Paediatric computed tomography radiation dose: A review of the global dilemma

Time From Suspected Foreign Body Aspiration to Bronchoscopy at Odense University Hospital During a 5-Year Period

BACKGROUND

Foreign body aspiration (FBA) in children is a critical emergency, particularly for those under 3 years old, with mortality rates as high as 4% for infants. Delayed bronchoscopy is associated with an increased rate of complications. This study evaluates whether bronchoscopy for suspected FBA in children at Odense University Hospital was performed within 24 h, as recommended.

METHODS

This retrospective cohort study was conducted on children under 18 years admitted with suspected FBA from January 2018 to December 2022 at Odense University Hospital. Data were collected on demographics, symptoms, and outcomes. The primary outcome was time from aspiration event to bronchoscopy, with delays defined as procedures performed more than 24 h after the event. Secondary outcomes included complications such as pneumonia, delayed extubation, and admission to the pediatric intensive care unit.

RESULTS

We identified 82 cases of children undergoing bronchoscopy in the study period. The median time to bronchoscopy was 18.8 h (IQR: 8-41), but in 30 cases (37%), the time to bronchoscopy exceeded 24 h. A foreign body was confirmed in 23 cases. Complications, including delayed extubation, pneumonia, oxygen and nebulizer treatments, and admission to the pediatric intensive care unit, occurred in 22 of all 82 cases, with a higher frequency in the delayed than the nondelayed group (37% vs. 22%). All children with confirmed FBA who underwent delayed bronchoscopy experienced complications.

CONCLUSION

Between 2018 and 2022, 63% of children admitted to Odense University Hospital with suspected FBA underwent bronchoscopy within 24 h. Delays occurred in one-third of cases, primarily because FBA was not initially suspected.

EDITORIAL COMMENT

This 5 year analysis of confirmed or suspected aspiration of foreign bodies at Odense University Hospital underlines the importance of timely emergency care of children. Confirmed FBA continues to have a very high morbity in children regardless of time of treatment. A "right patient, right place, right time" approach remains critical to reduce adverse events.

Adult national diagnostic reference levels for common computed tomography examinations in Zambia: A preliminary study with findings from public hospitals

INTRODUCTION

While many European and American countries have established national diagnostic reference levels (NDRLs), few African countries have. Therefore, this study aimed to propose adult NDRLs for common computed tomography (CT) examinations in Zambia.

METHODS

1360 CT patient data for the brain, chest, abdomen and pelvis were collected from 10 public CT facilities. The CT images were assessed for acceptable image quality and patient anthropometry was done, with patients' anteroposterior diameter used as the patient parameter. NDRLs were set at the 75th percentile of the distribution of volume-based CT dose index (CTDIvol) and dose length product (DLP) and were compared to countries' NDRLs.

RESULTS

NDRLs for CTDIvol in mGy were calculated as follows; non-contrast brain 70.5, contrast brain 56.74, non-contrast chest 20.24, contrast chest 20, non-contrast abdomen/pelvis, 21.3, contrast abdomen/pelvic 21.3, non-contrast chest/abdomen/pelvis 20 and contrast chest/abdomen/pelvis 19.1. The corresponding NDRLs for DLP in mGy.cm are 1455, 1206, 745.8, DLP 666.7, 1103, 1103, 1237 and 1141. Variations in DLP values between facilities were statistically significant (p < 0.0001). NDRLs for the brain and chest were higher than those from other countries but lower for the abdomen/pelvis and chest/abdomen/pelvis. Correlations between the CT scanner's number of detector rows and CTDIvol were (r = 0.08285, p < 0.0.0022) and (r = 0.5038, p < 0.0001) between patients' AP diameter and CTDIvol. CONCLUSION: The proposed NDRLs confirmed the need to optimise CT scan parameters and protocols in Zambia. Therefore, extensive training of all CT radiographers in optimising CT image acquisition parameters and regular dose audits is recommended.

IMPLICATION OF PRACTICE

NDRLs will likely provide a benchmarking mechanism for dose optimisation practices among CT radiographers in Zambia and beyond.

Development of optimised protocols for paediatric whole-body computed tomography examinations: a figure-of-merit approach

BACKGROUND

Whole-body computed tomography (WBCT) technique involves higher radiation doses, resulting in increased stochastic health risks, especially when used for paediatric patients. Hence, protocol optimisation is recommended to maximise its benefit-risk ratio, with several available strategies to achieve it. This study used the figure-of-merit (FOM) approach to develop optimised protocols for paediatric WBCT examinations. The rationale is to enhance diagnostic accuracy while minimising radiation exposure, ultimately improving patient safety and outcomes for paediatric patients undergoing WBCT.

METHODS

Newborn and child (5-year-old) anthropomorphic phantoms were scanned with different scan protocols and evaluated for dose and image quality using the CT-Expo and ImageJ programs, respectively. The protocols for trunk examinations were divided into arterialphase-only and combined arterial and venous phase to develop appropriate protocols based on patients' initial focused assessment with sonography for trauma (FAST) results. The protocols with the highest FOMs were selected as the best optimised protocols.

RESULTS

The estimated WBCT ED (WBED) for the optimised protocols ranged from 2.6 mSv to 5.8 mSv with estimated FOM of 3.83 to 59.35. The mean effective doses (EDs) for newborn and child arterial phase-only protocols were not significantly lower than the combined arterial and venous phase protocols (p = 0.069, 0.082 respectively), while the mean signal-to-noise ratio of the combined phase protocols for newborn and child phantoms were insignificantly higher than the single-phase protocol (p = 0.089, 0.662 respectively).

