A paediatric X-ray exposure chart

Cumulative radiation dose from medical imaging in paediatric congenital heart disease patients with epicardial cardiac implantable electronic devices

Aims

To determine whether paediatric congenital heart disease (CHD) patients with epicardial cardiac implantable electronic devices (CIEDs) receive high cumulative effective doses (CEDs) of ionizing radiation from medical imaging tests.

Methods and results

We compared 28 paediatric CHD patients with epicardial CIEDs (cases) against 40 patients with no CIED matched by age at operation, sex, surgical era, and CHD diagnosis (controls). We performed a retrospective review of radiation exposure from medical imaging exams between 2006 and 2022. Radiation dose from computed tomography (CT) and X-ray radiography was calculated using the National Cancer Institute Radiation Dosimetry Tool. We performed univariate analysis to compare the CED between the two groups. In the case subgroup, we convened experts' review to adjudicate the prevalence of CT exams that should have been performed with magnetic resonance imaging (MRI) in the absence of a CIED. Children (median age 2.5 years at implant) with CIEDs received significantly higher median CED compared with matched controls (6.90 vs. 1.72 mSv, P = 0.0018). In cases, expert adjudication showed that 80% of the CT exams would have been performed with MRI in the absence of a CIED. This resulted, on average, a five-fold increase in the effective dose (ED) from post-lead implant CTs.

Conclusion

Paediatric CHD patients with CIED received four times higher CED than matched controls. Improved access to medical imaging tests without ionizing radiation, such as MRI, could potentially reduce the ED in CIED patients by up to five times.

An Overview of Factors Affecting Exposure Level in Digital Detector Systems and their Relevance in Constructing Exposure Tables in Equine Digital Radiography

The aim of this review is to describe the steps of constructing exposure tables for use of digital detector systems (DRx) in equine practice. Introductory, selected underlying technical aspects of digital radiography are illustrated. Unlike screen-film radiography (SFR), DRx have a uniform signal response of the detector over a large dose range. This enables generation of diagnostic images from exposures that were previously nondiagnostic on SFR, thus reducing retakes. However, with decreasing detector entrance dose, image noise increasingly hampers the image quality. Conversely, unlike the blackening observed on SFR, overexposures can go visibly undetected by the observer. In DRx the numeric exposure indicator value is the only dose-control tool. In digital radiography the challenge is to reduce the dose and reduce the radiation risk to staff whilst maintaining diagnostic image quality. We provide a stepwise method of developing exposure tables as tools for controlling exposure levels. The identified kVp - mAs combinations in the table are derived from the predefined exposure indicator values of the detector system. Further recommendations are given as to how the exposure indicator can be integrated into routine workflow for rechecking the reliability of the formerly identified settings and how these tables might serve a basis for further reduction of the exposure level. Detector quantum efficiency (DQE) is an important parameter of assessing performance of an imaging system. Detectors with higher DQE can generate diagnostic images with a lower dose, thus having a greater potential for dose reduction than detectors with low DQE.

Recommendations for reducing exposure to medical X-ray irradiation (Review)

With the increasing frequency of X-ray examinations in clinical medicine, public concern regarding the harm caused by exposure to X-ray radiation is also increasing. However, some physicians are not completely aware of the dangers of exposure to X-ray irradiation. Individuals specialized in this field, including physicians, have a better understanding of these dangers, which limits the use of X-rays in medicine. The present study aimed to address strategies for reducing the harm caused by exposure to medical X-rays and increase public awareness regarding X-ray radiation. Through a literature search and review, combined with the current status of clinical X-ray examination and the authors' professional experience, the present study highlights the importance of reducing X-ray exposure, and proposes several specific recommendations and measures for reducing the frequency or dose of X-ray irradiation. On the whole, the finding discussed in the present review suggest the minimal use of medical X-ray examinations and that alternative tests should be selected whenever possible. When medical X-ray screening and treatments are necessary, the risk-benefit ratio should be assessed, possibly aiming to achieve avoidable exposure. Further attention should be paid to protect sensitive glands and reduce the risks in children.

