Ultrafast pediatric chest computed tomography: comparison of free-breathing vs. breath-hold imaging with and without anesthesia in young children

Efficacy and Safety of Dexmedetomidine Compared to Other Needle-Free Pharmacological Sedation Methods in Pediatric Patients Undergoing Imaging Procedures

BACKGROUND

Pediatric patients often require sedation during magnetic resonance imaging (MRI) and computed tomography (CT) to ensure stillness and minimize stress. This meta-analysis compared the effectiveness and safety of 3 sedative agents-dexmedetomidine, midazolam, and chloral hydrate-for pediatric MRI/CT sedation.

METHODS

Six studies with a total of 633 patients were included in the analysis. Quality assessment revealed varying levels of bias risk. Dexmedetomidine exhibited a significantly higher successful sedation rate compared to midazolam (risk ratio [RR] = 0.43, 95% confidence interval [CI] [0.29-0.64]), but no statistically significant difference compared to chloral hydrate (RR = 0.94, 95% CI [0.60-1.45]). Chloral hydrate also showed a higher successful sedation rate compared to midazolam (RR = 0.46, 95% CI [0.25-0.83]). The onset of sedation time did not significantly differ between the 3 agents.

RESULTS

The dexmedetomidine group had a significantly higher incidence of bradycardia compared to the chloral hydrate group (RR = 0.17, 95% CI [0.05-0.59]), but no significant difference compared to the midazolam group (RR = 0.29, 95% CI [0.06-1.26]). No statistically significant differences were observed in the incidence of nausea and vomiting between the 3 groups.

CONCLUSIONS

Dexmedetomidine demonstrates effectiveness in pediatric MRI/CT sedation, offering advantages over midazolam and similar efficacy to chloral hydrate. Careful cardiovascular monitoring is essential during administration, particularly in patients with congenital heart disease. Sublingual and intranasal administration of dexmedetomidine is a viable option with high bioavailability. This meta-analysis contributes valuable insights into refining sedation protocols for pediatric imaging procedures, emphasizing efficacy and safety considerations.

Advancements in imaging in ChILD

Interstitial and diffuse lung diseases in children constitute a range of congenital and acquired disorders. These disorders present with signs and symptoms of respiratory disease accompanied by diffuse radiographic changes. In many cases, radiographic findings are nonspecific, while in other disorders, chest computed tomography (CT) is diagnostic in the appropriate context. Regardless, chest imaging remains central in the evaluation of the patient with suspected childhood interstitial lung disease (chILD). Several newly described chILD entities, spanning both genetic and acquired etiologies, have imaging that aid in their diagnoses. Advances in CT scanning technology and CT analysis techniques continue to improve scan quality as well as expand use of chest CT as a research tool. Finally, ongoing research is expanding use of imaging modalities without ionizing radiation. Magnetic resonance imaging is being applied to investigate pulmonary structure and function, and ultrasound of the lung and pleura is a novel technique with an emerging role in chILD disorders. This review describes the current state of imaging in chILD including recently described diagnoses, advances in conventional imaging techniques and applications, and evolving new imaging modalities that expand the clinical and research roles for imaging in these disorders.

Urgent and emergent pediatric cardiovascular imaging

The need for urgent or emergent cardiovascular imaging in children is rare when compared to adults. Patients may present from the neonatal period up to adolescence, and may require imaging for both traumatic and non-traumatic causes. In children, coronary pathology is rarely the cause of an emergency unlike in adults where it is the main cause. Radiology, including chest radiography and computed tomography in conjunction with echocardiography, often plays the most important role in the acute management of these patients. Magnetic resonance imaging can occasionally be useful and may be suitable in more subacute cases. Radiologists' knowledge of how to manage and interpret these acute conditions including knowing which imaging technique to use is fundamental to appropriate care. In this review, we will concentrate on the most common cardiovascular emergencies in the thoracic region, including thoracic traumatic and non-traumatic emergencies and pulmonary vascular emergencies, as well as acute clinical disorders as a consequence of primary and postoperative congenital heart disease. This review will cover situations where cardiovascular imaging may be acutely needed, and not strictly emergencies only. Imaging recommendations will be discussed according to the different clinical presentations and underlying pathology.

Tracheobronchial abnormalities on computed tomography angiography in children with congenital heart disease

OBJECTIVES

To evaluate the assortment of tracheobronchial abnormalities on computed tomography angiography (CTA) in children with congenital heart disease (CHD).

