significantly higher in PFA (14 ± 6 vs. 9 ± 5min, p < 0.001 and 14 ± 9 vs. 11 ± 9Gy cm2, p = 0.046, respectively). One patient in the vHPSD-RF group suffered a stroke, not directly linked to the procedure (0 vs. 1 major complication, p = 0.366). Based on this retrospective single-center study, PFA and vHPSD-RF were associated with similar effectiveness and safety profiles. PFA was linked to shorter procedure times and higher radiation exposure compared to vHPSD-RF.

Evaluation of the performance of digital x-ray systems in pelvis radiography

The aim of this study was to investigate the performance of eight digital radiography systems and to optimise the dose-image quality relationship for digital pelvis radiography. The study involved eight digital radiography systems used for general examinations at Vilnius University Hospital Santaros Klinikos. An anthropomorphic pelvic phantom (CIRS, US) was used to simulate a patient undergoing clinical pelvis radiography. Dose quantities entrance surface dose, dose area product (DAP) and exposure parameters (kVp, mA, mAs) were measured and the effects on the images were evaluated, considering physical contrast to noise ratio (CNR) and observer-based evaluations as image quality metrics. Increasing the tube voltage by 5 kVp from standard protocol led to a reduction in radiation dose (DAP) by 12%–20% with a slight impact on image quality (CNR decreases by 2%–10%). There was an inter-observer variability in image rating across different equipment (kappa value between 0 and 0.3); however, both observers agreed that increasing kVp up to 85–90 kV had no effect on perceived image quality. The results indicate that optimisation strategies should be tailored specifically for each x-ray system since significant performance differences and wide variations in radiation dose exist across various digital radiography systems used in clinical settings. The use of high kVp can be used for dose optimisation in digital pelvis radiography without compromising image diagnostic accuracy.

Impact of 3D TEE guided ASD transcatheter closure on procedure outcome and radiation exposure

Abstract Background Transcatheter ASD device closure of secondum ASD is widely accepted in closure of ASD. Radiation exposure increases the risk of cancer for both patients and staff members, fusion of 3- D TEE and fluoroscopy has helped us decrease radiation exposure during whole procedure. Aim to assess feasibility of 3 D TEE guidance in transcatheter ASD closure and assess its value in reducing radiation exposure as compared to control patients. Methods This study was conducted on 30 patients with secundum ASD referred to cardiology department - Ain Shams University for percutaneous ASD device closure under 3D TEE guidance and 54 control patients who performed percutaneous ASD device closure using conventional method. we calculated total procedure time (min), total DAP (mGy/cm2), (FT) fluoroscopy time (min), total air kerma (mGy), maximum ASD diameter (mm) and we recorded implanted device size and device type for all the patients. Results There was no significant difference between both groups regarding FT, total air kerma, dose area product. Operative time of study group was significantly longer than control group although FT reduced significantly in last case of the study. In the last 10 cases of the study radiation exposure decreases and was significantly lower than control group. Conclusion The Use of 3 D-TEE by well-trained imaging cardiologist on tracking catheter during percutaneous ASD device closure decrease significantly radiation exposure of patients as well as medical personnel.

Factors affecting radiation dose, radiation exposure time and procedural time in arterial embolization for active hemorrhage.

To evaluate patient and procedure-related factors contributing to the radiation dose, cumulative fluoroscopy time (CFT), and procedural time (PT) of Arterial Embolization (AE) for suspected active bleeding. Data on patients who underwent AE for suspected bleeding was retrospectively gathered between January 2019 and April 2022. Data collected included the dependent variables consisting of dose-area product (DAP), CFT, PT, and independent variables consisting of demographic, bleeding-specific, and procedure-specific parameters. All statistical computations were performed in SPSS statistics. The alpha value was set at 0.05. Data from a total of 148 AE were collected with an average patient's age of 61.06 ± 21.57 years. Higher DAP was independently associated with male sex (p < 0.002), age ranges between 46 and 65 years (p = 0.019) and > 66 years (p = 0.027), BMI above 30 (p = 0.016), attending with less than 10 years of experience (p = 0.01), and bleeding in the abdomen and pelvis (p = 0.027). Longer CFT was independently associated with attending with less than 10 years of experience (p < 0.001), having 2 (p = 0.004) or > 3 (p = 0.005) foci of bleed, and age between 46 and 65 years (p = 0.007) and ≥ 66 years (p = 0.017). Longer PT was independently associated with attending with less than 10 years of experience (p < 0.001) and having 2 (p = 0.014) or > 3 (p = 0.005) foci of bleed. The interventionist experience influenced radiation dose, CFT and PT. Dose was also affected by patients' sex, age, BMI, as well as bleeding location. CFT was also affected by patients' age, and both CFT and PT were also affected by the number of bleeding foci. These findings highlight the multifaceted factors that affect radiation dose and procedural time, emphasizing the importance of interventionist expertise, patient's age, sex, BMI, location and number of bleeds.

