ALARA: is there a cause for alarm? Reducing radiation risks from computed tomography scanning in children

LIT-Former: Linking In-Plane and Through-Plane Transformers for Simultaneous CT Image Denoising and Deblurring

This paper studies 3D low-dose computed tomography (CT) imaging. Although various deep learning methods were developed in this context, typically they focus on 2D images and perform denoising due to low-dose and deblurring for super-resolution separately. Up to date, little work was done for simultaneous in-plane denoising and through-plane deblurring, which is important to obtain high-quality 3D CT images with lower radiation and faster imaging speed. For this task, a straightforward method is to directly train an end-to-end 3D network. However, it demands much more training data and expensive computational costs. Here, we propose to link in-plane and through-plane transformers for simultaneous in-plane denoising and through-plane deblurring, termed as LIT-Former, which can efficiently synergize in-plane and through-plane sub-tasks for 3D CT imaging and enjoy the advantages of both convolution and transformer networks. LIT-Former has two novel designs: efficient multi-head self-attention modules (eMSM) and efficient convolutional feed-forward networks (eCFN). First, eMSM integrates in-plane 2D self-attention and through-plane 1D self-attention to efficiently capture global interactions of 3D self-attention, the core unit of transformer networks. Second, eCFN integrates 2D convolution and 1D convolution to extract local information of 3D convolution in the same fashion. As a result, the proposed LIT-Former synergizes these two sub-tasks, significantly reducing the computational complexity as compared to 3D counterparts and enabling rapid convergence. Extensive experimental results on simulated and clinical datasets demonstrate superior performance over state-of-the-art models. The source code is made available at https://github.com/hao1635/LIT-Former.

Hierarchical decomposed dual-domain deep learning for sparse-view CT reconstruction

Objective. X-ray computed tomography employing sparse projection views has emerged as a contemporary technique to mitigate radiation dose. However, due to the inadequate number of projection views, an analytic reconstruction method utilizing filtered backprojection results in severe streaking artifacts. Recently, deep learning (DL) strategies employing image-domain networks have demonstrated remarkable performance in eliminating the streaking artifact caused by analytic reconstruction methods with sparse projection views. Nevertheless, it is difficult to clarify the theoretical justification for applying DL to sparse view computed tomography (CT) reconstruction, and it has been understood as restoration by removing image artifacts, not reconstruction.Approach. By leveraging the theory of deep convolutional framelets (DCF) and the hierarchical decomposition of measurement, this research reveals the constraints of conventional image and projection-domain DL methodologies, subsequently, the research proposes a novel dual-domain DL framework utilizing hierarchical decomposed measurements. Specifically, the research elucidates how the performance of the projection-domain network can be enhanced through a low-rank property of DCF and a bowtie support of hierarchical decomposed measurement in the Fourier domain.Main results. This study demonstrated performance improvement of the proposed framework based on the low-rank property, resulting in superior reconstruction performance compared to conventional analytic and DL methods.Significance. By providing a theoretically justified DL approach for sparse-view CT reconstruction, this study not only offers a superior alternative to existing methods but also opens new avenues for research in medical imaging. It highlights the potential of dual-domain DL frameworks to achieve high-quality reconstructions with lower radiation doses, thereby advancing the field towards safer and more efficient diagnostic techniques. The code is available athttps://github.com/hanyoseob/HDD-DL-for-SVCT.

Low Dose Pediatric CT Head Protocol using Iterative Reconstruction Techniques: A Comparison with Standard Dose Protocol

PURPOSE

Pediatric computed tomography (CT) head examination has also increased in recent years with the advancement in CT technology; however, children exposed to radiation at the youngest age are more vulnerable to the risks of radiation. The aim of the study is to evaluate radiation dose and image quality of low dose pediatric CT head protocol compared to standard dose pediatric CT head protocol.

METHODS

This was a prospective study. Group 1 included 73 patients aged < 1 year and 70 patients in the 1-5 years age group and had undergone CT head examination using the standard dose protocol. Group 2 included 31 patients aged < 1 year and 40 patients in the 1-5 years age group and had undergone CT head examination using the low dose protocol. The radiation dose was measured and image quality was assessed quantitatively and qualitatively.

RESULTS

There was a significant difference in radiation dose between the standard and low dose protocols (p > 0.05) with lower radiation dose for low dose group. The qualitative analysis did not show a significant difference between the standard and low dose protocols. The gray-white matter differentiation (GWMD), attenuation, contrast to noise ratio (CNR) and figure of merit (FOM) were higher in the low dose protocol compared to the standard dose with a significant difference (p > 0.05).

CONCLUSION

The study concludes that a low dose protocol at 80 kV tube voltage/150 mAs tube current exposure time product/iterative reconstruction-iDose4 (level 3) for < 1 year age group and 100 kV/200m As/iDose4 (level 3) for 1-5 years age group provides ultra-low effective dose with diagnostically acceptable image quality for pediatric CT head examination compared with standard dose protocol.

Deep convolutional dictionary learning network for sparse view CT reconstruction with a group sparse prior

Purpose Numerous techniques based on deep learning have been utilized in sparse view computed tomography (CT) imaging. Nevertheless, the majority of techniques are instinctively constructed utilizing state-of-the-art opaque convolutional neural networks (CNNs) and lack interpretability. Moreover, CNNs tend to focus on local receptive fields and neglect nonlocal self-similarity prior information. Obtaining diagnostically valuable images from sparsely sampled projections is a challenging and ill-posed task. Method To address this issue, we propose a unique and understandable model named DCDL-GS for sparse view CT imaging. This model relies on a network comprised of convolutional dictionary learning and a nonlocal group sparse prior. To enhance the quality of image reconstruction, we utilize a neural network in conjunction with a statistical iterative reconstruction framework and perform a set number of iterations. Inspired by group sparsity priors, we adopt a novel group thresholding operation to improve the feature representation and constraint ability and obtain a theoretical interpretation. Furthermore, our DCDL-GS model incorporates filtered backprojection (FBP) reconstruction, fast sliding window nonlocal self-similarity operations, and a lightweight and interpretable convolutional dictionary learning network to enhance the applicability of the model. Results The efficiency of our proposed DCDL-GS model in preserving edges and recovering features is demonstrated by the visual results obtained on the LDCT-P and UIH datasets. Compared to the results of the most advanced techniques, the quantitative results are enhanced, with increases of 0.6-0.8 dB for the peak signal-to-noise ratio (PSNR), 0.005-0.01 for the structural similarity index measure (SSIM), and 1-1.3 for the regulated Fréchet inception distance (rFID) on the test dataset. The quantitative results also show the effectiveness of our proposed deep convolution iterative reconstruction module and nonlocal group sparse prior. Conclusion In this paper, we create a consolidated and enhanced mathematical model by integrating projection data and prior knowledge of images into a deep iterative model. The model is more practical and interpretable than existing approaches. The results from the experiment show that the proposed model performs well in comparison to the others.

A Case of Hematogenous Osteomyelitis in a 5-Week-Old Male

Pediatric osteomyelitis is a rare diagnosis associated with devastating consequences when treatment is delayed. We report a case of hematogenous osteomyelitis in a 5-week-old male presenting to the emergency department (ED) with a flaccid right upper extremity. In the ED, the patient was evaluated with comprehensive infectious and trauma workups. Initial CT imaging of the head and X-ray imaging of the extremity were unremarkable. C-reactive protein was elevated at 0.8; all other laboratory markers were within normal range. Over the course of the ED evaluation, the extremity weakness spontaneously resolved; however, the infant developed a fever of 100.5 F. Empiric broad spectrum antibiotics were initiated, and the infant was admitted to the pediatric service. At 48 hours following presentation, cultures resulted positive for Staphylococcus aureus and MRI imaging revealed osteomyelitis of the proximal right humeral metadiaphysis. Given the subtle presentation of early hematogenous osteomyelitis, emergency providers should maintain a high index of suspicion for infection as the underlying cause in infants presenting with a flaccid extremity.