Optimization of Image Quality and Organ Absorbed Dose for Pediatric Chest X-Ray Examination: In-House Developed Chest Phantom Study

Purpose

This study aimed to identify proper exposure techniques to maintain optimal diagnostic image quality with minimum radiation dose for anteroposterior chest X-ray projection in pediatric patients.

Methods

Briefly, an in-house developed pediatric chest phantom was constructed. Next, nanodot OSLDs were used for organ absorbed dose measurement and placed in the lung area, and the phantom was exposed to various exposure techniques (ranging from 50 to 70 kVp with 1.6, 2, and 2.5 mAs). After that, the phantom was used to assess image quality parameters, including SNR and CNR. Two radiologists assessed the subjective image quality using a visual grading analysis (VGA) technique. Finally, the figure of merit (FOM) was analyzed.

Results

The developed phantom was constructed successfully and could be useful for dose measurement and image quality assessment. The absorbed dose varied from 0.009 to 0.031 mGy for the range of exposure techniques used. SNR and CNR showed a gradually increasing trend, while kVp and mAs values were increased. The highest kVp (70 kVp) produced the highest SNR and CNR, exhibiting a significant difference compared with 50 and 60 kVp (P < 0.05). The overall VGA score was 3.2 ± 0.3, and the low kVp technique demonstrated better image quality compared with the reference image.

Conclusion

The optimized exposure technique was identified as 60 kV and 2.5 mAs, indicating the highest FOM score. This work revealed practicable techniques that could be implemented into clinical practice for performing pediatric chest radiography.

Method of determining technique from weight and height to achieve targeted detector exposures in portable chest and abdominal digital radiography

This study presents a methodology to develop an X-ray technique chart for portable chest and abdomen imaging which utilizes patient data available in the modality worklist (MWL) to reliably achieve a predetermined exposure index (EI) at the detector for any patient size. The method assumes a correlation between the patients' tissue equivalent thickness and the square root of the ratio of the patient's weight to height. To assess variability in detector exposures, the EI statistics for 75 chest examinations and 99 abdominal portable X-ray images acquired with the new technique chart were compared to those from a single portable unit (chest: 3877 images; abdomen: 200 images) using a conventional technique chart with three patient sizes, and to a stationary radiography room utilizing automatic exposure control (AEC) (chest: 360 images; abdomen: 112 images). The results showed that when using the new technique chart on a group of portable units, the variability in EI was significantly reduced (p < 0.01) for both AP chest and AP abdomen images compared to the single portable using a standard technique chart with three patient sizes. The variability in EI for the images acquired with the new chart was comparable to the stationary X-ray room with an AEC system (p > 0.05). This method could be used to streamline the entire imaging chain by automatically selecting an X-ray technique based on patient demographic information contained in the MWL to provide higher quality examinations to clinicians by eliminating outliers. In addition, patient height and weight can be used to estimate the patients' tissue equivalent thickness.

Neonatal digital chest radiography- should we be using additional copper filtration?

OBJECTIVES

Copper filtration removes lower energy X-ray photons, which do not enhance image quality but would otherwise contribute to patient radiation dose. This study explores the use of additional copper filtration for neonatal mobile chest imaging.

METHODS

A controlled factorial-designed experiment was used to determine the effect of independent variables on image quality and radiation dose. These variables included: copper filtration (0 Cu, 0.1 Cu and 0.2 Cu), exposure factors, source-to-image distance and image receptor position (direct / tray). Image quality was evaluated using absolute visual grading analysis (VGA) and contrast-to-noise ratio (CNR) and entrance surface dose (ESD) was derived using an ionising chamber within the central X-ray beam.