Pulmonary vein isolation using pulsed field ablation vs. high-power short-duration radiofrequency ablation in paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up (PRIORI study).

Pulsed field ablation (PFA) is a novel, non-thermal, cardiac tissue-selective ablation modality. To date, radiofrequency (RF)-guided high-power short-duration (HPSD) ablation represents the gold standard besides cryo-ablation for pulmonary vein isolation (PVI). This single-centre, retrospective study investigated the efficacy of PFA-PVI vs. HPSD-RF PVI in terms of single-procedure arrhythmia-free outcome and safety in a real-world setting. Consecutive, paroxysmal atrial fibrillation (AF) patients who underwent PVI using PFA or HPSD-RF were enrolled. In group PFA, PVI was performed using a pentaspline PFA catheter. The ablation procedure in group HPSD-RF was performed with RF energy (45 W, ablation index). A total of 410 patients (group PFA, 201; group HPSD-RF, 209) were included. There was no difference between both groups regarding age, gender, and CHA2DS2-VASc score. The procedure time was significantly shorter in group PFA [61 (44-103) vs. 125 (105-143) min; P < 0.001]; fluoroscopy time and dose area product were significantly higher in group PFA [16 (13-20) vs. 4 (2-5) min; P < 0.01 and 412 (270-739) vs. 129 (58-265) μGym2; P < 0.01]. The overall complication rates were 2.9% in group PFA and 6.2% in group HPSD (P = 0.158). There was one fatal stroke in the PFA group. The 1-year Kaplan-Meier estimated freedom from any atrial tachyarrhythmia was 85% with PFA and 79% with HPSD-RF (log-rank P = 0.160). In 56 repeat ablation procedures, the PV reconnection rate was 30% after PFA and 38% after HPSD-RF (P = 0.372). Both PFA and HPSD-RF were highly efficient and effective in achieving PVI in paroxysmal AF patients. The arrhythmia-free survival is comparable. The PV reconnection rate was not different.

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.

Added Value of a Robotic-assisted Bronchoscopy Platform in Cone Beam Computed Tomography-guided Bronchoscopy for the Diagnosis of Pulmonary Parenchymal Lesions.

Cone beam computed tomography (CBCT)-guided bronchoscopic sampling of peripheral pulmonary lesions (PPLs) is associated with superior diagnostic outcomes. However, the added value of a robotic-assisted bronchoscopy platform in CBCT-guided diagnostic procedures is unknown. We performed a retrospective review of 100 consecutive PPLs sampled using conventional flexible bronchoscopy under CBCT guidance (FB-CBCT) and 100 consecutive PPLs sampled using an electromagnetic navigation-guided robotic-assisted bronchoscopy platform under CBCT guidance (RB-CBCT). Patient demographics, PPL features, procedural characteristics, and procedural outcomes were compared between the 2 cohorts. Patient and PPL characteristics were similar between the FB-CBCT and RB-CBCT cohorts, and there were no significant differences in diagnostic yield (88% vs. 90% for RB-CBCT, P=0.822) or incidence of complications between the 2 groups. As compared with FB-CBCT cases, RB-CBCT cases were significantly shorter (median 58 min vs. 92 min, P<0.0001) and used significantly less diagnostic radiation (median dose area product 5114 µGy•m2 vs. 8755 µGy•m2, P<0.0001). CBCT-guided bronchoscopy with or without a robotic-assisted bronchoscopy platform is a safe and effective method for sampling PPLs, although the integration of a robotic-assisted platform was associated with significantly shorter procedure times and significantly less radiation exposure.

