Pulmonary fibrosis may begin in infancy: from childhood to adult interstitial lung disease.

BACKGROUND: Childhood interstitial lung disease (chILD) encompasses a group of rare heterogeneous respiratory conditions associated with significant morbidity and mortality. Reports suggest that many patients diagnosed with chILD continue to have potentially progressive or fibrosing disease into adulthood. Over the last decade, the spectrum of conditions within chILD has widened substantially, with the discovery of novel entities through advanced genetic testing. However, most evidence is often limited to small case series, with reports disseminated across an array of subspecialty, clinical and molecular journals. In particular, the frequency, management and outcome of paediatric pulmonary fibrosis is not well characterised, unlike in adults, where clear diagnosis and treatment guidelines are available. METHODS AND RESULTS: This review assesses the current understanding of pulmonary fibrosis in chILD. Based on registry data, we have provisionally estimated the occurrence of fibrosis in various manifestations of chILD, with 47 different potentially fibrotic chILD entities identified. Published evidence for fibrosis in the spectrum of chILD entities is assessed, and current and future issues in management of pulmonary fibrosis in childhood, continuing into adulthood, are considered. CONCLUSIONS: There is a need for improved knowledge of chILD among pulmonologists to optimise the transition of care from paediatric to adult facilities. Updated evidence-based guidelines are needed that incorporate recommendations for the diagnosis and management of immune-mediated disorders, as well as chILD in older children approaching adulthood.

Computed tomographic findings in TBX4 mutation: a common cause of severe pulmonary artery hypertension in children.

BACKGROUND: Mutations in the T-Box 4 (TBX4) gene are a lesser-known cause of heritable pulmonary arterial hypertension (PAH). Patients with heritable PAH typically have worse outcomes when compared with patients with idiopathic PAH, yet little is known about the phenotypical presentation of this mutation. OBJECTIVE: This article reviews the pattern of chest CT findings in pediatric patients with PAH and TBX4 mutations and compares their radiographic presentation with those of age-matched patients with PAH but without TBX4 mutations. MATERIALS AND METHODS: A retrospective chart review of the pulmonary arterial hypertension database was performed. Pediatric patients with PAH-confirmed TBX4 mutations and an available high CT were included. Fifteen (9 females) patients met the inclusion criteria. Fourteen (8 females) age-matched controls with diagnosed PAH but without TBX4 mutations were also evaluated. The median age at diagnosis was 7.4 years (range: 0.1-16.4 years). Demographic information and clinical outcomes were collected. CTs of the chest were reviewed for multiple airway, parenchymal, and structural abnormalities (16 imaging findings in total). Chi-square tests were used to compare the prevalence of each imaging finding in the TBX4 cohort compared to the control group. RESULTS: Patients with TBX-4 mutations had increased presence of peripheral or subpleural irregularity (73% vs 0%, P < 0.01), cystic lucencies (67% vs 7%, P < 0.01), and linear or reticular opacity (53% vs 0%, P < 0.01) compared to the control group. Ground glass opacities, bronchiectasis, and centrilobular nodules were not significantly different between the two patient groups (P > 0.05). CONCLUSION: TBX4 mutations have distinct imaging phenotypes in pediatric patients with PAH. Compared to patients without this mutation, patients with TBX-4 genes typically present with peripheral or subpleural irregularity, cystic lucencies, and linear or reticular opacity.

Early Anti-Tumor-Necrosis-Factor Therapy for Crohn's Disease-Related Abdominal Abscesses and Phlegmon in Children.

