Low Radiation Exposure Research Articles

Leveraging mixed reality in mitraclip implantation: A preliminary case series toward a pilot study

Abstract Introduction The advent of mixed reality (MR) technology, particularly when combined with Hololens 2.0 and specialized software for three-dimensional DICOM image visualization, offers a promising avenue for enhancing the precision and spatial awareness in interventional cardiology procedures. This case series aims to preliminarily evaluate the impact of MR on MitraClip implantation processes, setting a foundation for an ensuing comprehensive pilot study. Methods We conducted a comparative analysis within a case series of four MitraClip implantations, categorizing them into two groups based on the utilization of MR support. We examined procedural efficiency, radiation metrics (SKIA and DAP), and operator stress indicators, including cortisol levels, heart rate variability, QTc interval, and subjective assessments through NASA TLX, STAI Y, and SSQ questionnaires. Results Initial findings from the MR-assisted procedures suggest a notable improvement in procedural efficiency and a reduction in operator stress. Specifically, MR use was associated with shorter procedural times (ranging from 60 to 130 minutes) and lower radiation exposure, with SKIA durations between 15.5 and 40.5 minutes. Moreover, operators in the MR group showed reduced cortisol levels (8.2-9.2 mmol/L), indicating decreased physiological stress. Heart rate variability analysis further supported superior stress management among MR-supported operators. Subjective evaluations reinforced these physiological findings. NASA TLX scores in the MR group (13-20) markedly contrasted with those in the control group (30-45), signifying a significant reduction in perceived workload. SSQ scores remained minimal, implying good MR tolerability, and STAI Y scores (30-35) were lower than those in the control group (40-50), highlighting reduced anxiety levels during MR-assisted procedures. Conclusion This explorative case series lays the groundwork for a forthcoming pilot study, revealing MR's potential to not only streamline MitraClip implantation but also to alleviate operator stress. Both objective and subjective data advocate for expanded research to definitively ascertain MR's benefits in cardiac interventions, promising to refine procedural workflows and enhance patient outcomes. This series acts as a stepping stone towards a larger-scale evaluation that could solidify MR's role in the future of interventional cardiology.Operator's View and Technology PreviewFunction diagram

Optimisation of cone beam CT radiotherapy imaging protocols using a novel 3D printed head and neck anthropomorphic phantom

Objective.This study aimed to optimise Cone Beam Computed Tomography (CBCT) protocols for head and neck (H&N) radiotherapy treatments using a 3D printed anthropomorphic phantom. It focused on precise patient positioning in conventional treatment and adaptive radiotherapy (ART).Approach.Ten CBCT protocols were evaluated with the 3D-printed H&N anthropomorphic phantom, including one baseline protocol currently used at our centre and nine new protocols. Adjustments were made to milliamperage and exposure time to explore their impact on radiation dose and image quality. Additionally, the effect on image quality of varying the scatter correction parameter for each of the protocols was assessed. Each protocol was compared against a reference CT scan. Usability was assessed by three Clinical Scientists using a Likert scale, and statistical validation was performed on the findings.Main results. The work revealed variability in the effectiveness of protocols. Protocols optimised for lower radiation exposure maintained sufficient image quality for patient setup in a conventional radiotherapy pathway, suggesting the potential for reducing patient radiation dose by over 50% without compromising efficacy. Optimising ART protocols involves balancing accuracy across brain, bone, and soft tissue, as no single protocol or scatter correction parameter achieves optimal results for all simultaneously.Significance.This study underscores the importance of optimising CBCT protocols in H&N radiotherapy. Our findings highlight the potential to maintain the usability of CBCT for bony registration in patient setup while significantly reducing the radiation dose, emphasizing the significance of optimising imaging protocols for the task in hand (registering to soft tissue or bone) and aligning with the as low as reasonably achievable principle. More studies are needed to assess these protocols for ART, including CBCT dose measurements and CT comparisons. Furthermore, the novel 3D printed anthropomorphic phantom demonstrated to be a useful tool when optimising CBCT protocols.

Pediatric contrast-enhanced chest CT on a photon-counting detector CT: radiation dose and image quality compared to energy-integrated detector CT.