CONCLUSION

The estimated EDWB from this study were lower than established values. The selected protocols are recommended for newborns and children (1-7 years) using the GE Revolution CT and Siemens SOMATOM Definition Edge CT scanners.

Improved image quality and micronodule detection in thyroid spectral computed tomography using modified swimmer's position

Background

Spectral computed tomography (CT) can be used as a valuable complement to ultrasound (US) in the detection of thyroid nodules. This study sought to investigate the effects of various arm positions during thyroid spectral CT scans in terms of radiation exposure, image quality, and micronodule detection (≤10 mm).

Methods

A total of 180 patients (mean age: 48 years; 136 females) who underwent thyroid spectral CT were assigned to the traditional position (TDN; n=60), swimmer's position (SWIM; n=60), and modified swimmer's position (M-SWIM; n=60) groups. Image quality in the plain, arterial, and venous phases was assessed using a 4-point grading scale, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR). Radiation exposure was assessed using the volume computed tomography dose index (CTDIvol), dose-length product (DLP), effective dose of the neck (EDN), and effective dose of the thyroid (EDT). The micronodule detection rates for spectral CT and US were compared using the pathology detection rate as a reference.

Results

The M-SWIM group had a significantly higher proportion of 4-point grading, SNR, and CNR than the TDN and SWIM groups (all P<0.001). The CTDIvol, DLP, EDN, and EDT were similar among the three groups (all P>0.05). The micronodule detection rate was higher in the M-SWIM group than the TDN and SWIM groups (total: 90.6% vs. 70.1% vs. 46.8%; benign: 89.1% vs. 66.7% vs. 45.5%; malignant: 94.3% vs. 79.5% vs. 51.5%; all P<0.001), but comparable to that of the US group (total: 90.6% vs. 91.2%; benign: 89.1% vs. 90.6%; malignant: 94.3% vs. 92.5%; all P>0.05).

Conclusions

The proposed M-SWIM improved the image quality of thyroid spectral CT without increasing the radiation dose, and significantly enhanced the micronodule detection rate.

Universal 120-kV Dual-Source Ultra-High Pitch Protocol on the Photon-Counting CT System for Pediatric Abdomen of All Sizes: A Phantom Investigation Comparing With Energy-Integrating CT

OBJECTIVES

The purpose of this study is to determine if a universal 120-kV ultra-high pitch and virtual monoenergetic images (VMIs) protocol on the photon-counting computed tomography (PCCT) system can provide sufficient image quality for pediatric abdominal imaging, regardless of size, compared with protocols using a size-dependent kV and dual-source flash mode on the energy-integrating CT (EICT) system.

MATERIALS AND METHODS

One solid water insert and 3 iodine (2, 5, 10 mg I/mL) inserts were attached or inserted into phantoms of variable sizes, simulating the abdomens of a newborn, 5-year-old, 10-year-old, and adult-sized pediatric patients. Each phantom setting was scanned on an EICT using clinical size-specific kV dual-source protocols with a pitch of 3.0. The scans were performed with fixed scanning parameters, and the CTDI vol values of full dose were 0.30, 0.71, 1.05, and 7.40 mGy for newborn to adult size, respectively. In addition, half dose scans were acquired on EICT. Each phantom was then scanned on a PCCT (Siemens Alpha) using a universal 120-kV protocol with the same full dose and half dose as determined above on the EICT scanner. All other parameters matched to EICT settings. Virtual monoenergetic images were generated from PCCT scans between 40 and 80 keV with a 5-keV interval. Image quality metrics were compared between PCCT VMIs and EICT, including image noise (measured as standard deviation of solid water), contrast-to-noise ratio (CNR) (measured at iodine inserts with solid water as background), and noise power spectrum (measured in uniform phantom regions).

RESULTS

Noise at a PCCT VMI of 70 keV (7.0 ± 0.6 HU for newborn, 14.7 ± 1.6 HU for adult) is comparable ( P > 0.05, t test) or significantly lower ( P < 0.05, t test) compared with EICT (7.8 ± 0.8 HU for newborn, 15.3 ± 1.5 HU for adult). Iodine CNR from PCCT VMI at 50 keV (50.8 ± 8.4 for newborn, 27.3 ± 2.8 for adult) is comparable ( P > 0.05, t test) or significantly higher ( P < 0.05, t test) to the corresponding EICT measurements (57.5 ± 6.7 for newborn, 13.8 ± 1.7 for adult). The noise power spectrum curve shape of PCCT VMI is similar to EICT, despite PCCT VMI exhibiting higher noise at low keV levels.

CONCLUSIONS

The universal PCCT 120 kV with ultra-high pitch and postprocessed VMIs demonstrated equivalent or improved performance in noise (70 keV) and iodine CNR (50 keV) for pediatric abdominal CT, compared with size-specific kV images on the EICT.

Variation in thoracic inlet measurements and its correlation with pulmonary dysfunction in kyphoscoliotic deformities: a prospective case-control study

BACKGROUND

Pulmonary dysfunction in thoracic kyphoscoliosis has been correlated with chest wall distortion, uneven trunk growth and restrictive pattern. The study aims to analyse the variation in thoracic inlet measurements on pulmonary dysfunction with varying curve magnitude and thoracic cage parameters.

METHODS

In a non-randomised, prospective case-control study, 80 consecutive patients with thoracic kyphoscoliosis were divided into 3 groups based on Cobb angle: Group 1 (31-50), Group 2 (51-80) and Group 3 (> 80). Thoracic inlet measurement was calculated by thoracic inlet index (TI) on MRI at the sternal level. Pulmonary function and thoracic cage parameters [hemi thorax height, rib-apex distance, AP chest diameter at sternal level and transverse thoracic diameter] were documented. TI values were compared with 20 age-matched asymptomatic controls. Multivariate correlation and regression analysis were performed to investigate the correlations.