Learnable PM diffusion coefficients and reformative coordinate attention network for low dose CT denoising

Objective.Various deep learning methods have recently been used for low dose CT (LDCT) denoising. Aggressive denoising may destroy the edge and fine anatomical structures of CT images. Therefore a key issue in LDCT denoising tasks is the difficulty of balancing noise/artifact suppression and edge/structure preservation.Approach.We proposed an LDCT denoising network based on the encoder-decoder structure, namely the Learnable PM diffusion coefficient and efficient attention network (PMA-Net). First, using the powerful feature modeling capability of partial differential equations, we constructed a multiple learnable edge module to generate precise edge information, incorporating the anisotropic image processing idea of Perona-Malik (PM) model into the neural network. Second, a multiscale reformative coordinate attention module was designed to extract multiscale information. Non-overlapping dilated convolution capturing abundant contextual content was combined with coordinate attention which could embed the spatial location information of important features into the channel attention map. Finally, we imposed additional constraints on the edge information using edge-enhanced multiscale perceptual loss to avoid structure loss and over-smoothing.Main results.Experiments are conducted on simulated and real datasets. The quantitative and qualitative results show that the proposed method has better performance in suppressing noise/artifacts and preserving edges/structures.Significance.This work proposes a novel edge feature extraction method that unfolds partial differential equation into neural networks, which contributes to the interpretability and clinical application value of neural network.

A constructive non-local means algorithm for low-dose computed tomography denoising with morphological residual processing

Low-dose computed tomography (LDCT) has attracted significant attention in the domain of medical imaging due to the inherent risks of normal-dose computed tomography (NDCT) based X-ray radiations to patients. However, reducing radiation dose in CT imaging produces noise and artifacts that degrade image quality and subsequently hinders medical disease diagnostic performance. In order to address these problems, this research article presents a competent low-dose computed tomography image denoising algorithm based on a constructive non-local means algorithm with morphological residual processing to achieve the task of removing noise from the LDCT images. We propose an innovative constructive non-local image filtering algorithm by means of applications in low-dose computed tomography technology. The nonlocal mean filter that was recently proposed was modified to construct our denoising algorithm. It constructs the discrete property of neighboring filtering to enable rapid vectorized and parallel implantation in contemporary shared memory computer platforms while simultaneously decreases computing complexity. Subsequently, the proposed method performs faster computation compared to a non-vectorized and serial implementation in terms of speed and scales linearly with image dimension. In addition, the morphological residual processing is employed for the purpose of edge-preserving image processing. It combines linear lowpass filtering with a nonlinear technique that enables the extraction of meaningful regions where edges could be preserved while removing residual artifacts from the images. Experimental results demonstrate that the proposed algorithm preserves more textural and structural features while reducing noise, enhances edges and significantly improves image quality more effectively. The proposed research article obtains better results both qualitatively and quantitively when compared to other comparative algorithms on publicly accessible datasets.

A Comprehensive Analysis of the Radiation Exposure and the Diagnostic Benefit of PanCT in Pediatric Cases with Multiple Trauma

Background and Objectives: The primary objective of this study was to obtain quantitative data, taking into account the amount of radiation exposure, about the clinical and diagnostic benefit obtained from panCT in pediatric trauma cases. Thus, we aim to create greater awareness in all physicians and primarily emergency medicine physicians regarding correct selection in terms of the patient group where this effective radiological method is to be applied, and to protect children from the adverse effects of radiation. Materials and Methods: The computed tomography (CT) images were retrieved from the hospital radiological archive system (PACS). The effective dose (Ed) was calculated using the standardized method including the tissue weighted parameters. The radiological pathologies determined as a result of CT imaging of the cases were categorized according to clinical significance in accordance with the Modified CT Colonography Reporting and Data System (C-RADS). Results: The data for a total of 268 patients were analyzed, comprising 89 (33.2%) females and 179 (66.8%) males with a mean age of 8.81 ± 5.21 years. The mean Ed was determined to be 18.14 ± 10.44 mSv. The Ed was determined to be statistically significantly higher in the 1-5 years age group than in the 15-18 years age group (p = 0.024). A statistically significant difference was determined between the age groups in terms of the pathologies determined (p = 0.028). Conclusions: In order to prevent performing unnecessary CT imaging, trauma teams in Emergency Departments (ED) should work in harmony and individual decision-making should be based on the severity of the trauma mechanism, the severity of the predicted injury, and the clinical status of the injured child.

The use of MRI in the study of patients with idiopathic scoliosis: a systematic review of the literature

Objective. To analyze the frequency of hidden neuraxial pathology in idiopathic scoliosis (IS), to substantiate the need for MRI in IS and to identify promising areas for the use of MRI in the examination of patients with IS.Material and Methods. The literature review was carried out using the PubMed and Google Scholar databases. Of the 780 papers on the research topic, 65 were selected after removing duplicates and checking for inclusion/exclusion criteria. As a result, 49 original studies were included in the analysis. Level of evidence – II.Results. According to modern literature, the main direction of using MRI in idiopathic scoliosis is the search for predictors of latent pathology of the spinal cord and craniovertebral junction. The frequency of neuraxial pathology in idiopathic scoliosis is 8 % for adolescent IS and 16 % for early IS. The main predictors of neuraxial pathology are male sex, early age of deformity onset, left-sided thoracic curve and thoracic hyperkyphosis. MRI in IS may be a useful addition to radiological diagnostic methods to identify risk factors and to study degenerative changes in the spine.Conclusion. MRI of the spine should be performed in the early stages of IS to detect latent spinal cord tethering. In type I Chiari anomalies, there is a possibility that early neurosurgery can prevent the development of scoliosis. The main signs of latent neuraxial pathology in IS are early progression of spinal deformity, left-sided thoracic curve, male gender and thoracic kyphosis over 40° according to Cobb.MRI can be used as an effective non-invasive tool in research aimed at identifying risk factors for IS, including helping to track early degeneration of intervertebral discs.

ESTABLISHMENT OF LOCAL DIAGNOSTIC REFERENCE LEVEL FOR ROUTINE PAEDIATRIC COMPUTED TOMOGRAPHY EXAMINATIONS IN BAFOUSSAM WEST CAMEROON

The main purpose of this study was to determine local diagnostic reference level (LDRL) for routine computed tomography (CT) examination in Bafoussam, western Cameroon. The exposure parameters and dose quantities were collected manually. This retrospective, evaluative and comparative study was conducted to determine LDRLs for routine head CT examination in Bafoussam, to optimize these procedures in the region. The 75th percentile values of the calculated volume CT dose index (CTDIvol) and dose length product (DLP) were proposed as LDRL. The sample was classified in four age groups: < 1, 1-5, 5-10 and 10-15 y. The LDRLs obtained for the four age groups were: 24 mGy and 381.32 mGy.cm, 42.5 mGy and 875.55 mGy.cm, 45.85 mGy and 939.62 mGy.cm, 57.12 mGy and 1222.3 mGy.cm, respectively. The 75th percentile CTDIvol and DLP dose values for this study are higher than international values. We propose a coordinating discussions and collaboration about patient's and specific equipment's change information's, between radiologists, medical imaging technicians and medical physicist, which can reduce absorbed doses and improved medical practice in hospitals.