BACKGROUND: Internally penetrating Crohn's Disease complications, including abscesses and phlegmon, represent a high-risk Crohn's Disease phenotype. Anti-tumor-necrosis-factor-α (Anti-TNF) therapies are effective in treating penetrating Crohn's Disease and early initiation has shown unique benefits. However, timing of anti-TNF initiation in the setting of internally penetrating Crohn's Disease complications is typically heterogenous due to concern over precipitating serious infections. Recent studies demonstrate such an association may not exist. AIMS: We aimed to describe the multidisciplinary management of pediatric patients with internally penetrating Crohn's Disease complications, focusing on the utilization and timing of anti-TNF therapy relative to complication resolution and adverse events. METHODS: We performed a single-center retrospective cohort study of pediatric patients with internally penetrating Crohn's Disease complications from 2007 to 2021. The safety and effectiveness of anti-TNF therapy initiation prior to complication resolution was assessed by comparing rates of infectious and Crohn's Disease-related adverse events between those who received anti-TNF therapy prior to complication resolution, versus those who did not. RESULTS: Twenty-one patients with internally penetrating Crohn's Disease complications were identified. 7/21 received anti-TNF therapy prior to complication resolution. Infectious adverse events within 90 days of complication occurred in 0/7 patients initiating anti-TNF therapy prior to complication resolution and 10/14 patients who did not (p = 0.004). Crohn's Disease-related surgeries and hospitalizations within 1 year of complication occurred in 12/20 patients, with similar frequency between groups. CONCLUSIONS: Initiating anti-TNF therapy prior to internally penetrating Crohn's Disease complication resolution may be a safe and effective strategy to improve clinical outcomes.

Radiation dose reduction using spectral shaping in pediatric non-contrast sinus CT.

BACKGROUND: CT is the standard imaging technique to evaluate pediatric sinuses. Given the potential risks of radiation exposure in children, it is important to reduce pediatric CT dose and maintain image quality. OBJECTIVE: To study the utility of spectral shaping with tin filtration to improve dose efficiency for pediatric sinus CT exams. MATERIALS AND METHODS: A head phantom was scanned on a commercial dual-source CT using a conventional protocol (120 kV) and a proposed 100 kV with a 0.4-mm tin filter (Sn100 kV) protocol for comparison. Entrance point dose (EPD) of eye and parotid gland region was measured by an ion chamber. Sixty pediatric sinus CT exams (33 acquired with 120 kV, 27 acquired with Sn100 kV) were retrospectively collected. All patient images were objectively measured for image quality and blindly reviewed by 4 pediatric neuroradiologists for overall noise, overall diagnostic quality, and delineation of 4 critical paranasal sinus structures, using a 5-point Likert scale. RESULTS: Phantom CTDIvol from Sn100 kV is 4.35 mGy, compared to CTDIvol of 5.73 mGy from 120 kV at an identical noise level. EPD of sensitive organs decreases in Sn100 kV (e.g., right eye EPD 3.83±0.42 mGy), compared to 120 kV (5.26±0.24 mGy). Patients in the 2 protocol groups were age and weight (unpaired T test P>0.05) matched. The patient CTDIvol of Sn100 kV (4.45±0.47 mGy) is significantly lower than 120 kV (5.56±0.48 mGy, unpaired T test P<0.001). No statistically significant difference for any subjective readers' score (Wilcoxon test P>0.05) was found between the two groups, indicating proposed spectral shaping provides equivalent diagnostic image quality. CONCLUSION: Phantom and patient results demonstrate that spectral shaping can significantly reduce radiation dose for non-contrast pediatric sinus CT without compromising diagnostic quality.

Unexpected extracardiac findings in cardiac computed tomography from neonates to young adults.

BACKGROUND: Modern CT scanners with lower radiation doses have resulted in large numbers of cardiac CTs being performed in children. As seen in adults, pediatric cardiac CT has the potential to demonstrate extracardiac variants and pathology that can occur in conjunction with congenital heart disease (CHD). Prior publications demonstrated a high incidence of extracardiac findings in various locations but the prevalence of urgent unexpected extracardiac findings in children is unknown. OBJECTIVE: The purpose of this study was to describe the incidence, distribution and clinical significance of the extracardiac findings on pediatric cardiac CT at a tertiary referral center. MATERIALS AND METHODS: We reviewed all reports (n = 648) for 554 children through young adults who received a cardiac CT study between Jan. 2, 2018, and March 10, 2020, at our tertiary referral pediatric hospital. We interrogated CT reports for extracardiac findings and categorized them by system (airway, pulmonary, abdomen, malpositioned lines and musculoskeletal). We then subclassified each of these findings by level of clinical importance based upon the need for intervention or treatment into low, medium or high importance. High-importance findings were confirmed with a focused chart review. If a patient had more than one CT with a persistent extracardiac finding, the finding was only counted once. RESULTS: We identified 562 individual extracardiac findings, with one or more extracardiac findings present in 91% of the study population. Extracardiac findings with high clinical importance, requiring urgent attention or intervention, were present in 10% (57/554) of cases. The most common location of extracardiac findings was pulmonary (50%; 280/562), followed by airway (22%; 125/562) and abdomen (9%; 52/562). CONCLUSION: Unexpected highly important extracardiac findings were found in 10% of patients. Therefore, extracardiac structures should be scrutinized for the timely identification of potentially highly important findings.