RESULTS

The mean age of the study cohort was 14.1 ± 4.4 years, including Group 1 (6 patients), Group 2 (55 patients) and Group 3 (19 patients) versus 12.9 ± 2.2 years in controls. The mean TI was 2.8 ± 0.56 in Group 1, 3.7 ± 0.9 in Group 2 and 4.0 ± 1.12 in Group 3 versus 2.6 ± 0.43 in controls. Pulmonary dysfunction was severe with TI > 7.1 (p < 0.001) in Group 3 patients with thoracic hypokyphosis. Multivariate regression for thoracic parameters and TI > 5.6 showed significant correlation of pulmonary dysfunction in Group 2 and 3 curves with apex between T1 and T4, whereas transverse thoracic diameter, rib-apex distance and hemi thorax height were weakly associated.

CONCLUSION

Thoracic inlet index (TI), a neglected pre-operative variable associated with pulmonary dysfunction in thoracic kyphoscoliosis, can be evaluated on MRI without an additional cost and radiation.

LEVEL OF EVIDENCE: 3

Neuroimaging in Nonsyndromic Craniosynostosis: Key Concepts to Unlock Innovation

Craniosynostoses (CRS) are caused by the premature fusion of one or more cranial sutures, with isolated nonsyndromic CRS accounting for most of the clinical manifestations. Such premature suture fusion impacts both skull and brain morphology and involves regions far beyond the immediate area of fusion. The combined use of different neuroimaging tools allows for an accurate depiction of the most prominent clinical-radiological features in nonsyndromic CRS but can also contribute to a deeper investigation of more subtle alterations in the underlying nervous tissue organization that may impact normal brain development. This review paper aims to provide a comprehensive framework for a better understanding of the present and future potential applications of neuroimaging techniques for evaluating nonsyndromic CRS, highlighting strategies for optimizing their use in clinical practice and offering an overview of the most relevant technological advancements in terms of diagnostic performance, radiation exposure, and cost-effectiveness.

A Rare Case of Gastric Trichobezoar Managed by Laparotomy

Trichobezoars, rare gastrointestinal foreign bodies composed of ingested hair, typically affect females with psychiatric disorders such as trichotillomania and pica. This case report highlights the diagnostic and treatment challenges in an 18-year-old female presenting with a left upper quadrant mass and pain, who was found to have a large gastric trichobezoar. After diagnostic imaging confirmed the bezoar, it was surgically removed, and the patient had an uneventful recovery. Psychiatric follow-up was arranged to address the underlying disorders and prevent recurrence. This case underscores the importance of early recognition and management of trichobezoars to avoid serious complications.

Optimal image quality and radiation doses with optimal tube voltages/currents for pediatric anthropomorphic phantom brains

OBJECTIVE

Using pediatric anthropomorphic phantoms (APs), we aimed to determine the scanning tube voltage/current combinations that could achieve optimal image quality and avoid excessive radiation exposure in pediatric patients.

MATERIALS AND METHODS

A 64-slice scanner was used to scan a standard test phantom to determine the volume CT dose indices (CTDIvol), and three pediatric anthropomorphic phantoms (APs) with highly accurate anatomy and tissue-equivalent materials were studied. These specialized APs represented the average 1-year-old, 5-year-old, and 10-year-old children, respectively. The physical phantoms were constructed with brain tissue-equivalent materials having a density of ρ = 1.07 g/cm3, comprising 22 numbered 2.54-cm-thick sections for the 1-year-old, 26 sections for the 5-year-old, and 32 sections for the 10-year-old. They were scanned to acquire brain CT images and determine the standard deviations (SDs), effective doses (EDs), and contrast-to noise ratios (CNRs). The APs were scanned by 21 combinations of tube voltages/currents (80, 100, or 120 kVp/10, 40, 80, 120, 150, 200, or 250 mA) and rotation time/pitch settings of 1 s/0.984:1.

RESULTS

The optimal tube voltage/current combinations yielding optimal image quality were 80 kVp/80 mA for the 1-year-old AP; 80 kVp/120 mA for the 5-year-old AP; and 80 kVp/150 mA for the 10-year-old AP. Because these scanning tube voltages/currents yielded SDs, respectively, of 12.81, 13.09, and 12.26 HU, along with small EDs of 0.31, 0.34, and 0.31 mSv, these parameters and the induced values were expediently defined as optimal.

CONCLUSIONS

The optimal tube voltages/currents that yielded optimal brain image quality, SDs, CNRs, and EDs herein are novel and essentially important. Clinical translation of these optimal values may allow CT diagnosis with low radiation doses to children's heads.

A Segmentation-based Automated Calculation of Patient Size and Size-specific Dose Estimates in Pediatric Computed Tomography Scans

Background and Purpose

Size-specific dose estimates (SSDE) have been introduced into computed tomography (CT) dosimetry to tailor patients' unique sizes to facilitate accurate CT radiation dose quantification and optimization. The purpose of this study was to develop and validate an automated algorithm for the determination of patient size (effective diameter) and SSDE.

Materials and Methods

A MATLAB platform was used to develop software of algorithms based on image segmentation techniques to automate the calculation of patient size and SSDE. The algorithm was used to automatically estimate the individual size and SSDE of four CT dose index phantoms and 80 CT images of pediatric patients comprising head, thorax, and abdomen scans. For validation, the American Association of Physicists in Medicine (AAPM) manual methods were used to determine the patient's size and SSDE for the same subjects. The accuracy of the proposed algorithm in size and SSDE calculation was evaluated for agreement with the AAPM's estimations (manual) using Bland-Altman's agreement and Pearson's correlation coefficient. The normalized error, system bias, and limits of agreement (LOA) between methods were derived.