Emerging Techniques and Future Directions: Fast and Portable Magnetic Resonance Imaging

Fast MRI and portable MRI are emerging as promising technologies to improve the speed, efficiency, and availability of MR imaging. Fast MRI methods are increasingly being adopted to create screening protocols for the diagnosis and management of acute pathology in the emergency department. Faster imaging can facilitate timely diagnosis, reduce motion artifacts, and improve departmental MR operations. Point-of-care and portable MRI are emerging technologies that require radiologists to reenvision the role of MRI as a tool with greater accessibility, fewer siting constraints, and the ability to provide valuable diagnostic information at the bedside. Recently introduced commercially available pulse sequences and new MRI scanners are bringing these technologies closer to the patient's clinical setting, and we expect their use to only increase over the coming decade. This article provides an overview of these emerging technologies for emergency radiologists.

End-to-end deep learning for interior tomography with low-dose x-ray CT

Objective. There are several x-ray computed tomography (CT) scanning strategies used to reduce radiation dose, such as (1) sparse-view CT, (2) low-dose CT and (3) region-of-interest (ROI) CT (called interior tomography). To further reduce the dose, sparse-view and/or low-dose CT settings can be applied together with interior tomography. Interior tomography has various advantages in terms of reducing the number of detectors and decreasing the x-ray radiation dose. However, a large patient or a small field-of-view (FOV) detector can cause truncated projections, and then the reconstructed images suffer from severe cupping artifacts. In addition, although low-dose CT can reduce the radiation exposure dose, analytic reconstruction algorithms produce image noise. Recently, many researchers have utilized image-domain deep learning (DL) approaches to remove each artifact and demonstrated impressive performances, and the theory of deep convolutional framelets supports the reason for the performance improvement. Approach. In this paper, we found that it is difficult to solve coupled artifacts using an image-domain convolutional neural network (CNN) based on deep convolutional framelets. Significance. To address the coupled problem, we decouple it into two sub-problems: (i) image-domain noise reduction inside the truncated projection to solve low-dose CT problem and (ii) extrapolation of the projection outside the truncated projection to solve the ROI CT problem. The decoupled sub-problems are solved directly with a novel proposed end-to-end learning method using dual-domain CNNs. Main results. We demonstrate that the proposed method outperforms the conventional image-domain DL methods, and a projection-domain CNN shows better performance than the image-domain CNNs commonly used by many researchers.

Paediatric minor head injury applied to Paediatric Emergency Care Applied Research Network CT recommendations: An audit

Background

Traumatic brain injury (TBI) is a common cause of paediatric morbidity and mortality, with higher TBI rates in low- and middle-income countries. Non-contrast brain CT is the gold standard for diagnosing intracranial injuries; however, it exposes patients to ionising radiation. The Paediatric Emergency Care Applied Research Network (PECARN) clinical decision rule (CDR) aids clinicians in their decision-making processes whilst deciding whether a patient at very low risk of a clinically important TBI (ciTBI) requires a CT scan.

Objectives

To establish whether the introduction of the PECARN CDR would affect CT utilisation rates for paediatric patients presenting with minor blunt head injuries to an academic hospital in Gauteng, South Africa.

Method

This was an audit of paediatric patients who presented with minor blunt head injuries and were referred for CT imaging at an academic hospital in Gauteng, compared with PECARN CDR recommendations, over a 1-year period.

Results

A total of 100 patients were referred for CT imaging. Twenty patients were classified as very low risk, none of whom had any CT findings of a TBI or ciTBI (p < 0.01). A total of 61 patients were classified as intermediate risk and 19 as high risk. In all, 23% of the intermediate and 47% of the high-risk patients had CT features of a TBI, whilst 8% and 37% had a ciTBI, respectively.

Conclusion

Computed tomography brain imaging may be omitted in patients classified as very low risk without missing a clinically important TBI. Implementing the PECARN CDR in appropriate patients would reduce CT utilisation rates.

An assessment of Sri Lankan radiographer's knowledge and awareness of radiation protection and imaging parameters related to patient dose and image quality in computed tomography (CT)

INTRODUCTION

As computed tomography (CT) examinations have considerably risen, safe operation is essential to reduce the patients' dose. The main objective of this study was to evaluate the level of knowledge and awareness regarding the CT exposure parameters and radiation protection in CT imaging among Sri Lankan radiographers.

METHODS

An online survey-based study was devised and distributed among the Sri Lankan CT radiographers working in 63 CT units. Questions were divided into three subsections that collected data on the participants' demographic features, knowledge of the radiation protection, and imaging parameters.

RESULTS

Eighty-eight radiographers from 32 CT units (out of 63 CT units) distributed across 11 districts (out of 27 districts) participated in this survey.The percentages of correct responses for the questions related to radiation protection, imaging parameters, noise, Diagnostic Reference Level (DRL), and CT dosimetric parameters were 71%, 79%, 87%, 50%, and 66%, respectively. Although the years of experience did not influence any of above aspects, the level of education significantly impacted the knowledge about radiation protection, exposure parameters, and noise.

CONCLUSION

The radiographer's knowledge of radiation protection and most imaging parameters associated with patient safety and image quality is satisfactory. However, findings also show that participants should fill the knowledge gap in radiation-related risks, CT exposure parameters, dosimetric parameters, and DRL.

IMPLICATIONS FOR PRACTICE

The study suggests the necessity of initiating continuous education programs for radiographers in line with national radiation protection legislation requirements that can be linked with code of practice.

The Use of Rapid Sequence Magnetic Resonance Imaging of the Brain as a Screening Tool for the Detection of Gross Intracranial Pathology in Children Presenting to the Emergency Department With a Chief Complaint of Persistent or Recurrent Headaches

OBJECTIVE

The purpose of the study, was to assess the utility of rapid sequence brain magnetic resonance imaging (RS-MRI), as a screening tool to detect gross intracranial pathology in children that present to the emergency department, with a chief complaint of persistent or recurrent headaches. Rapid sequence MRI of the brain is a radiation-free technique that is used to evaluate ventricular size in children with shunted hydrocephalus, who present to the emergency department with symptomatology consistent with shunt malfunction.

METHODS

The study evaluated RS-MRI radiographic findings of 105 children that presented to a busy tertiary care pediatric emergency/trauma center between May 1, 2013, and May 31, 2015. The inclusion criteria for the study are as follows: (1) patient's age up to 12 years, (2) patient history of persistent or recurrent headaches, (3) no history of recent specialized intracranial imaging studies. The exclusion criteria are as follows: (1) a history of recent head injury or trauma, (2) known intracranial pathology, (3) clinical findings consistent with intracranial pathology, (4) patients that required intraprocedural sedation. A detailed explanation was given to the patient's parents/guardian, specifying that this was a "screening test" for detection of gross intracranial abnormalities and not a complete radiological evaluation that would rule out all pathology. Appropriate informed consent was obtained by the attending emergency medicine specialist, and was documented in the patient's medical record.

RESULTS

A total of 105 RS-MRI examinations were performed with an average imaging time of 75 seconds. None of the children required intraprocedural sedation, and there were no failed examinations. One patient was excluded from the study due to a pilocytic astrocytoma (not disclosed initially). There were 81 (77%) of 105 normal studies and 24 (23%) of 105 abnormal studies. One patient returned to the emergency department 2 times and was enrolled twice during the 2-year study. Of the 24 abnormal studies, 18 (75%) of 24 cases were diagnosed with sinusitis, and 1 (4.1%) of 24 cases was diagnosed with an abnormal brain mass with mild hydrocephalus due to obstruction of the caudal aspect of the fourth ventricle.

CONCLUSIONS

Rapid sequence MRI is a radiation-free useful alternative to computer tomography of the brain, when used as a screening tool for children with persistent or recurrent headaches presenting to the emergency department. This rapid imaging modality was particularly useful in identifying children with sinus disease, and contributed significantly to patient/family satisfaction with the care they receive during the emergency department visit. Additionally, RS-MRI screening was successful in detecting a serious neurosurgical emergency in one child with a cerebellar mass causing increased intracranial pressure. Further studies with large sample size are needed to corroborate our findings.

