Results of routine thoracic radiographic examinations rarely impact the plan to proceed with anesthetic procedures in dogs with presumed acute intervertebral disc herniation

Introduction

Acute thoracolumbar intervertebral disc herniation (IVDH) constitutes an emergency because associated neurological clinical signs can be progressive, with prognosis dependent on preoperative presence of deep pain perception. Pre-anesthetic thoracic radiographs are routinely performed to evaluate for potential pathology that could result in increased risk or change in overall prognosis. However, due to the emergent nature of this disease, the weight of thoracic radiographic findings on treatment plans for these dogs in unknown. The objective of this study was to investigate the clinical benefit of thoracic radiographs prior to advanced spinal imaging and surgery for acute non-ambulatory dogs with suspected T3-L3 myelopathy.

Methods

Consecutive dogs presented with presumed acute IVDH between July 2020-July 2022 were identified, and medical records were reviewed retrospectively. Age, body weight, and alteration of treatment plan were compared between the dogs with positive thoracic pathology identified on thoracic radiographs and those with negative thoracic pathology.

Results

Only 2/105 dogs had their diagnostic and treatment plans changed due to thoracic radiographic findings. Dogs with radiographic pathology diagnosed (2/16) were more likely to have their treatment plans changed than dogs with no radiographic pathology (0/89) (p = 0.014). The odds of radiographic thoracic pathology were 4.6 times higher in dogs aged 12 years or older [OR 4.6 (95%CI 1.2-17, p = 0.026].

Discussion

Performing routine thoracic radiography prior to advanced (anesthetized) diagnostic spinal imaging in presumed IVDH cases rarely resulted in a change to the treatment plan, thought eh practice may be clinically relevant in dogs 12 years of age or older.

Radiation exposure to the orthopedic surgeon-a dosimetric comparison of two mini C-arm fluoroscopy models: a pilot study

OBJECTIVE

Perform a cadaveric experimental pilot study to measure and compare potential radiation exposure to an orthopedic surgeon from 2 different-generation mini C-arm models during a simulated orthopedic surgery.

SAMPLE

16 radiation dosimeters.

METHODS

Mock surgery setups were constructed with a canine cadaver thoracic limb and 2 different-generation mini C-arm models. Four radiation dosimeters were placed near the mini C-arm to mimic common locations of radiation exposure during image acquisition. One mini C-arm was placed in auto technique mode, and 100 static images were acquired. The dosimeters were replaced, and a 5-minute-long dynamic image was acquired. The same protocols were repeated for the second mini C-arm. The dosimetry badges were then submitted for radiation exposure quantification.

RESULTS

All but 1 dosimeter had radiation exposure levels below the detectable limits of the dosimeter. The dosimeter closest to the primary x-ray beam of 1 mini C-arm during dynamic image acquisition had a reading of 1 mrem.

CLINICAL RELEVANCE

Intraoperative radiation exposure from the mini C-arm is low, specifically to areas not protected by lead and in close proximity to the primary x-ray beam. That being said, surgeons should always practice the principles of ALARA (ie, as low as reasonably achievable) to minimize radiation exposure in the workplace.

Radiation from the equine perineal region is low compared with the elbow and head 24 hours after bone scintigraphic examination

The timing of follow-up radiography and ultrasound in horses that undergo skeletal scintigraphy for lameness investigation varies internationally and between equine hospitals. The prospective, one-group, pretest, posttest study aimed to estimate radiation levels from horses three and 24 h after injection of hydroxydiphosphonate labeled with metastable technetium (99mTc-HDP) and investigate which anatomical locations of the horse had higher radiation levels. Included were 46 horses referred for lameness investigation between June and December 2021. Radiation levels from the horse surface were measured using an electronic device from six anatomical locations (head, elbow, dorsum, ventrum, stifle, and perineum) at two time points and adjusted to three and 24 h after injection of 99mTc-HDP using the radioactive decay law. The radiation measured was significantly different in the various locations of the horses for both time points. At 3 h after injection of 99mTc-HDP, the ventrum had the highest radiation dose. At 24 h, the radiation emitted from the perineal region was significantly lower (P < .0001) than from the elbow and head, which had the highest values. There was a negative correlation between age and the radiation detected at 24 h postinjection (P = .02). Radiation from the perineal region was low compared with other regions of the horse 24 h postscintigraphy. Additional care should be taken around the ventrum area during the scintigraphy examination and around the elbow and head at 24 h postscintigraphy to minimize radiation to personnel.

Reducing frame rate and pulse rate for routine diagnostic cerebral angiography: ALARA principles in practice

OBJECTIVE

Diagnostic cerebral angiograms (DCAs) are widely used in neurosurgery due to their high sensitivity and specificity to diagnose and characterize pathology using ionizing radiation. Eliminating unnecessary radiation is critical to reduce risk to patients, providers, and health care staff. We investigated if reducing pulse and frame rates during routine DCAs would decrease radiation burden without compromising image quality.

METHODS

We performed a retrospective review of prospectively acquired data after implementing a quality improvement protocol in which pulse rate and frame rate were reduced from 15 p/s to 7.5 p/s and 7.5 f/s to 4.0 f/s respectively. Radiation doses and exposures were calculated. Two endovascular neurosurgeons reviewed randomly selected angiograms of both doses and blindly assessed their quality.

RESULTS

A total of 40 consecutive angiograms were retrospectively analyzed, 20 prior to the protocol change and 20 after. After the intervention, radiation dose, radiation per run, total exposure, and exposure per run were all significantly decreased even after adjustment for BMI (all p<0.05). On multivariable analysis, we identified a 46% decrease in total radiation dose and 39% decrease in exposure without compromising image quality or procedure time.

CONCLUSIONS

We demonstrated that for routine DCAs, pulse rate of 7.5 with a frame rate of 4.0 is sufficient to obtain diagnostic information without compromising image quality or elongating procedure time. In the interest of patient, provider, and health care staff safety, we strongly encourage all interventionalists to be cognizant of radiation usage to avoid unnecessary radiation exposure and consequential health risks.

The Accuracy of Guided Implant Surgery with Different Field of View of Cone-Beam Computed Tomography

Although a smaller size field of view (FOV) of Cone-Beam Computed Tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on eight identical scannable models (maxillae and mandibles) were randomly allocated to two FOV sizes: test (5cm x 5cm) and control (10cm x 10cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully-guided s-CAIS protocol. IOS captured the implant positions with the scanbody attached. Implant planning software measured the angular deviation, 3D deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way ANOVA was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (p > 0.198) on angular deviation, 3D deviation at the crest, and 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT.

Development and clinical feasibility of a reduced-dose radiograph in children for feeding tube placement

BACKGROUND

Temporary feeding tubes are commonly used but may lead to complications if malpositioned. Radiographs are the gold standard for assessing tube position, but clinician concern over radiation risks may curtail their use.

OBJECTIVE

We describe development and use of a reduced dose feeding tube radiograph (RDFTR) targeted for evaluation of feeding tube position.

MATERIALS AND METHODS

Age-based abdominal radiograph was adapted to use the lowest mAs setting of 0.32 mAs with field of view between carina and iliac crests. The protocol was tested in DIGI-13 line-pair plates and anthropomorphic phantoms. Retrospective review of initial clinical use compared dose area product (DAP) for RDFTR and routine abdomen, chest, or infant chest and abdomen. Review of RDFTR reports assessed tube visibility, malpositioning, and incidental critical findings.

RESULTS

Testing through a line-pair phantom showed loss of spatial resolution from 2.2 line pairs to 0.6 line pairs but preserved visibility of feeding tube tip in RDFTR protocol. DAP comparisons across 23,789 exams showed RDFTR reduced median DAP 72-93% compared to abdomen, 55-78% compared to chest, and 76-79% compared to infant chest and abdomen (p<0.001). Review of 3286 reports showed tube was visible in 3256 (99.1%), malpositioned in airway 8 times (0.2%) and in the esophagus 74 times (2.3%). The tip was not visualized in 30 (0.9%). Pneumothorax or pneumoperitoneum was noted seven times (0.2%) but was expected or spurious in five of these cases.

CONCLUSION

RDFTR significantly reduces radiation dose in children with temporary feeding tubes while maintaining visibility of tube tip.