Photon counting detector (PCD) CT benefits from reduced noise compared with conventional energy-integrating detector (EID) CT, which should translate to improved image quality and reduced radiation exposure for pediatric patients undergoing chest CT with IV contrast. To determine the differences in radiation exposure and image quality of PCD CT and EID CT in pediatric chest CT with intravenous (IV) contrast. In this institutional review board-approved retrospective observational study, 20 scan pairs (20 PCD CT; 20 EID CT) for children who underwent chest CT with IV contrast on both a PCD CT (Siemens NAEOTOM Alpha) and an EID CT (Siemens SOMATOM Definition Edge or Force) within 12months were reviewed independently by three pediatric radiologists for three subjective quality features on 5-point Likert scales: overall quality, small structure delineation, and motion artifact. Objective measures of image quality (image noise, signal-to-noise ratio, and contrast-to-noise ratio) were assessed by a single radiologist in several locations in the chest through region of interest measurement of Hounsfield units (HU) and standard deviation. Patient-related and radiation exposure parameters were collected for each scan and summarized with median and interquartile range (IQR). The Wilcoxon rank-sum test was utilized to compare groups. A P < 0.05 indicated statistical significance. Inter-observer agreement of subjective image quality metrics was analyzed using weighted kappa. Age (14.2years vs 13.8years, P= 0.15), height (P= 0.13), weight (P= 0.21), and BMI (P = 0.24) did not significantly differ between groups. There were 10 male and 3 female patients. Compared to EID CT, PCD CT showed lower radiation exposure parameters including volumetric CT dose index, 1.7mGy (IQR 1.1-2.4mGy) vs 3.8mGy (IQR 2.0-4.7mGy) (P< 0.01), and size-specific dose estimate, 2.6mGy (IQR 1.8-3.1mGy) vs 5.0mGy (IQR 3.3-6.2mGy) (P< 0.01). Objective image quality of lung parenchyma was improved on the PCD CT scanner, including image noise 119.5 HU (IQR 95.4-135.7 HU) vs 143.1 HU (IQR 125.4-169.8 HU) (P < 0.01), signal-to-noise ratio (SNR) -6.1 (IQR -8.4 to -4.8) vs -4.9 (IQR -5.6 to -3.8) (P= 0.01), and contrast-to-noise ratio -63.9 (-84.1 to -57.5) vs -60.5 (-76.3 to -52.5) (P = 0.01). Motion artifact was improved on the PCD CT scanner (P< 0.01). No significant differences in overall image quality or small structure delineation were identified (P= 0.06 and P= 0.31). PCD CT pediatric chest CT had significantly reduced radiation exposure, improved image quality, and reduced motion artifact compared with EID CT.

Comparation of abdominal aortic balloon occlusion versus uterine artery embolization in the treatment of cesarean scar pregnancy

Study objectiveThis study is to uncover the advantages of abdominal aortic balloon occlusion in the uterine curettage treatment for patients with cesarean scar pregnancy (CSP).MethodsTo retrospectively analyze the clinical data of eighty patients with CSP after treatment in our hospital from 01/10/2019 to 01/05/2021. The 80 patients were divided into 2 groups: 41 patients were treated with abdominal aortic balloon occlusion and the control group (n = 39) underwent Uterine artery embolization (UAE). The amount of bleeding during the operation, the operation time of the uterine curettage, the X-ray fluoroscopy time under DSA, the surface dose in radiation, the length of hospital stay (LOS), and the postoperative complications were compared between these 2 groups (type II and type III).ResultsAll the operations successfully retained the uterus. No balloon-related complications occurred in the experimental group. And in the control group, there were 14 cases of fever and 19 cases of pain after UAE. The fluoroscopy time of experimental group and control group were: (type II: (20.3 ± 7.1)s vs. (593.7 ± 284.5)s, p &amp;lt; 0.01), (type III: (21.2 ± 7.2)s vs. (509.8 ± 164.2)s, p &amp;lt; 0.01), the surface dose in radiation: (type II: (1.9 ± 0.7)mGy vs. (248.3 ± 85.9)mGy, p &amp;lt; 0.01), (type III: (2.1 ± 0.8)mGy vs.(252.0 ± 74.9)mGy, p &amp;lt; 0.01), the amount of bleeding during the operation: (type II:30.0(20.0, 50.0)ml vs. 20.0(10.0, 50.0)ml, p = 0.113), (type III:50.0 (17.5,162.5)ml vs. 50.0 (22.5, 72.5)ml, p = 0.623), the operation time of the uterine curettage:(type II: (54.8 ± 19.4)min vs.(43.9 ± 21.9)min, p = 0.071), (type III: (65.2 ± 50.4)min vs.(52.8 ± 20.1)min, p = 0.426), LOS: (type II:(5.4 ± 1.7)d vs.(5.4 ± 1.2)d, p = 0.816), (type III:(5.8 ± 2.4)d vs. (7.0 ± 1.7)d, p = 0.161). The follow-up was more than 3 months. No adverse reaction in the experimental group and 6 patients in the control group presented menstrual volume decrease.ConclusionNo balloon-related complications occurred in the abdominal aortic balloon occlusion and lower radiation exposure for both the operator and patient. And both abdominal aortic balloon occlusion and UAE can effectively reduce the bleeding during uterine curettage in patients with type II and III CSP.

Comparing Low-to-Zero Fluoroscopic Navigation Systems for AVNRT Catheter Ablation: A Network Meta-Analysis.