METHODS

In this study approved by the Institute ethics committee, CTA studies of 182 children (age range: 2 days-8 years) with CHD, performed from July 2021 to March 2023 were analyzed. Two pediatric radiologists independently assessed the tracheobronchial airways (from the trachea to lobar bronchi) for developmental and branching anomalies and airway compromise (narrowing). In cases which demonstrated airway compromise, the extent and the cause of airway narrowing were evaluated, and the etiology were divided into extrinsic and intrinsic causes. Interobserver agreement between the two radiologists was calculated using kappa statistics.

RESULTS

One hundred children demonstrated normal airway anatomy and no luminal narrowing. Airway narrowing was observed in 63 (34.6%) children (κ: 0.954), and developmental airway anomalies were seen in 32 (17.5%) children (κ: 0.935). Of the 63 children with airway narrowing, 47 (25.8%) children had extrinsic cause for narrowing, 11 (6%) children had intrinsic causes for narrowing, and 5 (2.7%) children had both intrinsic and extrinsic causes attributing to airway compromise. Significant airway narrowing (>50% reduction) was seen in 35 (19.2%) children (κ: 0.945).

CONCLUSION

Tracheobronchial airway abnormalities are frequently associated in children with CHD and need to be appraised preoperatively. Cross-sectional imaging with CTA provides excellent information on tracheobronchial airway anatomy and caliber as well as delineates the possible etiology of airway narrowing, thus accurately diagnosing airway anomalies.

Multi-institutional Protocol Guidance for Pediatric Photon-counting CT

Performing CT in children comes with unique challenges such as greater degrees of patient motion, smaller and densely packed anatomy, and potential risks of radiation exposure. The technical advancements of photon-counting detector (PCD) CT enable decreased radiation dose and noise, as well as increased spatial and contrast resolution across all ages, compared with conventional energy-integrating detector CT. It is therefore valuable to review the relevant technical aspects and principles specific to protocol development on the new PCD CT platform to realize the potential benefits for this population. The purpose of this article, based on multi-institutional clinical and research experience from pediatric radiologists and medical physicists, is to provide protocol guidance for use of PCD CT in the imaging of pediatric patients.

Photon-counting CT in Thoracic Imaging: Early Clinical Evidence and Incorporation Into Clinical Practice

Photon-counting CT (PCCT) is an emerging advanced CT technology that differs from conventional CT in its ability to directly convert incident x-ray photon energies into electrical signals. The detector design also permits substantial improvements in spatial resolution and radiation dose efficiency and allows for concurrent high-pitch and high-temporal-resolution multienergy imaging. This review summarizes (a) key differences in PCCT image acquisition and image reconstruction compared with conventional CT; (b) early evidence for the clinical benefit of PCCT for high-spatial-resolution diagnostic tasks in thoracic imaging, such as assessment of airway and parenchymal diseases, as well as benefits of high-pitch and multienergy scanning; (c) anticipated radiation dose reduction, depending on the diagnostic task, and increased utility for routine low-dose thoracic CT imaging; (d) adaptations for thoracic imaging in children; (e) potential for further quantitation of thoracic diseases; and (f) limitations and trade-offs. Moreover, important points for conducting and interpreting clinical studies examining the benefit of PCCT relative to conventional CT and integration of PCCT systems into multivendor, multispecialty radiology practices are discussed.

CT Scan in Children Suspected of Foreign Body Aspiration: A Systematic Review and Meta-analysis

OBJECTIVE

The goal of this study is to evaluate the sensitivity and specificity of computed tomography (CT) scans in the diagnosis of foreign body aspiration (FBA) in children, and to determine whether chest CT scans would reduce the need for diagnostic rigid bronchoscopies.

DATA SOURCES

MEDLINE, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched for relevant articles and conference proceedings that were published in English through November 1, 2022.

REVIEW METHODS

We included prospective and retrospective studies comparing chest CT scans and rigid bronchoscopy for the diagnosis of FBA in pediatric patients (<16 years old). The pooled estimates of the sensitivity and specificity of the chest CT scan in the diagnosis of FBA were calculated using a fixed- or common-effects analysis and a random-effects analysis that accounts for heterogeneity if present. Forest plots were constructed to combine the evidence identified during the systematic review.

RESULTS

Eighteen articles (4178 patients) were included. The average age of the children was 2.26 (±0.75) years, and 65% (±5.64%) of them were boys. Cough was the most prevalent symptom upon presentation. The pooled analysis showed that the sensitivity of chest CT scan in detecting a foreign body in children was 99% (95% confidence interval, CI [97, 100]; I2  = 72%, τ2  = 0.0065, p < .01). The false negative rate was 1.8% (95% CI [0.3, 2.7]; I2  = 72%, p < .01). The specificity of chest CT scan was 92% (95% CI [83, 98]; I2  = 83%, τ2  = 0.0437, p < .01).