Results

The results demonstrated good agreement and accuracy between the automated and AAPM's patient size estimations with an error rate of 1.9% and 0.27% on the patient and phantoms study, respectively. A 1% percentage difference was found between the automated and manual (AAPM) SSDE estimates. A strong degree of correlation was seen with a narrow LOA between methods for clinical study (r > 0.9771) and phantom study (r > 0.9999).

Conclusion

The proposed automated algorithm provides an accurate estimation of patient size and SSDE with negligible error after validation.

Multimodality 3D image fusion with live fluoroscopy reduces radiation dose during catheterization of congenital heart defects

Introduction

Imaging fusion technology is promising as it is radiation and contrast sparing. Herein, we compare conventional biplane angiography to multimodality image fusion with live fluoroscopy using two-dimensional (2D)-three-dimensional (3D) registration (MMIF2D-3D) and assess MMIF2D-3D impact on radiation exposure and contrast volume during cardiac catheterization of patients with congenital heart disease (CHD).

Methods

We matched institutional MMIF2D-3D procedures and controls according to patient characteristics (body mass index, age, and gender) and the seven procedure-type subgroups. Then, we matched the number of tests and controls per subgroup using chronological ordering or propensity score matching. Subsequently, we combined the matched subgroups into larger subgroups of similar procedure type, keeping subgroups with at least 10 test and 10 control cases. Air kerma (AK) and dose area product (DAP) were normalized by body weight (BW), product of body weight and fluoroscopy time (BW × FT), or product of body weight and number of frames (BW × FR), and stratified by acquisition plane and irradiation event type (fluoroscopy or acquisition). Three senior interventionists evaluated the relevance of MMIF2D-3D (5-point Likert scale).

Results

The Overall group consisted of 54 MMIF2D-3D cases. The combined and matched subgroups were pulmonary artery stenting (StentPUL), aorta angioplasty (PlastyAO), pulmonary artery angioplasty (PlastyPUL), or a combination of the latter two (Plasty). The FT of the lateral plane reduced significantly by 69.6% for the Overall MMIF2D-3D population. AKBW and DAPBW decreased, respectively, by 43.9% and 39.3% (Overall group), 49.3% and 54.9% (PlastyAO), and 36.7% and 44.4% for the Plasty subgroup. All the aforementioned reductions were statistically significant except for DAPBW in the Overall and Plasty (sub)groups. The decrease of AKBW and DAPBW in the StentPUL and PlastyPUL subgroups was not statistically significant. The decrease in the median values of the weight-normalized contrast volume (CMCBW) in all five subgroups was not significant. Cardiologists considered MMIF2D-3D very useful with a median score of 4.

Conclusion

In our institution, MMIF2D-3D overall enabled significant AKBW reduction during the catheterization of CHD patients and was mainly driven by reduced FT in the lateral plane. We observed significant AKBW reduction in the Plasty and PlastyAO subgroups and DAPBW reduction in the PlastyAO subgroup. However, the decrease in CMCBW was not significant.

How confident are UK radiographers at performing paediatric computed tomography trauma scans?

INTRODUCTION

Approximately 45% of paediatric deaths in the United Kingdom (UK) were as a result of trauma. Computed tomography (CT) provides time efficient and accurate diagnosis, increasing chances of survival. Whilst use of CT in evaluating paediatric trauma has been invaluable it carries significant radiation risks, largely because children have greater radiation sensitivity than adults. Although national paediatric trauma workload in the UK is proportionately low, the majority of paediatric patients are conveyed to hospitals which predominantly undertake CT scans on adult patients. This research aimed to determine the confidence levels of radiographers when performing paediatric CT trauma scans in three public hospitals in the UK, and whether a teaching intervention improved their perceived self-confidence.

METHODS

Individual questionnaires containing eight qualitative and quantitative questions were used to ascertain radiographers' perceived confidence levels. A teaching intervention was developed based on responses. A post-intervention questionnaire was used to determine whether radiographers' confidence levels had improved.

RESULTS

Radiographers (n = 45) reported a mean confidence score of 5.6 (standard deviation 2.2) and 8.0 (standard deviation 1.7) scanning paediatric trauma patients pre- and post-intervention respectively. A paired two group t-test found this difference to be statistically significant at p < .00001. Radiographers reported several factors which negatively influenced confidence levels, including limited experience and postgraduate education.

CONCLUSION

Radiographers reported to be less confident scanning paediatric CT trauma patients compared to adults, pre- and post-intervention, however this research does not clarify whether this is as a result of an increase in competence. Further research regarding this concept warrants investigation.

IMPLICATIONS FOR PRACTICE

Results suggest further training based on negative factors reported by radiographers can increase confidence when performing this type of scan, assisting radiographers in optimising paediatric patient doses.