Computed tomographic parenchymal lung findings in premature infants with pulmonary vein stenosis.

BACKGROUND: Developmental pulmonary vein pulmonary vein stenosis in the setting of prematurity is a rare and poorly understood condition. Diagnosis can be challenging in the setting of chronic lung disease of prematurity. High-resolution non-contrast chest computed tomography (CT) is the conventional method of evaluating neonates for potential structural changes contributing to severe lung dysfunction and pulmonary hypertension but may miss pulmonary venous stenosis due to the absence of contrast and potential overlap in findings between developmental pulmonary vein pulmonary vein stenosis and lung disease of prematurity. OBJECTIVE: To describe the parenchymal changes of pediatric patients with both prematurity and pulmonary vein stenosis, correlate them with venous disease and to describe the phenotypes associated with this disease. MATERIALS AND METHODS: A 5-year retrospective review of chest CT angiography (CTA) imaging in patients with catheterization-confirmed pulmonary vein stenosis was performed to identify pediatric patients (< 18 years) who had a history of prematurity (< 35 weeks gestation). Demographic and clinical data associated with each patient were collected, and the patients' CTAs were re-reviewed to evaluate pulmonary veins and parenchyma. Patients with post-operative pulmonary vein stenosis and those with congenital heart disease were excluded. Data was analyzed and correlated for descriptive purposes. RESULTS: A total of 17 patients met the inclusion criteria (12 female, 5 male). All had pulmonary hypertension. There was no correlation between mild, moderate, and severe grades of bronchopulmonary dysplasia and the degree of pulmonary vein stenosis. There was a median of 2 (range 1-4) diseased pulmonary veins per patient. In total, 41% of the diseased pulmonary veins were atretic. The right upper and left upper lobe pulmonary veins were the most frequently diseased (n = 13/17, 35%, n = 10/17, 27%, respectively). Focal ground glass opacification, interlobular septal thickening, and hilar soft tissue enlargement were always associated with the atresia of an ipsilateral vein. CONCLUSION: Recognition of the focal parenchymal changes that imply pulmonary vein stenosis, rather than chronic lung disease of prematurity changes, may improve the detection of a potentially treatable source of pulmonary hypertension, particularly where nonangiographic studies result in a limited direct venous assessment.

Computed tomography evaluation of pediatric pulmonary hypertension.

Although rare in the pediatric population, pulmonary hypertension is a significant cause of morbidity and mortality in affected individuals. In addition to evaluating potential causes and severity of parenchymal lung diseases, non-contrast high-resolution CT of the chest can aid in the diagnosis of heritable and acquired causes. In addition to evaluating parenchymal lung disease, CT angiography can help to confirm findings of pulmonary hypertension using criteria similar to echocardiography, and provide detailed assessment of the pulmonary vascularity in specific causes.

Chest computed tomography findings of ground-glass nodules with enhancing central vessel/nodule in pediatric patients with BMPR2 mutations and plexogenic arteriopathy.

