Radiation Dose Reduction Techniques Research Articles

Techniques and Strategies to Minimize Radiation Exposure in Pediatric Computed Tomography (CT) Abdominal Examinations: A Review.

As children are more vulnerable to radiation-induced cancers and have longer life expectancies, it is essential to implement strict radiation protection measures in pediatric imaging. This study aimed to review radiation dose-minimizing measures in pediatric abdominal computed tomography (CT) examinations. A systematic search across various databases, including Web of Science, PubMed, SpringerLink, ScienceDirect, and Google Scholar, yielded a total of 7,314 articles. The search used keywords that aligned with the objectives of the study. This study included 77 publications after applying the criteria for inclusion and exclusion. We carefully reviewed these selected articles for compliance with the inclusion criteria and excluded them if they did not meet the specified criteria. Only 12 articles fulfilled the strict criteria. An in-depth review of 12 selected articles demonstrated the radiation dose reduction techniques and strategies, which include prefiltering and post-processing algorithms, careful adjustment of exposure parameters such as tube voltage (kVp) and current (mAs), and the establishment of diagnostic reference levels (DRL). Reduction of radiation exposure in pediatric CT imaging demands multifaceted approaches. To reduce the ionizing radiation dose while still obtaining high-quality diagnostic images, healthcare practitioners should adhere to DRL, adjust exposure factors, implement prefiltration, employ AI, and use post-processing algorithms.

Large variation in radiation dose for routine abdomen CT: reasons for excess and easy tips for reduction

ObjectiveTo characterize the use and impact of radiation dose reduction techniques in actual practice for routine abdomen CT.MethodsWe retrospectively analyzed consecutive routine abdomen CT scans in adults from a large dose registry, contributed by 95 hospitals and imaging facilities. Grouping exams into deciles by, first, patient size, and second, size-adjusted dose length product (DLP), we summarized dose and technical parameters and estimated which parameters contributed most to between-protocols dose variation. Lastly, we modeled the total population dose if all protocols with mean size-adjusted DLP above 433 or 645 mGy-cm were reduced to these thresholds.ResultsA total of 748,846 CTs were performed using 1033 unique protocols. When sorted by patient size, patients with larger abdominal diameters had increased dose and effective mAs (milliampere seconds), even after adjusting for patient size. When sorted by size-adjusted dose, patients in the highest versus the lowest decile in size-adjusted DLP received 6.4 times the average dose (1680 vs 265 mGy-cm) even though diameter was no different (312 vs 309 mm). Effective mAs was 2.1-fold higher, unadjusted CTDIvol 2.9-fold, and phase 2.5-fold for patients in the highest versus lowest size-adjusted DLP decile. There was virtually no change in kV (kilovolt). Automatic exposure control was widely used to modulate mAs, whereas kV modulation was rare. Phase was the strongest driver of between-protocols variation. Broad adoption of optimized protocols could result in total population dose reductions of 18.6–40%.ConclusionThere are large variations in radiation doses for routine abdomen CT unrelated to patient size. Modification of kV and single-phase scanning could result in substantial dose reduction.Clinical relevanceRadiation dose-optimization techniques for routine abdomen CT are routinely under-utilized leading to higher doses than needed. Greater modification of technical parameters and number of phases could result in substantial reduction in radiation exposure to patients.Key Points• Based on an analysis of 748,846 routine abdomen CT scans in adults, radiation doses varied tremendously across patients of the same size and optimization techniques were routinely under-utilized.• The difference in observed dose was due to variation in technical parameters and phase count. Automatic exposure control was commonly used to modify effective mAs, whereas kV was rarely adjusted for patient size. Routine abdomen CT should be performed using a single phase, yet multi-phase was common.• kV modulation by patient size and restriction to a single phase for routine abdomen indications could result in substantial reduction in radiation doses using well-established dose optimization approaches.