Longitudinal reduction in fluoroscopy with continued use of 3-dimensional electroanatomic mapping systems in catheter ablation of supraventricular tachycardia – then and now

BackgroundCatheter ablation is a first-line treatment for symptomatic, recurrent supraventricular tachycardia (SVT). This study aims to demonstrate if 3D-electroanatomic mapping (EAM) during SVT ablation reduces fluoroscopy time (FT) and determine if further reductions in FT are observed longitudinally. MethodsAll cases of SVT ablation between May 2011–May 2022 at a single tertiary centre were prospectively recruited. FT between the cohorts with and without EAM were compared. Within the EAM subset, the trend of FT across the years was analysed. ResultsThere were 1758 cases included, 563 without EAM, 1195 with EAM. EAM was associated with a longer procedure time (mean + 8.8 min, p = 0.001), but with mean reductions in FT and dose area product (DAP) by 19.6 min and 18 621 mGy*cm2 respectively (p < 0.001). There was comparable efficacy without any increase in complication rates. Over time (2011–2022), further reduction in FT of 0.9 min year on year was observed (p = 0.001). Between 2011 and 2017, there was a significant reduction in FT of 1.1 min year on year (p = 0.019), which was not observed from 2017 onwards (p = 0.061). The greatest reduction in FT was after the first year of adoption. ConclusionEAM in SVT ablation reduces fluoroscopy use. FT was initially observed to reduce further over time before plateauing, likely due to increased operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in complex cases.

Effectiveness of an X-ray shielding sheet with lower shielding ability to enable both bone mineral density determination and morphological diagnosis

Bone Mineral Density (BMD) can be determined by applying the Digital Image Processing (DIP) method using medical X-ray diagnosis. Although only the second metacarpal bone is analyzed in this approach, other parts of the body are exposed to X-ray radiation. We here propose a novel procedure in which parts of the hand surrounding the area of interest are shielded with an X-ray shielding sheet having low shielding performance. In our procedure, the main diagnostic area is not shielded, and other areas are covered with an X-ray shielding sheet with a low shielding performance. The sheet was fabricated by embedding Bi2O3 particles in resin sheet. We assessed the clinical performance of this method using three types of hand phantoms and conventional diagnostic X-ray equipment. The dose reduction for the entire hand region was evaluated by the Dose Area Product (DAPHand), which was measured with a small dosimeter, and the hand area was determined from the X-ray image. The X-ray image of the second metacarpal bone is affected by the contribution of X-rays that penetrate the object of interest and are scattered in other areas of the hand. Because our X-ray shielding sheet suppressed the generation of scattered X-rays, the pixel value of the second metacarpal bone and corresponding BMD value are varied. To address this issue, we developed a correction algorithm. We found that the X-ray shields with Dose Reduction Factor (DRF) values of 40–60% were appropriate for our methodology. Our method was estimated to have a percentage uncertainty of approximately 5% for the derivation of BMD values. Morphological information of the hand and bones could thus be clearly observed. We verified that both morphological diagnosis and quantitative determination of BMD are possible when DIP procedure is conducted using our shield.

Minimizing Exposure to Ionizing Radiation in Catheter-Based Treatment of Atrial Fibrillation: Safety and Efficacy