Low-to-zero fluoroscopic navigation systems lower radiation exposure which improves health outcomes. Conventional x-ray fluoroscopy (CF) has long been the standard to guide to catheter location for cardiac ablation. With advancements in technology, alternative safety navigation systems have been developed. Three primary modalities commonly utilized are three-dimensional electroanatomic mapping (3D-EAM), magnetic navigation system (MNS), and intracardiac echocardiography (ICE), all of which can reduce radiation exposure during the procedure. We aim to compare the efficacy and safety among ICE, EAM, MNS, and CF in ablation of atrioventricular nodal reentrant tachycardia (AVNRT). This is a meta-analysis consisting of observational studies and randomized controlled trials, which evaluated the performance of navigation systems of catheter ablation in AVNRT patients. Primary endpoint was to access the AVNRT recurrence after the procedure during follow-up periods. Secondary endpoints were technical success, fluoroscopic time, fluoroscopic dose area product, radiofrequency ablation time, and adverse events. Random-effect model was applied for pooled estimated effects of included studies. A total of 21 studies (21 CF, 2 ICE, 9 EAM, 11 MNS) including 1716 patients who underwent catheter ablation for AVNRT treatment were analyzed. Of these, 16 were observational studies and 5 were randomized controlled trials. Point estimation of AVNRT recurrence showed ICE exhibited a pooled odds ratio (ORs) of 1.06 (95% confidence interval [CI]: 0.064-17.322), MNS with ORs of 0.51 (95% CI: 0.214-1.219], and EAM with ORs of 0.394 (95% CI: 0.119-1.305) when compared to CF. EAM had significant higher technical success with ORs of 2.781 (95% CI: 1.317-5.872) when compared to CF. Regarding fluoroscopy time, EAM showed the lowest time with mean differences (MD) of -10.348 min (95% CI: -13.385 to -7.3101) and P-score of 0.998. It was followed by MNS with MD of -3.712 min (95% CI: -7.128 to -0.295) and P-score of 0.586, ICE with MD of -1.150 min (95% CI: -6.963 to 4.662) with a P-score of 0.294 compared to CF, which has a P-score of 0.122. There were insignificant adverse events across the procedures. AVNRT ablation navigated by low-to-zero fluoroscopic navigation systems achieves higher efficacy and comparable safety to conventional fluoroscopywhile also reducing risk of radiation exposure time.

A More Efficient and Safer Improved Percutaneous Pedicle Screw Insertion Technique-Trajectory DynamicAdjustment Technique, Technical Note, and Clinical Efficacy.

Percutaneous pedicle screw fixation (PPSF) technique requires a very precise entry point of the Jamshidi needle, which leads to repeated adjustments, damaging the pedicle and increasing radiation exposure. This study was designed to propose an improved percutaneous pedicle screw fixation technique-trajectory dynamic adjustment (TDA) technique, and evaluate its feasibility and assess the clinical outcomes. A total of 445 patients with lumbar spondylolisthesis or lumbar spinal stenosis associated with instability from June 2017 to May 2022 were included in the retrospective study. They were randomly separated into two groups. Two hundred thirty-one patients underwent TDA technique (TDA group). Two hundred fourteen patients underwent traditional PPSF technique (PPSF group). All patients underwent postoperative CT to assess the accuracy of screw placement, superior facet joint violation (FJV). The evaluated clinical outcomes were needle insertion time, radiation exposure, blood loss, hospital stay, the Japanese Orthopedic Association (JOA) score, the Visual Analogue Scale (VAS) scores for lower back pain (LBP), and leg pain, lumbar interbody fusion rate, and postoperative complications. The independent-sample t test and paired t-test were used for continuous data. The contingency table and Mann-Whitney U test were used for categorical data. The time of the insertion in TDA group was significantly lower than that in PPSF group (p < 0.05). Similarly, the fluoroscopy frequency in TDA group was significantly lower than that in PPSF group (p < 0.05). There was no difference in intraoperative blood loss and hospital stay between the two groups (p > 0.05). Overall, there was no significant difference in the proportion of clinically acceptable screws between the two groups (p > 0.05). In addition, the lateral screw misplacement in TDA group was higher. Moreover, FJV rate was significantly lower than that in PPSF group (p < 0.05). In both TDA group and PPSF group, postoperative back and leg pain and the JOA score were significantly improved (p < 0.05). However, there were no significant differences in the pre- and postoperative VAS score for back and leg pain and the JOA score, JOA recovery rate, intervertebral fusion rate, and complications rate between the two groups (p > 0.05). Compared to traditional PPSF technique, TDA technique is a safer and more effective procedure which has shorter surgical time, lower radiation exposure, and lower facet joint violation rate.

DXA: New Concepts and Tools Beyond Bone Mineral Density.