CONCLUSIONS

Chest CT scan is a sensitive and specific test for the diagnosis of FBA in the pediatric population. Its use can help to reduce unnecessary rigid bronchoscopies, especially in patients with a low clinical suspicion of aspiration. It should not be a replacement for the gold standard bronchoscopy, particularly in cases where there is a clear history and symptoms suggestive of aspiration.

Potential benefits of photon counting detector computed tomography in pediatric imaging

Photon counting detector (PCD) CT represents the newest advance in CT technology, with improved radiation dose efficiency, increased spatial resolution, inherent spectral imaging capabilities, and the ability to eliminate electronic noise. Its design fundamentally differs from conventional energy integrating detector CT because photons are directly converted to electrical signal in a single step. Rather than converting X-rays to visible light and having an output signal that is a summation of energies, PCD directly counts each photon and records its individual energy information. The current commercially available PCD-CT utilizes a dual-source CT geometry, which allows 66 ms cardiac temporal resolution and high-pitch (up to 3.2) scanning. This can greatly benefit pediatric patients by facilitating high quality fast scanning to allow sedation-free imaging. The energy-resolving nature of the utilized PCDs allows "always-on" dual-energy imaging capabilities, such as the creation of virtual monoenergetic, virtual non-contrast, virtual non-calcium, and other material-specific images. These features may be combined with high-resolution imaging, made possible by the decreased size of individual detector elements and the absence of interelement septa. This work reviews the foundational concepts associated with PCD-CT and presents examples to highlight the benefits of PCD-CT in the pediatric population.

Clinical applications of photon counting detector CT

The X-ray detector is a fundamental component of a CT system that determines the image quality and dose efficiency. Until the approval of the first clinical photon-counting-detector (PCD) system in 2021, all clinical CT scanners used scintillating detectors, which do not capture information about individual photons in the two-step detection process. In contrast, PCDs use a one-step process whereby X-ray energy is converted directly into an electrical signal. This preserves information about individual photons such that the numbers of X-ray in different energy ranges can be counted. Primary advantages of PCDs include the absence of electronic noise, improved radiation dose efficiency, increased iodine signal and the ability to use lower doses of iodinated contrast material, and better spatial resolution. PCDs with more than one energy threshold can sort the detected photons into two or more energy bins, making energy-resolved information available for all acquisitions. This allows for material classification or quantitation tasks to be performed in conjunction with high spatial resolution, and in the case of dual-source CT, high pitch, or high temporal resolution acquisitions. Some of the most promising applications of PCD-CT involve imaging of anatomy where exquisite spatial resolution adds clinical value. These include imaging of the inner ear, bones, small blood vessels, heart, and lung. This review describes the clinical benefits observed to date and future directions for this technical advance in CT imaging. KEY POINTS: • Beneficial characteristics of photon-counting detectors include the absence of electronic noise, increased iodine signal-to-noise ratio, improved spatial resolution, and full-time multi-energy imaging. • Promising applications of PCD-CT involve imaging of anatomy where exquisite spatial resolution adds clinical value and applications requiring multi-energy data simultaneous with high spatial and/or temporal resolution. • Future applications of PCD-CT technology may include extremely high spatial resolution tasks, such as the detection of breast micro-calcifications, and quantitative imaging of native tissue types and novel contrast agents.

Paediatric CT made easy

Paediatric computed tomography (CT) imaging has always been associated with challenges. Although the technical background of CT imaging is complex, it is worth considering the baseline aspects of radiation exposure to prevent unwanted excess radiation in paediatric patients. In this review, we discuss the most relevant factors influencing radiation exposure, and provide a simplified and practical approach to optimise paediatric CT.

Chest magnetic resonance imaging in cystic fibrosis: technique and clinical benefits

Cystic fibrosis (CF) is one of the most common inherited and life-shortening pulmonary diseases in the Caucasian population. With the widespread introduction of newborn screening and the development of modulator therapy, tremendous advances have been made in recent years both in diagnosis and therapy. Since paediatric CF patients tend to be younger and have lower morbidity, the type of imaging modality that should be used to monitor the disease is often debated. Computed tomography (CT) is sensitive to many pulmonary pathologies, but radiation exposure limits its use, especially in children and adolescents. Conventional pulmonary magnetic resonance imaging (MRI) is a valid alternative to CT and, in most cases, provides sufficient information to guide treatment. Given the expected widespread availability of sequences with ultra-short echo times, there will be even fewer reasons to perform CT for follow-up of patients with CF. This review aims to provide an overview of the process and results of monitoring CF with MRI, particularly for centres not specialising in the disease.