Multidetector computed tomography utilization in an urban sub-Saharan Africa setting: user characteristics, indications and appropriateness

Introduction

multidetector computed tomography (MDCT) is a widely used cross-sectional imaging modality despite increasing concerns about radiation exposure and overuse. The aim of this study was to describe the socio-demographic characteristics of MDCT users in an urban city in Cameroon and to assess the clinical indications for appropriateness.

Methods

we conducted a survey of MDCT users and collected data on demographic attributes and socialization patterns, clinical indications for MDCT and time to obtain MDCT. MDCT appropriateness was assessed using the American College of Radiologists Appropriateness Criteria®. Frequencies, percentages, odds ratios and 95% confidence intervals were used to summarize the data.

Results

with a response rate of 79%, 511 MDCT users were surveyed. The mean (standard deviation) age was 45(19) years and male to female sex ratio 1:1. Seventy-eight percent (95% confidence interval [CI]: 74-83%) of respondents reported not having any health insurance. Head scans accounted for 52% (95%CI: 47-56%) of all scans with trauma (19% [95%CI: 15-22%]), low back pain (18% [95%CI: 14-21%]) and suspected stroke (10% [95%CI: 7-13%]) being the most frequent indications. Sixteen percent (95%CI: 13-20%) of the scans were judged to be inappropriate. Predictors of MDCT appropriateness after multivariable logistic regression modeling were age (aOR=0.97; P=0.009; 95%CI=0.94-0.99), health insurance ownership (aOR=0.40; P=0.034; 95%CI=0.18-0.94) and being referred by non-specialist physicians (aOR=0.20; P<0.001; 95%CI=0.09-0.47).

Conclusion

people from all social strata use MDCT, mostly appropriately and especially for head scans after trauma in this urban setting. However, the proportion of inappropriate studies was considerable suggesting the need for control measures.

Sonography of musculoskeletal infection in children

Musculoskeletal infection, especially in young children, often presents with non-specific clinical signs and symptoms necessitating early imaging to identify the source of infection. While MRI is the investigation of choice to demonstrate bone infection, it is expensive and often requires a general anaesthetic in the young child. Ultrasound can be a useful tool in the initial assessment due to its easy availability and portable equipment. It does not involve ionising radiation and is used to guide aspiration and drainage procedures. This review explains sonographic features of septic arthritis, osteomyelitis, pyomyositis and soft tissue infection in children and highlights advantages and limitations of sonography when assessing the child with suspected musculoskeletal infection.

Neonatal and Infant Appendicitis

Neonatal appendicitis is a rare disease with a high mortality rate. Appendicitis is difficult to diagnose in neonatal and infant populations because it mimics other more common conditions in these age groups. Furthermore, signs and symptoms of appendicitis are often nonspecific in nonverbal patients and a high index of suspicion is necessary to initiate the appropriate diagnostic work-up. The keys to successful management of appendicitis in infants include keeping the diagnosis on the differential in the setting of unexplained intra-abdominal sepsis, following a diagnostic algorithm in the work-up of infant abdominal pathology, and performing appendectomy once the diagnosis is confirmed.

The Jumping Up (J-Up) Test: Making the Diagnosis of Acute Appendicitis Easier in Children

We evaluate a new clinical test, jumping up (J-up) test, to diagnose easier appendicitis in children. A total of 407 patients, aged 5 to16 years, with right lower quadrant abdominal pain were asked to jump rising both hands and trying to reach a toy hanging down from the ceiling of the examination room. Bieri pediatric Face Pain Scale was used for recording the pain response. J-up test has sensitivity of 87% and specificity of 70%. A positive J-up test combined with leukocytosis (white blood cells count >12 000/mm³), neutrophilia >75%, neutrophil/lymphocyte >2, and C-reactive protein >5 mg/dL, achieved a posttest probability of appendicitis of 85%. A negative J-up test combined with the aforementioned blood markers within normal range had a posttest probability for non-appendicitis of 92%. J-up test is a reliable clinical test, which could be used even by an inexperienced doctor. Combined with classical blood markers, it could successfully predict which child is in urgent need or not of surgery.

Machine Learning Techniques Applied to Dose Prediction in Computed Tomography Tests

Increasingly more patients exposed to radiation from computed axial tomography (CT) will have a greater risk of developing tumors or cancer that are caused by cell mutation in the future. A minor dose level would decrease the number of these possible cases. However, this framework can result in medical specialists (radiologists) not being able to detect anomalies or lesions. This work explores a way of addressing these concerns, achieving the reduction of unnecessary radiation without compromising the diagnosis. We contribute with a novel methodology in the CT area to predict the precise radiation that a patient should be given to accomplish this goal. Specifically, from a real dataset composed of the dose data of over fifty thousand patients that have been classified into standardized protocols (skull, abdomen, thorax, pelvis, etc.), we eliminate atypical information (outliers), to later generate regression curves employing diverse well-known Machine Learning techniques. As a result, we have chosen the best analytical technique per protocol; a selection that was thoroughly carried out according to traditional dosimetry parameters to accurately quantify the dose level that the radiologist should apply in each CT test.

A clinical pathway to minimize computed tomography for suspected nephrolithiasis in children

INTRODUCTION

Ultrasound (US) imaging is preferred in the initial evaluation for children with suspected nephrolithiasis; however, computed tomography (CT) continues to be used in this setting with resultant unnecessary ionizing radiation exposure. The study institution implemented a standardized clinical pathway to reduce rates of CT utilization for children with nephrolithiasis.

OBJECTIVE

The aim of this study was to evaluate the impact of this pathway on initial imaging strategies for children with suspected nephrolithiasis.

STUDY DESIGN

A standardized pathway was designed and implemented using a systematic quality improvement process. A suspected cohort was created using 'reason for study' search terms consistent with a nephrolithiasis diagnosis. A confirmed cohort of children with a final diagnosis of nephrolithiasis was derived from this suspected cohort. The primary outcome was CT use as the initial imaging study in children with suspected or confirmed nephrolithiasis presenting to the emergency department (ED) between October 2013 and February 2018. Comparisons were made before and after pathway implementation (October 2015). Secondary outcomes included rates of CT scan within 30 days, while balancing measures included rates of admission, ED length of stay, and return visits.

RESULTS

A total of 534 children with suspected (220 prepathway; 314 postpathway) and 90 children with confirmed (37 prepathway; 53 postpathway) nephrolithiasis were included. For the suspected cohort, CT scans performed as the initial imaging evaluation (9.2% vs 2.5%, P = 0.001) and at any time during the index visit (15.7% vs 5.7%, P = 0.001) decreased after pathway implementation. Within the confirmed cohort, a non-significant decrease in initial CT rates was observed after implementation. No differences were observed in admission rates or ED length of stay after implementation. A trend toward lower return visits to the ED was seen after pathway implementation (5.5% vs 2.2%, P = 0.058).

DISCUSSION

Within a tertiary care pediatric ED associated with a strong institutional experience with clinical pathways, initial CT rates were decreased after pathway implementation for children with suspected nephrolithiasis. While retrospective assessment of suspected disease is limited, this is one of the first studies to address imaging patterns for nephrolithiasis beyond the final discharge diagnosis, thus capturing a broader cohort of children. Children with suspected nephrolithiasis can be safely managed with an US-first approach, and postvisit CT scans are rarely necessary for management.

CONCLUSIONS

A standardized clinical pathway for suspected nephrolithiasis can reduce rates of initial and overall CT utilization without adversely impacting downstream care.