Factors affecting radiographers' use of dose-reduction measures

This study investigates radiographers' views on implementing dose-reduction measures, with a focus on verifying patient identity and pregnancy status, practising gonad shielding in men and using compression. An electronic questionnaire was distributed to radiographers working in general radiography and/or computed tomography. The questionnaire was based on factors from a framework for analysing risk and safety in clinical medicine. Ordered logistic regressions were used to analyse associations among factors and use of dose-reduction measures. In total, 466 questionnaires were distributed and 170 radiographers (36%) completed them. Clear instructions and routines, support from colleagues, knowledge and experience, a strong safety culture, managerial support and access to proper equipment influence the likelihood of using dose-reduction measures. The strongest associations were found between support from colleagues and verifying pregnancy status (OR = 5.65,P= 0.026), safety culture and use of gonad shielding (OR = 2.36,P= 0.042), and having enough time and use of compression (OR = 2.11,P= 0.003). A strong safety culture and a supportive work environment appears to be essential for the use of dose-reduction measures, and education, training and stress management can improve utilisation of dose-reduction measures.

A Holistic Approach to CT Protocol and Dose Management

PURPOSE

Challenges from administrative support, scanners' heterogeneity, patient size variation, and protocol mapping hinder CT protocol and dose management. We present a holistic approach to overcome these challenges.

METHODS

A dose tracking software was selected with two key requirements: intelligent protocol mapping and customizable dose threshold settings according to the patient size. A multifaceted workflow was carefully implemented. It included patient size-dependent dose thresholds for e-mail alerts, a base protocol archive on a website with a unified format using an in-house developed reformat software upon protocol export, prompt dose alert follow-up, and well-controlled protocol changes. The thresholds were iteratively updated following protocol changes or review of dose statistics. The program outcome was evaluated using 11 protocols from January 2020 to May 2023 (N = 148,678) in comparison to ACR's achievable dose (AD) and dose reference levels (DRLs).

RESULTS

The 75th percentile dose data were lower than the ACR's DRL on average, ranging from -4.9% to -36%. The median doses were in a range of -23% to 19% on average in comparison with the ACR's AD. The median value from pulmonary embolism scans initially showed 36% higher than the AD but was gradually reduced to nearly 3% lower than the AD. The percentage of unjustified alerted cases decreased from 80% in first half year of 2020 to 17% in the first 5 months of 2023.

CONCLUSIONS

The results showed that our holistic approach to protocol and dose management has been effective. The impact to practice has been prompt and sustainable.

The Fluoroless Future in Electrophysiology: A State-of-the-Art Review

Fluoroscopy has always been the cornerstone imaging method of interventional cardiology procedures. However, radiation exposure is linked to an increased risk of malignancies and multiorgan diseases. The medical team is even more exposed to X-rays, and a higher incidence of malignancies was reported in this professional group. In the last years, X-ray exposure has increased rapidly, involving, above all, the medical team and young patients and forcing alternative fluoroless imaging methods. In cardiac electrophysiology (EP) and pacing, the advent of 3D electroanatomic mapping systems with dedicated catheters has allowed real-time, high-density reconstruction of both heart anatomy and electrical activity, significantly reducing the use of fluoroscopy. In addition, the diffusion of intracardiac echocardiography has provided high anatomical resolution of moving cardiac structures, providing intraprocedural guidance for more complex catheter ablation procedures. These methods have largely demonstrated safety and effectiveness, allowing for a dramatic reduction in X-ray delivery in most arrhythmias' ablations. However, some technical concerns, as well as higher costs, currently do not allow their spread out in EP labs and limit their use to only procedures that are considered highly complex and time-consuming and in young patients. In this review, we aim to update the current employment of fluoroless imaging in different EP procedures, focusing on its strengths and weaknesses.

Has fluoroless endourology (URS and PCNL) come of age? Evidence from a comprehensive literature review

INTRODUCTION

Radiation via the use of imaging is a key tool in management of kidney stones. Simple measures are largely taken by the endourologists to implement the 'As Low As Reasonably Achievable' (ALARA) principle, including the use of fluoroless technique. We performed a scoping literature review to investigate the success and safety of fluoroless ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) procedures for the treatment of KSD.

METHODS

A literature review was performed searching bibliographic databases PubMed, EMBASE and Cochrane library, and 14 full papers were included in the review in accordance with the PRISMA guidelines.

RESULTS

Of the 2535 total procedures analysed, 823 were fluoroless URS vs. 556 fluoroscopic URS; and 734 fluoroless PCNL vs. 277 fluoroscopic PCNL. The SFR for fluoroless vs. fluoroscopic guided URS was 85.3% and 77%, respectively (p=0.2), while for fluoroless PCNL vs. fluoroscopic group was 83.8% and 84.6%, respectively (p=0.9). The overall Clavien-Dindo I/II and III/IV complications for fluoroless and fluoroscopic guided procedures were 3.1% (n=71) and 8.5% (n=131), and 1.7% (n=23) and 3% (n=47) respectively. Only 5 studies reported a failure of the fluoroscopic approach with a total of 30 (1.3%) failed procedures.

CONCLUSION

The ALARA protocol has been implemented in endourology in numerous ways to protect both patients and healthcare workers during recent years. Fluoroless procedures for treatment of KSD are safe and effective with outcomes comparable to standard procedures and could become the new frontier of endourology in selected cases.

Newly Developed Low Dose 180-degree CBCT Protocol Reduces Radiation Dose Without Compromising Diagnostic Value

PURPOSE

To compare the standard 360-degree CBCT acquisition protocol to the low dose 180-degree CBCT protocol for implant planning.

MATERIALS AND METHODS

Two groups of patients, each consisting of 35 patients, were included in the study. The first group was imaged with the conventional 360-degree CBCT protocol, and the second group was imaged with the low dose 180-degree CBCT protocol. The primary outcome of this study was the number of scans that needed to be repeated due to poor image quality. In addition, six secondary parameters were evaluated quantitatively and qualitatively.

RESULTS

The results showed that there was no need to repeat any of the CBCT scans that were obtained in either group, which showed that 360-degree and 180-degree protocols had comparable image quality. As for the secondary parameters, the results showed that the evaluators were able to evaluate the six chosen parameters in a comparable manner.

CONCLUSIONS

The 180-degree low dose CBCT scan is a viable option for dental implant treatment planning in the posterior mandible as it provides comparable and adequate information regarding accuracy of measurements, identification of critical structures, evaluation of bone quality, and any pathology.

Assessment of radiographers' knowledge about radiation doses and DRLs in computed tomography departments in Jeddah, Saudi Arabia: A cross-sectional study

Objective

To assess radiographers' understanding of radiation safety considering the newly approved national diagnostic reference levels (DRLs) as an optimization tool for radiation dose.

Methods

A cross-sectional study was conducted in Saudi Arabia among radiographers working at local hospitals in Jeddah city from February to March 2022. The survey comprised of 22 questions involving demographic information; and general information related to radiation dose; CTDIvol and DRLs. Data were analyzed using IBM SPSS Statistics version 26. Chi-square test was used to compare demographic groups regarding their distribution of responses with 0.05 as the level of significance.

Results

A total of 169 radiographers participated in the study (39 % females, 60 % males). Most of the participants (91 %) were aware of the description of the ALARA principle. It was noted that (47 %) of the participants indicated that the routine scanning protocols are designed by the radiologists. The majority of them (78 %) were confident to manipulate the CT scanning parameters properly. In addition, half of the participants (53 %) were aware of the CTDIvol and DLP. Unexpectedly, none of the demographic variables were significantly associated with the radiographers' knowledge about radiation dose, p-values are > 0.05.

Conclusion

Although radiographers demonstrated good knowledge of radiation protection, limited awareness of DRLs was noted among radiographers and lack of implementing and optimizing the local dose of the DRLs in this study. Therefore, education and training for healthcare professionals including radiographers are necessary to enhance clinical practical performance in radiology departments.

High-pitched tin-filtered CT pulmonary angiography in radiation dose reduction for pulmonary embolism investigations in young females

INTRODUCTION

Computed tomography pulmonary angiography (CTPA) is the gold standard test to investigate pulmonary embolism (PE). This technique carries significant radiation risk in young females because of radiosensitive breast and thyroid tissues. A high-pitched CT technique offers significant radiation dose reduction (RDR) and minimises breathing artefact. The addition of CT tube tin-filtration may offer further RDR. The aim of this retrospective study was to assess RDR and image quality (IQ) of high-pitch tin-filtered (HPTF)-CTPA against conventional-CTPA.