Future Perspective for Radiation Dose Reduction techniques in Computed Tomography - A Study

The Computed Tomography (CT) image quality is determining by appropriate radiation dose in CT examination. Increases of the radiation dose become dangerous for our health such as induces of cancer, skin injuries, heritable mutations, reddening, burn the skins, etc. Therefore, the dose management study in the CT scanning procedure is one of the most important factors. This research article focuses on the use of the dose effectively in pediatric CT and cardiac CT scan procedures. Besides, the paper comprises dose hunt-down, auditing the scanner utilization, patient safety for the hospital association. This research article discusses radiation dose reduction techniques for effective dose in the view of future perspective in CT scan. This research article suggesting an appropriate technique to reduce the dose effectively in CT images during scanning. The effective dose test was conducted after reviews and ideas from future perspective designs.

Procedure for optimal implementation of automatic tube potential selection in pediatric CT to reduce radiation dose and improve workflow.

It is important to employ radiation dose reduction techniques in pediatric computed tomography (CT) to reduce potential risks of radiation‐induced malignancy. Automatic tube potential (kV) selection tools have been developed and become available on many CT scanners, which select the optimum kV based on the patient size and clinical task to improve the radiation dose efficiency. However, its use in pediatric CT has been mostly empirical, following manufacturer’s default recommendation without solid demonstration for quality improvement. This study aimed to implement an automatic tube potential tool (CAREkV, Siemens Healthcare) into routine pediatric CT practice, using the “Plan‐Do‐Study‐Act” quality improvement process, in place of an existing kV/mAs technique chart. The design of this quality improvement project involved Plan‐Do‐Study‐Act stages. Plan and Do stages identified the criteria for optimal automatic kV selection; a range of phantoms representing typical pediatric groups were scanned on a dual‐source 128‐slice scanner using a fast‐pitch scanning mode. The identified CAREkV settings were implemented into the CT protocol and evaluated after a 6‐month period. In the Study stage, an objective evaluation of the image metrics and radiation dose for two similar patient cohorts using CAREkV and the technique‐chart, respectively, were compared. The kV selected, image quality and radiation dose determined by CAREkV were comparable to those obtained while using the technique‐chart. The CAREkV was successfully implemented into our pediatric abdominopelvic CT practice. By utilizing the “PDSA” process optimal image quality and radiation dose reduction were achieved with an automatic kV selection tool to improve CT workflow.

Radiation dose and risk to the lens of the eye during CT examinations of the brain.

Cataracts are the leading cause of blindness and visual disability worldwide. Of the known contributing factors to this condition, ionising radiation is considered the primary concern in a radiological context given the particular radiosensitivity of the lens of the eye. In light of the substantially increased application of computed tomography in brain imaging, an investigation of the relevent literature is warranted to assess thresholds, lens radiation doses and dose reduction techniques in respect to the cataractogenic risk of such examinations. The value and very existence of a lens dose threshold is debatable given different considerations of radiation dose, latency, opacity classifications and historical sample populations, though ICRP guidelines suggest a threshold of 0.5Gy. Documented CT-specific radiation doses to the eye following scans of the brain are highly variable between studies (2-130mGy), primarily owing to discrepancies in scanning technique. These findings, when coupled with the relative ambiguity of known threshold values, present difficulties in assessing the overall risk of cataracts following serial CT examinations to the head. In the absence of definitive risk evaluations, a cautionary approach is advised. The implementation of gantry tilt along the supraorbital margin is recommended as standard practice on account of its highly effective radiation dose reduction outcomes. Organ-based tube modulation and reductions in tube current may also be considered beneficial. Bismuth eye shielding is only advised where gantry tilting is unachievable, and in such cases, ensure careful adherence to appropriate shield placement and infection control measures.

First experiences of a low-dose protocol for CT-guided musculoskeletal biopsies combining different radiation dose reduction techniques.