ESTIMATION OF PEDIATRIC DOSE DESCRIPTORS ADAPTED TO INDIVIDUAL SPECIFIC SIZE FROM CT EXAMINATIONS

Clinical challenges in pediatrics dose estimation by the displayed computed tomography (CT) dose indices may lead to inaccuracy, and thus size-specific dose estimate (SSDE) is introduced for better-personalized dose estimation. This study aims to estimate pediatric dose adapted to specific size. This retrospective study involved pediatric population aged 0-12 y. SSDE was derived from scanner reported volume CT dose index (CTDIvol), based on individual effective diameter (Deff) with corresponding size correction factors. The correlations of Deff with other associated factors such as age, exposure setting, CTDIvol and SSDE were also studied. The average Deff of Malaysian pediatric was smaller than reference phantom size (confidence interval, CI = 0.28, mean = 14.79) and (CI = 0.51, mean = 16.33) for head and abdomen, respectively. These have led to underestimation of pediatric dose as SSDE was higher than displayed CTDIvol. The percentage differences were statistically significant (p < .001) ranged from 0 to 17% and 37 to 60% for head and abdominal CT, respectively. In conclusion, the clinical implementation of SSDE in pediatric CT imaging is highly relevant to reduce radiation risk.

Diagnostic reference levels for computed tomography examinations in pediatric population - A systematic review

Computed tomography (CT) has vital role in diagnosis of various pathologies using cross sectional images. Besides the advantages of CT in pediatric radiology, radiation dose has a significant adverse effect as children are more vulnerable than adults. Establishing Diagnostic Reference levels (DRLs) will determine unusual increase in radiation doses and therefore helps in optimizing the radiation dose by maintaining optimum diagnostic image quality. The objective of the review is to explore the literature on DRLs in pediatric CT examinations and techniques that have been used to establish them. Detailed search was done in PubMed-Medline, Scopus CINAHL, Web of Science, and the Cochrane Library databases to find studies that have established DRLs for pediatric CT examinations. The Preferred Reporting Items for Systematic Review and Meta-Analyses methodology was used to assess the relevant articles. The articles which assessed DRLs in pediatric CT examinations were included. A total of 501 articles were identified, of which 21 articles were included after a detailed screening process. Our review showed increased in pediatric patient dose surveys across the world and also increased in awareness for establishing DRLS among pediatric CT examinations. The review also demonstrated wide variation in DRLs and also deviation in the scanning techniques, protocols used and categorization methods used for establishing DRLs. As the pediatric population is more sensitive to radiation, the current review emphasizes the need for optimization of protocols and international standardization for establishing DRLs to facilitate a more feasible way of comparison of dose globally across CT sites.

Local Diagnostic Reference Levels for Paediatric Head CT Procedures

Background.

Patients, especially children, are exposed to substantially high doses of ionising radiation during computed tomography (CT) procedures. Children are several times more susceptible to ionising radiation than adults. Diagnostic reference levels (DRLs) are an important tool for monitoring and optimising patient radiation exposure from radiological procedures. The aim of this study is to estimate the ionising radiation exposure doses and set local DRLs for head CT examinations according to age and to compare local DRLs with national and European DRLs and with literature data in other countries.

Materials and methods.

Scan parameters of single-phase head CT examinations were collected. Patients were grouped by age in the following intervals: <1, 1−5, 5−10, 10−15 and 15−18 years. Local age-based DRLs set as the 3^rd quartile of the median dose-length product (DLP) were calculated. Literature analysis was performed on PubMed search engine on inclusion criteria: publication date 2015–2020, used keywords paediatric computed tomography, paediatric CT, diagnostic reference levels (DRLs). The 23 articles discussing paediatric DRLs were further analysed.

Results.

Data was collected from 194 paediatric head CT examinations performed in 2019. The median DLP values for head CT were 144.3, 233.7, 246.4, 288.9, 315.5 for <1, 1−5, 5−10, 10−15 and 15−18 years old groups. Estimated local DRLs for head CT examinations are 170, 300, 310, 320, 360 mGy*cm for <1, 1−5, 5−10, 10−15 and 15−18 years age groups respectively and 130, 210, 275, 320 mGy*cm for 0−3 months, 3 months−1 year, 1−6 years and ≥ 6 years age groups respectively.

Conclusions.

Results of this study showed that settled new local DRLs of head CT examinations were 2–4 times lower than national DRLs and about 2 times lower than European DRLs. Moreover, the study indicated that paediatric head CT doses are significantly lower in comparison with those indicated in the majority of published data from other hospitals over the last 6 years. Patient dose assessment and local DRLs establishment plays important role in future exposure optimisation.

Rare shear-type fracture of the talar head in a thirteen-year-old child - Is this a transitional fracture: A case report and review of the literature

BACKGROUND

Talar fractures are exceedingly rare in childhood. There are very few studies on the clinical aspects, the long-term outcomes and the appropriate treatment of these fractures in pediatric patients. The mechanism of trauma consists of the application of a sudden dorsiflexion force on a fully plantar-flexed foot. Traumatic mechanism, symptoms and imaging of injuries of the talar head are similar to transitional fractures that are normally described at the distal epiphysis of the tibia: the so-called transitional fracture is defined as an epiphyseal injury when the growth plate has already started to close.

CASE SUMMARY

A thirteen-year-old girl reported a high-energy trauma to her right foot, due to falling from her horse. X-rays at the Emergency Department were negative. Because of persistent pain, the patient was assessed by an orthopedic surgeon after two weeks and computed tomography scans revealed a misdiagnosed displaced shear-type fracture of the talar head. Hence, surgical open reduction and fixation with two headless screws was performed. The girl was assessed regularly, and plain films at follow-up revealed complete healing of the fracture. Within six months after surgery, the patient returned to pre-injury sport activities reporting no complications.

CONCLUSION

Injuries of the talar head in childhood should be considered as transitional fractures. Open reduction with internal fixation aims to reduce malalignment and osteoarthritis. Computed tomography scans are recommended in these cases.