Chest radiography and computed tomography imaging in cystic fibrosis: current challenges and new perspectives

Imaging plays a pivotal role in the noninvasive assessment of cystic fibrosis (CF)-related lung damage, which remains the main cause of morbidity and mortality in children with CF. The development of new imaging techniques has significantly changed clinical practice, and advances in therapies have posed diagnostic and monitoring challenges. The authors summarise these challenges and offer new perspectives in the use of imaging for children with CF for both clinicians and radiologists. This article focuses on chest radiography and CT, which are the two main radiologic techniques used in most cystic fibrosis centres. Advantages and disadvantages of radiography and CT for imaging in CF are described, with attention to new developments in these techniques, such as the use of artificial intelligence (AI) image analysis strategies to improve the sensitivity of radiography and CT and the introduction of the photon-counting detector CT scanner to increase spatial resolution at no dose expense.

Impact of a Faster Computed Tomography Scanner on Sedation for Pediatric Head Computed Tomography Scans in 2 Large Emergency Departments-A Retrospective Study

OBJECTIVES

Children in the emergency department (ED) often require sedation for head computed tomography (CT) to ensure adequate image quality. Image acquisition time for a head CT using a conventional single-source CT scanner is approximately 12 seconds; however, after installation in November 2017 of 2 new dual-source dual-energy CT scanners, that time decreased to 1 to 3 seconds. We hypothesized that fewer patients would require sedation using the faster CT scanners.

METHODS

We conducted a retrospective chart review of patients aged 0 to 18 years undergoing head CT at 2 pediatric EDs within 1 hospital system, 2 years before and 2 years after installation of the faster CT scanner. Patients undergoing multiple CTs or other procedures were excluded. Demographic information, diagnosis, disposition, sedatives (chloral hydrate, dexmedetomidine, etomidate, fentanyl, ketamine, midazolam, methohexital, pentobarbital, and propofol) administered before imaging, and ED length of stay were analyzed.

RESULTS

A total of 15,175 patient encounters met inclusion criteria, 7412 before and 7763 after installation of the new CT. The median age was 7 years and 44% were female. Before the new CT scanner was installed 8% required sedation, compared with 7% after (effect size, 0.0341). Midazolam was the most commonly administered sedative. Fewer patients required deep sedation using the faster CT scanner.

CONCLUSIONS

After installation of a dual-source dual-energy CT scanner, fewer patients required sedation to complete head CT in the pediatric ED. Faster image acquisition time decreased the need for deep sedation.

Airway abnormalities associated with congenital heart disease

Airway abnormalities are important but sometimes overlooked problems in children with congenital heart disease. It is often difficult to separate symptoms related to cardiac disease from those associated with airway or lung disease. Some of the lesions are incidental while others cause significant symptoms and are important in overall functional outcome. Congenital and acquired as well as intrinsic and extrinsic lesions occur and can overlap. We review and illustrate these lesions here. Imaging plays a crucial role in diagnosing and assessing the severity of airway abnormalities and guiding medical and surgical management decisions.

Dual-source computed tomography protocols for the pediatric chest - scan optimization techniques

The gold standard for pediatric chest imaging remains the CT scan. An ideal pediatric chest CT has the lowest radiation dose with the least motion degradation possible in a diagnostic scan. Because of the known inherent risks and costs of anesthesia, non-sedate options are preferred. Dual-source CTs are currently the fastest, lowest-dose CT scanners available, utilizing an ultra-high-pitch mode resulting in sub-second CTs. The dual-energy technique, available on dual-source CT scanners, gathers additional information such as pulmonary blood volume and includes relative contrast enhancement and metallic artifact reduction, features that are not available in high-pitch flash mode. In this article we discuss the benefits and tradeoffs of dual-source CT scan modes and tips on image optimization.