BACKGROUND: Germline mutation in bone morphogenetic protein type II (BMPR2) is the most common cause of idiopathic/heritable pulmonary hypertension in pediatric patients. Despite the discovery of this gene there are no known descriptions of the CT or CT angiography findings in these children. OBJECTIVE: To correlate the clinical presentation, pathology and chest CT findings in pediatric patients with pulmonary hypertension caused by mutations in the BMPR2 gene. MATERIALS AND METHODS: We performed a search to identify pediatric patients with a BMPR2 mutation and CT or CT angiography with the clinical history of pulmonary hypertension. Three pediatric radiologists reviewed the children's CT imaging findings and ranked the dominant findings in order of prevalence via consensus. RESULTS: We identified three children with pulmonary hypertension and confirmed germline BMPR2 mutations, two of whom had undergone lung biopsy. We then correlated the imaging findings with histopathology and clinical course. CONCLUSION: All of our patients with BMPR2 mutations demonstrated a distinct CT pattern of ground-glass nodules with a prominent central enhancing vessel/nodule. These findings correlated well with the pathological findings of plexogenic arteriopathy.

The use of ultrasound in establishing COVID-19 infection as part of a trauma evaluation.

PURPOSE: The use of lung ultrasound for diagnosis of COVID-19 has emerged during the pandemic as a beneficial diagnostic modality due to its rapid availability, bedside use, and lack of radiation. This study aimed to determine if routine ultrasound (US) imaging of the lungs of trauma patients with COVID-19 infections who undergo extended focused assessment with sonography for trauma (EFAST) correlates with computed tomography (CT) imaging and X-ray findings, as previously reported in other populations. METHODS: This was a prospective, observational feasibility study performed at two level 1 trauma centers. US, CT, and X-ray imaging were retrospectively reviewed by a surgical trainee and a board-certified radiologist to determine any correlation of imaging findings in patients with active COVID-19 infection. RESULTS: There were 53 patients with lung US images from EFAST available for evaluation and COVID-19 testing. The overall COVID-19 positivity rate was 7.5%. COVID-19 infection was accurately identified by one patient on US by the trainee, but there was a 15.1% false-positive rate for infection based on the radiologist examination. CONCLUSIONS: Evaluation of the lung during EFAST cannot be used in the trauma setting to identify patients with active COVID-19 infection or to stratify patients as high or low risk of infection. This is likely due to differences in lung imaging technique and the presence of concomitant thoracic injury.

Stevens-Johnson Syndrome in Children: Consider Monitoring for Bronchiolitis Obliterans.

We reviewed patients with Stevens-Johnson syndrome (SJS) evaluated at Children's Hospital Colorado and investigated the occurrence of bronchiolitis obliterans (BO). Approximately 9% of patients with SJS developed BO. Pediatricians should consider monitoring patients with SJS for BO, especially those with recurrent SJS and patients treated with mechanical ventilation.

Visualization of proximal coronary arteries on high-pitch electrocardiogram-triggered computed tomography in pediatric congenital heart disease: effects of heart rate and body surface area.

BACKGROUND: As CT technology has advanced, techniques for pediatric cardiac CT in congenital heart disease have evolved from retrospective electrocardiography (ECG)-gating with relatively high radiation doses to lower-dose prospective ECG-gating and even single-beat gated scans. Despite these advances, coronary artery imaging in children remains challenging because of their small vessel size and high heart rates, often necessitating retrospective gating. OBJECTIVE: Evaluate coronary artery visualization in pediatric patients (<20 years) who underwent low-dose high-pitch ECG-triggered scans and stratify the probability of coronary artery visualization based upon heart rate and body surface area (BSA). MATERIALS AND METHODS: Two hundred eleven high-pitch ECG-triggered studies from April 2014 to November 2017 were reviewed by two pediatric cardiac imagers in this retrospective study. Patient age, gender, BSA, average heart rate, heart rate variability and use of general anesthesia were recorded as well as dose-length product (DLP) and volumetric CT dose index (CTDIvol). We assessed the coronary artery score using a 5-point scale, with score of ≥3 considered of diagnostic quality. We performed multivariate statistical analysis including logistic regression to analyze effects of heart rate and BSA. RESULTS: Patient age range was 1 day to 19 years (median age 3 years). Heart rate range was 49-188 beats per minute (bpm; median 122 bpm) and BSA range was 0.15-2.07 m2 (median 0.53 m2). The origin and proximal coronary arteries were confidently seen (score ≥3) in 61% of studies in this cohort. Coronary artery visualization scores further increased with increased BSA (P<0.002) and with decreased heart rate (P<0.001). At heart rates <100 bpm or in patients with BSA>0.58, adequate coronary artery visualization was present 72% of the time. CONCLUSION: While in many patients the coronary artery origins are visualized using high-pitch ECG-triggered technique, the importance of coronary artery visualization needs to be weighed with the radiation dose penalty in individual patients to achieve optimal imaging.

