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BACKGROUND: Computed Tomography (CT) of the abdomen is one of the most frequently performed scans in adults for various abdominal pathologies. Its popularity stems from the immediate image reconstruction following acquisition. However, CT scans are known for their high radiation doses compared to other diagnostic X-ray procedures. This study aimed to analyze the effective dose in patients with varying body habitus during multidetector CT of the abdomen using automatic exposure control. METHODS: This prospective study was conducted in the Department of Radiodiagnosis and Imaging from February 2017 to March 2018. Patients aged 18 and older, regardless of gender, undergoing routine Contrast-Enhanced CT (CECT) of the abdomen were included. Participants were categorized into three groups based on Body Mass Index (BMI): normal weight, overweight, and obese. RESULTS: A total of 168 patients were enrolled, with a mean age of 49.8 ± 15.6 years, predominantly male (66.1%). Obese individuals exhibited significantly higher effective dose values (16.57 ± 2.27 mSv) compared to normal weight (9.45 ± 0.92 mSv) and overweight individuals (11.88 ± 0.77 mSv) (p < 0.01). Similarly, obese patients had significantly higher values for Computed Tomography Dose Index Volume (CTDIvol) (18.32 ± 2.54 mGy) and Dose Length Product (DLP) (1104.86 ± 151.84 mGycm) compared to normal weight (CTDIvol: 11.38 ± 1.24 mGy; DLP: 630.55 ± 61.57 mGycm) and overweight individuals (CTDIvol: 13.56 ± 1.15 mGy; DLP: 792.37 ± 51.56 mGy*cm) (p < 0.05). CONCLUSION: The effective dose received by obese patients during abdominal CT exams with Automatic Exposure Control (AEC) is nearly double that of normal-weight patients. [ABSTRACT FROM AUTHOR]

This study aimed to assess the amount of X radiation absorbed by the chest and abdomen during diagnostic procedures. In three public and three private hospitals, the radiation exposures of 45 patients were estimated. The results showed that the entrance skin air kerma (ESAK) and tube load in milliampere-second (mA s) values varied significantly in all three hospitals. All hospitals were educated in standardized abdomen and chest imaging protocols, focusing on exact parameter calibration to provide the best picture quality and patient safety. These findings underscore the significance of continuous training, collaboration, and compliance with dose optimization protocols during radiological operations. In conclusion, accurate parameter modification is crucial for abdominal and chest imaging to ensure diagnostic efficacy and minimize radiation risks. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study is the reduction of effective dose for CT scan of brain on traumatic patients in NIMS Hospital, Jaipur, Rajasthan. Methods: It was an observational descriptive study. A total of 384 patients from the department of Radio-diagnosis and Imaging, NIMS Hospital, Jaipur, were selected and scan was taken at different technical factors. Result: Out of 384 patients selected for the study, 275 (71.61%) were males and 109 (28.38%) were females. The outcome shows that out of all three groups, males are the most affected traumatic patients when compared to females. Out of the result obtained based on image quality, Group A (with 120 kVp and 450 mAs) and Group B (with 120 kVp and 400 mAs) serves 100% excellent quality images whereas Group C (with 100 kVp and 350 mAs) serves 98.44% average quality images. Conclusion: Although better image quality needs to be maintained on contradict to this, radiation dose to the patients cannot be compromised for better image quality. Thereby according to cardinal principles for radiation protection, ALARA principles1 need to be implemented at all times. Optimization of technical factors yielded a difference is image quality and Group-B gave the best image quality. [ABSTRACT FROM AUTHOR]