Assessing and conveying risks and benefits of imaging in neonates using ionizing radiation and sedation/anesthesia

Neonates represent a unique subset of the pediatric population that requires special attention and careful thought when implementing advanced cross-sectional imaging with CT or MRI. The ionizing radiation associated with CT and the sedation/anesthesia occasionally required for MRI present risks that must be balanced against the perceived benefit of the imaging examination in the unique and particularly susceptible neonatal population. We review the perceived risks of ionizing radiation and the more concrete risks of sedation/anesthesia in term and preterm neonates in the context of an imaging paradigm. When the expected diagnostic yield from CT and MRI is similar, and sedation is required for MRI but not for CT, CT likely has the higher benefit-to-risk ratio in the neonate. However, despite the risks, the most appropriate imaging modality should always be chosen after thoughtful consideration is given to each unique patient and informed discussions including radiology, anesthesia, neonatology and the parents/caregivers are pursued.

Impact of airway and a standardized recruitment maneuver on CT chest imaging quality in a pediatric population: A retrospective review

INTRODUCTION

When performing computerized tomography chest imaging in children, obtaining high quality, motion-free images is important in the accurate diagnosis of underlying pathology. General anesthesia is associated with the development of atelectasis, which can impair accurate diagnosis by obscuring or altering the appearance of the lung parenchyma or airways. Recruitment maneuvers, performed by anesthesiologists, can be used to effectively re-expand atelectatic lung.

METHODS

The computerized tomography chest imaging in 44 children aged between 2 months and 7 years, undergoing serial imaging for monitoring of cystic fibrosis, were reviewed and graded for atelectasis. The first scan performed on each child was performed with a supraglottic airway device and a non-standardized recruitment maneuver. The second scan on each child was performed with a cuffed endotracheal tube and a standardized recruitment maneuver.

RESULTS

When a supraglottic airway device and a non-standardized recruitment maneuver were used, 77% of patients demonstrated atelectasis of any degree on their computerized tomography chest imaging, compared with only 39% when a cuffed endotracheal tube and standardized recruitment maneuver were used. The percentage of computerized tomography chest scans that were scored acceptable (with either a total combined lung atelectasis score of 0 or 1) improved from 37% to 75% when a cuffed endotracheal tube and standardized recruitment maneuver were used. In particular, the mean atelectasis score for both lungs improved from 2.91 (SD ± 2.6) to 1.11 (SD ± 1.9), with a mean difference of 1.8 (95% CI 0.82-2.77; p: .0004).

CONCLUSION

The use of a cuffed endotracheal tube and a standardized recruitment maneuver is an effective way to reduce atelectasis as a result of general anesthesia. Anesthesiologists can actively contribute toward improved image quality through their choice of airway and recruitment maneuver.

State-of-the-art review of lung imaging in cystic fibrosis with recommendations for pulmonologists and radiologists from the "iMAging managEment of cySTic fibROsis" (MAESTRO) consortium

OBJECTIVE

Imaging represents an important noninvasive means to assess cystic fibrosis (CF) lung disease, which remains the main cause of morbidity and mortality in CF patients. While the development of new imaging techniques has revolutionised clinical practice, advances have posed diagnostic and monitoring challenges. The authors aim to summarise these challenges and make evidence-based recommendations regarding imaging assessment for both clinicians and radiologists.

STUDY DESIGN

A committee of 21 experts in CF from the 10 largest specialist centres in Italy was convened, including a radiologist and a pulmonologist from each centre, with the overall aim of developing clear and actionable recommendations for lung imaging in CF. An a priori threshold of at least 80% of the votes was required for acceptance of each statement of recommendation.

RESULTS

After a systematic review of the relevant literature, the committee convened to evaluate 167 articles. Following five RAND conferences, consensus statements were developed by an executive subcommittee. The entire consensus committee voted and approved 28 main statements.

CONCLUSIONS

There is a need for international guidelines regarding the appropriate timing and selection of imaging modality for patients with CF lung disease; timing and selection depends upon the clinical scenario, the patient's age, lung function and type of treatment. Despite its ubiquity, the use of the chest radiograph remains controversial. Both computed tomography and magnetic resonance imaging should be routinely used to monitor CF lung disease. Future studies should focus on imaging protocol harmonisation both for computed tomography and for magnetic resonance imaging. The introduction of artificial intelligence imaging analysis may further revolutionise clinical practice by providing fast and reliable quantitative outcomes to assess disease status. To date, there is no evidence supporting the use of lung ultrasound to monitor CF lung disease.