RESULTS

VGA, CNR and ESD significantly reduced (p < 0.01) when using added copper filtration. For 0.1 Cu, the percentage reduction was much greater for ESD (60%) than for VGA (14%) and CNR (20%), respectively. When compared to the optimal combinations of parameters for incubator imaging using no copper filtration, an increase in kV and mAs when using 0.1-mm Cu resulted in better image quality at the same radiation dose (direct) or, equal image quality at reduced dose (in-tray). The use of 0.1-mm Cu for neonatal chest imaging with a corresponding increase in kV and mAs is therefore recommended.

CONCLUSION

Using additional copper filtration significantly reduces radiation dose (at increased mAs) without a detrimental effect on image quality.

ADVANCES IN KNOWLEDGE

This is the first study, using an anthropomorphic phantom, to explore the use of additional Cu for digital radiography neonatal chest imaging and therefore helps inform practice to standardise and optimise this imaging examination.

Use of weight-based vs age-based groupings in the study of typical values of air kerma area product (PKA) for paediatric radiographs of chest and abdomen

OBJECTIVE

To compare age groupings versus weight groupings in the calculation of typical air kerma area product (P_KA) values in paediatric X-ray exams of chest and abdomen in our hospital.

METHODS

Data were analysed from 687 abdominal and 1374 chest X-ray examinations. The P_KA of exams was extracted with Radimetrics, and patient weights were collected from electronic records. Data were organised in different age groups and typical P_KA values were estimated. The process was repeated by organising data in different weight groups.

RESULTS

Typical P_KA values for the four younger age groups (<1m, 1m - < 4y, 4y - < 10y and 10y - < 14y) were comparable to typical values for their equivalent weight groups (<5 kg, 5-15 kg, 15-30 kg and 30-50 kg, respectively). However, typical P_KA values at the late adolescent age group (14y - < 18y) were much lower than its equivalent weight group (>50 kg).

CONCLUSIONS

Age and weight groupings were found at our site to be interchangeable for the calculation of typical paediatric P_KA values. The only exception was the late adolescent group, whose weight distribution can account for the difference in typical P_KA results within its equivalent weight group.

ADVANCES IN KNOWLEDGE

In calculating typical P_KA values for radiological paediatric body examinations, departments must ascertain if using age groups, which is typical practice, is equivalent to using weight groups. Otherwise, results may misrepresent local practice.

STATUS OF RADIATION DOSE LEVELS IN PAEDIATRIC CHEST RADIOGRAPHY IN A TERTIARY HOSPITAL IN GHANA

Determination of appropriate radiation doses to paediatric patients in accordance with the as low as reasonably achievable (ALARA) principle is important, as it allows for effective optimization of imaging techniques. This study assessed the status of radiation dose levels in paediatric patients undergoing chest X-ray examinations at a tertiary hospital in Ghana. A population encompassing 86 paediatric patients categorised as infants (<1 y), young children (1-5 y) and older children (6-12 y) was selected using a quasi-experimental study design. The patients' anatomical data and X-ray beam exposure parameters were used to indirectly calculate the entrance surface doses (ESDs) received during the examinations. The infants received the highest mean ESD of 196 μGy (uncertainty = 0.37) compared to 158 μGy (uncertainty = 0.46) among the older children. The risk of developing radiation-induced biological effects was therefore higher for infant patients. The ESDs were generally higher than the internationally recommended reference doses. Careful adoption of internationally accepted exposure factors (high tube voltage and low tube load) is most recommended to optimise the dose.

Adenoid measurement accuracy: A comparison of lateral skull film, flexible endoscopy, and intraoperative rigid endoscopy (gold standard)

OBJECTIVE

To compare the accuracy of lateral skull film, flexible endoscopy, and intraoperative rigid endoscopy in assessment of adenoid size.

METHODS

A cross-sectional study was conducted in 43 pediatric patients undergoing ENT surgery from July 2017 to December 2018. All patients underwent preoperative lateral skull film, flexible endoscopy, and intraoperative rigid endoscopy.