Introduction: High kVp techniques, 15% or 10‐kVp rules, are well‐known dose reduction methods. Traditionally, the use of high tube potential (i.e. increased kVp) is associated with decreased radiographic contrast and overall image quality. Recent studies suggest contrast and image quality are not heavily reliant on kVp with digital systems. This study aims to assess the effects of the high tube potential technique on clinical radiographic image quality when using digital systems, to validate high kVp as a dose saving technique. Methods: A selection of comparable pelvis and lumbar spine radiographs were collected from the hospital's picture archiving and communication system (PACS), with technical factors recorded. All clinical radiographs were assessed by 5 senior radiographers using a 15‐point visual grading analysis (VGA) rubric. Results: For 40 AP pelvis radiographs and 40 lateral lumbar spine radiographs, reduction in the dose area product (DAP) with higher kVp is seen. Average pelvis DAP at 75 kVp = 14.06 mGy.cm2; 85 kVp = 7.47 mGy.cm2. Average lumbar spine DAP at 80 kVp = 15.76 mGy.cm2; 90 kVp = 14.83 mGy.cm2. Image quality and contrast scores showed no statistically significant difference between the high and low kVp groups (z = 0.06 and 0.12, respectively). Average pelvis VGA score at 75 kVp = 11.26; 85 kVp = 12.55. Average lumbar spine VGA score at 80 kVp = 9.23; 90 kVp = 10.64. Conclusions: The high tube potential techniques allowed for reduced patient radiation doses whilst showing no degradation of diagnostic image quality in a clinical setting. This study successfully validates the high kVp technique as a useful tool for reducing patient radiation doses whilst maintaining high diagnostic image quality for digital pelvis and lumbar spine radiography. [ABSTRACT FROM AUTHOR]

Frontlinjearbeiderne i NAV skal avklare behov og rettigheter, men også stille krav, aktivere og sanksjonere. Artikkelen studerer hvordan frontlinjearbeidere tilnærmer seg situasjoner der stønadsmottakere ikke imøtekommer vilkår og aktivitetskrav, og i hvilken grad disse blir sanksjonert. Studien viser at når aktivitetskrav brytes, legger frontlinjearbeiderne stor vekt på å klargjøre om stønadsmottakerne hadde forutsetninger for å kunne imøtekomme vilkårene, snarere enn å sanksjonere. Når vilkårene oppfattes som rimelige og stønadsmottakeren er informert og advart på tilfredsstillende måte, sanksjonerer imidlertid frontlinjearbeiderne i betydelig grad brudd på aktivitetskravene.

The purpose of this quantitative, quasi-experimental study was to analyze whether the education of radiology personnel mandated by the American Registry of Radiologic Technologists (ARRT) affects the quality of care delivered to radiology patients. One area of radiology quality of care was focused on the findings presented in this study: radiation dosage. Three groups of study participants were used. The participants were chosen and divided into groups based on their radiology background, non-radiology medical background, or lack of medical background. All study participants were required to complete an assessment asking participants what radiation dosage and shields they would use for a standard set of radiographic examinations. A training video was shown to those participants with no radiology background prior to the assessment. The data provided by each group was compared to determine similarities and variances between the groups and ANOVA calculations were completed. Differences were found between the assessments completed by members of all three groups. The results support the perception that ARRT-mandated education does affect radiation dosage chosen in the care of radiology patients.

Purpose: To assess quantitative and qualitative effects of kVp on oral contrast density.Materials and Methods: Three readers retrospectively reviewed 100 CT scans performed at a range of high- and low-energy settings, independently determining their preferred window and level settings for evaluation of the oral-contrast-opacified bowel. Contrast density was also assessed quantitatively in the stomach, jejunum, and ileum. Subsequently, a range of oral contrast dilutions were imaged at varying kVp’s in a commercially available CIRS tissue equivalent phantom model.Results: In the retrospective patient study, mean oral contrast density increased significantly in the ileum compared to the jejunum (455.2 and 308.8 HU, respectively, p < 0.01). Similar findings were seen in patients regardless of patients’ weight. Mean oral contrast density was higher on lower-energy scans, requiring more window/level adjustment. An oral contrast iodine concentration of 5.82-7.77 mg I/mL most closely approximated a target oral contrast density of 200 HU.Conclusions: Oral contrast density is strongly influenced by kVp, supporting use of more dilute oral contrast when using lower-kVp techniques. [ABSTRACT FROM AUTHOR]