Assessment of patient dose and noise level of clinical CT images: automated measurements

We investigated comparisons between patient dose and noise in pelvic, abdominal, thoracic and head CT images using an automatic method. 113 patient images (37 pelvis, 34 abdominal, 25 thoracic, and 17 head examinations) were retrospectively and automatically examined in this study. Water-equivalent diameter (Dw), size-specific dose estimates (SSDE) and noise were automatically calculated from the center slice for every patient image. The Dw was calculated based on auto-contouring of the patients' edges, and the SSDE was calculated as the product of the volume CT dose index (CTDIvol) extracted from the Digital Imaging and Communications in Medicine (DICOM) header and the size conversion factor based on the Dw obtained from AAPM 204. The noise was automatically measured as a minimum standard deviation in the map of standard deviations. A square region of interest of about 1 cm² was used in the automated noise measurement. The SSDE values for the pelvis, abdomen, thorax, and head were 21.8 ± 7.3 mGy, 22.0 ± 4.5 mGy, 21.5 ± 4.7 mGy, and 65.1 ± 1.7 mGy, respectively. The SSDEs for the pelvis, abdomen, and thorax increased linearly with increasing Dw, and for the head with constant tube current, the SSDE decreased with increasing Dw. The noise in the pelvis, abdomen, thorax, and head were 5.9 ± 1.5 HU, 5.2 ± 1.4 HU, 4.9 ± 0.8 HU and 3.9 ± 0.2 HU, respectively. The noise levels for the pelvis, abdomen, and thorax of the patients were relatively constant with Dw because of tube current modulation. The noise in the head image was also relatively constant because Dw variations in the head are very small. The automated approach provides a convenient and objective tool for dose optimizations.

Second follow-up of a German cohort on childhood cancer incidence after exposure to postnatal diagnostic x-ray

Studies on children exposed to ionising radiation by computed tomography (CT) indicate an increased risk of leukemia and central nervous system (CNS) tumors. Evidence of the risks associated with diagnostic x-ray examinations, the most frequent examination in pediatric radiology, in which the radiation dose is up to 750 times lower compared to CT examinations, is less clear. This study presents results of the second follow-up for the risk of childhood cancer in a cohort of children (<15 years) with diagnostic x-ray exposure at a large German hospital during 1976-2003 followed for additional 10 years until 2016. With a latency period of 6 months, 92 998 children contributed 794 549 person-years. The median effective dose was 7 μSv. Hundred incident cancer cases were identified: 35 leukemia, 13 lymphomas, 12 CNS tumors, 15 blastomas, 15 sarcomas and 10 other solid tumors, consisting of six germ cells tumors, three thyroid cancers and one adrenocortical carcinoma. For all cancer cases combined the standardised incidence ratio (SIR) was 1.14 (95% confidence interval (CI) 0.93-1.39), for leukemia 1.15 (95% CI 0.63-1.61), for lymphomas 1.03 (95% CI 0.55-1.76), for CNS tumors 0.65 (95% CI 0.34-1.14), for blastomas 1.77 (95% CI 0.91-2.91), for sarcomas 1.28 (95% CI 0.71-2.11) and for other solid tumors 2.38 (95% CI 1.14-4.38). Dose-response analysis using Poisson regression revealed no significant trend for dose groups. Results did not differ substantially with a latency period of 2 years for all cancer entities and 5 years for solid tumors in sensitivity analyses. Overall, the null results of the first follow-up were confirmed. Although an association between radiation exposure and a risk for certain solid tumors like thyroid cancer is known, the significantly increased SIR in the group of other solid tumors must be critically interpreted in the context of the small number of cases and the very low doses of radiation exposure in this group.

Concurrent lymphoma and hemophilia B in a pediatric patient: A case report

INTRODUCTION

Lymphoma is the third most common cancer among children in the United States and Europe. Hemophilia is a congenital bleeding disorder characterized by deficiency of coagulation factor VIII or IX. Hemophilia B is a consequence of factor IX deficiency and has an incidence of 1 in 20,000 male births. A concurrence of these 2 uncommon diseases is rare except in patients infected with the human immunodeficiency virus (HIV). We report a case of a patient with both Burkitt lymphoma and hemophilia B; this is only such report in China since 1987.

PATIENT CONCERNS

A 3-year-old boy was admitted to our hospital because of melena and jaundice for several days. His older brother had died due to hemophilia B and ventricular septal defect. The patient had not experienced any previous episodes of severe bleeding. Gradual abdominal distention was observed after admission; the patient's superficial lymph nodes were not enlarged. Results of blood routine and bone marrow examinations showed no abnormalities. He was diagnosed with sclerosing cholangitis, abdominal infection, and hepatitis. However, after treatment of reducing enzyme activity and eliminating jaundice, the patient's condition deteriorated. Hydrops abdominis was detected on abdominal ultrasonography. Tumor cells were found by pathological examination of peritoneal effusion. Both a c-myc gene translocation and a c-myc-IgH gene fusion were detected.

DIAGNOSIS

Burkitt lymphoma and hemophilia B.

INTERVENTIONS

The patient was transferred to the Pediatric Hematology Department of our hospital and treated with a modified B-NHL-BFM-95 protocol. During chemotherapy, platelet changes were monitored regularly and blood products were infused timely.

OUTCOMES

The patient died of infection and bleeding after chemotherapy.

CONCLUSION

Concurrent hemophilia and lymphoma are rare, especially in children. When encountering a patient with unexplained obstructive jaundice and massive ascites, the possibility of a tumor should be considered. Early diagnosis and adequate treatment of such tumor may improve prognosis.

Pediatric CT radiation exposure: where we were, and where we are now

Since the turn of the last millennium, the pediatric radiology community has blazed a patient-quality and safety trail in helping to effectively address the public and the news media's concerns about the implications of ionizing radiation from CT scanners in children. As such, this article (1) reviews the potential deleterious effects of ionizing radiation, (2) discusses why limiting radiation exposure in children is so important, (3) tells the history of pediatric CT radiation exposure concerns, (4) explains the interventions that took place to address these concerns and (5) touches on the current school of thought on pediatric CT dose reduction.

Image quality and radiation dose of ECG-triggered High-Pitch Dual-Source cardiac computed tomography angiography in children for the evaluation of central vascular stents

Assess image quality and radiation dose of ECG-triggered High-Pitch Dual-Source CTA for the evaluation central vascular stents in children. We included all children ≤ 21 years old with one or more central vascular stents and available prospective ECG-triggered High-Pitch Dual-Source CTA performed at our institution between January 2015 and August 2017. Demographic and scanner information was retrieved. Two board-certified pediatric radiologists blinded to the clinical data, independently reviewed and scored each case using a four-point quality score. Scores 1, 2 and 3 were considered of diagnostic image quality. Inter-observer agreement and non-parametric test were used. 18 patients (10 girls, 8 boys) with a mean age of 9.47 ± 7.38 years (mean ± SD) met inclusion criteria. Thirty-two central vascular stents were evaluated. Mean quality score was 2.07 ± 0.94 with 12.5% (4/32) of the cases classified as unevaluable. Interobserver agreement was excellent (k = 0.86). There is no significant difference between quality score and stent location (p = 0.07). There is a significant difference with stent material as all non-diagnostic scores were only seen in covered stents made of platinum-iridium (p < 0.001). There was no association between image quality and age, height, weight, BSA, heart rate, radiation dose or stent lumen size (p > 0.05). ECG-triggered high-pitch spiral DS-CTA offers appropriate image quality for assessment of central vascular stents in children.

Fractured pediatric central venous catheters - Repair or replace?

INTRODUCTION

Central venous catheter (CVC) fracture is a common complication. The aim of this study is to examine risk factors resulting in CVC fracture and compare outcomes of children undergoing CVC repair versus replacement.