METHODS

Retrospective review of consecutive adult females age < 50 years undergoing high pitch tin filtration (HPTF) and standard pitch no tin filtration (SPNF) during a 3-year period beginning in November 2017. CTs in both groups were compared for radiation dose, pulmonary arteries contrast density (Hounsfield units (HU)) and movement artefact. Findings of both groups were compared with the Student's T-test and Mann-Whitney U test, where p < 0.05 being considered significant. Diagnostic quality was also recorded.

RESULTS

Ten female patients (mean age 33, 6/10 pregnant) in HPTF group and 10 female patients (mean age 36, 1/10 pregnant) in SPNF group were included. The HPTF group achieved 93% RDR (dose length product: 25.15 mGy.cm vs 337.10 mGy.cm, p < 0.01). There was significant contrast density difference between the two groups in the main, left or right pulmonary arteries (322.72 HU, 311.85 HU and 319.41 HU in HPTF group vs 418.60 HU, 405.10 HU and 415.96 HU in SPNF group respectively, p = 0.03, p = 0.03 and p = 0.04). 8/10 HPTF group and 10/10 in the control group were > 250 HU in all three vessels; the remaining 2 HPTF CTPA were > 210HU. All CT scans in both groups were of diagnostic quality and none exhibited movement artefact.

CONCLUSION

This study was the first to demonstrate significant RDR with the HPTF technique whilst maintaining IQ in patients undergoing chest CTPA. This technique is particularly beneficial in young females and pregnant females with suspected PE.

Paediatric CT made easy

Paediatric computed tomography (CT) imaging has always been associated with challenges. Although the technical background of CT imaging is complex, it is worth considering the baseline aspects of radiation exposure to prevent unwanted excess radiation in paediatric patients. In this review, we discuss the most relevant factors influencing radiation exposure, and provide a simplified and practical approach to optimise paediatric CT.

Rational Usage of Fracture Imaging in Children and Adolescents

In this paper, authors introduce the basic prerequisite for rational, targeted, and above all, child-oriented diagnosis of fractures and dislocations in children and adolescents is in-depth prior knowledge of the special features of trauma in the growth age group. This review summarizes the authors' many years of experience and the state of the current pediatric traumatology literature. It aims to provide recommendations for rational, child-specific diagnostics appropriate to the child, especially for the area of extremity injuries in the growth age. The plain radiograph remains the indispensable standard in diagnosing fractures and dislocations of the musculoskeletal system in childhood and adolescence. Plain radiographs in two planes are the norm, but in certain situations, one plane is sufficient. X-rays of the opposite side in acute diagnostics are obsolete. Images to show consolidation after conservative treatment is rarely necessary. Before metal removal, however, they are indispensable. The upcoming diagnostical tool in pediatric trauma is ultrasound. More and more studies show that in elected injuries and using standardized protocols, fracture ultrasound is as accurate as plain radiographs to detect and control osseous and articular injuries. In acute trauma, CT scans have only a few indications, especially in epiphyseal fractures in adolescents, such as transitional fractures of the distal tibia or coronal shear fractures of the distal humerus. CT protocols must be adapted to children and adolescents to minimize radiation exposure. MRI has no indication in the detection or understanding of acute fractures in infants and children. It has its place in articular injuries of the knee and shoulder to show damage to ligaments, cartilage, and other soft tissues. Furthermore, MRI is useful in cases of remaining pain after trauma without radiological proof of a fracture and in the visualization of premature closure of growth plates after trauma to plan therapy. Several everyday examples of rational diagnostic workflows, as the authors recommend them, are mentioned. The necessity of radiation protection must be taken into consideration.

Low dose pediatric chest computed tomography on a photon counting detector system - initial clinical experience

BACKGROUND

With the clinical release of a photon counting detector-based computed tomography (CT) system, the potential benefits of this new technology need to be evaluated clinically. Literature concerning this new generation of detector is sparse, especially in the field of pediatric radiology. Therefore, this study outlines our initial experience with ultra-low dose chest CT imaging on the new photon counting CT system.

MATERIALS AND METHODS

A pediatric phantom (1-year old, CIRS ATOM phantom, model 704 [CIRS-computerized imaging reference system, Norfolk, VA]) was scanned at different dose levels and different image quality levels to define a protocol for clinical examinations. Next, 20 consecutive pediatric non-contrast ultra-low dose chest CT examinations were evaluated for radiation dose and diagnostic image quality using a 4-point Likert-scale-1 = excellent, 4 = bad image quality-by two radiologists in a consensus reading. This retrospective analysis was approved by the local research ethics committee.

RESULTS

Chest CT examinations performed at ultra-low radiation dose (effective dose 0.19 ± 0.07 mSv; size-specific dose estimate 0.45 ± 0.14 mGy) in pediatric patients ages (2.6 ± 1.8 years) show good to excellent image quality for lung structures (1.4 ± 0.4) and moderate image quality for soft tissue structures (2.8 ± 0.2).

CONCLUSION

Pediatric ultra-low dose chest CT examinations are feasible with the new generation photon counting detector-based CT system. The benefits of this technology must be evaluated for pediatric patients from the outset.

Are dental x-rays safe? Content analysis of English and Chinese YouTube videos

Objective

This study provided a content analysis of English and Chinese YouTube videos related to dental radiation safety.

Method

The search string, entered in English and Chinese respectively, was: (dental x-ray safe). The searches were performed and exported with Apify YouTube scraper. By screening the resultant videos and their related videos (as recommended by YouTube), a total of 89 videos were screened. Finally, 45 videos (36 English and nine Chinese) were included and analyzed. The specific information regarding dental radiation was evaluated. The Patient Education Material Assessment Tool for Audiovisual Materials was used to assess understandability and actionability.

Results

There was no significant difference between the English and Chinese videos in terms of view count, like count, comment count, and video duration. Half of the videos explicitly reassured the audience that dental x-rays are safe. Two of the English videos specifically stated that dental x-rays do not cause cancers. Numerous analogies were made in regard to radiation dose, such as equivalence to taking a flight or eating some bananas. About 41.7% of the English videos and 33.3% of the Chinese videos mentioned that patients could be further protected from scatter radiation by wearing a lead apron and thyroid collar. Videos had a good understandability score (91.3) but a poor actionability score (0).

Conclusions

Some of the analogies and the claimed radiation dose were questionable. One Chinese video even wrongly stated that dental x-rays are nonionizing radiation. The videos generally did not mention their information sources or the underlying radiation protection principles.

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

Background

Iterative reconstruction algorithm (IR) techniques were developed to maintain a lower radiation dose for patients as much as possible while achieving the required image quality and medical benefits. The main purpose of the current research was to assess the level and usage extent of IR techniques in computed tomographic (CT) scan exams. Also, the obligation of practitioners in several hospitals in Saudi Arabia to implement IR in CT exams was assessed.

Material and Methodology

The recent research was based on two studies: data collection and a survey study. Data on the CT scan examinations were retrospectively collected from CT scanners. The survey was conducted using a questionnaire to evaluate radiographers’ and radiologists’ perceptions about IR and their practices with IR techniques. The statistical analysis results were performed to measure the usage strength level of IR methods.

Results and Discussions

The IR strength level of 50% was selected for nearly 80% of different CT examinations and patients of different ages and weights. About 46% of the participants had not learned about IR methods during their college studies, and 54% had not received formal training in applying IR techniques. Only 32% of the participants had adequate experience with IR. Half of the participants were not involved in the updating process of the CT protocol.

Conclusion

The results indicate that the majority of radiographer and radiologist at four different hospitals in Saudi Arabia have no explicit or understandable knowledge of selecting IR strength levels during the CT examination of patients. There is a need for more training in IR applications for both radiologists and radiographers. Training sessions were suggested to support radiographers and radiologists to efficiently utilize IR techniques to optimize image quality. Further studies are required to adjust CT exam protocols effectively to utilize the IR technique.

ALARA in Urology: Steps to Minimise Radiation Exposure During All Parts of the Endourological Journey

Purpose of the Review

The global burden of kidney stone disease (KSD) and its management relies on ionising radiation. This includes the diagnosis, treatment and follow-up of KSD patients. The concept ‘As Low As Reasonably Achievable’ (ALARA) developed in response to the radiation risks and the key principles include optimisation, justification and limitation of radiation. This article provides an overview of the topic including background to the risks and steps that can be taken during all stages of endourological management.