RESULTS

The average adenoidal-nasopharyngeal (A/N) ratio obtained from lateral skull film, flexible endoscopy, and intraoperative rigid endoscopy was 72.9, 79.5, and 81.6, respectively. There was a moderate correlation between A/N ratio from lateral skull film and intraoperative rigid endoscopy (Pearson's correlation: 0.567, p˂0.001). Whereas, the A/N ratio from flexible endoscopy compared to intraoperative rigid endoscopy showed a stronger correlation (Pearson's correlation: 0.791, p˂0.001). From linear regression analysis, the intraoperative adenoid measurement was estimated from the results of flexible endoscopy (intraoperative rigid endoscopy: 0.72 [flexible endoscopy] +24.47) and lateral skull film (intraoperative rigid endoscopy = 0.65 [lateral skull film] + 34) CONCLUSION: Flexible endoscopy yields the most accuracy in the assessment of adenoid size and nasopharynx visualization, without radiation exposure or anesthesia. Despite less accuracy, lateral skull film is more availability in every hospital. The correlation of adenoid size measurement in this study can also be applied for the actual size of adenoid.

Cumulative diagnostic imaging radiation exposure in premature neonates

BACKGROUND

To date, there has been limited work evaluating the total cumulative effective radiation dose received by infants in the neonatal intensive care unit. Most previous publications report that the total radiation dose received falls within the safe limits but does not include all types of ionizing radiation studies typically performed on this vulnerable patient population. We aimed to provide an estimate of the cumulative effective ionizing radiation dose (cED) in microSieverts (μSv) received by premature infants ≤32 weeks from diagnostic studies performed throughout their NICU stay, and predictors of exposures.

METHODS

Retrospective chart review from 2004-2011. Data included demographics, gestational age (GA), birth weight (BW), length of stay (LOS), clinical diagnosis, and radiological studies.

RESULTS

1045 charts were reviewed. Median GA = 30.0 weeks (SD 2.7, range 22.0-32.6). Median BW = 1340.0 grams (SD 445.4, range 420-2470). Median number of radiographic studies = 9 (SD 28.5, range 0-210). Median cED = 162μSv (range 0-9248). The cED was positively associated with LOS (p <  0.001) and inversely correlated with GA (p <  0.001) and BW (p <  0.001). Infants with intestinal perforation had the highest median cED 1661μSv compared to 162μSv for others (p <  0.001).

CONCLUSION

Our results provide an estimate of the cumulative effective radiation dose received by premature infants in a level 4 neonatal intensive care unit from all radiological studies involving ionizing radiation and identifies risk factors and predictors of such exposure. Radiation exposure in NICU is highest among the most premature and among infants who suffer from intestinal perforation.

Prescription practice and clinical utility of chest radiographs in a pediatric intensive care unit: a prospective observational study

Background

Chest radiograph (CXR) prescribing pattern and practice vary widely among pediatric intensive care units (PICU). ‘On demand’ approach is increasingly recommended as against daily ‘routine’ CXRs; however, the real-world practice is largely unknown.

Methods

This was a prospective observational study performed in children younger than 12 years admitted to PICU of a tertiary care teaching hospital in India. Data were collected on all consecutive CXRs performed between December 2016 and April 2017. The primary outcome was to assess the factors that were associated with higher chest radiograph prescriptions in PICU. Secondary outcomes were to study the indications, association with mechanical ventilation, image quality and avoidable radiation exposure.