METHODS

A retrospective chart review was conducted from 2000 to 2016 for children with tunneled CVCs. Children with CVC fractures were compared to those without to identify risk factors resulting in fracture. Children with fractured CVCs were divided into repair or replacement treatment groups and outcomes compared. A logistic regression model determined independent predictors of CVC-associated bloodstream infections (CLABSI) after fracture.

RESULTS

In the 236 children with CVCs, the fracture rate was 29.2%. Fractured CVCs were more common with double lumen CVC (p = 0.040) and children whose indication was total parenteral nutrition (p = 0.003). Given children often underwent multiple repairs or replacements. 98 CVC repairs and 41 replacements were analyzed. CVC replacements had longer durability than repair (181.98 vs. 98.9 days, p = 0.038). There were no differences in CLABSI incidence for repair vs. replacement (OR 0.5 CI 0.05-4.97) after controlling for other factors.

CONCLUSIONS

CVC fracture is a frequent complication in children with tunneled CVCs. CVC repair has no increased incidence of CLABSI but eliminates the intraoperative and anesthetic risks of CVC replacement.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

Level III.

Depiction of the native coronary arteries during ECG-triggered High-Pitch Dual-Source Coronary Computed Tomography Angiography in children: Determinants of image quality

OBJECTIVE

Assess the image quality of ECG-triggered High-Pitch Dual-Source CTA for the evaluation of native coronaries in children.

MATERIALS AND METHODS

Between August 2014 and September 2017, 45 children with morphologically normal cardiac chambers had cardiac prospective ECG-triggered High-Pitch Dual-Source CTA. Two pediatric radiologists blinded to clinical data, independently reviewed each case. The coronary arteries were evaluated using a four-point scale quality score according to the coronary segment. Attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured using values from the air, inter-ventricular septum and ascending aorta at the level of the sinuses of Valsalva.

RESULTS

225 coronary segments were assessed showed a mean score of 2.40 ± 0.73, 94.2% had diagnostic image quality. The best and worst average quality were seen in segment 5 and 2, respectively. Inter-observer agreement was moderate for all segments except for segment 1, which was excellent. Worse quality scores were significantly associated with younger patients and low body mass index as well as with higher heart rates in all segments. The mean observed heart rate and BSA in patients with diagnostic image quality were below 77 bpm and over 1.4 m² respectively. There is no significant association between attenuation, SNR and CNR with image quality.

CONCLUSIONS

Prospective ECG-triggered High-Pitch Dual-Source Computed Tomography Angiography achieves consistent and diagnostic image quality for coronary artery assessment at a low effective dose in pediatric patients.

Evaluation of an iterative model-based reconstruction of pediatric abdominal CT with regard to image quality and radiation dose

Background In pediatric patients, computed tomography (CT) is important in the medical chain of diagnosing and monitoring various diseases. Because children are more radiosensitive than adults, they require minimal radiation exposure. One way to achieve this goal is to implement new technical solutions, like iterative reconstruction. Purpose To evaluate the potential of a new, iterative, model-based method for reconstructing (IMR) pediatric abdominal CT at a low radiation dose and determine whether it maintains or improves image quality, compared to the current reconstruction method. Material and Methods Forty pediatric patients underwent abdominal CT. Twenty patients were examined with the standard dose settings and 20 patients were examined with a 32% lower radiation dose. Images from the standard examination were reconstructed with a hybrid iterative reconstruction method (iDose⁴), and images from the low-dose examinations were reconstructed with both iDose⁴ and IMR. Image quality was evaluated subjectively by three observers, according to modified EU image quality criteria, and evaluated objectively based on the noise observed in liver images. Results Visual grading characteristics analyses showed no difference in image quality between the standard dose examination reconstructed with iDose⁴ and the low dose examination reconstructed with IMR. IMR showed lower image noise in the liver compared to iDose⁴ images. Inter- and intra-observer variance was low: the intraclass coefficient was 0.66 (95% confidence interval = 0.60-0.71) for the three observers. Conclusion IMR provided image quality equivalent or superior to the standard iDose⁴ method for evaluating pediatric abdominal CT, even with a 32% dose reduction.

The cost effectiveness and utility of a "quick MRI" for the evaluation of intra-abdominal abscess after acute appendicitis in the pediatric patient population

INTRODUCTION

Contrast-enhanced CT remains the first-line imaging for evaluating postoperative abscess (POA) after appendicitis. Given concerns of ionizing radiation use in children, we began utilizing quick MRI to evaluate POA and summarize our findings in this study.

MATERIALS AND METHODS

Children imaged with quick MRI from 2015 to 2017 were compared to children evaluated with CT from 2012 to 2014 using an age and weight matched case-control model. Radiation exposure, size and number of abscesses, length of exam, drain placement, and patient outcomes were compared.

RESULTS

There was no difference in age or weight (p>0.60) between children evaluated with quick MRI (n=16) and CT (n=16). Mean imaging time was longer (18.2±8.5min) for MRI (p<0.001), but there was no difference in time from imaging order to drain placement (p=0.969). No children required sedation or had non-diagnostic imaging. There were no differences in abscess volume (p=0.346) or drain placement (p=0.332). Thirty-day follow-up showed no difference in readmissions (p=0.551) and no missed abscesses. Quick MRI reduced imaging charges to $1871 from $5650 with CT.

CONCLUSION

Quick MRI demonstrated equivalent outcomes to CT in terms of POA detection, drain placement, and 30-day complications suggesting that MRI provides an equally effective, less expensive, and non-radiation modality for the identification of POA.

TYPE OF STUDY

Retrospective Case-Control Study.

LEVEL OF EVIDENCE

Level III.

DEVELOPMENT OF A SET OF MESH-BASED AND AGE-DEPENDENT CHINESE PHANTOMS AND APPLICATION FOR CT DOSE CALCULATIONS

Phantoms for organ dose calculations are essential in radiation protection dosimetry. This article describes the development of a set of mesh-based and age-dependent phantoms for Chinese populations using reference data recommended by the Chinese government and by the International Atomic Energy Agency (IAEA). Existing mesh-based RPI adult male (RPI-AM) and RPI adult female (RPI-AF) phantoms were deformed to form new phantoms according to anatomical data for the height and weight of Chinese individuals of 5 years old male, 5 years old female, 10 years old male, 10 years old female,15 years old male, 15 years old female, adult male and adult female-named USTC-5 M, USTC-5F, USTC-10M, USTC-10F, USTC-15M, USTC-15F, USTC-AM and USTC-AF, respectively. Following procedures to ensure the accuracy, more than 120 organs/tissues in each model were adjusted to match the Chinese reference parameters and the mass errors were within 0.5%. To demonstrate the usefulness, these new set of phantoms were combined with a fully validated model of the GE LightSpeed Pro 16 multi-detector computed tomography (MDCT) scanner and the GPU-based ARCHER Monte Carlo code to compute organ doses from CT examinations. Organ doses for adult models were then compared with the data of RPI-AM and RPI-AF under the same conditions. The absorbed doses and the effective doses of RPI phantoms are found to be lower than these of the USTC adult phantoms whose body sizes are smaller. Comparisons for the doses among different ages and genders were also made. It was found that teenagers receive more radiation doses than adults do. Such Chinese-specific phantoms are clearly better suited in organ dose studies for the Chinese individuals than phantoms designed for western populations. As already demonstrated, data derived from age-specific Chinese phantoms can help CT operators and designers to optimize image quality and doses.