Pulmonary vein isolation using radiofrequency ablation is the most common method of catheter treatment for atrial fibrillation. Performing this procedure involves the use of X-ray radiation, which at certain stages of the procedure is an indispensable method for navigation and visualization of intracardiac structures. Approaches to minimize X-ray exposure during catheter interventions are attracting increased attention of the electrophysiology community due to the potential risks of adverse effects of ionizing radiation on patients and medical personnel. The aim. To evaluate the effectiveness and safety of performing the pulmonary vein isolation procedure with the intention to minimize X-ray exposure of patients and medical personnel. Materials and methods. Forty-three patients with various forms of atrial fibrillation were selected for the study: 28(65%) with paroxysmal and 15 (35%) with persistent forms. All the patients underwent pulmonary vein isolation usingcatheter radiofrequency ablation with the intention to minimize X-ray exposure at the National Amosov Institute of Cardiovascular Surgery in the period from June 2023 to April 2024. Results. In all 43 patients it was possible to electrically isolate all the veins. Catheter ablation of the cavotricuspidisthmus was performed in 5 (31.2%) patients from group A (“Zero-fluoro”), 7 (33.3%) from group B (“Near Zero-fluoro”) and 3 (50%) from group C (“Non Zero-fluoro”) (p = 0.696). Intraoperative reconnection of the pulmonary veins with the left atrium was observed in 6 (37.5%) patients of group A, 11 (52.3%) of group B, and 4 (66%) of group C (p = 0.429). X-ray time for transseptal puncture did not differ between groups A and B (3.56 ± 2.37 vs. 3.69 ± 2.3 min., p = 0.532), however, X-ray time for pulmonary vein isolation in group A was significantly less than that in group B (0.27 ± 0.13 vs. 1.96 ± 1.21 min., p &lt; 0.001). The total time in the left atrium was not statistically different between these two groups (81.33 ± 22.32 vs. 98.6 ± 29.83 min., p = 0.106). In group C (“Non Zero-fluoro”), the aforementioned parameters were not recorded. Total dose area product (DAP) and total radiation dose, as well as total X-ray time and total procedure time, were significantly lower when using the ionizing exposure minimization approach. DAP and total radiation dose in group A were the lowest (7.29 ± 5.16 Gy/cm2 and 76.62 ± 70.82 mGy, respectively) and significantly differed from those in group C (107.67 ± 97.59 Gy/cm2 and 882.32 ± 868.62 mGy, p &lt; 0.001 and p = 0.001, respectively). No intraoperative complications were observed in the studied sample. Conclusions. Minimizing X-ray exposure using modern navigation systems during pulmonary vein isolation using catheter radiofrequency ablation is not associated with increased intraprocedural complications in patients with paroxysmal and persistent atrial fibrillation. This approach allows you to significantly lower total DAP and the radiation dosewithout increasing the time of performing the pulmonary vein isolation procedure.

Investigation of the optimal tube voltage kV exposure parameters for general X-ray of dental cone-beam computed tomography: A cephalometric view

This study aims to investigate and optimize the effect of different exposure parameters on the reduction of noise and radiation dose and to find the optimal balance among tube voltage, tube current, and exposure time for the latest-generation cone-beam computed tomography system (CBCT) at Advanced Medical and Dental Institute, Universiti Sains Malaysia, using the dose area product (DAP) meter. The DAP meter was attached to the X-ray detector of the CBCT device to cover the entire irradiated area and then connected to a Raysafe electrometer. The DAP meter was scanned with the following exposure parameter: constant tube voltage of 70 kV with a varying tube current ranging from 5 mA &amp;ndash; 16 mA and then at a constant tube current of 10mA and a varying tube voltage ranging from 60 kV &amp;ndash; 80 kV. For each scanning protocol, the noise was determined. At constant tube voltage and varying tube current, the noise level ranged from 41.99 &amp;ndash; 82.16, while at constant tube current and varying tube voltage, the noise level ranged from 50.66 &amp;ndash; 60.76 with equal exposure time. A 0.09% increase in noise was observed when the tube voltage was varied. Therefore, low noise protocols should consist of a reduction in the tube current setting rather than a reduction in peak voltage (kVp), as this would result in a smaller level of noise and consequently less quality degradation in the image.

Reduction of radiation exposure during coronary interventions using coronary roadmap imaging software

BackgroundCoronary Roadmap (CR), a modern imaging software, provides real-time information for decision-making during coronary interventions. However, whether CR also reduces the required volume of contrast medium and radiation dose remains uncertain. In this study, the volume of contrast medium and radiation exposure for both patients and operators in the CR-guided interventions were compared with those in the conventional group. MethodsIn this single center and case control study, 124 patients receiving percutaneous coronary interventions were retrospectively studied and divided into the conventional and CR-guided coronary intervention group. The contrast medium volume used, Dose-Area Product (DAP), and corresponding skin doses of the patients as well as the radiation exposures of the operators were recorded and compared. SPSS. ResultsDespite no significant differences between age and underlying comorbidities, there were significantly lower DAP and skin doses in patients receiving CR-guided interventions compared with those receiving conventional ones. Moreover, the volume of contrast medium was significantly reduced in the CR group. Regarding the radiation exposure for the operators, there was a significantly lower exposure in the CR-guided group than in the conventional group. ConclusionThe CR-guided interventions may significantly reduce the required volume of contrast medium and radiation exposure compared with conventional interventions. More comprehensive applications of the CR-guided intervention is suggested for clinical use.