Computed tomography (CT) imaging of fossils has revolutionised the field of palaeontology, allowing researchers to gain a better understanding of fossil anatomy, preservation and conservation. Micro focus X-ray computed tomography (μXCT) has been far more extensively used for these purposes than medical CT (XCT) – mostly because of the exquisite detail that the μXCT scanning modality, using slices of micron thicknesses, can produce. High energy X-rays can potentially penetrate breccia more effectively than lower energy beams. This study demonstrates that lower energy beams produce superior images for prioritising breccia for preparation. Additionally, XCT scanners are numerous, accessible, fast and relatively cost-effective when compared to μXCT scanners – the latter are not freely available, scanning times are much longer and there are significant limitations on the size and weight of scannable objects. Breccia blocks from Malapa were scanned at high and lower energy and images were analysed for image quality, artifact and certainty of diagnosis. Results show that lower energy images are deemed superior to higher energy images for this particular application. This finding, taken together with the limitations associated with the use of μXCT for the imaging of the large breccia from Malapa, shows that XCT is the better modality for this specific application. The ability to choose fossil-bearing breccia, ahead of manual mechanical preparation by laboratory technicians, would allow for the optimal use of limited resources, manual preparatory skills as well as the curtailment of costs. Significance: • ‘Blind’ manual preparation of fossil-bearing breccia is a costly and time-consuming exercise – and often results in a low yield. • The ability to triage fossil-bearing breccia ahead of manual preparation would allow for the optimal use of limited resources. • Medical CT is better than micro-CT to triage breccia to allow for prioritisation of rocks for manual preparation.

Introduction: X-rays are used to diagnose abnormalities in body. However, during radiographs patients will receive radiation doses. As X-ray machine has different quantities and quality of X-rays, it is therefore important for radiological technologists to set radiation doses for particular patients. Objectives: To study the X-ray tube output for general x-ray equipment and to evaluate radiation dose of patient at Hua Hin Hospital, Prachuap Khiri khan. Materials and methods: Relationship between kVp and X-ray tube output of the X-ray machine (Shimadzu HD150B-30 SN: 6114462, Philips Duo Diagnost SN: 04612 and Carestream DRX Revolution SN: 0722) was studied. Entrance surface air kerma of patients exposed from general X-ray machine was evaluated according to the guidelines of IAEA TRS No. 457. Results: Regression of output from Shimadzu HD150B-30, Philips Duo Diagnost output, and Carestream DRX Revolution was 0.003707 x kVp-0.137668, 0.003598 x kVp-0.134144, and 0.003712 x kVp -0.136235, respectively. ESAKs of Skull AP 1.37, 1.32, 1.18 and lateral 0.86, 0.83, 0.90 mGy, chest PA 0.13, 0.12, 0.06 and lateral 0.80, 0.77, 0.64 mGy, T spine AP 1.85, 1.83, 1.33 and lateral 8.80, 8.52, 7.22 mGy, abdomen AP 1.94, 1.88, 1.37 mGy, LS spine AP 2.16, 2.14, 1.55 and lateral 10.99, 10.64, 8.32 mGy, pelvis AP 1.55, 1.50, 0.96 mGy and hip AP 1.32, 1.28, 0.75 mGy were observed from Shimadzu HD150B-30, Philips Duo Diagnost and Carestream DRX Revolution, respectively. Conclusion: ESAKs of this study were lower than dose reference levels of IAEA.