Knowledge and Awareness of CT Radiation Dose and Risk Among Patients

The study aims to assess the level of patients’ awareness and knowledge regarding radiation and dosage along with the associated risks from computed tomography (CT) scan. This cross-sectional study used questionnaires, which were distributed to the diagnostic imaging departments of six large local hospitals in Jordan between September 2014 and March 2015. A total of 600 patients completed the questionnaire, out of which, 52.33% of respondents were female and 47.6% male. The findings show insignificant effects of gender on patient’s knowledge ( P = .596) and significant effect of employment and profession on positive scores ( P = .000). Similarly, no statistical differences were found between gender and correct answers ( P = .707). This cohort of patients demonstrated a lack of awareness and knowledge about the use of ionizing radiation for diagnostic imaging. Thus, there may exist a similar lack of information that will require imaging professionals to raise patients’ awareness and offer them the appropriate information.

Changing Trends in Brain Imaging Technique for Pediatric Patients with Ventriculoperitoneal Shunts

BACKGROUND

Children with ventriculoperitoneal shunts (VPS) undergoing brain computed tomography (CT) for shunt malfunction evaluation are at risk for later malignancy due to radiation exposure. We aimed to determine if and how hospitals have adopted radiation-avoiding magnetic resonance imaging (MRI) techniques.

METHODS

We performed a secondary analysis of the Pediatric Health Information System (PHIS) database. Children with VPS presenting to acute wards at 31 PHIS hospitals between January 1, 2007 and January 2, 2015 and receiving noncontrast neuroimaging on day of service 0/1 were included. Outcome measures were (1) incidence of MRI over time and (2) comparison of demographic characteristics between hospitals with MRI representing higher versus lower proportions (>15% or <15%) of total brain imaging.

RESULTS

MRIs increased by 18.1% from 2007 to 2015. Hospitals were assigned to high-use (n = 12) or minimal-use (n = 19) MRI groups based on year 2014/2015 MRI percentages. The only identified difference was an older mean age in the high-use group (8.1 vs. 7.5 years; p = 0.03).

CONCLUSIONS

MRI is increasingly used to evaluate patients with VPS. Hospitals with more MRI use had older patients and no increase in cost or length of stay. Initiating local quality improvement projects may help identify barriers to MRI uptake and increase use.

Selective Non-operative Management of Patients with Abdominal Trauma-Is CECT Scan Mandatory?

CECT scan is considered essential for selective non-operative management (SNOM) of patients with abdominal trauma. However, CECT has its own hazards and limitations. We evaluated the safety and efficacy of selective non-operative management of patients with abdominal trauma without the mandatory use of CECT scan in a prospective study. Patients with peritonitis and ongoing intra-abdominal bleed were excluded. Consenting FAST positive, hemodynamically stable patients with blunt and penetrating abdominal trauma between 18 and 60 years of age were included and admitted for SNOM and detailed ultrasonography of the abdomen (in all) with or without CECT abdomen (selectively). Eighty-four patients with abdominal trauma were admitted during the study period. Twenty-two patients did not satisfy the inclusion criteria and 18 required immediate laparotomy based on primary survey. Remaining 44 patients were admitted for SNOM: mean ± SD age of these patients was 27 ± 8.7 years; 40 (89 %) were males. Thirty-five patients (79.54 %) sustained blunt trauma (RTI = 16, Fall = 16, others = 3) while nine patients (20.45 %) sustained penetrating trauma. SNOM without CECT was successful in 36 (81.82 %) patients. Five (11.36 %) patients underwent delayed emergency laparotomy based on clinical and detailed USG evaluation. CECT was not done in these patients. Three patients underwent CECT for various reasons; however, they were managed with SNOM. Thus, SNOM without abdominal CECT was successful in 36 (81.82 %) patients. SNOM failed in five patients but abdominal USG was sufficient. SNOM can be practised safely in patients of abdominal trauma with limited use of CECT scan.

Optimal Utilization of Pediatric Computed Tomography to Minimize Radiation Exposure: What the Clinician Must Know s

The number of computed tomography (CT) scans being done for children all over the world is on the rise ever since the advent of Multi-Detector CT (MDCT). However, CT is a potential source of harmful ionizing radiation, and children are more susceptible to its adverse effects. It is essential for the pediatrician as well as the radiologist to be aware of some important principles and guidelines, by following which, radiation exposure to the child can be minimized to the bare essential. It is important to have knowledge of the valid and justifiable indications of CT for the child, the correct technique of performing the scan, and the new technological innovations now available on modern scanners that help to minimize radiation dose.

An Algorithmic Approach Using Ultrasonography in the Diagnosis of Pediatric Nasal Bone Fracture

BACKGROUND

Ultrasonography (US) was recently reported as a reliable modality for diagnosing nasal bone fractures. However, whether US is reliable as a screening tool in the pediatric emergency department (ED) remains unknown. This prospective cohort study had a 2-fold aim: to assess the utility of US in the diagnosis of pediatric nasal bone fracture, and to evaluate the validity of our protocol for managing pediatric nasal bone fractures (Fuchu-Kids algorithm).

PATIENTS AND METHODS

Among the patients who presented at the ED with facial trauma, those with a suspected nasal bone fracture were enrolled in the study. Patients were treated according to Fuchu-Kids algorithm, and the validity of the protocol using US imaging was evaluated.

RESULTS

Among 81 patients who were enrolled during the 1-year study period, 63 patients were able to complete the process described in our protocol for further examination. The diagnostic power of the Fuchu-Kids algorithm had a sensitivity of 91.7%, a specificity of 92.3%, a positive predictive value (PPV) of 88%, and a negative predictive value (NPV) of 94.7%. However, when the performance of US was assessed as a single examination, its sensitivity, specificity, PPV, and NPV were 75%, 92.3%, 85.7%, and 85.7%, respectively.

CONCLUSION

Using our algorithm, the majority of patients with nasal bone fracture were successfully diagnosed and screened out successfully. Repeated US imaging is effective when clinical symptoms persist even if the first US imaging was negative for nasal bone fracture. However, a detailed medical interview and clinical examination are mandatory, regardless of the use of US.

Back pain and scoliosis in children: When to image, what to consider

Back pain and scoliosis in children most commonly present as benign and self-limited entities. However, persistent back pain and/or progressive scoliosis should always be taken seriously in children. Dedicated diagnostic work-up should exclude etiologies that may result in significant morbidity. Clinical evaluation and management require a comprehensive history and physical and neurological examination. A correct imaging approach is important to define a clear diagnosis and should be reserved for children with persistent symptoms or concerning clinical and laboratory findings. This article reviews the role of different imaging techniques in the diagnostic approach to back pain and scoliosis, and offers a comprehensive review of the main imaging findings associated with common and uncommon causes of back pain and scoliosis in the pediatric population.

A prospective evaluation of the contrast, radiation dose and image quality of contrast-enhanced CT scans of paediatric abdomens using a low-concentration iodinated contrast agent and low tube voltage combined with 70% ASIR algorithm

PURPOSE

To quantitatively and subjectively assess the image quality of and radiation dose for an abdominal enhanced computed tomography (CT) scan with a low tube voltage and a low concentration of iodinated contrast agent in children.

METHODS

Forty-eight patients were randomised to one of the two following protocols: Group A (n=24, mean age 46.96±44.65 months, mean weight 15.71±9.11 kg, BMI 16.48±2.40 kg/m(2) ) and Group B (n=24, mean age 41.33±44.59 months, mean weight 18.15±17.67 kg, BMI 17.50±3.73 kg/m(2) ). Group A: 80 kVp tube voltage, 270 mg iodine (I)/mL contrast agent (Visipaque, GE Healthcare) and images were reconstructed using 70% adaptive statistical iterative reconstruction (ASIR). Group B: 100 kVp tube voltage, 370 mg I/mL contrast agent (Iopamiro, Bracco) and images were reconstructed using 50% ASIR. The volume of the contrast agent was 1.30 mL/kg in both Groups A and B. The degree of enhancement and noise in the abdominal aorta (AO) in the arterial phase (AP) and the portal vein (PV) in the portal venous phase (PVP) was measured; while the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for the AO and PV were calculated. A 5-point scale was used to subjectively evaluate the image quality and image noise by two radiologists with more than 10 years of experience. Dose-length product (DLP) (mGy-cm) and CTDIvol (mGy) were calculated. Objective measurements and subjective quality scores for the two groups were compared using paired t-tests and Mann-Whitney U tests, respectively.