Recent Findings

Our review suggests that ionising radiation is an invaluable tool in delineating the anatomy, localising disease, guiding manoeuvres and monitoring treatment in patients with KSD. It therefore plays an integral role in many stages of patient care; preoperatively, intraoperatively and postoperatively.

The reduction of radiation pre- and post-surgical intervention relies on the use of low-radiation CT scan and ultrasound scan. It can also be achieved through various intraoperative techniques or fluoroless techniques in selected patients/procedures, customised to the patients and procedural complexity.

Summary

There are many parts of the patient journey where exposure to radiation can take place. Urologists must be diligent to minimise and mitigate this wherever possible as they too face exposure risks. Implementation of strategies such as teaching programmes, fluoroscopy checklists and judicious use of CT imaging among other things is a step towards improving practice in this area.

Impact of radiographic field-of-view volume on alignment accuracy during virtual implant planning: A noninterventional retrospective pilot study

OBJECTIVE

To evaluate the impact of reducing the radiographic field-of-view (FOV) on the trueness and precision of the alignment between cone beam computed tomography (CBCT) and intraoral scanning data for implant planning.

MATERIALS AND METHODS

Fifteen participants presenting with one of three clinical scenarios: single tooth loss (ST, n=5), multiple missing teeth (MT, n=5), and presence of radiographic artifacts (AR, n=5) were included. CBCT volumes covering the full arch (FA) were reduced to the quadrant (Q) or the adjacent tooth/teeth (A). Two operators, an expert (exp) in virtual implant planning and an inexperienced clinician, performed multiple superimpositions, with FA-exp serving as a reference. The deviations were calculated at the implant apex and shoulder levels. Thereafter, linear mixed models were adapted to investigate the influence of FOV on discrepancies.

RESULTS

Evaluation of trueness compared to FA-exp resulted in the largest mean (AR-A: 0.10 ± 0.33 mm) and single maximum discrepancy (AR-Q: 1.44 mm) in the presence of artifacts. Furthermore, for the ST group, the largest mean error (-0.06 ± 0.2 mm, shoulder) was calculated with the FA-FOV, while for MT, with the intermediate volume (-0.07 ± 0.24 mm, Q). In terms of precision, the mean SD intervals were ≤0.25 mm (A-exp). Precision was influenced by FOV volume (FA<Q<A) but not by operator expertise.

CONCLUSIONS

For single posterior missing teeth, an extended FOV does not improve registration accuracy. However, in the presence of artifacts or multiple missing posterior teeth, caution is recommended when reducing FOV.

A software-based approach for calculating spatially resolved radiation exposure for structural radiation protection in nuclear medical imaging

The objective of the work described is the development of a software tool to provide the calculation routines for structural radiation protection from positron and gamma emitters, for example,¹⁸F. The calculation of the generated local annual dose in the vicinity of these radioactive sources supports the engineering of structural measures necessary to meet regulatory guidelines. In addition to accuracy and precision, a visual and intuitive presentation of the calculation results enables fast evaluation. Finally, the calculated results are presented in a contour plot for design, evaluation, and documentation purposes. A python program was used to provide the calculation routines for structural radiation protection. For simplicity, the radiating sources can be considered as point sources. The attenuation of structural elements can be specified or, in the case of lead, calculated by virtue of its thickness. The calculated attenuation for the lead shielding is always slightly underestimated, which leads to a marginally higher calculated local dose rate than would be physically present. With the conservatively determined value, the structural radiation protection can be optimised in accordance with the general rule of as low as reasonably achievable. The pointwise comparison between the software results and the standard procedure for calculating the dose of points in space leads to similar values. In comparison with the general approach of calculating single representative points in the radiation protection area, the visual and intuitive presentation of the results supports the design and documentation of the measures required for structural radiation protection. In the present version of the software, the local dose rate and local annual dose are overestimated by a maximum of 4.5% in the case of lead shields. The proposed software, termed RadSoft, was successfully used to develop the structural radiation protection of a controlled area for hybrid magnetic resonance - positron emission tomography imaging, with the focus herein being on the requirements for PET.

Assessment of Knowledge towards Radiation Protection Measures among Newly Graduated Dentists from Egypt and the Kingdom of Saudi Arabia: A Questionnaire-Based Cross-Sectional Study

Background: It is hypothesized that knowledge towards ionizing radiation (IR) protection measures is lacking among newly graduated dentists from Egypt and Saudi Arabia. The purpose of the present questionnaire-based study was to compare the IR protection knowledge among newly graduated dentists from Egypt and the Kingdom of Saudi Arabia (KSA). Methods: The present investigation was a questionnaire-based study and had a cross-sectional observational analytical design. Newly graduated dentists were defined as individuals who had graduated from a credentialed dental institution within the past 36-months. The questionnaire was related to knowledge about radiation safety, awareness and practices. The questionnaire comprised of 17 multiple choice questions. Questionnaires in which all the 17 questions were not answered or had missing pages were excluded. Odds ratios were computed for the number of correct and incorrect responses and 95% confidence intervals were determined. Individuals that provided up to 40%, 41% to 70% and >70% correct answers were categorized as having “low competence”; “moderate competence” and “high competence” in IR knowledge. p-values less than 0.05 were considered statistically significant. Results: The mean percentage of correct answers provided by dentists from Egypt and KSA were 56.9% and 67.4%, respectively. There was no statistically significant difference in the percentages of correct responses for the 17 questions submitted by respondents from Egypt and KSA. The overall percentage of correct responses ranged between 40.2−71.2% and 45.4−81.4% for respondents from Egypt and KSA, respectively. The odds ratios and 95% confidence intervals showed no statistically significant correlation in the responses from respondents from Egypt and KSA for each of the 17 questions addressed. Conclusion: Newly graduated dentists from Egypt and KSA are moderately competent regarding IR doses and related safety measures. It is recommended that modifications in the undergraduate dental education curriculum with emphasis on IR safety and practice would help enhance the knowledge and competence of students and newly graduated dentists. Moreover, routine continuing dental education seminars/programs may help enhance the IR knowledge of dental students and dentists.

Radiation dose reduction for chest radiography of infants in intensive care units using a high peak kilovoltage-technique

BACKGROUND

Chest radiography is an important tool in the care of infants in intensive care units. Image optimization must be monitored to minimize radiation exposure in this susceptible population.

OBJECTIVE

To examine the use of a high tube peak kilovoltage technique to achieve radiation dose reduction while maintaining adequate image quality.

MATERIALS AND METHODS

A retrospective study was conducted. Radiation doses of chest radiographs performed in the pediatric intensive care units in our institution were calculated. The radiographs were divided into two groups based on the value of the peak kilovoltage used: above and below 60 kilovolts (kV). Image quality was blindly assessed by two fellowship-trained pediatric radiologists. Air kerma, effective dose and quality score for the high versus the low peak kilovoltage group were compared and analyzed.

RESULTS

The study included 376 radiographs. One hundred and seven radiographs were performed using peak kilovoltage values equal to or above 60 kV and 269 radiographs were performed using values under 60 kV. The average air kerma for the lower peak kilovoltage group was 56.6 microgray (µGy) (30.7-81.9) vs. 22.9 µGy (11.8-34.4) for the higher peak kilovoltage group (P<0.0001). The mean difference in effective dose between the groups was 11.68 (P<0.0001). The mean difference for the quality score was 0.06 (±0.03, P=0.10), not statistically significant.

CONCLUSION

A high peak kilovoltage technique may enable a statistically significant radiation dose reduction without compromising the diagnostic value of the image.

Reducing Radiation Exposure from PET Patients

Objective: This study measured the typical emitted radiation rate from the urinary bladder of PET patients after their scan and investigated simple methods for reducing the emitted radiation before discharge. Methods: The study included 83 patients, 63 [¹⁸F]FDG and 20 [¹⁸F]NaF. Emitted radiation from the patients' urinary bladder was measured with an ionization survey meter at a 1-meter distance, presuming the urinary bladder to be the primary source of radiation. The measurements were taken at different time points after PET image acquisition: immediate (pre-void 1), voided (post-void 1), after waiting 30 min in the uptake room while drinking 500 mL of water (pre-void 2) and voided again (post-void 2). Results: For [¹⁸F]FDG patients, the reduction of emitted radiation due to drinking water and voiding alone from pre-void 1 to decay corrected post void 2 was an average of 22.49 ± 7.48% (13.65 ± 3.42 µSv/h to 10.48 ± 2.37 µSv/h, P = 0). As for [¹⁸F]NaF patients, the reduction was an average of 25.80 ± 10.03% (9.83 ± 2.01 µSv/h to 7.23 ± 1.49 µSv/h, P = 0). Conclusion: In addition to the physical decay of the radiotracers, utilizing the biological clearance properties have resulted in a significant decrease of the emitted radiation in this study. Implementing additional water consumption to facilitate voiding with 30 minutes of wait time before discharging certain [¹⁸F]FDG and [¹⁸F]NaF patients that need to be in close contact with others such as elderly, caregivers and inpatients, might facilitate lowering their emitted radiation by an average of 22-25% due to voiding, not counting in the physical decay which should add an additional 17% reduction.