M-Tree, Slim-Tree, DF-Tree, and Omni-Tree are some of the popular dynamic structures which can grow incrementally by splitting overflowed nodes, and adding new levels to the tree very much like the B-tree variants. Unfortunately, they have been shown to perform very poorly compared to flat structures such as AESA, LAESA, Spaghettis, and Kvp that use a fixed set of global pivots. HKvp index structure is an extension of Kvp allowing the elimination of pivots as well as the database objects. The number of pivots can be easily increased to provide more selectivity and query performance. However, there is an optimum number of pivots for a given query radius, and using too many pivots increases the costs of queries and index initialization. In this paper, a new set of pivot elimination mechanisms is proposed to determine the right number of pivots for different query radii. The suggested pivot elimination schemes perform significant cost reduction in terms of number of distance computations, and they estimate the drop rate value for HKvp on query time. [ABSTRACT FROM AUTHOR]

Chest radiography remains the most often utilized radiological modality in the neonatal intensive care unit. Neonates are more radiosensitive and are at higher risk of cancer than adults. In addition, they have a longer life expectancy, which increases the risk of cancer. Therefore, it is essential to protect neonates from radiation hazards. The study aims to assess the effectiveness of using high HKVp technique on reducing radiation dose to neonates undergoing Antero-posterior (AP) chest x-rays. The experiment used a newborn anthropomorphic phantom to simulate a neonate. Chest x-ray images were acquired using different combinations of KVp and mAs. Dose area product (DAP) was recorded in the Digital Imaging and Communications in Medicine (DICOM) header. The effective dose was determined using Monte Carlo simulation. Subjective assessment of image quality was evaluated by three radiologists blindly. The Objective assessment of image quality uses the calculation of the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR). The reduction in the DAP and effective dose at 50 KVp was 26.7% and 19.2%, respectively and for 60 KVp it was 22.9 and 20.2, respectively. While, the reduction in the DAP and effective dose at 70 KVp was 40% and 26%, respectively. There were no significant differences in the means of the DAP, SNR, CNR, and effective dose among different combinations of KVp and mAs. The use of the high KVp technique can play an important role in reducing radiation dose without significant loss of image quality. • Use of the high KVp technique can reduce radiation dose without significant loss of image quality. • At 70 KVp, the DAP and effective dose reduced by 40% and 26%, respectively. • Use of high kVp showed no significant difference in SNR, CNR and radiation dose. • Effort should be made to reduce patients' dose without compromising diagnostic outcome. [ABSTRACT FROM AUTHOR]

Background: This study aims to examine the accuracy of cone-beam computed tomography (CBCT) machines in detecting root fracture when using different metal artifact reduction (MAR) settings at different kilovoltage peak (kVp) levels., Methodology: Sixty-six tooth roots were treated endodontically using a standardized technique. Of these, 33 roots were randomly selected to be fractured; the other 33 roots were intact and used as controls. The roots were placed randomly in prepared beef ribs to mimic the alveolar bone. Imaging was performed by Planmeca ProMax® 3D (Planmeca, Helsinki, Finland) using different MAR settings (no, low, mid, and high) at three different levels of kVp: 70, 80, and 90. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated., Results: There was a significant difference in accuracy when using different MAR settings within the group of 70 kVp. Likewise, within the group of 90 kVp. There was no significant difference between different MAR settings at 80 kVp. Using low MAR/90 kVp had significantly higher accuracy relative to other MAR settings at 90 kVp; it also had the highest values of sensitivity, specificity, and AUC in the study. Using mid and high MAR at 70 kVp or 90 kVp decreased accuracy significantly. Mid MAR/90 kVp was the least effective setting in this study., Conclusions:  Using low MAR at 90 kVp significantly increased the accuracy within the group of 90 kVp. In contrast, mid MAR and high MAR in 70 and 90 kVp, respectively, decreased accuracy significantly., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Almeshari et al.)