The use of computed tomography (CT) for image guidance during biopsies is a powerful approach. The method is, however, often associated with a significant level of radiation exposure to the patient and operator. To investigate if a low-dose protocol for CT-guided musculoskeletal (MSK) biopsies, including a combination of different radiation dose (RD) techniques, is feasible in a clinical setting. Fifty-seven patients underwent CT-guided fine-needle aspiration cytology (FNAC) utilizing the low-dose protocol (group A). A similar number of patients underwent CT-guided FNAC using the reference protocol (group B). Between-group comparisons comprised radiation dose, success rate, image quality parameters, and workflow. In group A, the mean total dose-length product (DLP) was 41.2 ± 2.9 mGy*cm, which was statistically significantly lower than of group B (257.4 ± 22.0 mGy*cm), corresponding to a mean dose reduction of 84% ( P<0.001). The mean CTDIvol for the control scans were 1.88 ± 0.09 mGy and 13.16 ± 0.40 mGy for groups A and B, respectively ( P < 0.001). The success rate in group A was 91.2% and 87.9% in group B ( P = 0.56). No negative effect on image-quality parameters, time of FNAC, and number of control scans were found. We successfully developed a low-dose protocol for CT-guided MSK biopsies that maintains diagnostic accuracy and image quality at a fraction of the RD compared to the reference biopsy protocol at our clinic.

Rectal radiation dose-reduction techniques in prostate cancer: a focus on the rectal spacer.

Prostate cancer is the most common cancer in men. External beam radiotherapy by a variety of methods is a standard treatment option with excellent disease control. However, acute and late rectal side effects remain a limiting concern in intensification of therapy in higher-risk patients and in efforts to reduce treatment burden in others. A number of techniques have emerged that allow for high-radiation dose delivery to the prostate with reduced risk of rectal toxicity, including image-guided intensity-modulated radiation therapy, endorectal balloons and various forms of rectal spacers. Image-guided radiation therapy, either intensity-modulated radiation therapy or stereotactic ablative radiation therapy, in conjunction with a rectal spacer, is an efficacious means to reduce acute and long-term rectal toxicity.

(1)小児CT検査における撮影パラメータと被ばく低減技術(ワークショップ-より良い撮影技術を求めて(その120)-『小児CT撮影について再考する』,テーマB:CT『小児CT撮影の再考』,第62回放射線撮影分科会)

(1)小児CT検査における撮影パラメータと被ばく低減技術(ワークショップ-より良い撮影技術を求めて(その120)-『小児CT撮影について再考する』,テーマB:CT『小児CT撮影の再考』,第62回放射線撮影分科会)

A pilot study investigating two dose reduction techniques for AP lumbar spine radiography using direct dosimetry and Projection VR

IntroductionThe purpose of this study was to compare radiation dose measurements generated using a virtual radiography simulation with experimental dosimeter measurements for two radiation dose reduction techniques in digital radiography. MethodsEntrance Surface Dose (ESD) measurements were generated for an antero-posterior lumbar spine radiograph experimentally using NanoDOT™, single point dosimeters, for two radiographic systems (systems 1 and 2) and using Projection VR™, a virtual radiography simulation (system 3). Two dose reduction methods were tested, application of the 15% kVp rule, or simplified 10 kVp rule, and the exposure maintenance formula. The 15% or 10 kVp rules use a specified increase in kVp and halving of the mAs to reduce patient ESD. The exposure maintenance formula uses the increase in source-to-object distance to reduce ESD. ResultsIncreasing kVp from 75 to 96 kVp, with the concomitant decrease in mAs, resulted in percent ESD reduction of 59.5% (4.02–1.63 mGy), 60.8% (3.55–1.39 mGy), and 60.3% (6.65–2.64 mGy), for experimental systems 1 and 2, and virtual simulation (system 3), respectively. Increasing the SID (with the appropriate increase in mAs) from 100 to 140 cm reduced ESD by 22.3% 18.8%, and 23.5%, for experimental systems 1 and 2, and virtual simulation (system 3), respectively. ConclusionPercent dose reduction measurements were similar between the experimental and virtual measurement systems investigated. For the dose reduction practices tested, Projection VR™ provides a realistic alternate of percent dose reduction to direct dosimetry.