The three R's of reasonable in radiological protection: relationships, rationale, and resources

Central to applying the principle of optimisation in the system of radiological protection is the evaluation of what level of radiation exposure should be considered 'as low as reasonably achievable' (ALARA), after taking into account the prevailing circumstances. Determining what is 'reasonable' is an abstract, although somewhat intuitive concept with many potential interpretations depending on both the situation and those involved, whether individuals or organisations. There are common themes in the types of considerations that need to be addressed to determine 'reasonableness' regardless of the exposure situation. However, despite the consistent and agreeable nature of these themes, there remains a gap in how to apply them in real situations. For example, without measurable goalposts (or a clear process for setting such goalposts) for determining what constitutes ALARA, we can find ourselves misinterpreting the optimisation process as keeping exposures 'as low as possible'. We propose herein, by consolidating and building on existing ideas, an easily understandable and actionable 'reasonableness' framework. This simple, yet broadly applicable tool is intended to help radiation protection experts in the systematic, deliberative, and collaborative reflection on all of the factors that make up 'reasonable' before making a decision-whether it be a proposed medical treatment or clean-up of a contaminated site. Each process execution and decision itself will necessarily retain the complexity of the prevailing circumstance. The proposed 'Rs' of Reasonable represent Relationships (stakeholders, empathy, and trust), Rationale (contextual, technical, and ethical), and Resources (technological, financial, and time).

Correlation between Computed Tomography Clinical Diagnosis and Findings in Pediatric Computed Tomography

&lt;b&gt;Background and Objective:&lt;/b&gt; Pediatric Computed Tomography (CT) is a fast, accurate imaging examination using ionizing radiation to create detailed images of pathological conditions. The radiation benefit should be outweighing the risk through the procure justification and dose optimization. The study aimed to investigate the correlation between the physician's initial diagnosis and the CT findings to build procedure justification for a pediatric patient's head scan. &lt;b&gt;Materials and Methods:&lt;/b&gt; The study included 81 children examined clinically and by CT scan to diagnose cranial and cerebral pathology. Eighty-one pediatric patients were investigated by CT scan and clinical diagnosis. &lt;b&gt;Results:&lt;/b&gt; The patient age ranged between 1-15 years old, (44%) were male and (56%) females. The patients referred to the CT scan from emergency department n = 10 (7%), outpatient clinics n = 66, (84%) and inpatients clinics n = 5, (9%). The study showed that 46% of patients were normal with no CT findings. Almost half of the cases were negative and did not confirm the clinical diagnosis. &lt;b&gt;Conclusion:&lt;/b&gt; The study concluded that most head CT scans in children were not justified. An effort towards improving the refereeing physician's awareness about radiation dose and request justification should be conducted.

Nuclear medicine staff exposure to ionising radiation in 18F-FDG PET/CT practice: a preliminary retrospective study

This retrospective study provides an insight into the levels of radiation exposure of six nuclear medicine (NM) staff (four technologists and two nurses) performing routine diagnostic ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography-computed tomography (PET/CT) at the University Clinical Centre of the Republic of Srpska, Department of Nuclear Medicine and Thyroid Disorders, Banja Luka, Bosnia and Herzegovina. Data analysis included monthly staff exposure measured with personal thermoluminescent dosimeters (TLD) between June and December 2018, quantified in terms of normalised dose for the whole body [Hp(10)] and dominant hand [Hp(0.07)] and their comparison between each staff member and between the two groups (technologists and nurses). The study goal was to establish how our Department compared with reports from other PET/CT centres worldwide in terms of annual number of procedures and exposure limits and whether there could be room for further improvements in radiation protection. The number of procedures rose considerably from 208 in 2016 to 876 in 2019 and was 423 in the observed seven-month period. Mean individual whole-body exposure dose per GBq of injected ¹⁸F-FDG activity, [Hp(10)/A] was 18.55 μSv/GBq for the four technologists and 15.61 μSv/GBq for the two nurses. Mean dominant-hand exposure dose per GBq of injected ¹⁸F-FDG activity [Hp(0.07)/A] was 16.99 μSv/GBq and 25.44 μSv/GBq for the two groups, respectively. The average annual cumulative dose for all staff was (1.06±0.29) mSv for Hp(10) and (1.15±0.32) mSv for Hp(0.07). These results are comparable with those of similar studies. Staff doses were well below the annual limits. Nurses received slightly higher extremity doses than technologists. In view of the increasing trends in the number of PET/CT procedures, dose monitoring should be continued to identify exposure hotspots and maintain doses as low as possible.

ALARA in practice-4 decades of radiological protection at Goesgen NPP

This paper provides an overview of results achieved through a whole set of ALARA investigations at the Goesgen Nuclear Power Plant. Doses to workers, the public and the environment have significantly dropped in recent years. Even the doses to the most exposed workers at the plant are not bigger than doses from natural background radiation. Recent reviews of epidemiological data call attention to the importance of recognising that the risk of cancer at low doses is small and might contribute only a very small, non-detectable fraction to an individual's overall risk. Based on the global cultural change on how society is facing any kind of risk, the initial ALARA philosophy is moving more and more to a continuing expectation that optimisation is equivalent to reduction. This philosophy change is even more pronounced in the light of the ongoing discussions about the effects of low dose radiation. Multiple conservatisms in dose models and dose calculations will lead to an imbalance between radiation risks and benefits. Overweighting radiation risks from low doses causes anxiety among the public and unnecessary economic burden to nuclear facilities. In light of pressing global issues (i.e. climate change), a discussion about the meaning of the 'R' in ALARA is recommended.

Imaging diagnosis of canine hip dysplasia with and without human exposure to ionizing radiation

Hip dysplasia (HD) is one of the most common hereditary orthopaedic diseases in dogs, with serious implications for the quality of life of the affected animals. Radiographic screening is essential for the selection of breeding stock in some at-risk breeds, and radiography is also used in the diagnosis of clinical HD cases. A definitive diagnosis of HD is based on radiographic examination, and the most commonly used view is the ventrodorsal hip extended projection, sometimes in combination with various hip stress-based techniques. Radiographic images require high quality positioning and dogs are usually anesthetized and often manually restrained to facilitate optimal positioning. The 'as low as reasonably achievable' (ALARA) principle used in human radioprotection is not always fulfilled in veterinary practice, except in the UK, where human exposure to ionizing radiation in veterinary medicine is strictly regulated. While each dose of ionizing radiation is small, doses accumulate over a lifetime, which can eventually result in substantial radiation exposure. Therefore, manual restraint should be avoided and mechanical immobilization, sedation or general anaesthesia should be used. This review examines the biological effects of human exposure to ionizing radiation and common sources of veterinary exposure. The diagnostic quality of imaging methods for the diagnosis of canine HD is compared between manually restrained and hands-free dog positioning. Hands-free radiographic techniques are available to assess hip laxity, degenerative joint changes and hip osseous structure while preserving image quality, and can be used to select animals for breeding or for the diagnosis of HD.

Local diagnostic reference levels for routine chest X-ray examinations at a public sector hospital in central South Africa

BACKGROUND

Dose optimisation is a radiation protection guideline recommended by the International Commission on Radiological Protection (ICRP) for adherence to the 'as low as reasonably achievable' (ALARA) principle. Diagnostic reference levels (DRLs) are used to optimise patients' radiation protection for diagnostic and interventional procedures and are particularly useful for frequently performed examinations such as chest X-rays.

AIM

To establish the local diagnostic reference levels (LDRLs) for routine chest X-rays.

SETTING

Public sector hospital, Northern Cape province, South Africa.