Evaluation of Organ Doses for Pediatric Computed Tomography Using a Newly Designed Radiophotoluminescence Glass Dosimeter and Comparison with a Monte Carlo Simulation-based Dose Calculator

ABSTRACT

Management of patient dose is an effective way to help optimize computed tomography (CT) scanning conditions and CT dose. Organ dose is one of the preferred quantities for radiation protection because of its correlation with radiation risk. To date, the WAZA-ARI dose calculator is the only freely available CT dose calculator also applicable for pediatric patients. However, no reports of its evaluation have appeared since the latest version of WAZA-ARI was released. In this study, to evaluate the latest version of WAZA-ARI, we measured the organ dose in a 5-y-old anthropomorphic phantom by a newly developed radiophotoluminescence glass dosimeter (RGD) dosimetry system and compared these results with the calculation results from WAZA-ARI. The newly designed RGDs have less angular dependence because of the additional filter. RGDs were individually calibrated with the ISOVOLT TITAN-320 x-ray generator. All the experimental measurements for this study were performed using a CT scanner. To consider the difference of CT output between the nominal and actual machine, the measured CTDIair was used to correct the calculation results obtained from WAZA-ARI. After the corrections using the measured CTDIair, the calculation results from WAZA-ARI were relatively lower than the measured results with a range of 8-20%, which corresponds to the dose difference caused by the difference in effective diameter. In conclusion, the calculation accuracy of WAZA-ARI is guaranteed when the normalization factor specific to each CT scanner (CTDIair) and the shape of the phantom are taken into consideration.

Routine postoperative computed tomography scan after craniotomy: systematic review and evidence-based recommendations

Over the last few years, the role of early postoperative computed tomography (EPOCT) after cranial surgery has been repeatedly questioned, but there is yet no consensus on the practice. We conducted a systematic review to address the usefulness of EPOCT in association with neurological examination after elective craniotomies compared to the neurological examination alone. Studies were eligible if they provided information about the number of patients scanned, how many were asymptomatic or presented neurological deterioration before the scan and how many of each of those groups had their management changed due to imaging findings. CTs had to be performed in the first 48 h following surgery to be considered early. Eight studies were included. The retrospective studies enrolled a total of 3639 patients, with 3737 imaging examinations. Out of the 3696 CT scans performed in asymptomatic patients, less than 0.8% prompted an intervention, while 100% of patients with neurological deterioration were submitted to emergency surgery. Positive predictive values of altered scans were 0.584 for symptomatic patients and 0.125 for the asymptomatic. The number of altered scans necessary to predict (NNP) one change in management for the asymptomatic patients was 8, while for the clinically evident cases, it was 1.71. The number of scans needed to diagnose one clinically silent alteration is 134.75, and postoperative imaging of neurologically intact patients is 132 times less likely to issue an emergency intervention than an altered neurological examination alone. EPOCT following elective craniotomy in neurologically preserved patients is not supported by current evidence, and CT scanning should be performed only in particular conditions. The authors have developed an algorithm to help the judgment of each patient by the surgeon in a resource-limited context.

Implementing the National Institute for Health and Clinical Excellence Head Injury 2014 Guidelines in a major children's hospital emergency department

OBJECTIVES AND BACKGROUND

Head injury is a common paediatric emergency department presentation. The National Institute for Health and Clinical Excellence updated its guidance in January 2014 regarding imaging required for adults and children following a head injury (CG176). This study looked at the rates of computed tomography (CT) head scans performed and adherence rates to CG176.

PATIENTS AND METHODS

A single-centre audit was carried out, examining imaging practice in children with head injuries. CG176 was implemented formally in August 2014 to the new trainee doctors. The primary outcome was adherence to CG176. As the data were binary, 95% confidence intervals were used for comparison.

RESULTS

In all, 1797 patients were identified as having a head injury. Implementation at the Sheffield's Children NHS Foundation Trust resulted in a statistically significant increase in guideline adherence from 79.2% [95% confidence interval (CI): 76.4-81.9%] to 85.1% (95% CI: 82.9-87.4%). The greatest impact in adherence was found in CT head scans, from 95.8% (95% CI: 94.5-97.2%) to 97.7% (95% CI: 96.7-98.6%).

CONCLUSION

The implementation at the Sheffield's Children NHS Foundation Trust was successful in satisfying the aim of CG176 by increasing adherence and decreasing CT head scans. This success could be explained by the formal implementation to the new cohort of doctors and better physician agreement with the guidelines. The increase in adherence is contrary to the previous studies.

Neuroimaging in Pediatric Epilepsy

Pediatric epilepsy presents with various diagnostic challenges. Recent advances in neuroimaging play an important role in the diagnosis, management and in guiding the treatment of pediatric epilepsy. Structural neuroimaging techniques such as CT and MRI can identify underlying structural abnormalities associated with epileptic focus. Functional neuroimaging provides further information and may show abnormalities even in cases where MRI was normal, thus further helping in the localization of the epileptogenic foci and guiding the possible surgical management of intractable/refractory epilepsy when indicated. A multi-modal imaging approach helps in the diagnosis of refractory epilepsy. In this review, we will discuss various imaging techniques, as well as aspects of structural and functional neuroimaging and their application in the management of pediatric epilepsy.

Pediatric Residents' and Medical Interns' Awareness about Pediatric Ionizing Radiation Dose from Computed Tomography and Its Associated Risks in Tertiary Hospital in Ethiopia

Background

The international literature on physicians' knowledge regarding radiation dosages and risks due to computed tomography showed a widespread underestimation of diagnostic radiation doses. Hence, the objective of this work is to assess the awareness of pediatric residents and medical interns about pediatric CT dose and possible risks.