Optimization of orofacial cleft imaging protocols using device-specific low-dose cone-beam computed tomography.

The aim of this study was to present optimized device-specific low-dose cone-beam computed tomography (CBCT) protocols with sufficient image quality for pre-surgical diagnostics and three-dimensional (3D) modelling of cleft defects. Six paediatric skulls were acquired, and an artificial bony cleft was created. A high-resolution CBCT scan acted as a reference standard (Accuitomo 170, Morita, Kyoto, Japan) for comparing eight low-dose protocols of Newtom VGi-evo (QR Verona, Cefla, Verona, Italy), which included Eco and Regular protocols with different field of views (FOVs). Delineation of lamina dura, cementoenamel junction (CEJ), trabecular bone and bony bridge were assessed. A 3D model of the defect was also evaluated. The dose area product of low-dose protocols ranged from 31 to 254 mGy*cm2. Despite the dose difference of up to eight times between applied protocols, trabecular bone and CEJ exhibited appropriate image quality in all scans. However, Regular small FOV protocols (5 × 5 and 8 × 5 cm2), for both lamina dura and bony bridge, demonstrated a significant improvement in image quality compared to Eco FOV counterparts. Based on 3D defect analysis, no significant difference existed between low-dose protocols and the reference standard. The findings highlight the possibility of achieving a considerable reduction (up to eight times) in the radiation dose using low-dose CBCT protocols while maintaining sufficient image quality for assessing anatomical structures and 3D modelling in cleft cases.

Nontraumatic intraoperative pulmonary nodule localization with laser guide stamping in a hybrid operating room.

Lung nodule localization using conventional image-guided video-assisted thoracoscopic surgery involves lung puncture, which increases the risk of needle-related complications. We aimed to evaluate the feasibility and safety of a single-stage non-invasive laser-guided stamping localization technique followed by resection under general anesthesia in a hybrid operating room. We retrospectively reviewed consecutive patients who underwent thoracoscopic surgery for small pulmonary nodules using laser-guided dye-stamping localization methods in a hybrid operating room between June 2023 and October 2023. During the study period, 18 patients with 20 lesions underwent single-stage intraoperative image-guided stamping video-assisted thoracoscopic surgery in the hybrid operating room. The median size of the nodules was 7.4 mm (interquartile range [IQR] 5.7-9.8 mm), and median distance from the pleural surface was 9.8 mm (IQR 7.7-14.6 mm). The median localization time was 26 min (IQR 23-34 min), whereas median operation time was 69 min (IQR 62-87 min). The total median operating room time was 146 min (IQR 136-157 min). Twelve patients underwent less than two cone-beam computed tomography scans, while 6 underwent more than two scans. The total median dose area product, including cone-beam computed tomography scans, was 5731.4 uGym2. No localization-related complications were observed, and the postoperative length of stay was 1 day (IQR 1-2 days). The single-stage image-guided pleural stamping technique for localizing small pulmonary nodules in a hybrid operating room is feasible and safe. Future research with larger cohorts is required to further explore the benefits of this workflow.

Procedural efficiency is enhanced combining the pentaspline pulsed field ablation catheter with three-dimensional electroanatomical mapping system for pulmonary vein isolation

Abstract Background Pulsed field ablation (PFA) offers a safe, non-thermal alternative for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Currently, the pentaspline PFA-system relies heavily on fluoroscopy for catheter manipulation, which poses challenges due to the complexity of left atrium anatomy. Incorporating three-dimensional electroanatomical mapping (3D-EAM) could improve procedural efficiency reducing dependency on fluoroscopy guidance. This study aims to evaluate the effects of integration of 3D-EAM with PFA during PVI. Methods Between September 2022 and December 2023, we retrospectively enrolled 248 patients with paroxysmal or persistent AF undergoing PVI at our center using the pentaspline PFA catheter. The control group (n = 104) received conventional PFA with fluoroscopic guidance alone, while the intervention group (n = 144) underwent PVI with PFA with 3D-EAM integration. Primary outcomes were procedural time, fluoroscopy time (FT), and dose area product (DAP). Secondary endpoints included acute procedural success and incidence of periprocedural complications. Results In the 3D-EAM-PFA group, procedural time was 63.3 ± 14.3 min, compared to 65.6 ± 14.9 min in the control group (p = 0.22). The 3D-EAM group experienced significantly reduced FT (9.7 ± 4.4 min vs. 16.7 ± 5.2 min) and DAP (119.2 ± 121.7 cGycm2 vs. 338.7 ± 229.9 cGycm2) compared to the control group, respectively (p &lt; 0.001). Acute procedural success was achieved in all cases. No major complications were observed in either group. Conclusion Integration of 3D-EAM with the pentaspline PFA catheter for PVI in AF treatment offers a promising approach, with significantly reduced fluoroscopy exposure without compromising procedural time and efficacy. Graphical abstract