METHODS

Sixty patients referred for chest X-rays fulfilling the inclusion criteria participated in this study. Patients were ≥ 18 years of age and weighed between 60 kg and 80 kg. Consent for participation was obtained. The entrance skin air kerma (ESAK) was measured by using the indirect method recommended by the International Atomic Energy Agency (IAEA). Statistical software (SAS version 9.2) was used to determine the LDRLs for chest X-rays in three different rooms. In two rooms, computed radiography (CR) was used and the other one was a digital radiography (DR) unit. The LDRL values at the research site were compared with various published international values.

RESULTS

LDRLs for chest X-rays were established. The CR LDRL value for the posteroanterior (PA) chest projection was higher than the DR (flat panel detector [FPD]) LDRL value. The LDRLs of the PA chest projections were 0.3 mGy for CR and 0.2 mGy for DR. The lateral (LAT) chest projection LDRL value was 0.8 mGy for both CR and DR (FPD) projections. The resultant LDRL between rooms at the research site was 0.3 mGy for PA 0.3 mGy and 0.8 mGy for LAT chest projections.

CONCLUSION

The LDRLs for chest X-rays established at this research site were lower than internationally reported DRLs. We recommend that LDRLs for routine chest X-rays should be repeated every 3 years, according to the ICRP.

CONTRIBUTION

Currently, no established or published DRL values prescribed by the Directorate of Radiation Control (DRC) are available in South Africa. The LDRLs established for routine chest X-ray examinations at this research site can serve as a guideline for the establishment of DRL values for other anatomical regions at the research site and other radiology departments in the country.

'J'accuse.!': the continuous failure to address radiophobia and placing radiation in perspective

As far as carcinogens are concerned, radiation is one of the best studied, having been researched for more than 100 years. Yet, radiation remains feared in many contexts as a result of its invisibility, its relationship with cancers and congenital disorders, aided by a variety of heuristics and reinforced by negative imagery. The strong socio-psychological response relating to nuclear energy has made radiation a classical case in the risk literature. This is reflected clearly following the nuclear accidents that have taken place, where the socio-psychological impacts of the clear dissonance between real and perceived health effects due to radiation exposure have caused considerable health detriment, outweighing the actual radiological impacts. Despite considerable efforts to normalise humankind's relationship with radiation, there has been little shift away from the perceived uniqueness of the health risks of radiation. One consistent issue is the failure to place radiation within its proper perspective and context, which has ensured that radiophobia has persisted. The radiation protection community must get better at placing its research within the appropriate perspective and context, something that is far too rarely the case in discussions on radiation matters outside of the scientific community. Each member of the radiation protection community has an ethical, professional and moral obligation to set the record straight, to challenge the misconceptions and factual errors that surround radiation, as well as putting it into the proper perspective and context. Failing to do so, the well-established harms of radiophobia will remain, and the many benefits of nuclear technology risk being withheld.

Communicating radiation risk: the role of public engagement in reaching ALARA

The ALARA (an acronym for 'as low as reasonably achievable') principle, keeping the likelihood of incurring exposure, the number of people exposed and the magnitude of their individual doses 'as low as reasonably achievable, taking into account economic and societal factors', is at the core of radiation protection. For many decades the principle has been an area of continuous development, with recent work highlighting the importance of engaging not only with the decision-makers in the ALARA process but all stakeholders who may incur an exposure. This paper considers a particular case study in which the dredging of non-hazardous sediment in the United Kingdom near a now decommissioned nuclear power station raised substantial public concern about radiological exposure. This turned what was a straightforward construction activity into a complex public engagement and reassurance task, at a significant cost disproportionate to the level of radiological risk. This paper highlights the key lessons learnt from the case study, including not only the importance of engaging the public as part of the ALARA process but also of considering the societal impact arising from stress and concerns if misinformation is allowed to promulgate. A discussion is included on the need to underpin any engagement with a clear plan, including pre-engagement, implementation and reinforcement of messages. In addition, the role of the radiation protection professional is considered in ensuring that all stakeholders are informed, so that ultimately they can come to their own decision on what is safe.

Proper Management of the Clinical Exposure Index Based on Body Thickness Using Dose Optimization Tools in Digital Chest Radiography: A Phantom Study

In radiography, the exposure index (EI), as per the International Electrotechnical Commission standard, depends on the incident beam quality and exposure dose to the digital radiography system. Today automatic exposure control (AEC) systems are commonly employed to obtain the optimal image quality. An AEC system can maintain a constant incident exposure dose on the image receptor regardless of the patient thickness. In this study, we investigated the relationship between body thickness, entrance surface dose (ESD), EI, and the exposure indicator (S value) with the aim of using EI as the dose optimization tool in digital chest radiography (posterior-anterior and lateral projection). The exposure condition from the Korean national survey for determining diagnostic reference levels and two digital radiography systems (photostimulable phosphor plate and indirect flat panel detector) were used. As a result, ESD increased as the phantom became thicker with constant exposure indicator, which indicates similar settings to an AEC system, but the EI indicated comparatively constant values without following the tendency of ESD. Therefore, body thickness should be considered under the AEC system for introducing EI as the dose optimization tool in digital chest radiography.

[X-ray diagnostics of fractures in childhood and adolescence-Consensus report of the scientific working group of the pediatric traumatology section of the German Society for Trauma Surgery (DGU)]

Seit Jahrzehnten ist die Projektionsradiographie Standard in der Diagnostik von Frakturen und Verletzungen auch bei Patienten im Kindes- und Jugendalter. Bei jeder Untersuchung mit Röntgenstrahlen sollen aber auch individuell Nutzen und Risiko gegeneinander abgewogen werden. Die Sektion Kindertraumatologie der DGU hat zu verschiedenen Aspekten der Bildgebung zu Diagnostik und Verlaufsbeurteilung, zu Einstellungsmöglichkeiten der intraoperativen Bildgebung, zum Röntgen der Gegenseite, zu Polytrauma und CT, zu postoperativen radiologischen Kontrollen und dem Einsatz der Sonographie ein Konsenspapier erarbeitet.

Quantitative Performance Characterization of Radiation Dose for the Carestream CS9600 Cone-Beam Computed Tomography Machine

INTRODUCTION

Cone-beam computed tomography (CBCT) machines produce relatively low levels of harmful ionizing radiation, as compared with the computed tomography devices used in medical practices. The Carestream CS9600 CBCT imaging device has been recently introduced into the marketplace, and the manufacturer reports the use of an increased x-ray tube voltage (120 kVp) for the device, along with a reduced patient dose that is achieved using added filtration. Independent dosimetry studies are performed to ensure appropriate radiation exposure dose levels are within recommended safety guidelines.The purpose of this study is to independently evaluate and measure the radiation exposure dose performance parameters of the CS9600 CBCT, including its multiple field of view, exposure settings, and filtration options.

METHODS

A thimble ionization chamber and PMMA phantom were used to characterize dose index using the established SEDENTEXTCT evaluation method.

RESULTS

The phantom-obtained radiation dose index measures ranged from 0.128782-13.848 milligrays (mGy) for the various scanning options evaluated. The field of view, type of filter used, and phantom size all had a direct impact on the relationship between the experimentally obtained dose index measures and the dose area product values reported by the manufacturer.

CONCLUSIONS

A strong linear correlation was observed between the experimentally obtained dose index measures and the manufacturer-reported dose area product values. The 0.7 mm Cu filter that has been added to the CS9600 reduced the exposure dose index measures even with the x-ray tube kilovoltage peak (kVp) being increased to 120 kVp, as compared with the 0.15 mm Cu filter at 90 kVp.

Comprehensive strategies to minimize radiation exposure during Interventional electrophysiology procedures: state-of-the-art review

INTRODUCTION

Cardiac electrophysiology (EP) procedures are frequently performed in patients with cardiac arrhythmias, chronic heart failure, and sudden cardiac death. Most EP procedures involve fluoroscopy, which results in radiation exposure to physicians, patients, and EP lab staff. Accumulated radiation exposure is a known health detriment to patients and physicians.

AREA COVERED

This review will summarize radiation exposure, dose metrics, complications of radiation exposure, factors affecting radiation exposure, minimizing radiation exposure, zero or near-zero fluoroscopy strategies, and up-to-date research in the area of reducing radiation exposure and best practices.

EXPERT COMMENTARY

Comprehensive strategies should be implemented in EP laboratories to minimize radiation exposure with standard fluoroscopy. There are routine techniques that can mitigate significant amounts of radiation exposure using standard equipment within the EP lab. The operators need to emphasize that EP practices routinely incorporate non-ionizing radiation sources for cardiac imaging (e.g. magnetic resonance imaging, advanced electroanatomical mapping systems, intracardiac ultrasonography) in addition to other novel technologies to mitigate radiation exposure to patients and physicians.