Since its introduction in 1987, dual-energy X-ray absorptiometry (DXA) has revolutionized bone assessment, becoming the gold standard for measuring bone mineral density (BMD). Its low radiation exposure and high accuracy have made it indispensable in diagnosing osteoporosis, aligning with World Health Organization criteria. However, DXA evolution extends beyond BMD measurement, with emerging tools like the Trabecular Bone Score (TBS) and the DXA-based Bone Strain Index (BSI). TBS provides insights into trabecular bone architecture, enhancing the prediction of fracture risk. Despite limitations like body mass index correlation, TBS aids in evaluating patients with conditions such as diabetes and glucocorticoid exposure. BSI, introduced in 2019, evaluates bone strength using finite element analysis, complementing BMD and TBS by assessing bone fatigue.Advancements in DXA-based tools extend to Hip Structural Analysis and three-dimensional DXA software, offering valuable insights into hip fracture risk. Moreover, DXA serves beyond bone assessment, aiding in abdominal aortic calcification assessment, enhancing cardiovascular risk stratification. In summary, the expanding capabilities of DXA promise comprehensive skeletal and cardiovascular health evaluation, contributing significantly to clinical management and prevention strategies.

Intensity-modulated proton radiotherapy spares musculoskeletal structures in regional nodal irradiation for breast cancer: a dosimetric comparison.

Regional nodal irradiation (RNI) for breast cancer delivers radiation in proximity to the shoulder and torso, and radiation exposure may contribute to long-term upper extremity and postural morbidity. To date, no studies have assessed the differential dosimetric impact of proton versus photon radiation on shoulder and torso anatomy. This study examined clinically relevant musculoskeletal (MSK) structures and assessed the dose delivered with each modality. Ten MSK structures were contoured on IMPT (intensity-modulated proton therapy) and VMAT (volumetric modulated arc therapy) plans for 30 patients receiving RNI. Relevant dose metrics were compared for each of the structures. Intensity-modulated proton therapy dose was calculated using the relative biological effective value of 1.1. Hypo-fractionated plans were scaled to the equivalent dose in 2 Gy fractions (EQD2) using an alpha/beta ratio of four. Wilcoxon signed rank sum tests compared doses. Select three-dimensional and optimised VMAT plans were also informally compared. Each of the 10 structures received a statistically significantly lower dose with the use of IMPT compared with VMAT. Differences were greatest for posterior structures, including the trapezius, latissimus dorsi and glenohumeral joint. Mean absolute differences were as great as 23 Gy (supraspinatus D5cc) and up to 30-fold dose reductions were observed (deltoid D50cc). An average 3.7-fold relative dose reduction existed across all structures. Measures of low/intermediate dose (V15Gy and D50cc) showed the largest differences. Intensity-modulated proton therapy results in statistically lower radiation exposure to relevant shoulder and torso anatomy compared to photon radiation for patients requiring RNI. Prospective study is needed to correlate functional outcomes with radiation dose.

GREEN DENTISTRY: A SUSTAINABLE FUTURE FOR ORAL HEALTH CARE

The dental public health profession, like many others, is becoming increasingly aware of its environmental impact and the urgent need to adopt more sustainable practices. Green dentistry, also known as eco-friendly dentistry, is a growing movement that focuses on reducing waste, conserving energy, and minimizing pollution while maintaining high standards of patient care. By integrating environmentally conscious choices into daily practices—such as using digital technologies, reducing water consumption, and choosing biodegradable or recyclable materials—dentists can significantly contribute to environmental preservation without compromising the quality of their services. One of the core tenets of green dentistry is the shift towards digital dentistry. Traditional methods of record-keeping and patient management involve a considerable amount of paper and plastic waste. By adopting digital x-rays, patient records, and appointment scheduling systems, dental practices can dramatically reduce their paper use, lower radiation exposure, and decrease the need for disposable materials. Additionally, using energy-efficient equipment and eco-friendly sterilization techniques can help reduce the carbon footprint of dental offices, aligning with global sustainability goals. As the dental community moves towards greener practices, there is an opportunity for education and advocacy in dental public health. Dental schools and professional organizations play a crucial role in promoting awareness of sustainable practices among both practitioners and patients. By fostering a culture of environmental responsibility within the field, we not only contribute to a healthier planet but also inspire the next generation of dentists to prioritize sustainability in their professional lives. Green dentistry represents a vital step towards a more sustainable future for both the profession and the world at large.

Intentionally unilateral prostatic artery embolization: Patient selection, technique and potential benefits.