Sparse spatial selection (SSS) allows insertions of new database objects and dynamically promotes some of the new objects as pivots. In this paper, we argue that SSS has fundamental problems that result in poor query performance for clustered or otherwise skewed distributions. Real datasets have often been observed to show such characteristics. We show that SSS has been optimized to work for a symmetrical, balanced distribution and for a specific radius value. Our main contribution is offering a new pivot promotion scheme that can perform robustly for clustered or skewed distributions. We show that our new indexing scheme performs significantly better than tree-based dynamic structures while having lower insertion costs. [ABSTRACT FROM AUTHOR]

Purpose: To compare radiation dose and image quality of abdominal CT for patients who underwent repeated CT examinations before and after adjustment of scan protocol. Materials and Methods:We compared radiation dose and image quality of repeated abdominal CT scans (at three-year-interval) of 50 patients with chronic liver disease, 50 patients with early gastric cancer, and 50 patients with uterine cancer. To reduce radiation dose, we optimzed CT protocols by omitting unnecessary pre-contrast phase, reducing kVp, and setting higher noise index. Data o f dose reports were collected. Objective image quality was evaluated for noise level, signal to noise ratio (SNR), and con tra st noise ratio (CNR). For subjective image quality, we evaluated image noise, contrast, and overall diagnostic acceptability. Results: The mean values of dose length product of 2011 CT scans compared to those of 2008 CT scans were 27.6% to 45.7%. The image noise level, SNR, and CNR were significantly (p< 0.05) worse in 2011 CT scans compared to 2008 CT scans. For subjective image quality, image noise was also significantly (p <0.05) worse in 2011. However, CNR and diagnostic acceptability showed variable results. No CT scans were considered as unacceptable image. Conclusion: We modified abdominal CT protocols to reduce radiation exposure. [ABSTRACT FROM AUTHOR]

Patients, referring physicians, the media, and government agencies have all expressed concern over the risks of medical radiation, particularly as it relates to CT. This concern is particularly paramount when associated with a screening examination such as CT colonography. These theoretical risks must be weighed realistically against the substantial benefits of colon cancer screening as well as against the risks inherent in the major alternative screening option, optical colonoscopy. When put into perspective, the risk-benefit ratio is highly in favor of the performance of CT colonography. Nevertheless, in following the ALARA principle, there is an ever increasing armamentarium of options that can be employed in the pursuit of CT radiation dose reduction, all of which can be used in many synergistic combinations allowing for dose reduction while simultaneously preserving image quality and minimizing image noise. After a brief tutorial on estimating radiation dose, various strategies will be discussed including reductions in tube current and tube voltage as well as the use of automatic dose modulation and iterative reconstruction. Other practical considerations will also be reviewed including proper patient isocentering, optimization of colonic insufflation to minimize additional decubitus scans, proper choice of scan volumes to avoid overranging, and variation of slice thickness and window width to minimize perceived image noise. Finally, a strategy for how to incrementally introduce these methods as well as a way to compare dose reduction efforts across institutions throughout the country will be offered. [ABSTRACT FROM AUTHOR]

It is important to optimize digital radiographic technique settings for small animal imaging in order to maximize image quality while minimizing radiation exposure to personnel. The purpose of this study was to evaluate two objective methods for determining optimal k Vp values for an indirect flat panel digital detector. One method considered both image quality and personnel exposure as endpoints and one considered only image quality. Phantoms simulated veterinary patients of varying thicknesses with lesions of varying sizes. Phantoms were exposed to a range of kVp values (60, 81, 100, and 121), using different mAs settings for each phantom. Additionally, all phantoms were exposed to a standard test exposure of 100 k Vp/2.5 m As. Scattered radiation was recorded and used as a measure of personnel exposure. When personnel exposure was considered, a figure of merit was calculated as an endpoint of optimization. The optimal k Vp value for each phantom was determined based on the highest signal difference-to-noise ratio with or without inclusion of the figure of merit. When personnel exposure was not considered, increasing k Vp resulted in higher signal difference-to-noise ratios and personnel exposure increased when both patient thickness and k Vp increased. Findings indicated that a single standard technique of 100 k Vp/2.5 m As was only optimal for most medium-sized patients. Images of thinner patients should be made with a lower k Vp. Very large patients require a higher k Vp than 100 regardless of the optimization method used. Personnel exposure from optimized techniques was low and not expected to exceed annual occupational dose limits. [ABSTRACT FROM AUTHOR]