RESULTS

There was no significant difference in age, weight or body mass index (BMI) between the two groups (all P>.5). The iodine load in Group A (5517.3±3197.2 mg I) was 37% lower than that in Group B (8772.1±8474.6 mg I), although there was no significant difference between them (P=.111). The DLP and the CT dose index (CTDIvol ) for Group A were also lower than for Group B, but were not statistically significantly different (DLP, 104 mGy-cm±45.81 vs 224.5 mGy-cm±45.83; CTDIvol, 1.44 mGy±0.50 vs 2.08 mGy±1.87, all P>.05). The mean arterial and portal venous enhancement (255.33 HU±83.42, 146.41 HU±23.45, respectively), noise (AP 14.96 HU±2.09, PVP 16.30 HU±3.21), CNRs (AO 14.54±7.12, PV 5.07±1.73) and SNRs (AO 20.76±6.76, PV 12.43±3.24) for Group A were similar to Group B (enhancement: 226.55 HU±77.71, 138.69 HU±33.22; noise: 14.92 HU±3.12, 15.36 HU±3.48; CNRs: 12.96±7.14, 5.16±2.28; SNRs: 19.13±7.30, 12.69±4.22; all P>.05). The mean scores of the quality of the AP and PVP images in Group B were 4.31±0.53 and 4.35±0.52, respectively, while the scores obtained in Group A were 4.29±0.51 and 4.25±0.51; there were no statistically significant differences between the two groups.

CONCLUSION

The scanning protocol using a low tube voltage (80 kVp) together with 70% ASIR and a low-concentration iodinated contrast agent (270 mg I/mL) enables a 37% reduction in iodine load and a 30% reduction in radiation dose while maintaining compatible image quality.

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.

Magnetic Resonance Three-dimensional Cube Technique in the Measurement of Piglet Femoral Anteversion

BACKGROUND

The accurate measurement of the femoral anteversion (FA) angle is always a topic of much debate in the orthopedic surgery and radiology research. We aimed to explore a new FA measurement method to acquire accurate results without radiation damage using piglet model.

METHODS

A total of thirty piglets were assigned to two groups based on the age. Bilateral femora were imaged with 3.0-T magnetic resonance (MR) and 64-slice computed tomography (CT) examinations on all piglets. FA was measured on MR-three-dimensional (3D) postprocessing software with a four-step method: initial validation of the femoral condylar axis, validation of the condylar plane, validation of the femoral neck axis, and line-plane angle measurement of FA. After MR and CT examinations, all piglets were sacrificed and their degree of FA was measured using their excised, dried femora. MR, CT, and dried-femur measurement results were analyzed statistically; MR and CT measurements were compared for accuracy against each other and against the gold standard dried femur measurement.

RESULTS

In both groups, the mean FA value measured by MR was lower than that measured by CT. A statistically significant difference was observed between CT- and dried-femur measurements but not between MR- and dried-femur measurements. A higher correlation (0.783 vs. 0.408) and a higher consistency (0.863 vs. 0.578) with dried-femur measurement results were seen for MR measurements than CT measurements in the 1-week age group. However, in the 8-week age group, similar correlations (0.707 vs. 0.669) and consistencies (0.864 vs. 0.821) were observed.

CONCLUSIONS

Noninvasive MR-3D-Cube reconstruction was able to accurately measure FA in piglets. Particularly in the 1-week age group with a larger proportion of cartilaginous structures, the correlation and consistency between MR- and dried-femur measurement results were higher than those between CT- and dried-femur measurements, suggesting that MR may be a new useful examination tool for FA-related diseases in children.

Expert Facilitated Development of an Objective Assessment Tool for Point-of-Care Ultrasound Performance in Undergraduate Medical Education

BACKGROUND

With the various applications of point-of-care ultrasound (PoCUS) steadily increasing, many medical schools across North America are incorporating PoCUS training into their undergraduate curricula. The Faculty of Medicine at Memorial University also intends to introduce PoCUS training into its own undergraduate medical program. The proposed approach is to introduce a PoCUS curriculum focusing on anatomy and physiology while developing cognitive and psychomotor skills that are later transferred into clinical applications. This has been the common approach taken by most undergraduate ultrasound programs in the United States. This project highlights the development and the challenges involved in creating an objective assessment tool that meets the unique needs of this proposed undergraduate ultrasound curriculum.

METHODS

After a thorough review of existing literature and input from experts in PoCUS, a prototype global rating scale (GRS) and three exam-specific checklists were created by researchers. The exam-specific checklists include aorta exam, subxiphoid cardiac exam, and focused abdominal exam. A panel of 18 emergency room physicians certified in PoCUS were recruited to evaluate the GRS and three checklists. This was accomplished using a modified Delphi technique. The items were rated on a 5-point Likert scale. If an item received a mean score of less than 4, it was deemed unimportant for the assessment of PoCUS performance in undergraduate medical learners and was excluded. Experts were also encouraged to provide comments and suggest further items to be added to the GRS or checklists. Items were modified according to these comments. All of the edits were then sent back to the experts for revisions.

RESULTS

A consensus was achieved after three rounds of surveys, with the final GRS containing nine items. The final aorta checklist contained nine items, and the subxiphoid cardiac and focused abdominal checklists each contained 11 items.

CONCLUSION

By using a modified Delphi technique, we developed a single GRS and three checklists. A panel of independent PoCUS practitioners supports the content validity of these tools. Research is currently ongoing to evaluate their validity for assessing PoCUS competency in undergraduate medical students.

CT versus ultrasound guidance for percutaneous drainages in the pediatric population: an institutional review meant to limit radiation

Computed tomography (CT)-guided percutaneous drainage is a minimally invasive procedure that allows for accurate diagnosis and therapy with minimal complications. The drawback is that CT guidance carries a significant amount of radiation exposure. CT-guided percutaneous drainages have been widely used in adults and have been gaining momentum within the pediatric population. Through a thorough review of our institution's (Montefiore Medical Center) CT-guided percutaneous drainages within our pediatric patients, we assessed the radiation exposure per study as well as which studies were deemed possible under ultrasound guidance as a possible alternative.

CT-abnormalities, bacteriology and symptoms of sinonasal disease in children with Cystic Fibrosis

BACKGROUND

Sinonasal pathology in adults with Cystic Fibrosis (CF) is common but the extent of CT-abnormalities and symptoms of sinonasal disease in children with CF and the age of onset are less frequently studied.

METHODS

In this observational, cross-sectional study 58 children with CF from two CF centres were included. All subjects completed a questionnaire regarding sinonasal symptoms, underwent a CT scan of the paranasal sinuses, and in each subject a culture of the upper airways was performed. Subjects were divided in 6 age cohorts (0-2, 3-5, 6-8, 9-11, 12-14 and 15-17years) and were divided into severe and mild CF based on their CFTR mutation. Opacification of the sinonasal system of the subjects was compared with opacification on MRI-scans of an age-matched control group without CF.

RESULTS

Most frequently reported symptoms were nasal obstruction and posterior/anterior nasal discharge. Opacification was abundant in every age cohort of the study group and was significantly more compared to the control group. In patients with severe CF the opacification was higher than subjects with mild CF. Upper airway cultures showed predominantly Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa.

CONCLUSION

CT-abnormalities indicating sinonasal disease and symptoms are present from shortly after birth which may argue for a thorough examination of the upper airways in children with CF.