Prostatic artery embolization (PAE) is a promising but also technically demanding interventional radiologic treatment for symptomatic benign prostatic hyperplasia. Many technical challenges in PAE are associated with the complex anatomy of prostatic arteries (PAs) and with the systematic attempts to catheterize the PAs of both pelvic sides. Long procedure times and high radiation doses are often the result of these attempts and are considered significant disadvantages of PAE. The authors hypothesized that, in selected patients, these disadvantages could be mitigated by intentionally embolizing PAs of only one pelvic side. To describe the authors' approach for intentionally unilateral PAE (IU-PAE) and its potential benefits. This was a single-center retrospective study of patients treated with IU-PAE during a period of 2 years. IU-PAE was applied in patients with opacification of more than half of the contralateral prostatic lobe after angiography of the ipsilateral PA (subgroup A), or with markedly asymmetric prostatic enlargement, with the dominant prostatic lobe occupying at least two thirds of the entire gland (subgroup B). All patients treated with IU-PAE also fulfilled at least one of the following criteria: Severe tortuosity or severe atheromatosis of the pelvic arteries, non-visualization, or visualization of a tiny (< 1 mm) contralateral PA on preprocedural computed tomographic angiography. Intraprocedural contrast-enhanced ultrasonography (iCEUS) was applied to monitor prostatic infarction. IU-PAE patients were compared to a control group treated with bilateral PAE. IU-PAE was performed in a total 13 patients (subgroup A, n = 7; subgroup B, n = 6). Dose-area product, fluoroscopy time and operation time in the IU-PAE group (9767.8 μGy∙m2, 30.3 minutes, 64.0 minutes, respectively) were significantly shorter (45.4%, 35.9%, 45.8% respectively, P < 0.01) compared to the control group. Clinical and imaging outcomes did not differ significantly between the IU-PAE group and the control group. In the 2 clinical failures of IU-PAE (both in subgroup A), the extent of prostatic infarction (demonstrated by iCEUS) was significantly smaller compared to the rest of the IU-PAE group. In selected patients, IU-PAE is associated with comparable outcomes, but with lower radiation exposure and a shorter procedure compared to bilateral PAE. iCEUS could facilitate patient selection for IU-PAE.

Ablation of Supraventricular Arrhythmias With as Low as Reasonably Achievable X-Ray exposure (AALARA): Results of Prospective, Observational, Multicenter, Multinational, Open-Label Registry Study on Real World Data Using Routine Ensite 3D Mapping During SVT Ablation.

The reduction of fluoroscopic exposure during catheter ablation of supraventricular arrhythmias is widely adopted by experienced electrophysiology physicians with a relatively short learning curve and is becoming the standard of care in many parts of the world. While observational studies in the United States and some parts of Western Europe have evaluated the minimal fluoroscopic approach, there are scarce real-world data for this technique and the generalizability of outcomes in other economic regions. The AALARA study is a prospective, observational, multicenter, and multinational open-label study. Patients were recruited from 13 countries across Central Eastern Europe, North and South Africa, the Middle East, and the CIS (Commonwealth of Independent States), with different levels of operator expertise using minimal fluoroscopic exposure techniques. Data on radiation exposure, procedural success, complications, recurrence, and quality of life changes were collected and analyzed. A total of 680 patients were enrolled and followed for 6 months. The majority were ablation naïve with the commonest arrhythmia ablated being typical AVNRT (58%) followed by Atrial Flutter (23%). Zero fluoroscopy exposure was observed in almost 90% of the cases. Fluoroscopy was most commonly used during the ablation phase of the procedure. We observed a high acute success rate (99%), a low complication rate (0.4%), and a 6-month recurrence rate of 3.8%. There was a significant improvement in the patient's symptoms and quality of life as measured by patient global assessment. The routine use of a 3D mapping system during right-sided ablation was associated with low radiation exposure and associated with high acute success rate, low complications, and recurrence rate along with significant improvement in quality of life. The data confirm the reproducibility of this approach in real-world settings across different healthcare systems, and operator experience supporting this approach to minimize radiation exposure without compromising efficacy and safety. NCT04716270.

Diagnostic performance of simultaneous PET-magnetic resonance versus PET-computed tomography in oncology with an overview on clinical utility and referral pattern of PET-magnetic resonance: a single institutional study.