Methods

A cross-sectional study was conducted on May/2016 among year I to year III pediatric residents and 2015/2016 year medical interns attaching Pediatrics Department during the study period in Tikur Anbessa Specialized Referral and Teaching Hospital. Data was collected by distributing standardized structured questionnaires. Finally, after the data was checked for clarity and completeness, it was analyzed by using SPSS software.

Result

While the majority (76.3%) of the residents and interns knew that children were more sensitive to radiation than adults, 93.7% did not know that there is currently no annual dose limit set for medical exposure of patients. The majority of the respondents (81.3%) know the risk of cancer from CT scan, but most (60%) of the respondents did not know that many imaging facilities still use adult doses for pediatric patients. Furthermore, 18.8% thought that magnetic resonance imaging involves ionizing radiation, and 8.9% of the physicians associated ultrasound examinations with ionizing radiation.

Conclusion

Within resident group, since the level of clinical experience did not affect the outcome, we recommend that formal education and training on awareness of radiation with special concern on pediatric population is mandatory especially for pediatric residents and pediatricians who are major caretakers of children.

Routine Postoperative Computed Tomography Is Not Helpful After Elective Craniotomy

BACKGROUND

Next-day postoperative computed tomography (CT) has been routinely used to obtain radiographic "clearance" for transferring patients after elective craniotomy out of the intensive care unit. The value of this traditional policy, however, has repeatedly been questioned. However, the limited patient numbers might have underestimated the very rare, but catastrophic, events. Therefore, we analyzed the value of routine postoperative CT in a larger cohort of elective tumor, epilepsy, and vascular cases.

METHODS

All the patients who had undergone elective craniotomy were included in our study. The routine postoperative CT scans were analyzed by a neuroradiologist who was unaware of the clinical data. The medical records were retrospectively reviewed for events of arterial hypertension and clinical deterioration.

RESULTS

The data from 660 patients with tumors (n = 393; 59.5%), aneurysms (n = 107; 16.2%), and skull base lesions were evaluated. In nearly one half of the patients (n = 264; 45.8%), CT depicted the presence of blood that was not associated with symptoms. Of the 660 patients, 21 (3.6%) showed a mass effect radiographically, 11 of whom underwent revision surgery. Arterial hypertension was documented in only 8 patients (1.3%) and was related to the revision surgery (P = 0.018). The overall revision rate was 2.7% (n = 18). All patients who had undergone revision for postoperative hematoma had presented with a new neurological deficit immediately before CT.

CONCLUSION

Routine postoperative CT did not reveal 1 patient with a serious hematoma that would not have been identified by clinical examination. Patients could be transferred safely from the intensive care unit, if the weaning process and clinical observation findings were uneventful, without deterioration of neurological symptoms or consciousness.

Gastric ulceration and perforation secondary to large trichobezoar - A case report describing the role of magnetic resonance imaging in diagnosis

INTRODUCTION

Trichotillomania and trichotillophagia can result in huge intraluminal coagulations of hair. Rarely, these can present with gastric perforation. This work has been reported in line with the SCARE criteria (Agha et al., 2016) [1].

PRESENTATION OF CASE

We report the case of a 15 year old girl who attended the emergency department with abdominal pain and vomiting. Ultrasound abdomen and pelvis identified free fluid within the pelvis concerning for inflammatory bowel disease. A subsequent magnetic resonance enterography (MRE) demonstrated a giant gastric trichobezoar which resulted in gastric perforation necessitating laparotomy and gastrotomy. The patient recovered well from the surgery and was reviewed by the psychiatry service prior to discharge.

DISCUSSION

Trichobezoar is a challenging diagnosis and as clinician, we must always include it in our differential diagnosis. The clinical presentation, signs and symptoms depend on the size of the trichobezoar and the presence of complications. Management is almost always surgical.

CONCLUSION

This case illustrates the infrequent perforation risk of gastric bezoars and the important role of magnetic resonance imaging in diagnosis, particularly in a population who must not be exposed to excessive radiation.

Long-term changes in computed tomography and ultrasound utilization in a pediatric emergency department

Objective

Many studies have proposed reducing unnecessary use of computed tomography (CT), and ongoing studies in pediatric populations are aiming to decrease radiation dosages whenever possible. We aimed to evaluate the long-term changes in the utilization patterns of CT and ultrasound (US) in pediatric emergency departments (PEDs).

Methods

This retrospective study reviewed the electronic medical data of patients who underwent CT and/or US in the PED of a tertiary referral hospital from 2000 to 2014. We compared the changes in utilization patterns of brain and abdominal CT scans in pediatric patients and analyzed changes in abdominal US utilization in the PED.

Results

During the study period, 196,371 patients visited the PED. A total of 12,996 brain and abdominal CT scans and 12,424 abdominal US were performed in the PED. Comparison of CT use in pediatric patients before and after 2007 showed statistically decreasing trends after 2007, expressed as the coefficient values of the differences in groups. The numbers of brain and abdominal CT scans showed a significant decreasing trend in children, except for abdominal CT in adolescents. The abdominal US/CT ratio in the PED showed a statistically significant increase (2.68; 95% confidence interval, 1.87 to 3.49) except for the adolescent group (5.82; 95% confidence interval, -2.06 to 13.69).

Conclusion

Overall, CT use in pediatric patients has decreased since 2007. Pediatric US use has also shown a decreasing trend; however, the abdominal US/CT ratio in pediatric patients showed an increasing trend, except for adolescents.