Purpose: To present a novel method for analyzing the voltage waveform from high-frequency X-ray generators for radiographic systems. Material and Methods: The output signal of the actual voltage across the tube of a high-frequency generator was measured using the built-in voltage sense taps that are used for voltage regulation feedback in X-ray generators. The output signal was stored in an analyzing recorder, and the waveforms were analyzed using FFT analysis. The FFT analysis of high-frequency generators consisted of obtaining the power spectrum, comparing the major frequency components in the tube voltage waveforms, and examining the intensity of each frequency component. Results: FFT analysis enables an objective comparison of the complex tube voltage waveforms in high-frequency X-ray generators. FFT analysis detected the change in the X-ray tube voltage waveform that occurred when there were problems with the high-frequency generator. Conclusion: High-frequency X-ray generators are becoming the universal choice for radiographic systems. The X-ray tube voltage and its waveform are important features of an X-ray generator, and quality assurance (QA) is important, too. As a tool for engineers involved in the design and development of X-ray generators, we can see that our methods (FFT analysis) might have some value as a means of describing generator performance under varying conditions. Furthermore, since the X-ray tube voltage waveform of a high-frequency generator is complex, FFT analysis may be useful for QA of the waveform. [ABSTRACT FROM AUTHOR]

This study compares the real-time dosimetric performance of a bpw34 photodiode (PD) and cold white light-emitting diodes (LEDs) based on diagnostic X-ray-induced signals. Signals were extracted when both the transducers were under identical exposure settings, including source-to-detector distance (SDD), tube voltage (kVp), and current-time product (mAs). The transducers were in a photovoltaic configuration, and black vinyl tape was applied on transducer active areas as a form of optical shielding. X-ray beam spectra and energies were simulated using Matlab-based Spektr functions. Transducer performance analysis was based on signal linearity to mAs and air kerma, and sensitivity dependence on absorbed dose, energy, and dose rate. Bpw34 PD and cold white LED output signals were 84.8% and 85.5% precise, respectively. PD signals were 94.7% linear to mAs, whereas LED signals were 91.9%. PD and LED signal linearity to dose coefficients were 0.9397 and 0.9128, respectively. Both transducers exhibited similar dose and energy dependence. However, cold white LEDs were 0.73% less dose rate dependent than the bpw34 PD. Cold white LEDs demonstrated potential in detecting diagnostic X-rays because their performance was similar to that of the bpw34 PD. Moreover, the cold white LED array's dosimetric response was independent of the heel effect. Although cold white LED signals were lower than bpw34 PD signals, they were quantifiable and electronically amplifiable. • LED-based diagnostic X-ray detection and dosimetry is innovative. • LEDs generated lower radiation-induced signals than the photodiode. • Both the photodiode and LEDs exhibited similar dose and energy dependence. • LEDs were slightly less dose rate dependent than the photodiode. • Both the photodiode and LED radiation-induced signals were ~ 85% precise. [ABSTRACT FROM AUTHOR]

Significant anxiety has been expressed by some over the radiation risks associated with computed tomography (CT), particularly when it applies to a screening examination such as CT colonography. These theoretic risks are far outweighed by the significant benefits colorectal cancer screening offers. Regardless of how significant the theoretic risk of CT radiation is in the older population, the ALARA principle maintains that radiation dose should be reduced to As Low As Reasonably Achievable. This article will discuss various strategies that may be utilized to reduce radiation dose and mitigate any increase in image noise that may occur., (Copyright © 2018 Elsevier Inc. All rights reserved.)