Magnetic resonance imaging for congenital lung malformations

Congenital lung malformations are most often identified on prenatal US screening. Fetal MRI is often performed to further evaluate these lesions. Although some of these lesions might cause prenatal or early postnatal symptoms that require urgent management, the majority are asymptomatic at birth and might be subtle or invisible on chest radiographs. Postnatal imaging is frequently deferred until 3-6 months of age, when surgery or long-term conservative management is contemplated. High-quality imaging and interpretation is needed to assist with appropriate decision-making. Contrast-enhanced chest CT, typically with angiographic technique, has been the usual postnatal imaging choice. In this review, the author discusses and illustrates the indications and use of postnatal MR imaging for bronchopulmonary malformations as well as some differential diagnoses and the advantages and disadvantages of MR versus CT.

Should I irradiate with computed tomography or sedate for magnetic resonance imaging?

In the context of pediatric cross-sectional imaging, the risk of ionizing radiation for CT and the potential adverse effects associated with sedation/anesthesia for MRI continue to provoke lively discussions in the pediatric literature and lay press. This is particularly true for issues relating to the risks of ionizing radiation for CT, which has been a topic of discussion for nearly two decades. In addition to understanding these potential risks and the importance of minimizing individual pediatric patient exposure to ionizing radiation, it is equally important for radiologists to be able to frame these risks with respect to the potential for adverse outcomes associated with the use of anesthesia for cross-sectional imaging in the pediatric population. Notably, before such risks can be estimated and compared, one should always consider the potential utility of each imaging modality for a given diagnosis. If one cross-sectional imaging modality is likely to be far superior to the other for a specific clinical question, every effort must be made to safely image the child, even if sedation/anesthesia is required.

Efficacy and Safety of Intranasal Dexmedetomidine vs. Oral Chloral Hydrate for Sedation in Children Undergoing Computed Tomography/Magnetic Resonance Imaging: A Meta-Analysis

OBJECTIVE

This meta-analysis aims to evaluate the sedative efficacy and safety of intranasal administration of dexmedetomidine (DEX) compared with oral chloral hydrate for Computed tomography (CT) or Magnetic Resonance Imaging (MRI) examination in Children.

METHODS

Cochrane Library, PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and China WanFang Databases were searched to collect randomized controlled trials (RCTs) investigating intranasal DEX (test group) vs. oral chloral hydrate (control group) in pediatric CT/MRI examinations up to December 30, 2021. The data were analyzed using Stata 15.0 software.

RESULTS

Seven RCTs with 1,846 children were identified. The meta-analysis results showed that the success rate of sedation (RR = 1.14, 95% CI: 1.03-1.26, P = 0.011), sedation onset time [weighted mean difference (WMD) = -0.87, 95% CI: -1.42 to -0.31, P = 0.002], sedation duration (WMD = -9.05, 95% CI:-14.69 to -3.42, P = 0.002), time to awakening (WMD = -9.75, 95% CI:-17.57 to -1.94, P = 0.014), and incidence of nausea and vomiting [relative risk (RR) = 0.09, 95% CI:0.04-0.23, P < 0.001) of the test group were significantly better than those of the control group. However, no significant differences were identified in incidence of hypotension (RR = 1.18, 95% CI: 0.51-2.74) and bradycardia (RR = 1.17, 95% CI: 0.13-22.11) between the two groups.

CONCLUSION

Intranasal administration of DEX is superior to oral chloral hydrate for sedation during pediatric CT/MRI examinations and has a better safety profile.

Outpatient Respiratory Management of Infants, Children, and Adolescents with Post-Prematurity Respiratory Disease: An Official American Thoracic Society Clinical Practice Guideline

Background: Premature birth affects millions of neonates each year, placing them at risk for respiratory disease due to prematurity. Bronchopulmonary dysplasia is the most common chronic lung disease of infancy, but recent data suggest that even premature infants who do not meet the strict definition of bronchopulmonary dysplasia can develop adverse pulmonary outcomes later in life. This post-prematurity respiratory disease (PPRD) manifests as chronic respiratory symptoms, including cough, recurrent wheezing, exercise limitation, and reduced pulmonary function. This document provides an evidence-based clinical practice guideline on the outpatient management of infants, children, and adolescents with PPRD. Methods: A multidisciplinary panel of experts posed questions regarding the outpatient management of PPRD. We conducted a systematic review of the relevant literature. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of the clinical recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations were developed for or against three common medical therapies and four diagnostic evaluations in the context of the outpatient management of PPRD. Conclusions: The panel developed recommendations for the outpatient management of patients with PPRD on the basis of limited evidence and expert opinion. Important areas for future research were identified.

Thoracic CTA in infants and young children: Image quality of dual-source CT (DSCT) with high-pitch spiral scan mode (turbo flash spiral mode) with or without general anesthesia with free-breathing technique

PURPOSE

To determine whether diagnostic quality thoracic computed tomography angiography (CTA) studies can be obtained without general anesthesia (GA) in infants and young children using dual-source computed tomography (DSCT) with turbo flash spiral mode (TFSM) and free-breathing technique.