CT radiation dose awareness among paediatricians

BACKGROUND

The radiation dose delivered from computed tomography (CT) scanning and the risks associated with ionising radiation are major concerns in paediatric imaging. Compared to adults, children have increased organ sensitivity and a longer expected lifetime in which cancer may develop. Therefore, it is important to investigate the awareness of paediatricians (referring physicians) regarding radiation doses and the associated risks.

METHODS

A multiple-choice survey was distributed among paediatricians in 8 hospitals in Riyadh, the capital of Saudi Arabia.

RESULTS

Among the 162 respondents, only 24 (15 %) were aware of the As Low As Reasonably Achievable (ALARA) principle. Approximately half (54 %) of the respondents believed that multi-slice CT delivered a low radiation dose, and 100 (62 %) of the respondents were not aware that radiation is considered carcinogenic by the Food and Drug Administration in the United States. Among the respondents, 110 (68 %) did not have any specific education regarding radiation during their training. There was an overall underestimation (83 %) of the CT radiation dose, and 70 % thought that magnetic resonance imaging (MRI) delivered some level of ionising radiation.

CONCLUSIONS

Among paediatricians in Saudi Arabian hospitals, there was a wide underestimation of the CT radiation dose and the associated risks for children. We should improve paediatricians' knowledge about radiation doses. Radiologists, paediatricians, radiation technologists and medical physicists should work together to optimise CT guidelines and protocols to reduce the radiation risks for children.

Establishment of diagnostic reference levels in computed tomography for paediatric patients in Sudan: a pilot study

Paediatric patients are recognised to be at higher risk of developing radiation-induced cancer than adults. The purpose of this pilot study was to evaluate the radiation doses to paediatric patients during computed tomography (CT) procedures in order to propose local diagnostic reference levels (DRLs). A total of 296 patients (aged 6-10 y) were investigated in 8 hospitals equipped with 64-, 16- and dual-slice CT machines. The mean dose length product values were 772, 446 and 178 mGy cm for head, abdomen and chest, respectively. Imaging protocols were not adapted to the patient's weight in certain CT machines. The results confirmed that paediatric patients are exposed to an unnecessary radiation dose. The established DRLs were higher than those available in other countries. This study showed the need for harmonisation of the practice in CT departments and radiation dose optimisation.

Radiation exposure during X-ray examinations in a large paediatric hospital in Serbia

Objective of this work is to evaluate radiation exposure from X-ray examinations in a large paediatric hospital in Serbia, including radiographic, fluoroscopic and computed tomography (CT) examinations in four age groups: 0-1, 1-5, 5-10 and 10-15 y. Incident air kerma was assessed for the following radiographies: chest (AP, PA, LAT), spine (AP, LAT), pelvis (AP), urinary tract (AP, PA) and skull (AP, PA, LAT). Kerma-area product was measured for the fluoroscopy examinations: barium swallow, barium meal, barium enema and micturating cystography. Dose in CT was assessed in terms of volume CT dose index and dose-length product for examinations of the head, chest and abdomen. The collected data were compared with other similar studies, which indicated a need to expand such survey to other paediatric hospitals in Serbia.

[Imaging in pediatric urology]

BACKGROUND

For many years, sonography and the intravenous pyelogram (IVP) were the most important examination methods for the evaluation of the urinary tract in children. Both methods have their pros and cons: sonography provides ideal visualization of normal kidneys and the evaluation of the pelvicalyceal system. For detection or exclusion of renal scarring, however, this method is not well suited. It provides no information regarding kidney function.

METHODS

With an IVP, it is possible to evaluate urinary excretion and, thus, indirectly assess kidney function. As this examination method involves radiation exposure and the necessity of a contrast agent, it should be avoided in the examination of children. The CT is an excellent examination method that can diagnose nearly all urological diseases in children or answer urological questions; however, a CT scan applies the highest radiation dose of all discussed methods. For this reason, examination via MRI is of increasing importance in uroradiology. Initially only the T2 sequences for the visualization of the urinary tract in children were applied.

CONCLUSION

The current technical developments as well as the use of the contrast agent gadolinium and the antidiuretic agent furosemide allow an all-in-one evaluation of the kidneys and urinary tract.

Thyroid doses and risk to paediatric patients undergoing neck CT examinations

OBJECTIVE

To estimate thyroid doses and cancer risk for paediatric patients undergoing neck computed tomography (CT).

METHODS

We used average CTDI(vol) (mGy) values from 75 paediatric neck CT examinations to estimate thyroid dose in a mathematical anthropomorphic phantom (ImPACT Patient CT Dosimetry Calculator). Patient dose was estimated by modelling the neck as mass equivalent water cylinder. A patient size correction factor was obtained using published relative dose data as a function of water cylinder size. Additional correction factors included scan length and radiation intensity variation secondary to tube-current modulation.

RESULTS

The mean water cylinder diameter that modelled the neck was 14 ± 3.5 cm. The mathematical anthropomorphic phantom has a 16.5-cm neck, and for a constant CT exposure, would have thyroid doses that are 13-17% lower than the average paediatric patient. CTDI(vol) was independent of age and sex. The average thyroid doses were 31 ± 18 mGy (males) and 34 ± 15 mGy (females). Thyroid cancer incidence risk was highest for infant females (0.2%), lowest for teenage males (0.01%).

CONCLUSIONS

Estimated absorbed thyroid doses in paediatric neck CT did not significantly vary with age and gender. However, the corresponding thyroid cancer risk is determined by gender and age.

KEY POINTS

• Thyroid doses can be estimated from the CTDI(vol) in paediatric neck CT . • Scan length, neck size, and radiation intensity variation should be accounted for. • Estimated absorbed thyroid doses did not significantly vary with age and gender. • Thyroid cancer incidence risk is primarily determined by gender and age.