PET-magnetic resonance (PETMR) imaging is an upcoming investigative modality with a few installations in Asia and only three in India. PET-Computed tomography (PETCT) is an established diagnostic cornerstone for oncological indications but with limited resolution for small lesions due to low soft-tissue contrast and additional radiation exposure. Our primary objective was to evaluate the diagnostic performance of simultaneous PETMR and PETCT in lesion detection in oncological practice. Secondly to assess the referral pattern and study the clinical utility of PETMR in a university hospital practice. A total of 100 consecutive biopsy-proven cancer patients (breast or lung malignancy with suspected metastases) underwent 18F fluorodeoxyglucose (FDG) PETMR and PETCT for staging as a single injection, double examination protocol. Morphological lesion detection on correlative imaging/histopathology was used as the gold standard. Analysing the referral pattern, a total of 9366 patients underwent simultaneous PETMR imaging for indications in the past 5 years since installation. 18F FDG PETMR detected 100% of primary tumours in breast/lung carcinoma (Ca) patients while PETCT was positive in 96%. Overall accuracy of nodal metastases detection for PETMR and PETCT was 96 and 88%, while for distant metastases the accuracy was 100 and 93%, respectively. FDG PETMR proved more sensitive and specific than PETCT for regional nodal (P = 0.011 and P < 0.001) and distant metastases detection (P = 0.017 and P < 0.001, respectively). Analysing the general referral pattern for PETMR, the majority were oncology referrals (66.5, 33.5%) when compared to nononcological indications. About 66.24% were FDG based, followed by Ga prostate-specific membrane antigen and dodecane tetraacetic acid. The general utility of PETMR was found incremental in better delineation of small lesions especially in head, neck, liver, brain and gynaecological malignancies. In our past 5 years of PETMR practice, we found that simultaneous PETMR is a highly recommended ideal imaging technique for oncological and nononcological indications. It has excellent diagnostic performance with high sensitivity, specificity and accuracy when compared to PETCT in tumour, nodal metastases staging in specific subgroup of breast and lung malignancy patients.

Low-dose high-resolution chest CT in adults with cystic fibrosis: intraindividual comparison between photon-counting and energy-integrating detector CT

BackgroundRegular disease monitoring with low-dose high-resolution (LD-HR) computed tomography (CT) scans is necessary for the clinical management of people with cystic fibrosis (pwCF). The aim of this study was to compare the image quality and radiation dose of LD-HR protocols between photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) in pwCF.MethodsThis retrospective study included 23 pwCF undergoing LD-HR chest CT with PCCT who had previously undergone LD-HR chest CT with EID-CT. An intraindividual comparison of radiation dose and image quality was conducted. The study measured the dose-length product, volumetric CT dose index, effective dose and signal-to-noise ratio (SNR). Three blinded radiologists assessed the overall image quality, image sharpness, and image noise using a 5-point Likert scale ranging from 1 (deficient) to 5 (very good) for image quality and image sharpness and from 1 (very high) to 5 (very low) for image noise.ResultsPCCT used approximately 42% less radiation dose than EID-CT (median effective dose 0.54 versus 0.93 mSv, p < 0.001). PCCT was consistently rated higher than EID-CT for overall image quality and image sharpness. Additionally, image noise was lower with PCCT compared to EID-CT. The average SNR of the lung parenchyma was lower with PCCT compared to EID-CT (p < 0.001).ConclusionIn pwCF, LD-HR chest CT protocols using PCCT scans provided significantly better image quality and reduced radiation exposure compared to EID-CT.Relevance statementIn pwCF, regular follow-up could be performed through photon-counting CT instead of EID-CT, with substantial advantages in terms of both lower radiation exposure and increased image quality.Key PointsPhoton-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) were compared in 23 people with cystic fibrosis (pwCF).Image quality was rated higher for PCCT than for EID-CT.PCCT used approximately 42% less radiation dose and offered superior image quality than EID-CT.Graphical

Педиатрическая рентгенография: проблемы и решения

Background: Because of children's distinct physiological and anatomical features, pediatric radiography necessitates particular techniques. Recent advances in medical physics have considerably improved the accuracy and safety of pediatric radiological procedures. However, these developments bring new obstacles. Objective: This article evaluates the most recent advances in medical physics relevant to pediatric radiography, highlights the accompanying problems, and provides feasible solutions to improve clinical results and patient safety. Methods: A thorough literature analysis focused on current research and technology advancements in pediatric radiology. The main advances in imaging technology, radiation dose control, and diagnostic accuracy were examined. Expert comments and case studies were also analyzed for common issues and solutions. Results: Low-dose imaging methods, such as digital radiography, pediatric-specific computed tomography (CT), and magnetic resonance imaging (MRI), have advanced significantly. These enhancements have resulted in better image quality and lower radiation exposure. However, patient size heterogeneity, motion artifacts, and the necessity for age-specific procedures remain common. Conclusion: Medical physics advancements have significantly enhanced pediatric radiology, allowing for higher diagnostic capabilities while reducing hazards. To address the remaining difficulties, radiologists must continue research, adopt standardized methods, and get continual education. Future advances should focus on lowering radiation exposure and enhancing imaging technologies' flexibility to meet pediatric patients' demands.

Improving Image Quality and Diagnostic Performance of CCTA in Patients with Challenging Heart Rate Conditions Using a Deep Learning-Based Motion Correction Algorithm.