High Altitude Pulmonary Edema in Children: A Single Referral Center Evaluation.

OBJECTIVE: To describe the clinical features of children who presented to Children's Hospital Colorado (CHCO) with high-altitude pulmonary edema (HAPE). STUDY DESIGN: We performed a retrospective chart review in children discharged from CHCO (an elevation of 1668 m) with a clinical diagnosis of HAPE and a chest radiograph consistent with noncardiogenic pulmonary edema. Descriptive statistics were used to describe the demographics, presentations, and treatment strategies. RESULTS: From 2004 to 2014, 50 children presented to CHCO who were found to have a clinical diagnosis of HAPE and a chest radiograph consistent with noncardiogenic pulmonary edema. Most (72%) patients were male, and most (60%) of the children in the study were diagnosed with classic HAPE, 38% with re-entry HAPE, and 2% with high altitude resident pulmonary edema. Elevation at symptom presentation ranged from 1840 to 3536 m. Patients were treated with a variety of medications, including diuretics, steroids, and antibiotics. Four patients were newly diagnosed with structural heart findings: 2 patients with patent foramen ovale and 2 with atrial septal defects. Eleven patients had findings consistent with pulmonary hypertension at the time of echocardiography. CONCLUSIONS: HAPE symptoms may develop below 2500 m, so providers should not rule out HAPE based on elevation alone. Structural heart findings and pulmonary hypertension are associated with HAPE susceptibility and their presence may inform treatment. Inappropriate use of antibiotics and diuretics in children with HAPE suggest that further education of providers is warranted.

High-resolution computed tomography findings of thyroid transcription factor 1 deficiency (NKX2-1 mutations).

BACKGROUND: The expression of the NKX2-1 gene and its encoded protein, thyroid transcription factor 1 (TTF-1), plays a role in pulmonary surfactant homeostasis and lung development. NKX2-1 mutations have been associated with neonatal respiratory distress, hypotonia, choreoathetosis and congenital hypothyroidism. These clinical findings have been coined brain-lung-thyroid syndrome, although not all three organs are always involved. While many of these children develop interstitial lung disease, no systematic review of chest high-resolution CT (HRCT) findings has been reported. OBJECTIVE: To summarize the clinical presentations, pathology and HRCT imaging findings of children with NKX2-1 mutations. MATERIALS AND METHODS: We identified six children with NKX2-1 mutations, deletions or duplications confirmed via genetic testing at our institution. Three pediatric radiologists reviewed the children's HRCT imaging findings and ranked the dominant findings in order of prevalence via consensus. We then correlated the imaging findings with histopathology and clinical course. RESULTS: All children in the study were heterozygous for NKX2-1 mutations, deletions or duplications. Ground-glass opacities were the most common imaging feature, present in all but one child. Consolidation was also a prevalent finding in 4/6 of the children. Architectural distortion was less common. CONCLUSION: HRCT findings of TTF-1 deficiency are heterogeneous and evolve over time. There is significant overlap between the HRCT findings of TTF-1 deficiency, other surfactant dysfunction mutations, and pulmonary interstitial glycogenosis. TTF-1 deficiency should be considered in term infants presenting with interstitial lung disease, especially if hypotonia or hypothyroidism is present.

Initial Imaging for Pediatric Renal Tumors: An Opportunity for Improvement.