Cone beam CT paranasal sinuses versus standard multidetector and low dose multidetector CT studies

Cone-beam computed tomography (CBCT) is a promising modality for quick outpatient imaging with lower radiation dose and less metal artifact when compared to conventional CT (MDCT) scans.This article will be providing evidence on the diagnostic and treatment-planning applications of CBCT in sinus imaging, mainly, in patients with chronic sinusitis for surgical planning, which retrospectively assessed 21 patients over a period of one year at Queen Elisabeth Hospital, Birmingham, UK. The main objective was to compare the absorbed dose of radiation from CBCT and conventional CT, and to compare the clarity and image quality for important structures in sinus anatomy in patients with sinus disease meriting CT scan imaging.Results of the mean effective dose of twenty-one consecutive CBCTs of paranasal sinuses were 0.27mSv (range 0.05–0.48mSv). This dose was approximately 40% lower when compared to a similar cohort of standard MDCT examinations and 30% lower when compared to low dose sinus CT scans.The visualization of high-contrast bone morphology on CBCT was comparable to standard sinus CT, allowing clear delineation of the principal surgically relevant osseous structures. Soft tissue visibility was however limited. We concluded that, CBCT scan provides a fast and efficient alternative to conventional CT with substantial radiation dose reduction and low dose MDCT techniques. However for more advanced sinus disease, conventional CT scan is preferable. ObjectivesThe main objective was to compare the absorbed dose in the cone beam computed tomography (CBCT) and conventional CT and to compare the clarity and image quality for important structures in sinus anatomy. DesignRetrospective scan review. SettingWe compared both the image characteristics and the effective dose used in CBCT and conventional MDCT sinus imaging, performed at Queen Elizabeth Hospital Birmingham over a 1year period. ParticipantsPatient with sinus disease meriting CT scan imaging. Main outcome measureComparison of effective dose exposure and image quality. ResultsThe mean effective dose of twenty one consecutive CBCTs of paranasal sinuses performed in our institution over a one year period was 0.27mSv (range 0.05–0.48mSv). The dose was approximately 40% lower when compared to a similar cohort of standard MDCT examinations and 30% lower when compared to low dose sinus CT scans.The visualization of high-contrast bone morphology on CBCT was comparable to standard sinus CT, allowing clear delineation of the principal surgically relevant osseous structures. Soft tissue visibility was however limited. ConclusionCone beam CT scan is a quick and efficient alternative to conventional CT with substantial radiation dose reduction over conventional and low dose MDCT techniques. However for more advanced sinus disease, conventional CT scan is preferable.

CT Urography: An Update in Imaging Technique

For decades, traditional IVU studies have been the mainstay in the investigation of urinary tract calculi and obstruction. However, they have been largely superseded by non-contrast CT in the present day. The use of contrast material further expands the utility of CT in the evaluation of urinary tract disease, allowing detection and characterization of renal masses and urothelial lesions. In this review article, we discuss the development and current role of CT urography as the complete imaging investigation in the genitourinary system. Conventional multiphasic protocols and split-bolus techniques for radiation dose reduction are considered. We then focus on how recent technological advances have allowed dual-energy CT to play a complementary role in CT evaluation of the genitourinary system, allowing stone and renal mass characterization, as well as creation of virtual unenhanced datasets. The use of associated post-processing software applications in the clinical context is illustrated.

Strategies and Scientific Basis of Dose Reduction on State-of-the-Art Multirow Detector X-Ray CT Systems.