MATERIALS AND METHODS

All consecutive infants and young children (≤ 6 years old) who underwent thoracic CTA studies from January 2018 to October 2020 for suspected congenital thoracic disorders were categorized into two groups: with GA (Group 1) and without GA (Group 2). All thoracic CTA studies were performed on a DSCT scanner using TFSM and free-breathing technique. Two pediatric thoracic radiologists independently evaluated motion artifact in three lung zones (upper, mid, and lower). Degree of motion artifact was graded 0-3 (0, none; 1, mild; 2, moderate; and 3, severe). Logistic models adjusted for age and gender were used to compare the degree of motion artifact between lung zones. Interobserver agreement between reviewers was evaluated with kappa statistics.

RESULTS

There were a total of 73 pediatric patients (43 males (59%) and 30 females (41%); mean age, 1.4 years; range, 0-5.9 years). Among these 73 patients, 42 patients (58%) underwent thoracic CTA studies with GA (Group 1) and the remaining 31 patients (42%) underwent thoracic CTA studies without GA (Group 2). Overall, the degree of motion artifact was higher for Group 2 (without GA). However, only a very small minority (1/31, 3%) of Group 2 (without GA) thoracic CTA studies had severe motion artifact. There was no significant difference between the two groups with respect to the presence of severe motion artifact (odds ratio [OR] = 6, p = .222). When two groups were compared with respect to the presence of motion artifact for individual lung zones, motion artifact was significantly higher in the upper lung zone for Group 2 (without GA) (OR = 20, p = .043). Interobserver agreement for motion artifact was high, the average Kappa being 0.81 for Group 1 and 0.95 for Group 2.

CONCLUSION

Although the degree of motion artifact was higher in the group without GA, only a small minority (3%) of thoracic CTA studies performed without GA had severe motion artifact, rendering the study nondiagnostic. Therefore, the results of this study support the use of thoracic CTA without GA using DSCT with TFSM and free-breathing in infants and young children. In addition, given that motion artifact was significantly higher in the upper lung zone without GA, increased stabilization in the upper chest and extremities should be considered.

Surveillance recommendations for DICER1 pathogenic variant carriers: a report from the SIOPE Host Genome Working Group and CanGene-CanVar Clinical Guideline Working Group

DICER1 syndrome is a rare genetic disorder that predisposes to a wide spectrum of tumors. Developing surveillance protocols for this syndrome is challenging because uncertainty exists about the clinical efficacy of surveillance, and appraisal of potential benefits and harms vary. In addition, there is increasing evidence that germline DICER1 pathogenic variants are associated with lower penetrance for cancer than previously assumed. To address these issues and to harmonize DICER1 syndrome surveillance programs within Europe, the Host Genome Working Group of the European branch of the International Society of Pediatric Oncology (SIOPE HGWG) and Clinical Guideline Working Group of the CanGene-CanVar project in the United Kingdom reviewed current surveillance strategies and evaluated additional relevant literature. Consensus was achieved for a new surveillance protocol and information leaflet that informs patients about potential symptoms of DICER1-associated tumors. The surveillance protocol comprises a minimum program and an extended version for consideration. The key recommendations of the minimum program are: annual clinical examination from birth to age 20 years, six-monthly chest X-ray and renal ultrasound from birth to age 6 years, and thyroid ultrasound every 3 years from age 8 to age 40 years. The surveillance program for consideration comprises additional surveillance procedures, and recommendations for DICER1 pathogenic variant carriers outside the ages of the surveillance interval. Patients have to be supported in choosing the surveillance program that best meets their needs. Prospective evaluation of the efficacy and patient perspectives of proposed surveillance recommendations is required to expand the evidence base for DICER1 surveillance protocols.

Chest CT in patients with shortness of breath: Comparing high pitch CT and conventional CT on respiratory artefacts and dose

INTRODUCTION

To investigate chest respiratory artefact reduction using High Pitch Dual Source Computed Tomography (HPCT) compared to conventional CT (CCT) in symptomatic patients with shortness of breath.

METHODS

Forty patients were prospectively examined on a second-generation Dual Source scanner. They were randomly divided into two groups: twenty patients underwent an experimental HPCT protocol and twenty control cases CCT protocol. Respiratory artefacts were evaluated using an ordinal score (0, 1 and 2) assigned by two readers with five and thirty years of experience. A qualitative assessment was performed using two categorical groups, group 1 = acceptable and group 2 = unacceptable. Dose Length Product (DLP) was compared.