Results

Of 303 children admitted during the study period, 159 underwent a total of 524 CXRs in PICU. Median (IQR) age of the study cohort was 2 (0.6–5) years. More than two thirds [n = 115, 72.3%] were mechanically ventilated. Most CXRs (n = 449, 85.7%) were performed on mechanically ventilated patients, amounting to a median (IQR) of 3 (2–5) radiographs per ventilated patient. With increasing duration of ventilation, the number of CXRs proportionately increased in the first two weeks of mechanical ventilation. In non-ventilated children, about two thirds (68%) underwent only one CXR. Majority of the prescriptions were on demand (n = 461, 88%). Most common indications were peri-procedure prescriptions (37%) followed by evaluation for respiratory disease status (24%). About 40% CXRs resulted in interventions; adjustment in ventilator settings (13.5%) was the most frequent intervention. In 26% (n = 138) of radiographs, image quality required improvement. One or more additional body part exposure other than chest and upper abdomen were noted 336 (64%) images. Children with > 3 CXR had higher PRISM III score, more often mechanically ventilated, had higher number of indwelling devices [mean (SD) 2.6 (1.2) vs. 1.7 (1.0)] and stayed longer in PICU [median (IQR) 11(7.5–18.5) vs. 6 (3–9)].

Conclusion

On demand prescription was the prevalent practice in our PICU. Most non-ventilated children underwent only one CXR while duration of PICU stay and the number of devices determined the number of CXRs in mechanically ventilated children. Quality improvement strategies should concentrate on the process of acquisition of images and limiting the radiation exposure to unwanted body parts.

Contemporary research in digital radiography

Whilst digital radiography (DR) is often seen as the "bread and butter" of medical imaging, there have been considerable advances in technology in the last two decades. Research and education need to move with these new technologies to recognise and take advantage of evolving technologies and optimisation methods that are not constrained by film/screen limitations. Now is an excellent time for radiographers, physicists and students to embark on original and contemporary research into DR.

Imaging neonates within an incubator - A survey to determine existing working practice

INTRODUCTION

There is limited and confusing evidence within the literature regarding the optimal techniques when imaging neonates within incubators; in particular, whether to place the image receptor directly behind the neonate or in the incubator tray. For this reason, radiology departments across Wales and North West England were surveyed to explore existing working practice with regards to incubator imaging.

METHOD

A self-designed survey was developed using a systematic approach. The survey was sent to 31 radiology departments across Wales and North West England whom had a neonatal unit in order to assess existing techniques used when imaging neonates within the incubator. The survey was split into three main domains: 1) general/demographics, 2) exposure factors and technique, and 3) incubator design.

RESULTS

Nineteen departments responded (64%) demonstrating a wide variation in practice for incubator imaging. The minimum and maximum exposure factors used for neonatal chest x-ray imaging varied from 55 kV to 65 kV and 0.5 mAs-2 mAs. Fifty-eight percent of departments used the incubator tray as standard practice with the remaining forty two percent not using the tray for various reasons including, image quality, artefacts and misalignment. Sixty-three percent of departments use the maximum achievable SID for incubator imaging which demonstrates wide variability as the SID would be dependent upon: incubator design, portable machine and radiographer height.

CONCLUSION

The survey demonstrates a wide variation in existing practice for neonatal incubator imaging.

IMPLICATIONS FOR PRACTICE

This study supports the need for standardisation and further optimisation work to ensure best practice for this vulnerable patient group.

RADIATION EXPOSURE OF PAEDIATRIC GENERAL RADIOGRAPHY, FLUOROSCOPY AND CT PROCEDURES IN THE CZECH REPUBLIC-PILOT STUDY

The pilot dose survey on paediatric general radiography, fluoroscopy and CT procedures was performed in four university hospitals. The analysis of data was focused on the radiography and CT imaging of head, chest, abdomen, pelvis and spine and fluoroscopic procedures of gastrointestinal and urinary tracts. The survey was conducted by the National Radiation Protection Institute. Two hospitals exported data from the patient dose management system, while the others collected the data manually. The methodology of diagnostic reference levels assessment was proposed and tested. Local diagnostic reference levels were calculated in terms of air kerma-area product $P_{KA}$, CT air kerma-length product $P_{KL,CT}$ and volumetric CT air kerma index $C_{VOL}$. The lack of procedure standardisation, e.g. in tube voltage setting irrespective of patient's weight, was revealed at one hospital. Dose and exposure parameters distributions with respect to patient's anatomical constitution are presented in this article. In future, this pilot study will be a base for national survey of paediatric diagnostic reference levels.