Radiation exposure in pediatric videourodynamics: An evaluation of safety in comparison to voiding cystourethrogram

Children with spina bifida (SB) undergo a videourodynamic study (VUDS) or urodynamic study and voiding cystourethrogram (VCUG). A standardized protocol for imaging during a pediatric VUDS has not been established. Our aim is to quantify radiation exposure and establish a baseline for children with spina bifida (SB) undergoing VUDS in current practice at our institution. This is a retrospective study from 2013 to 2020 of consecutive pediatric SB patients undergoing VUDS by a single provider. Patients were categorized into three groups based on age; group 1 (0-2YR), group 2 (2-10YR), group 3 (>10YR). Radiation data was reported as mean air kerma (AK), dose area product (DAP) and exposure time (seconds). Effective dose (ED) was calculated based on radiation quantity (Air Kerma, AK) and organ sensitivity. The lifetime attributable risk (LAR) was calculated based on AK and a risk coefficient. Data points calculated for patients undergoing VUDS were then compared to age matched institutional VCUG data in the same age groups. 398 patients undergoing VUDS met inclusion criteria and 262 independent patients underwent VCUG. ED increased with age in both VUDS and VCUG. All VCUG groups were found to have a higher ED than VUDS. The LAR for VUDS groups 1-3 was 0.001, 0.002, and 0.006, respectively. Reported in percentages, there is a 0.1%, 0.2%, and 0.6% chance, respectively, of age groups 1, 2 and 3 developing cancer as a result of the radiation exposure from a VUDS. Our study found that ED was low across all age groups for VUDS, comparing favorably to the VCUG groups. VCUG was selected as a benchmark comparison for its diagnostic similarities and, at times, overlapping indications. Few studies have described ED with respect to VUDS or extrapolate the ED of VUDS into LAR in the pediatric population. We recognize that we have not determined the true ED of the gonads and bladder, rather we have overestimated, as the data is based on an international reference point proximal to the exposed individual. However, LAR was calculated for each age group and revealed that patients are at a negligible increased risk of developing malignancy secondary to exposure compared to the general population. Our current practice for pediatric VUDS has exhibited consistently low radiation exposure amongst all age groups. Moving forward, we have the foundation and flexibility to create an imaging protocol for pediatric VUDS, while taking more calculated steps toward incorporating ALARA, as low as reasonably achievable, principles. A protocol adhering to the ALARA principle could provide consistency across institutions and aid in multi-institutional studies.

Preclinical and Preliminary Evaluation of Perceived Image Quality of AI-Processed Low-Dose CBCT Analysis of a Single Tooth.

This study assessed AI-processed low-dose cone-beam computed tomography (CBCT) images for single-tooth diagnosis. Human-equivalent phantoms were used to evaluate CBCT image quality with a focus on the right mandibular first molar. Two CBCT machines were used for evaluation. The first CBCT machine was used for the experimental group, in which images were acquired using four protocols and enhanced with AI processing to improve quality. The other machine was used for the control group, where images were taken in one protocol without AI processing. The dose-area product (DAP) was measured for each protocol. Subjective clinical image quality was assessed twice by five dentists, with a 2-month interval in between, using 11 parameters and a six-point rating scale. Agreement and statistical significance were assessed with Fleiss' kappa coefficient and intra-class correlation coefficient. The AI-processed protocols exhibited lower DAP/field of view values than non-processed protocols, while demonstrating subjective clinical evaluation results comparable to those of non-processed protocols. The Fleiss' kappa coefficient value revealed statistical significance and substantial agreement. The intra-class correlation coefficient showed statistical significance and almost perfect agreement. These findings highlight the importance of minimizing radiation exposure while maintaining diagnostic quality as the usage of CBCT increases in single-tooth diagnosis.