Challenging HR conditions, such as elevated Heart Rate (HR) and Heart Rate Variability (HRV), are major contributors to motion artifacts in Coronary Computed Tomography Angiography (CCTA). This study aims to assess the impact of a deep learning-based motion correction algorithm (MCA) on motion artifacts in patients with challenging HR conditions, focusing on image quality and diagnostic performance of CCTA. This retrospective study included 240 patients (mean HR: 88.1 ± 14.5 bpm; mean HRV: 32.6 ± 45.5 bpm) who underwent CCTA between June, 2020 and December, 2020. CCTA images were reconstructed with and without the MCA. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured to assess objective image quality. Subjective image quality was evaluated by two radiologists using a 5-point scale regarding vessel visualization, diagnostic confidence, and overall image quality. Moreover, all vessels with scores ≥ 3 were considered clinically interpretable. The diagnostic performance of CCTA with and without MCA for detecting significant stenosis (≥ 50%) was assessed in 34 patients at both per-vessel and per-patient levels, using invasive coronary angiography as the reference standard. The MCA significantly improved subjective image quality, increasing the vessel interpretability from 89.9% (CI: 0.88-0.92) to 98.8% (CI: 0.98-0.99) (p < 0.001). The use of MCA resulted in significantly higher diagnostic performance in both patient-based (AUC: 0.83 vs. 0.58, p = 0.04) and vessel-based (AUC: 0.92 vs. 0.81, p < 0.001) analyses, with the vessel-based accuracy notably increased from 79.4% (CI: 0.72-0.86) to 91.2% (CI: 0.85-0.95) (p = 0.01). There were no significant differences in objective image quality between the two reconstructions. The mean effective dose in this study was 2.8 ± 1.1 mSv. The use of MCA allows for obtaining high-quality CCTA images and superior diagnostic performance with low radiation exposure in patients with elevated HR and HRV.

Image Quality of Cardiac Silicon Photomultiplier PET/CT Using an Infant Phantom of Extremely Low Birth Weight.

The lack of pediatrics-specific equipment for nuclear medicine imaging has resulted in insufficient diagnostic information for newborns, especially low-birth-weight infants. Although PET offers high spatial resolution and low radiation exposure, its use in newborns is limited. This study investigated the feasibility of cardiac PET imaging using the latest silicon photomultiplier (SiPM) PET technology in infants of extremely low birth weight (ELBW) using a phantom model. Methods: The study used a phantom model representing a 500-g ELBW infant with brain, cardiac, liver, and lung tissues. The cardiac tissue included a 3-mm-thick defect mimicking myocardial infarction. Organ tracer concentrations were calculated assuming 18F-FDG myocardial viability scans and 18F-flurpiridaz myocardial perfusion scans and were added to the phantom organs. Imaging was performed using an SiPM PET/CT scanner with a 5-min acquisition. The data acquired in list mode were reconstructed using 3-dimensional ordered-subsets expectation maximization with varying iterations. Image evaluation was based on the depiction of the myocardial defect compared with normal myocardial accumulation. Results: Increasing the number of iterations improved the contrast of the myocardial defect for both tracers, with 18F-flurpiridaz showing higher contrast than 18F-FDG. However, even at 50 iterations, both tracers overestimated the defect accumulation. A bull's-eye image can display the flow metabolism mismatch using images from both tracers. Conclusion: SiPM PET enabled cardiac PET imaging in a 500-g ELBW phantom with a 1-g heart. However, there were limitations in adequately depicting these defects. Considering the image quality and defect contrast,18F-flurpiridaz appears more desirable than 18F-FDG if only one of the two can be used.

Automated classification of mandibular canal in relation to third molar using CBCT images

Background Dental radiology has significantly benefited from cone-beam computed tomography (CBCT) because of its compact size and low radiation exposure. Canal tracking is an important application of CBCT for determining the relationship between the inferior alveolar nerve and third molar. Usually, canal tacking is performed manually, which takes a lot of time. This study aimed to develop an artificial intelligence (AI) model to automate classification of the mandibular canal in relation to the third molar. Methods This retrospective study was conducted using 434 CBCT images. 3D slicer software was used to annotate and classify the data into lingual, buccal, and inferior categories. Two convolution neural network models, AlexNet and ResNet50, were developed to classify this relationship. The study included 262 images for training and 172 images for testing, with the model performance evaluated by sensitivity, precision, and F1 score. Results The performance of the two models was evaluated using a 3 × 3 confusion matrix, with the data categorized into 3 clases: lingual, buccal, and inferior. The mandibular canal and third molar have a close anatomical relationship, highlighting the need for precise imaging in dental and surgical settings. To accurately classify the mandibular canal in relation to the third molar, both AlexNet and ResNet50 demonstrated high accuracy, with F1 scores ranging from 0.64 to 0.92 for different classes, with accuracy of 81% and 83%, respectively, for accurately classifying the mandibular canal in relation to the third molar. Conclusion The present study developed and evaluated AI models to accurately classify and establish the relationship between the mandibular canal and third molars using CBCT images with a higher accuracy rate.