The continued development in multirow detector computed tomography (MDCT) technology accompanied by tremendous enhancement in the clinical utility and rapid increase in the number of MDCT scanners worldwide are causing a steep rise in the number of diagnostic computed tomography (CT) procedures performed each year. The everincreasing use of this X-radiation-based imaging technique has raised radiation protection concerns among the clinical community and general public. To address these concerns, significant efforts have been made by the clinical community as well as industry, research, and government organizations. Because of these efforts, modern MDCT systems are now equipped with a variety of tools that can lead to "radiation dose-optimized" CT images if used properly. This review describes CT dose metrics and their limitations, radiation dose reduction techniques and strategies implemented using modern MDCT scanners, and the role of research and regulatory organizations in developing guidelines and regulations to facilitate the adoption of the dose reduction strategies. An account of further developments required to achieve submillisievert X-ray CT doses and to make X-ray CT a radiation risk-free imaging modality is also given. A detailed description of the scientific basis and controversies surrounding the linear no threshold (LNT) model, which forms the basis of all radiation dose reduction strategies, is also provided in this review. According to the LNT model, there is no amount of radiation that is safe or beneficial for human beings. Based on recent epidemiological studies, despite all of the controversies, the LNT model continues to be the basis of the ALARA (as low as reasonably achievable) principle of radiation protection framework in CT.

WE‐D‐18A‐05: Construction of Realistic Liver Phantoms From Patient Images and a Commercial 3D Printer

Purpose:To assess image quality and radiation dose reduction in abdominal CT imaging, physical phantoms having realistic background textures and lesions are highly desirable. The purpose of this work was to construct a liver phantom with realistic background and lesions using patient CT images and a 3D printer.Methods:Patient CT images containing liver lesions were segmented into liver tissue, contrast‐enhanced vessels, and liver lesions using commercial software (Mimics, Materialise, Belgium). Stereolithography (STL) files of each segmented object were created and imported to a 3D printer (Object350 Connex, Stratasys, MN). After test scans were performed to map the eight available printing materials into CT numbers, printing materials were assigned to each object and a physical liver phantom printed. The printed phantom was scanned on a clinical CT scanner and resulting images were compared with the original patient CT images.Results:The eight available materials used to print the liver phantom had CT number ranging from 62 to 117 HU. In scans of the liver phantom, the liver lesions and veins represented in the STL files were all visible. Although the absolute value of the CT number in the background liver material (approx. 85 HU) was higher than in patients (approx. 40 HU), the difference in CT numbers between lesions and background were representative of the low contrast values needed for optimization tasks. Future work will investigate materials with contrast sufficient to emulate contrast‐enhanced arteries.Conclusion:Realistic liver phantoms can be constructed from patient CT images using a commercial 3D printer. This technique may provide phantoms able to determine the effect of radiation dose reduction and noise reduction techniques on the ability to detect subtle liver lesions in the context of realistic background textures.

Iterative Reconstruction Techniques for Radiation Dose Reduction

Iterative Reconstruction Techniques for Radiation Dose Reduction

Survey of radiography, radiographic equipment and radiation protection in Jeddah, Saudi Arabia

Objective: The objective was to survey dentists in Jeddah, Saudi Arabia (in government and private sector) to assess their level of knowledge on dental radiography, radiographic equipment and radiation protection, and to evaluate if current dental radiology practices are in accordance with guidelines of UK. Materials and Methods: A survey questionnaire (English and Arabic) containing 15 questions was delivered by hand to 462 dentists. It contained questions on intraoral techniques, image receptor, collimator, film speed, processing, viewing mode, kVp, panoramic equipment, lead apron, person taking radiographs, radiation monitors, and local dental radiology manual. Results: A total of 373 (81%) dentists responded to the survey. Results show a lack of awareness in radiation protection and dose reduction techniques. A high proportion of respondents did not know about, film speed (45%), collimator type (42%), kVp of intraoral equipment (31%), and local dental radiology manual (66%). Further, only 13% use rectangular collimator, 55% use beam alignment, 25% use D speed film, 10% use background light for viewing, 7% of intraoral equipment is operated at 50 kVp, and 21% use digital intraoral equipment. Only 20% of the government sector dentists are directly involved in taking intraoral radiographs compared to 52% in the private sector. Responses from the government sector showed a higher proportion of do not know answers compared with the private sector. Conclusion: It is required to implement internationally recommended standards to improve awareness and knowledge among dentists regarding dental radiography and radiation protection. Furthermore, improvement in undergraduate education level and establishment of postgraduate courses on dental radiology are strongly recommended.