PURPOSE: Current Children's Oncology Group studies on renal malignancy focus on minimizing treatment side effects with a goal of decreasing long-term complications. In this series we evaluate the patterns of initial imaging in children with renal tumors. MATERIALS AND METHODS: We retrospectively reviewed records of 122 patients treated for renal tumors at our institution between 2005 and 2016. Ideal imaging was defined as cross-sectional imaging of the chest, abdomen and pelvis in a single setting without any additional ionizing radiation exposing scans. RESULTS: Median patient age was 33.5 months (range 1 to 195). A total of 101 patients (83%) were initially evaluated elsewhere and subsequently referred to oncology (67.2%) for further evaluation. Before treatment 58 patients (47.5%) underwent imaging that was obtained in an ideal manner. Compared to those undergoing ideal imaging, median additional radiation exposure was 2.31 mSv (range 0.9 to 11.5), 3.08 mSv (0.6 to 11.7) and 5.1 mSv (1.2 to 16) in patients younger than 5 years, 5 to 9 years old and 10 years or older, respectively. Factors associated with undergoing ideal imaging included undergoing abdominal ultrasound as an initial scan (OR 3.637, p = 0.001), while presentation to an emergency department resulted in a reduced likelihood of undergoing ideal imaging (OR 0.351, p = 0.012). Factors associated with a decreased likelihood of undergoing initial screening ultrasound included presenting with vague symptoms (OR 0.072, p = 0.045) and presenting to a tertiary care emergency department (OR 0.228, p = 0.027). CONCLUSIONS: Current patterns of initial imaging for pediatric renal tumors are often associated with unnecessary and avoidable imaging studies, resulting in increased radiation exposure. Presenting to the emergency room as the initial point of contact with vague symptoms is associated with a decreased likelihood of undergoing appropriate or ideal pretherapy imaging, while initial evaluation with ultrasound is associated with a greater likelihood of undergoing ideal imaging, reducing overall radiation exposure. We advocate initial abdominal ultrasound in all pediatric patients suspected of having an abdominal mass. Our data highlight an opportunity for quality improvement across specialties caring for children with renal tumors.

High-resolution CT findings of pulmonary interstitial glycogenosis.

BACKGROUND: Pulmonary interstitial glycogenosis is a form of childhood interstitial lung disease characterized by the histological finding of abundant glycogen-laden mesenchymal cells within the pulmonary interstitium. Patients present in the neonatal period with disproportionate respiratory distress. Often, pulmonary interstitial glycogenosis is accompanied by alveolar simplification complicating recognition and diagnosis. Despite the recognition of pulmonary interstitial glycogenosis as a distinct entity, only a few case reports describing imaging findings are found in the literature, with no published systematic review available. OBJECTIVE: The purpose of this review is to provide a review of CT findings of pulmonary interstitial glycogenosis with histological correlation to aid in early diagnosis and management. MATERIALS AND METHODS: A 10-year retrospective review was performed to identify pediatric patients <18 years who underwent biopsy and CT within the last 10 years at our institution. The inclusion criteria include patients who had a CT within 3 months of biopsy and pathology-proven pulmonary interstitial glycogenosis CTs that were evaluated by three radiologists using a standardized scoring system. RESULTS: Fifteen patients met inclusion criteria (9 male, 6 female). At the time of initial pre-biopsy CT, ages ranged from 2 weeks to 5 months. Pulmonary symptoms presented at birth in the majority of patients (n=13). Two patients presented in early infancy at 3 months (n=1) and 5 months (n=1). Ground glass opacities were the most common CT finding (n=14), which varied from diffuse to scattered. Cystic lucencies (n=11) were noted in the majority of patients as well. Interlobular septal thickening (n=10) and architectural distortion (n=8) were less common findings. CONCLUSION: The most common CT findings of pulmonary interstitial glycogenosis are ground glass opacities with cystic lucencies. While the imaging findings are distinct from the typical presentation of neuroendocrine hyperplasia of infancy, there is significant overlap of these findings with surfactant dysfunction mutations, entities that also present with respiratory distress in the neonatal period. Therefore, imaging findings in pulmonary interstitial glycogenosis are helpful in guiding the need for genetic testing and/or biopsy.

Lung and airway shape in neuroendocrine cell hyperplasia of infancy.