Clinical experience of pulmonary vein isolation via single transseptal puncture in atrial fibrillation patients: Comprehensive characterization and follow-up

BackgroundAtrial fibrillation is the most commonly observed cardiac rhythm disorder. Pulmonary vein isolation (PVI) is an effective treatment option to maintain sinus rhythm. This study evaluates the safety, efficacy, clinical outcomes and radiation exposures using a standardized single transseptal puncture (STP)-strategy. MethodsWe analyzed data from patients who underwent our STP-ablation technique with transesophageal echocardiography (TEE) guidance at a university hospital and a regional tertiary health center in Switzerland between January 1, 2017, and May 30, 2022. Collected data included demographics, symptoms, echocardiography results, procedural details, complications and outcomes. Mean follow-up time was 21.4 ± 16 months. ResultsThe study population included 304 patients with a median age of 67 years, who had at least one ablation using our STP-approach. Among these, 248 (82 %) patients underwent de novo PVI with this technique. Ablation was successful in all patients with isolation of all pulmonary veins, with an average procedure duration of 120 min and an average fluoroscopy time of 3 min, resulting in a mean X-ray dose of 252 cGy × cm2. TEE guidance was performed in 235 (95 %) patients. During the first intervention, 17 complications occurred in 13 patients (5 %). After the first PVI, 135 (54 %) patients experienced no recurrence during the follow-up period. The one-year recurrence rate for atrial fibrillation requiring therapy was 30 %. ConclusionOur STP- approach demonstrated comparable success rates to traditional methods, with similar procedural durations, low radiation exposure and a low complication rate. Therefore, this method may offer procedural, economic and safety benefits without compromising efficacy or safety.

3D Landmark scout imaging accurately assesses presence and extent of coronary calcification with lower radiation exposure

BackgroundCardiac CT for coronary artery calcium (CAC) scoring exposes patients to 1 ​mSv of radiation. A new CT scout method utilizing ultra-low dose CT (3D Landmark) offers tomographic cross-sectional imaging, which provides axial images from which CAC can be estimated. The purpose of our study is to analyze the association between estimated CAC burden on 3D Landmark scout imaging vs dedicated ECG-gated CACS. MethodsConsecutive patients over a 9-month period undergoing non-contrast ECG-gated CACS planned with 3D Landmark scout imaging were included. Extent of CAC on 3D Landmark scout imaging was scored from 0 to 3 (none, mild, moderate, severe). Agatston CACS was converted to an ordinal score from 0 to 3, corresponding to absent (0), mild (1–99), moderate (100–400), or severe (>400). Fischer's exact test, weighted kappa coefficient, and paired t-tests were used for analysis. ResultsOf 150 patients, 51.3% were female with mean age 49.0 ​± ​16.8 and BMI 28.6 ​± ​12.3. Sensitivity of 3D Landmark in identifying calcium was 96.2%, with specificity of 100%. There was strong interrater agreement between 3D Landmark calcium scoring and CACS, with weighted kappa coefficient 0.97 ​± ​0.01(CI 0.95–0.99).Radiation dose-length-product was significantly lower for 3D Landmark imaging vs. dedicated ECG-gated CACS (9.7 ​± ​3.6 vs 43.8 ​± ​26.4 ​mGy ​cm, p ​< ​0.001) despite longer scan length (465.0 ​± ​160.8 vs 123.0 ​± ​12.7 ​mm, respectively). ConclusionEstimated coronary artery calcium on 3D Landmark scout images correlates strongly with Agatston CACS, demonstrating utility in assessing cardiovascular risk without introducing additional radiation or costs.

Innovative nano-shielding for minimizing stray radiation dose in external radiation therapy: A promising approach to enhance patient safety

This study investigates the effectiveness of novel nanocomposite shielding materials in reducing out-of-field radiation doses during radiation therapy, employing Geant4 Monte Carlo (MC) simulations alongside an anthropomorphic female phantom. The research focuses on two radiation modalities: 6 MV beams with and without flattening filters. Utilizing the Geant4 MC code, detailed simulations of a Varian Clinac 2100C/D linear accelerator and an ICRP-145 mesh-type human phantom were conducted to estimate the doses to out-of-field organs from unintended secondary radiation. This involved simulating a comprehensive linac model, including all relevant beam-line components, and assessing the shielding effects of three different nanocomposites doped with metal nanoparticles at various thicknesses. The nanocomposites, comprising Polytetrafluoroethylene (PTFE), with PtO2, IrO2, and Bi2O3 nanoparticles, were evaluated for their potential to reduce patient organ doses from stray photon doses. The results showed that these materials could significantly lower radiation exposure to non-target tissues.