Effect of Real-Time Radiation Dose Feedback on Pediatric Interventional Radiology Staff Radiation Exposure

PurposeTo measure and compare individual staff radiation dose levels during interventional radiologic (IR) procedures with and without real-time feedback to evaluate whether it has any impact on staff radiation dose. Materials and MethodsA prospective trial was performed in which individuals filling five different staff roles wore radiation dosimeters during all IR procedures during two phases: a 12-week “closed” phase (measurements recorded but display was off, so no feedback was provided) and a 17-week “open” phase (display was on and provided real-time feedback). Radiation dose rates were recorded and compared by Mann–Whitney U test. ResultsThere was no significant difference in median procedure time, fluoroscopy time, or patient dose (dose–area product normalized to fluoroscopy time) between the two phases. Overall, the median staff dose was lower in the open phase (0.56 µSv/min of fluoroscopy time) than in the closed phase (3.01 µSv/min; P < .05). The IR attending physician dose decreased significantly for procedures for which the physicians were close to the patient, but not for ones for which they were far away. ConclusionsA radiation dose monitoring system that provides real-time feedback to the interventional staff can significantly reduce radiation exposure to the primary operator, most likely by increasing staff compliance with use of radiation protection equipment and dose reduction techniques.

Effectiveness of combined radiation dose reduction techniques in pulmonary vein anatomy imaging with 320-row computed tomography in a community based practice

Effectiveness of combined radiation dose reduction techniques in pulmonary vein anatomy imaging with 320-row computed tomography in a community based practice

Raise the Bar and Lower the Dose: Current and Future Strategies for Radiation Dose Reduction in Head and Neck Imaging

Technologic advances in CT have generated a dramatic increase in the number of CT studies, with a resultant increase in the radiation dose related to CT scanning. Such increase in radiation dose is becoming a concern for the radiology community, especially with increasing public awareness of the dose burden related to examinations. To cope with the increase in CT-related radiation exposure, it is becoming necessary to optimize CT imaging protocols and apply radiation dose reduction techniques to ensure the best imaging with the lowest radiation dose.

Multiple opportunities to reduce radiation dose from myocardial perfusion imaging

Multiple opportunities to reduce radiation dose from myocardial perfusion imaging

Compliance of Indian dentists with oral radiology safety measures

Objectives: The aim of this study was to determine the dentist's knowledge and practice about dose reduction techniques, radiographic equipment and quality of dental radiographic service among private dental practitioners in Davangere City, India. Materials and Methods: The survey was performed on 80 dental practitioners from Davangere City, India. Information on the demographic characteristics of the dentists, radiographic equipment, techniques and processing they used and radiation protection was obtained with a 40 point questionnaire. Results: The study yielded a response rate of 90%. The respondents' knowledge concerning the technical details of their equipment was limited, with 27.7% not knowing kVp settings of their equipment. Only 11% and 5% respondents reported having long and rectangular collimators respectively. Regarding the film speed 16.6% dental practitioners were unaware about it. The most preferred technique (81%) for periapical radiography was the bisecting angle technique. Lead aprons were worn more often by female dentists. None of the dental practitioners had thyroid collars. The distance of the dentist to the radiation tube during exposure was on average 2.2 m, although 13% of the dentists assisted in holding the image receptor inside the patient's mouth. Only 4% of the dental practitioners reported that they used automatic processor. About 40% of the dental practitioners used film badges. Conclusions: In the present study, the results indicate that for minimizing any unnecessary radiation, attempts should be made to improve dentists' knowledge about radiation dose reduction techniques. Some dose-reducing strategies are commonly used in Davangere Dental clinics, whereas others have not gained wide acceptance.