Occupational ALARA Planning for Reactor Pressure Vessel Dismantling at Kori Unit 1

Assessing workers’ safety and health during the decommissioning of nuclear power plants (NPPs) is an important procedure in terms of occupational radiation exposure (ORE). Optimizing the radiation exposure through the “As Low As Reasonably Achievable (ALARA)” principle is a very important procedure in the phase of nuclear decommissioning. Using the VISIPLAN 3D ALARA planning tool, this study aimed at assessing the radiological doses to workers during the dismantling of the reactor pressure vessel (RPV) at Kori NPP unit 1. Fragmentation and segmentation cutting processes were applied to cut the primary component. Using a simulation function in VISIPLAN, the external exposure doses were calculated for each work operation. Fragmentation involved 18 operations, whereas segmentation comprised 32 operations for each fragment. Six operations were additionally performed for both hot and cold legs of the RPV. The operations were conducted based on the radioactive waste drum’s dimensions. The results in this study indicated that the collective doses decreased as the components were cut into smaller segments. The fragmentation process showed a relatively higher collective dose compared to the segmentation operation. The active part of the RPV significantly contributed to the exposure dose and thus the shielding of workers and reduced working hours need to be considered. It was found that ⁶⁰Co contained in the stainless steel of the reactor vessel greatly contributed to the dose as an activation material. The sensitivity analysis, which was conducted for different cutting methods, showed that laser cutting took a much longer time than plasma cutting and contributed higher doses to the workers. This study will be helpful in carrying out the occupational safety and health management of decommissioning workers at Kori NPP unit 1 in the near future.

Effectiveness of Breast and Eye Shielding During Cervical Spine Radiography: An Experimental Study

Purpose

This study assessed the effectiveness of breast and eye shielding and measured the radiation dose to radiosensitive tissues (eyes and breasts) due to scatter radiation during cervical spine X-ray radiography examinations.

Methods

Using an anthropomorphic phantom, the scattered radiation dose was measured before and after the placement of the lead shield over the eyes and breasts in the anteroposterior (AP) and left lateral projection. A regression formula was utilized to determine the exposure. Mean values and standard deviation of breasts and eyes doses were calculated. The paired two sample t-test was used to compare the recorded dose before and after shielding placement.

Results

Radiation shielding of eyes and breasts during AP cervical spine X-ray decreased radiation dose to the breasts by 99.9% and to the left and right eye by 91% and 89%, respectively. For the left lateral cervical spine X-ray, the radiation dose decreased by 26% and 31% for the left and right eye, respectively, and by 23% and 99% for the left and right breast, respectively. A significant difference was noted comparing the dose before and after the implementing shielding on the eye and breast.

Conclusion

According to the results presented, the dose is significantly reduced, especially considering that they are not in the area of interest but are exposed to scatter radiation.

Death of the ALARA Radiation Protection Principle as Used in the Medical Sector

ALARA is the acronym for "As Low As Reasonably Achievable." It is a radiation protection concept borne from the linear no-threshold (LNT) hypothesis. There are no valid data today supporting the use of LNT in the low-dose range, so dose as a surrogate for risk in radiological imaging is not appropriate, and therefore, the use of the ALARA concept is obsolete. Continued use of an outdated and erroneous principle unnecessarily constrains medical professionals attempting to deliver high-quality care to patients by leading to a reluctance by doctors to order images, a resistance from patients/parents to receive images, subquality images, repeated imaging, increased radiation exposures, the stifling of low-dose radiation research and treatment, and the propagation of radiophobia and continued endorsement of ALARA by regulatory bodies. All these factors result from the fear of radiogenic cancer, many years in the future, that will not occur. It has been established that the dose threshold for leukemia is higher than previously thought. A low-dose radiation exposure from medical imaging will likely upregulate the body's adaptive protection systems leading to the prevention of future cancers. The ALARA principle, as used as a radiation protection principle throughout medicine, is scientifically defunct and should be abandoned.

Standing CT of the equine head: Reducing radiation dose maintains image quality

Multiple published studies involving computed tomographic (CT) examinations of the equine head utilise a wide range of mAs parameters for image acquisition. This prospective, experimental study assessed the effects of lowering mAs during CT image acquisition on image quality and scatter radiation on 10 cadaver equine heads. Each head was scanned three times at 300, 225, and 150 mAs, with all other scanning parameters remaining constant between series. An anthropomorphic phantom was positioned adjacent to each equine head during image acquisition, mimicking a human bystander, with an ionization chamber attached to the phantom at eye level. Each series was reconstructed using filtered back projection, using medium (H30) and high (H80) frequency reconstruction algorithms. Quantitative image quality assessment was performed by calculating signal to noise ratio (SNR) and contrast to noise ratio (CNR). Two qualitative image quality assessments were performed independently by three blinded board certified veterinary radiologists with a 4 week interval, using a visual grade analysis model adapted from peer reviewed medical literature. Ionization chamber measurements, calculated volume CT dose index (CTDIvol), and dose-length product (DLP) were recorded. Halving radiation dose during image acquisition from 300 to 150mAs resulted in comparable image quality between series. There was a statistically significant and linear relationship between mAs and scatter radiation to the bystander; halving mAs during image acquisition resulted in halving of scatter radiation. Results of this cadaveric study support the use of lower mAs settings during standing CT examinations of the equine head.

Ultrasound biosafety: Knowledge and opinions of health practitioners who perform obstetric scans in South Africa

BACKGROUND

Diagnostic ultrasound is generally considered as a safe test in pregnancy. To date there is no evidence that ultrasound has caused harm to the developing foetus. However, with the number of obstetric scans on the rise and the steep increase in acoustic output achieved by modern machines, the lack of evidence of absolute safety remains a concern. Acoustic output is under the direct control of the operator and is therefore the operator's responsibility to keep the intensity as low as reasonably achievable. A situation analysis in the South African context was deemed necessary to determine end user knowledge and opinions on safe antenatal ultrasound practice.

AIM

The aim of this quantitative descriptive, cross-sectional study was to evaluate the knowledge and practice of health practitioners who perform antenatal scans regarding safety aspects of diagnostic ultrasound.

SETTING

A self-administered questionnaire was distributed at two national congresses, hosted by the South African Society of Ultrasound and Obstetrics (SASUOG) and South African Society of Obstetricians (SASOG) committees.

METHOD

Quota non-probability sampling allowed for the identification of professional categories capable of providing information relevant to the study objectives. The sample represented a population with experience in obstetric ultrasound.

RESULTS

Compared to international studies, South African end users demonstrated better knowledge of safety indices than their international counterparts. It is, however, discouraging that end users still demonstrate insufficient knowledge regarding factors contributing to adverse biological effects.

CONCLUSION

With room for improvement, an effort should be made to comply with international standards through increased training efforts and raising awareness.

Development of Simple Methods to Reduce the Exposure of the Public to Radiation from Patients Who Have Undergone 18F-FDG PET/CT

At a time when reducing the radiation dose to patients and the public has become a major focus, we assessed the radiation exposure rate from patients after an ¹⁸F-FDG PET/CT scan and evaluated different interventions to reduce it. Methods: We enrolled 100 patients, divided into 2 groups. For both groups, the radiation dose rate was measured with an ionization survey meter immediately after the scan. For group 1, the patients then voided and their dose rate was measured again. For group 2, the patients waited 30 min before voiding, and we measured the dose rate before (group 2A) and after (group 2B) they voided. Results: In total, 74 of the 100 patients exceeded the 20 μSv/h (2 mR/h) threshold immediately after the scan. In group 1, the mean dose rate decreased by 20.0% from the postscan measurement, with 12 of 36 remaining at or above 20 μSv/h. In group 2A, the mean dose rate decreased by 23% from the postscan measurement, with 9 of 38 remaining at or above 20 μSv/h. In group 2B, the mean dose rate decreased by 35% from the postscan measurement, with 1 of 38 remaining at 20 μSv/h. Conclusion: Nearly 75% of patients undergoing an ¹⁸F-FDG PET/CT scan exceed 20 μSv/h when leaving the imaging facility. The most effective method to reduce radiation exposure was to have the patient void 30 min after the examination.

Improvement principles

INTRODUCTION

The improvement principles are a group of safety principles whose central message is that no risk level above zero is fully satisfactory, and that we should therefore always strive to improve safety. The major safety principles in this group are: as low as reasonably achievable (ALARA), best available technology (BAT), the substitution principle, vision zero, and continuous improvement.

