Structural lung disease in preschool children with cystic fibrosis: An 18 month natural history study.

BACKGROUND: This study was performed to describe the natural history of CF lung disease in young children over an 18 month period to assess the use of CT scanning as an outcome measure for intervention trials. METHODS: Chest CT scans were obtained at baseline and after 18 months in 42 two- to six-year-old children with CF. CT scans were scored by 2 experienced radiologists for the presence and severity of bronchiectasis, mucous plugging, and air trapping. RESULTS: Mean age at baseline 3.5 (1.3) (mean, sd) years. One or more findings of CF lung disease was seen on the first CT in 27 (64%) and at 18 months in 30 (75%). From baseline to 18 months bronchiectasis, mucous plugging, and air trapping increased from 50% to 53%, 14% to 28%, and 48% to 58% respectively. There was marked variability in the rate of progression, with subjects commonly showing improvement in lung disease. Bronchiectasis worsened in 14 (33%) and improved in 13 (31%). Single subjects with F508del/class III and F508del/class V demonstrated greater worsening and improvement respectively than F508del homozygous and class I genotypes. CONCLUSIONS: The natural history of CF lung disease over 18 months varies widely between subjects. Factors including genotype may affect natural history as well as the effectiveness of mediators and could be an important confounder if not recognized. These findings suggest that the use of CT scanning as an outcome surrogate for CF lung disease in young children may be more challenging than has been previously recognized.

Artificial intelligence in computed tomography for quantifying lung changes in the era of CFTR modulators.

BACKGROUND: Chest computed tomography (CT) remains the imaging standard for demonstrating cystic fibrosis (CF) airway structural disease in vivo. However, visual scoring systems as an outcome measure are time consuming, require training and lack high reproducibility. Our objective was to validate a fully automated artificial intelligence (AI)-driven scoring system of CF lung disease severity. METHODS: Data were retrospectively collected in three CF reference centres, between 2008 and 2020, in 184 patients aged 4-54 years. An algorithm using three 2D convolutional neural networks was trained with 78 patients' CT scans (23 530 CT slices) for the semantic labelling of bronchiectasis, peribronchial thickening, bronchial mucus, bronchiolar mucus and collapse/consolidation. 36 patients' CT scans (11 435 CT slices) were used for testing versus ground-truth labels. The method's clinical validity was assessed in an independent group of 70 patients with or without lumacaftor/ivacaftor treatment (n=10 and n=60, respectively) with repeat examinations. Similarity and reproducibility were assessed using the Dice coefficient, correlations using the Spearman test, and paired comparisons using the Wilcoxon rank test. RESULTS: The overall pixelwise similarity of AI-driven versus ground-truth labels was good (Dice 0.71). All AI-driven volumetric quantifications had moderate to very good correlations to a visual imaging scoring (p<0.001) and fair to good correlations to forced expiratory volume in 1 s % predicted at pulmonary function tests (p<0.001). Significant decreases in peribronchial thickening (p=0.005), bronchial mucus (p=0.005) and bronchiolar mucus (p=0.007) volumes were measured in patients with lumacaftor/ivacaftor. Conversely, bronchiectasis (p=0.002) and peribronchial thickening (p=0.008) volumes increased in patients without lumacaftor/ivacaftor. The reproducibility was almost perfect (Dice >0.99). CONCLUSION: AI allows fully automated volumetric quantification of CF-related modifications over an entire lung. The novel scoring system could provide a robust disease outcome in the era of effective CF transmembrane conductance regulator modulator therapy.

Ten rules for ordering chest CTs.

These "rules" are suggestions for clinicians who order chest computed tomography (CTs). The first three address CT scanning technique and the ordering details that we find cause the most confusion. The next three are on patient preparation, and specifically the use of sedation and anesthesia. Radiation risk is next, and we end with three, more philosophical, rules on how we can best work together as clinicians and imagers. This is not a complete or systematic review. You won't find detailed references (or any references for that matter), descriptions of the latest techniques, or lists of sample protocols. We hope that the reader will consult his or her imaging colleagues when more specific guidance is needed. The goal of this article is to provide simple answers to frequently asked questions and to address some of the concerns that arise when deciding how to perform a chest CT scan in a child. These are the opinions of the authors, two pediatric radiologists with special interest in chest imaging and 50 years combined experience in working with clinical colleagues to provide the best imaging care for their patients. We hope that sharing these thoughts will help to decrease confusion and increase understanding to the benefit of the children we serve.

Minimal change in structural, functional and inflammatory markers of lung disease in newborn screened infants with cystic fibrosis at one year.

BACKGROUND: With the widespread introduction of newborn screening for cystic fibrosis (CF), there has been considerable emphasis on the need to develop objective markers of lung health that can be used during infancy. We hypothesised that in a newborn screened (NBS) UK cohort, evidence of airway inflammation and infection at one year would be associated with adverse structural and functional outcomes at the same age. METHODS: Infants underwent lung function testing, chest CT scan and bronchoscopy with bronchoalveolar lavage (BAL) at 1 year of age when clinically well. Microbiology cultures were also available from routine cough swabs. RESULTS: 65 infants had lung function, CT and BAL. Mean (SD) lung clearance index and forced expiratory volume in 0.5 s z-scores were 0.9(1.2) and -0.6(1.1) respectively; median Brody II CF-CT air trapping score on chest CT =0 (interquartile range 0-1, maximum possible score 27). Infants isolating any significant pathogen by 1 yr of age had higher LCI z-score (mean difference 0.9; 95%CI:0.4-1.4; p = 0.001) and a trend towards higher air trapping scores on CT (p = 0.06). BAL neutrophil elastase was detectable in 23% (10/43) infants in whom BAL supernatant was available. This did not relate to air trapping score on CT. CONCLUSIONS: In this UK NBS cohort at one year of age, lung and airway damage is much milder and associations between inflammation, abnormal physiology and structural changes were at best weak, contrary to our hypothesis and previously published reports. Continued follow-up will clarify longer term implications of these very mild structural, functional and inflammatory changes.