OPTIMIZING IMAGE QUALITY, RADIATION DOSAGE TO THE PATIENT AND TO THE DETECTOR IN PEDIATRIC CHEST RADIOGRAPHY: A PHANTOM STUDY OF A PORTABLE DIGITAL RADIOGRAPHY SYSTEM

The present work aimed to optimize exposure settings in pediatric digital chest radiography (DR) with regard to image quality and radiation dosage. A pediatric phantom was imaged with a portable DR unit to examine different exposure settings (range: 75-109 kVp; 0.3-1.28 mAs) for patients of 10-20 kg. Fourteen experienced radiologists compared the structural image quality of the images with a reference image (85 kVp/1.28 mAs). A multiple-reader multiple-case analysis of the radiologists' interpretations was performed. Effective dose was computed and standardized exposure indices (EIs) were extracted for the different exposure settings. For the lowest tube voltage setting (75 kVp/1.28 mAs), radiation dosage could be reduced with 35% relative the reference settings without compromising image quality (p > 0.05). EI was within recommendations (250 ± 100). Lower tube voltage in pediatric DR permitted a dose reduction at maintained quality for the physical aspects and diagnostic performance. Other weight-classes should be examined and adjusted accordingly.

Muscle and bone dose in paediatric limb digital radiography: a Monte Carlo evaluation

The proliferation of digital radiography (DR) has led to a re-evaluation of exposure parameters and image quality. Currently, there is a move towards reducing X-ray tube voltage (kVp) in paediatric exposures down to 40 kVp to achieve better images. However, the effect on patient dose of these modifications is uncertain. The main aims of this phantom study were to evaluate the effect of reducing the kVp in paediatric limb DR exposures on contrast-to-noise ratio (CNR) and patient dose. For this purpose, Monte Carlo simulations of radiographic exposures on a paediatric limb phantom were performed. The phantom included muscle tissue and bone segments of five different densities in the range of 1.12 to 1.48 g/cm3. The overall thickness of the phantom varied between 1 and 12 cm. Dependence of the CNR at constant limb phantom muscle and bone doses and dependence of the CNR per unit of muscle and bone dose at constant detector dose on radiographic exposure factors and limb thickness were calculated. X-ray tube current-time product (mAs) values required to achieve equal detector dose versus limb thickness for different kVp were calculated, as well as muscle and bone doses for the limb phantom of varying thickness. Present work has shown that reducing the kVp in paediatric radiography of the extremities can result in a significant increase in radiation dose, particularly for thicker limbs. Low kVp radiography requires justification for use on the extremities.

Construction and validation of a low cost paediatric pelvis phantom

PURPOSE

Imaging phantoms can be cost prohibitive, therefore a need exists to produce low cost alternatives which are fit for purpose. This paper describes the development and validation of a low cost paediatric pelvis phantom based on the anatomy of a 5-year-old child.

METHODS

Tissue equivalent materials representing paediatric bone (Plaster of Paris; PoP) and soft tissue (Poly methyl methacrylate; PMMA) were used. PMMA was machined to match the bony anatomy identified from a CT scan of a 5-year-old child and cavities were created for infusing the PoP. Phantom validation comprised physical and visual measures. Physical included CT density comparison between a CT scan of a 5-year old child and the phantom and Signal to Noise Ratio (SNR) comparative analysis of anteroposterior phantom X-ray images against a commercial anthropomorphic phantom. Visual analysis using a psychometric image quality scale (face validity).