METHOD

This article investigates their similarities and differences, the ways in which they can incorporate compromises with objectives other than safety, and the difficulties that may arise in their application. A particular emphasis is put on comparisons with two major competing groups of principles, namely acceptance principles, which draw a sharp line between acceptable and unacceptable states of affairs, and weighing principles such as CBA that search for an optimized compromise between safety and other objectives.

RESULTS

In comparison to their main competitors, the improvement principles have the important advantage of consistently encouraging safety enhancements. However, some of the problems in their application can probably best be tackled by including them in a combined approach that also makes use of acceptance and/or weighing principles. Two such combined approaches are proposed. The choice between them should be based on the underlying value structure of the decision problem. Practical applications: Guidance is given for the choice of safety principles and for the combined use of more than one such principle.

Novel low-dose protocols using cone beam computed tomography in dental medicine: a review focusing on indications, limitations, and future possibilities

OBJECTIVES

A narrative review on the potential use of low-dose protocols for cone beam computed tomography (CBCT) was conducted to identify indications and their relevance for various dental disciplines.

MATERIALS AND METHODS

Google Scholar was searched using the words "low-dose CBCT". Reviews, consensus papers, clinical studies, and experimental studies were eligible for the initial screening process, but for data extraction only original articles were selected. Similar search procedures were then performed with the additional search words "pedo," "ortho," "endo," "implant," "perio," and "oral surgery." Furthermore, references of included articles were examined to identify further relevant articles.

RESULTS

After screening, 27 publications remained for the data extraction process. Low-dose protocols have been reported for specialties such as pediatric dentistry (evaluating orofacial clefts, periapical lesions, impacted teeth, and autotransplantation), orthodontics (cephalometric analysis and interim assessment of treatment results), endodontics (detecting root fractures, resorptions and periapical bone loss), implant dentistry (planning implant insertion, evaluating peri-implant fenestration and dehiscence), periodontology (assessing periodontal structures), and oral and maxillofacial surgery (assessing mandibular third molars and TMJs). Nevertheless, most of the literature available is related to non-clinical studies. Furthermore, there is a lack of position statements or guidelines from authoritative bodies regarding the use of low-dose protocols in dental medicine.

CONCLUSIONS

Low-dose protocols for CBCT imaging seem to have potential in various disciplines in dental medicine ranging from pediatric dentistry to oral and maxillofacial surgery. Dose reduction is usually achieved by mAs reduction, use of partial rotations, reduced number of projections, and larger voxel sizes, but seldom by kV reduction.

CLINICAL RELEVANCE

Albeit low-dose protocols have potential to result in a reduction of dose exposure for 3D imaging due to dental indications, there is a need to more clearly specify indications and limitations to avoid indiscriminate use of standard and high-dose CBCT scans in the future on the lines of ALARA/ALADA principles.

Radiation Mitigation Techniques in Kidney Stone Management

Patients with nephrolithiasis are exposed to significant quantities of ionizing radiation with the potential to cause secondary malignancy. This risk is magnified by the high recurrence rate of nephrolithiasis. In this article, we identify the risks of ionizing radiation as they pertain to patients with nephrolithiasis. We then identify evidence-based techniques for mitigating patient radiation exposure in the preoperative, intraoperative, and postoperative settings. Key factors include limiting the use of computed tomographic imaging, appropriate modulation of fluoroscopy settings, and minimizing rates of stone recurrence.

Radiophobia: 7 Reasons Why Radiography Used in Spine and Posture Rehabilitation Should Not Be Feared or Avoided

Evidence-based contemporary spinal rehabilitation often requires radiography. Use of radiography (X-rays or computed tomography scans) should not be feared, avoided, or have their exposures lessened to decrease patient dose possibly jeopardizing image quality. This is because all fears of radiation exposures from medical diagnostic imaging are based on complete fabrication of health risks based on an outdated, invalid linear model that has simply been propagated for decades. We present 7 main arguments for continued use of radiography for routine use in spinal rehabilitation: (1) the linear no-threshold model for radiation risk estimates is invalid for low-dose exposures; (2) low-dose radiation enhances health via the body's adaptive response mechanisms (ie, radiation hormesis); (3) an X-ray with low-dose radiation only induces 1 one-millionth the amount of cellular damage as compared to breathing air for a day; (4) radiography is below inescapable natural annual background radiation levels; (5) radiophobia stems from unwarranted fears and false beliefs; (6) radiography use leads to better patient outcomes; (7) the risk to benefit ratio is always beneficial for routine radiography. Radiography is a safe imaging method for routine use in patient assessment, screening, diagnosis, and biomechanical analysis and for monitoring treatment progress in daily clinical practice.

Reducing radiation hazard opportunities in neonatal unit: quality improvement in radiation safety practices

Aim

Guided by the ALARA - "As Low As Reasonably Achievable" principle in radiation safety, a quality improvement project to optimise the bedside diagnostic imaging process to the best standards of care was conducted over a six month period. The goal was too reduce the radiation hazard opportunities in the neonatal intensive care unit by at least 75% from the existing level at Q2/2015, within 6 months.

Methods

The existing bedside imaging process was critically analysed and the following quality improvement initiatives were implemented namely, mandatory lead protective gear to healthcare staff, gonadal shield for neonates, guidelines for optimal collimation of X-ray beam and optimal positioning of neonates. Radiation dosimetry results, regular staff awareness sessions and strong collaboration between neonatologists, radiologists, radiographers and neonatal nurses helped to ensure compliance to the revised imaging process. Radiation hazard opportunities were measured by analysing all radiographs done during the period under baby exposure and healthcare staff exposure categories.

Summary of results

Radiation hazard opportunities were reduced by 100% to healthcare staff and 75% to neonates, and the overall reduction was 83%. The rate of discordance between radiograph request forms and images taken was measured as a surrogate marker for compliance to the project initiatives and it declined by 77%. Mandatory orientation of staff to the revised policy on the standardised diagnostic imaging process, regular radiation awareness talks and staff feedback sessions are among several measures taken to sustain the project.

[Guidelines in medical imaging : objectives, limits and radiation protection]

CONTEXT

Guidelines in medical imaging are aimed at increasing the appropriateness of prescriptions, eliminating unnecessary examina- tions, reducing the exposure of the population and minimizing the costs to public health.

METHOD

Our analysis is based on a bibliographic search and the discussions of the " quality " working group of the BELMIP platform.

RESULTS

The introduction in 2004 and its 2014 revision of the guideliness in medical imaging in Belgium had no measurable effect on the imaging prescription. These recommendations are in fact unrecognized, incomplete, poorly constructed and often unusable.

CONCLUSION

Recommendations in medical imaging need to be reviewed and will be reviewed in the near future in order to be better structured and usable. The legal and medico-legal constraints should be integrated in order for Belgium to comply with the relevant European directive.

Approaching zero: Implications of a computed tomography reduction program for pediatric appendicitis evaluation

PURPOSE

Because of awareness of iatrogenic radiation exposure, there is a national trend of diminishing computed tomography (CT) use for pediatric suspected appendicitis. The purpose of this study was to evaluate the effects of a CT reduction program for evaluation of appendicitis.

METHODS

A multidisciplinary group (emergency medicine, radiology, and surgery) at a children's hospital developed a reduction program which included: ultrasound (U/S) first (2012), magnetic resonance imaging (MRI) second (2014), and standardized U/S reports (2016). Imaging modality, negative appendectomy rate, time from first image to incision, and imaging costs were evaluated over time.

RESULTS

Of the 571 patients evaluated from 2012 to 2016, there was a significant decrease in CT use and increase U/S and MRI use over the study period (all p<0.01). CT use approached zero in 2016. Time from first image to incision (median 10.7h, IQR 5.6-15.5) and negative appendectomy rate (mean 3.7±0.2%) did not change. Median imaging costs ($88, IQR $52-$169) and radiology percent of total costs (range 0.8%-3.9%) increased over time (both p<0.01).

CONCLUSION

Approaching zero CT use for evaluation of pediatric appendicitis is possible through a multidisciplinary protocol without impacting clinical outcomes. However, increased MRI use led to higher costs. Cost-effectiveness of replacing CT with MRI warrants further study.

TYPE OF STUDY

Retrospective comparative study.

LEVEL OF EVIDENCE

Level III.