BACKGROUND: Neuroendocrine cell hyperplasia of infancy (NEHI) is a rare lung disease associated with significant air trapping. Although chest CT is crucial in establishing a diagnosis, CT and biopsy findings do not reveal airway abnormalities to explain the air trapping. OBJECTIVE: We compared lung and airway morphology obtained from chest CT scans in children with NEHI and control children. In the children with NEHI, we explored relationships between lung and airway shape and lung function. MATERIALS AND METHODS: We performed a retrospective review of children with NEHI who underwent clinical chest CT. We identified control children of similar size and age. We created lung masks and airway skeletons using semi-automated software and compared them using statistical shape modeling methods. Then we calculated a logistic regression model using lung and airway shape to differentiate NEHI from controls, and we compared shape model parameters to lung function measurements. RESULTS: Airway and lung shapes were statistically different between children with NEHI and controls. We noted a broad lung apex in the children with NEHI and a significantly increased apical anterior-posterior lung diameter. A logistic regression model including lung shape was 90% accurate in differentiating children with NEHI from controls. Correlation coefficients were significant between lung function values and lung and airway shape. CONCLUSION: Lung and airway shapes were different between children with NEHI and control children in this cohort. Children with NEHI had an increased anteroposterior diameter of their lungs that might be useful in the diagnostic criteria.

Radiological features of healing in newborn clavicular fractures.

OBJECTIVES: Given the frequency of abusive fractures among infants, and the lack of research and or evidence for the phases of fracture healing seen in this age group, this study aims to describe a timetable of radiological features of fracture healing among infants in the first months of life. METHODS: We completed a retrospective cross-sectional time-series study of birth-related clavicle fractures from 2006-2013. A total of 108 digital images were available for review from 61 infants. The presence or absence of four features of healing including periosteal reaction, callus formation, bridging callus and remodelling were scored by three radiologists. RESULTS: The level of agreement between the radiologists was good to high (0.60-0.90). Features of healing were first seen at 7 days (periosteal reaction), 11 days (callus), 20 days (bridging) and 35 days (remodelling), respectively. The peak periods that each feature was present are as follows: periosteal reaction 11-42 days, callus 12-61 days, bridging 22-63 days and remodelling 49-59 days. CONCLUSIONS: Birth-associated clavicle fractures in infants follow a logical progression of healing changes. Understanding the expected progression and timing of fracture healing may be helpful as it pertains to the timing of injury in cases of abuse in infants. KEY POINTS: • Large study describing the time frames of fracture healing in young infants. • Features of fracture healing develop in a logical progression. • Evidence provided for determining fractures are consistent with a proposed time frame. • It is of critical importance to have sound evidence for the dating of fractures.

HRCT findings of childhood follicular bronchiolitis.

BACKGROUND: Follicular bronchiolitis is a lymphoproliferative form of interstitial lung disease (ILD) defined by the presence of peribronchial lymphoid follicles. Follicular bronchiolitis has been associated with viral infection, autoimmune disease and immunodeficiency. The most common clinical manifestation is respiratory distress in infancy followed by a prolonged course with gradual improvement. We found no reports of systematic review of high-resolution computed tomography (HRCT) findings in pediatric follicular bronchiolitis. OBJECTIVE: The purpose of this study was to describe the HRCT findings of follicular bronchiolitis in children and correlate these imaging findings with histopathology. MATERIALS AND METHODS: A 5-year retrospective review of all pathology-proven cases of follicular bronchiolitis was performed. Inclusion criteria were age <18 years and an HRCT within 6 months of lung biopsy. HRCTs were reviewed by three observers and scored using the system previously described by Brody et al. RESULTS: Six patients met the inclusion criteria with age range at HRCT of 7-82 months (median: 39.5 months). Pulmonary nodules (n=6) were the most common HRCT finding followed by focal consolidation (n=5), bronchiectasis (n=4) and lymphadenopathy (n=3). Tree and bud opacities and nodules on CT correlated with interstitial lymphocytic infiltrates and discrete lymphoid follicles on pathology. CONCLUSION: The salient HRCT findings of childhood follicular bronchiolitis are bilateral, lower lung zone predominant pulmonary nodules and bronchiectasis with infantile onset of symptoms. These characteristic HRCT findings help differentiate follicular bronchiolitis from other forms of infantile onset ILD.