RESULTS

CT density, the percentage difference between cortical bone, soft tissue and their equivalent tissue substitutes were -4.7 to -4.1% and -23.4%, respectively. For SNR, (mAs response) there was a strong positive correlation between the two phantoms (r > 0.95 for all kVps). For kVp response, there was a strong positive correlation between 1 and 8 mAs (r = 0.85), this then decreased as mAs increased (r = -0.21 at 20 mAs). Psychometric scale results produced a Cronbach's Alpha of almost 0.8.

CONCLUSIONS

Physical and visual measures suggest our low-cost phantom has suitable anatomical characteristics for X-ray imaging. Our phantom could have utility in dose and image quality optimisation studies.

Radiation dose optimisation for conventional imaging in infants and newborns using automatic dose management software: an application of the new 2013/59 EURATOM directive

Objective: The new 2013/59 EURATOM Directive (ED) demands dosimetric optimisation procedures without undue delay. The aim of this study was to optimise paediatric conventional radiology examinations applying the ED without compromising the clinical diagnosis.

METHODS

Automatic dose management software (ADMS) was used to analyse 2678 studies of children from birth to 5 years of age, obtaining local diagnostic reference levels (DRLs) in terms of entrance surface air kerma. Given local DRL for infants and chest examinations exceeded the European Commission (EC) DRL, an optimisation was performed decreasing the kVp and applying the automatic control exposure. To assess the image quality, an analysis of high-contrast resolution (HCSR), signal-to-noise ratio (SNR) and figure of merit (FOM) was performed, as well as a blind test based on the generalised estimating equations method.

RESULTS

For newborns and chest examinations, the local DRL exceeded the EC DRL by 113%. After the optimisation, a reduction of 54% was obtained. No significant differences were found in the image quality blind test. A decrease in SNR (-37%) and HCSR (-68%), and an increase in FOM (42%), was observed.

CONCLUSION

ADMS allows the fast calculation of local DRLs and the performance of optimisation procedures in babies without delay. However, physical and clinical analyses of image quality remain to be needed to ensure the diagnostic integrity after the optimisation process. Advances in knowledge: ADMS are useful to detect radiation protection problems and to perform optimisation procedures in paediatric conventional imaging without undue delay, as ED requires.

Do additional full-length radiographs of the humerus and forearm improve the decision making in children with supracondylar humerus fractures?

We sought to determine the diagnostic utility of additional full-length radiographs of the forearm and humerus for pediatric supracondylar humerus fractures. A pediatric orthopedic surgeon and a senior orthopedic resident individually reviewed the initial humerus, forearm, and elbow radiographs of 55 children with a supracondylar humerus fracture and recommended definitive treatment (operative vs. nonoperative) on the basis of the modified Gartland classification. Interobserver agreements for classification and the recommended treatment were highest for the elbow radiographs (weighted κ=0.92). All disagreements in the recommended treatment were in fractures classified as Gartland type I versus II fractures. Although two children (4%) had an ipsilateral distal forearm fracture, selective versus routine use of additional full-length radiographs in children with a supracondylar humerus fracture needs to be evaluated further.

Benchmarking the performance of fixed-image receptor digital radiography systems. Part 2: system performance metric

This is part two of a two-part study in benchmarking system performance of fixed digital radiographic systems. The study compares the system performance of seven fixed digital radiography systems based on quantitative metrics like modulation transfer function (sMTF), normalised noise power spectrum (sNNPS), detective quantum efficiency (sDQE) and entrance surface air kerma (ESAK). It was found that the most efficient image receptors (greatest sDQE) were not necessarily operating at the lowest ESAK. In part one of this study, sMTF is shown to depend on system configuration while sNNPS is shown to be relatively consistent across systems. Systems are ranked on their signal-to-noise ratio efficiency (sDQE) and their ESAK. Systems using the same equipment configuration do not necessarily have the same system performance. This implies radiographic practice at the site will have an impact on the overall system performance. In general, systems are more dose efficient at low dose settings.