RESULTS

The two groups showed a statistical difference in artefacts reduction (p < 0.0001). HPCT demonstrated no artefacts in 82% of cases, while CCT showed no artefacts in 39% of cases. DLP showed no statistical differences (p = 0.6) with mean = 266.9 for HPCT and mean = 282.65 for CCT. HPCT provides high table speed in the z-direction allowing a high temporal resolution, which reduces respiratory artefacts during free-breathing acquisition. Despite the use of two x-ray tubes, the HPCT did not increase the dose to the patient but provided the highest images quality.

CONCLUSIONS

In the emergency setting, HPCTs have been critical for achieving good image quality in uncooperative patients.

IMPLICATIONS FOR PRACTICE

Acute respiratory failure is a common emergency department presentation, and the choice of high-speed acquisition CT may increase image quality.

Vascular and pulmonary comorbidities in children with congenital EA/TEF

BACKGROUND

Esophageal atresia with tracheoesophageal fistula (EA/TEF) is associated with many congenital and vascular malformations; however, reports utilizing computed tomography (CT) and computed tomography angiography (CTA) are limited. The objective of this study is to review CT scans of the chest from patients with EA/TEF and report their pulmonary and vascular findings.

METHODS

We completed a retrospective chart review of children with congenital EA/TEF evaluated in the aerodigestive clinic at Children's Hospital Colorado. Results of the most recent CTA or CT of the chest were investigated. Demographics, medical conditions, and bronchoscopy findings were also recorded. The ratio of tracheal lumen area between inspiratory and expiratory CTA images was measured.

RESULTS

Of the patients with congenital EA/TEF seen in the program, 47 patients had a chest CT available for review. Eight patients (17%) had bronchiectasis. Of the contrast CT scans, 15 (58%) had a vascular abnormality and 16 (62%) demonstrated tracheal compression (38% at the level of the innominate artery, 35% from other structures). Nineteen of the CTAs had volumetric expiratory images of the trachea to evaluate tracheomalacia. The mean expiratory:inspiratory area was 0.57 (SD ± 0.23) at the level of the innominate.

CONCLUSION

Patients with EA/TEF frequently have vascular abnormalities that may alter airway mechanics as well as pulmonary comorbidities that may affect long-term management. For patients experiencing persistent respiratory symptoms, CTA of the chest should be considered adjunct to bronchoscopy to help with medical and surgical management of these children.

Multiplatform, Non-Breath-Hold Fast Scanning Protocols: Should We Stop Giving Breath-Hold Instructions for Routine Chest CT? [Formula: see text]

OBJECTIVE

We assessed if non-breath-hold (NBH) fast scanning protocol can provide respiratory motion-free images for interpretation of chest computed tomography (CT).

MATERIALS AND METHODS

In our 2-phase project, we first collected baseline data on frequency of respiratory motion artifacts on breath-hold chest CT in 826 adult patients. The second phase included 62 patients (mean age 66 ± 15 years; 21 females, 41 males) who underwent an NBH chest CT on either single-source (n = 32) or dual-source (n = 30) multidetector-row CT scanners. Clinical indications for chest CT, reason for using NBH CT, scanner type, scan duration, and radiation dose (CT dose index volume, dose length product) were recorded. Two thoracic radiologists (R1 and R2) independently graded respiratory motion artifacts (1 = no respiratory motion artifacts with unrestricted evaluation; 2 = minor motion artifacts limited to one lung lobe or less with good diagnostic quality; 3 = moderate motion artifacts limited to 2 to 3 lung lobes but adequate for clinical diagnosis; 4 = poor evaluability or unevaluable from severe motion artifacts; and 5 = limited quality due to other causes like high noise, beam hardening, or metallic artifacts), and recorded pulmonary and mediastinal findings. Descriptive analyses, Cohen κ test for interobserver agreement, and Student t test were performed for statistical analysis.

RESULTS

No NBH chest CT were deemed uninterpretable by either radiologist; most NBH CT (R1-59 of 62, 95%; R2-62 of 62, 100%) had no or minimal motion artifacts. Only 3 of 62 (R1) NBH chest CT had motion artifacts limiting diagnostic evaluation for lungs but not in the mediastinum.

CONCLUSION

Non-breath-hold fast protocol enables acquisition of diagnostic quality chest CT free of respiratory motion artifacts in patients who cannot hold their breath.