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.

Characterization of a 3D prototyping semi-automated filter holder system for RQR radiation qualities

Characterizing radiation measurement systems, such as diagnostic radiology systems for RQR and RQA, is essential for ensuring reliable results in standardized instrument calibration laboratories. Quality control of dosimetry devices, such as patient dose calibrators (PDCs), a reference meter, is crucial for ensuring accurate measurements. This study demonstrates the use of spectrometry and ionization chambers to characterize a set of semi-automated 3D prototyping filter holder systems, developed in a previously project, designed for applications such as Kerma-Area Product (KAP) meter calibration. The set of 3D prototypes were adjusted to a filter wheel and characterized using an X-ray spectrometer, followed by an ionization chamber, according to international standards. The characterization of radiation qualities from 50 to 150 kV in diagnostic radiology was performed using the substitution method: first with an ionization chamber, then with a PDC. The PDC was calibrated for KAP and Air Kerma quantities, considering the conditions of the X-ray system and factors such as temperature, humidity, and pressure. Spectrometric analysis and the use of an ionization chamber were effective in determining these parameters. Spectral characterization allowed for accurate measurements to establish proper quality control, then it is possible to use the PDC calibrated for calibration procedures for KAP meters. Future studies intend to compare these results with computational simulations using the TOPAS Monte Carlo code to validate the calibration method.

Early experience with patient-specific unibody bifurcated fenestrated-branched devices for complex endovascular aortic aneurysm repair

ObjectiveShort distances between the lowest visceral/renal artery and the aortic bifurcation are technically challenging during complex endovascular aortic aneurysm repair (EVAR), particularly after previous infrarenal repair. Traditionally, inverted limb bifurcated devices have been used in addition to fenestrated-branched (FB) endografts, but short overlap, difficult cannulation, and potential crushing of bridging stents are limitations for their use. This study reviews the early experience of patient-specific company manufactured devices (PS-CMDs) with a unibody bifurcated FB design for complex EVAR. MethodsConsecutive complex EVAR procedures over a 34-month period with unibody bifurcated FB-devices as part of physician-sponsored investigational device exemption studies at two institutions were reviewed. Unibody bifurcated FB designs included FB bifurcated or fenestrated inverted limb devices. End points included technical success, survival, frequency of type I or III endoleaks, limb occlusion, and secondary interventions. ResultsAmong 168 patients undergoing complex EVAR, 33 patients (19.6%; 78.7% male; mean age, 77 years) received unibody bifurcated FB PS-CMDs. FB bifurcated and fenestrated inverted limb devices were used in 31 (93.9%) and 2 (6.06%) patients, respectively. The median maximum aneurysm diameter was 61 mm (interquartile range [IQR], 55-69 mm). Prior EVAR was reported by 29 patients (87.9%), of whom 2 (6.06%) had suprarenal stents. A short distance between the lowest renal artery and aortic bifurcation was demonstrated in 30 patients (90.9%), with median distance of 47 mm (IQR, 38-54 mm). Preloaded devices were used in 23 patients (69.7%). A total of 128 fenestrations were planned; 22 (17.2%) were preloaded with guidewires and 5 (3.9%) with catheters. The median operative time was 238 minutes (226-300 minutes), with a median fluoroscopy time of 65.5 minutes (IQR, 56.0-77.7 minutes) and a median dose area product of 147 mGy∗cm2 (IQR, 105-194 mGy∗cm2). Exclusive femoral access was used in 14 procedures (42.4%). Technical success was 100%. Target vessel primary patency was 100% at a median follow-up time of 11.7 months (IQR, 3.5-18.6 months). Two patients (6.06%) required reintervention for iliac occlusion; one patient required stenting and the other a femoral-femoral bypass. No aortic-related deaths occurred after the procedure. During follow-up, 11 type II endoleaks (33.3%) and 1 type Ib endoleak (3.03%) were detected; the latter was treated with leg extension. No type Ia or III endoleaks occurred. ConclusionsComplex EVAR using unibody bifurcated FB-PS-CMDs is a simple, safe, and cost-effective alternative for the treatment of patients with short distances between the renal arteries and the aortic bifurcation. Further studies are required to assess benefits and durability of unibody bifurcated FB devices.