Mucus plugging, air trapping, and bronchiectasis are important outcome measures in assessing progressive childhood cystic fibrosis lung disease.

OBJECTIVE: To determine which outcome measures could detect early progression of disease in school-age children with mild cystic fibrosis (CF) lung disease over a two-year time interval utilizing chest computed tomography (CT) scores, quantitative CT air trapping (QAT), and spirometric measurements. METHODS: Thirty-six school-age children with mild CF lung disease (median [interquartile range] age 12 [3.7] years; percent predicted forced expiratory volume in 1 second (ppFEV1 ) 99 [12.5]) were evaluated by serial spirometer-controlled chest CT scans and spirometry at baseline, 3-month, 1- and 2-years. RESULTS: No significant changes were noted at 3-month for any variable except for decreased ppFEV1 . Mucus plugging score (MPS) and QATA1andA2 increased at 1- and 2-years. The bronchiectasis score (BS), and total score (TS) were increased at 2-year. All variables tested with the exception of bronchial wall thickness score, parenchymal score (PS), and ppFEV1 , were consistent with longitudinal worsening of lung disease. Multivariate analysis revealed baseline PS, baseline TS, and 1-year changes in BS and air trapping score were predictive of 2-year changes in BS. CONCLUSIONS: MPS and QATA1-A2 were the most sensitive indicators of progressive childhood CF lung disease. The 1-year change in the bronchiectasis score had the most positive predictive power for 2-year change in bronchiectasis.

Guidance for computed tomography (CT) imaging of the lungs for patients with cystic fibrosis (CF) in research studies.

Numerous issues must be addressed when developing standard operating procedures for clinical research studies involving chest computed tomography of lung disease in patients with cystic fibrosis (CF). Study success depends on the provision of adequate funding and the identification of personnel with the necessary expertise to conduct the study, along with clear guidelines that detail the CT operating procedure at each site, including breathing maneuvers, and image reconstruction. Close coordination of the quality assurance process between sites and the central review organization is required to maintain protocol adherence. The data transfer process must ensure the integrity and security of the data to comply with patient privacy regulations, and study outcome measures are best assessed with a scoring system or other structured method of imaging data analysis. The recommendations provided are designed to serve as a valuable reference guide for planning clinical research studies of patients with CF involving chest CT.

El intersticio pulmonar y sus enfermedades en la infancia. Deficiencia de ABCA3. Seguimiento durante doce años. Perspectivas ¿Un nuevo paradigma genético? / The pulmonary interstitium and its diseases in childhood. ABCA3 deficiency. Follow-up for 12 years. Perspectives. A new genetic paradigm?

Introducción. Sobre la base de un caso clínico, se presenta la descripción del cuadro intersticial por deficiencia de ABCA3, de una paciente de catorce años de edad, en seguimiento durante doce años. Método. Evaluación clínica con extensos estudios para descartar otras patologías semejantes. El diagnóstico definitivo fue determinado por el estudio genético para deficiencias de ABCA3 y otros defectos genéticos realizados por el Dr. Larry Nogee, Hospital Johns Hopkins, EE. UU. Objetivos. Describir detalladamente la evolución de la paciente durante doce años, con énfasis en los estudios anteriormente mencionados. Sugerir la presencia de un cambio de paradigma pronóstico en lo que se conocía sobre la evolución de esta enfermedad intersticial pulmonar grave, tratar de mejorar la calidad de vida y posiblemente el pronóstico. Presentar los hallazgos de genética, anatomía patológica y radiología en consultas y evaluaciones por centros de referencia. Resultados. Realizado su diagnóstico de deficiencia genética de ABCA3, presentamos su seguimiento actualizado hasta el año 2020. Esta debe ser sospechada en niños pequeños desde el nacimiento y durante los primeros años ante la persistencia de cuadros pulmonares crónicos con desaturación de oxígeno e imágenes tomográficas que sugieren cuadro intersticial. Se decidió tratar el cuadro en los años 2019-2020, durante seis meses, según bibliografía y consultas con centros de referencia en los Estados Unidos, con la finalidad de determinar la posible mejoría de su patología y decidir la continuación o suspensión de la medicación. Se usaron pulsos con metilprednisolona- hidroxicloroquina y azitromicina. Se logró mantener estable su función pulmonar y mejorar notablemente su calidad de vida. (AU)

Introduction. A clinical case diagnosed with ABCA3 deficiency is described. Patient is now fourteen years old. She´s being followed up since she was two years old. Methodology. clinical follow ­ up with extensive studies to rule out other similar pathologies. Final diagnosis was done through genetic studies done at Johns Hopkins Hospital by Nogee LM. Objective. To present a detailed evolution description of twelve years' follow-up with the support of the aforementioned studies, to suggest a change in diagnostic ­ prognostic paradigm on what was known of mortality in this severe pulmonary interstitial pathology to improve life quality and possibly prognosis. Present the findings of genetics, pathological anatomy and radiology in consultations and evaluations by reference centers. Results. Having made her diagnosis of genetic ABCA3 deficiency, we present her up dated follow-up until 2020. This should be suspected in young children from birth and during the first years due to the persistence of chronic pulmonary symptoms with oxygen desaturation and tomographic images that suggest interstitial symptoms. It was decided to treat the condition in the years 2019-2020, for six months, according to the bibliography and consultations with reference centers in the United States, in order to determine the possible improvement of her pathology and decide to continue or suspend the medication. Pulses with methylprednisolone hydroxychloroquine and azithromycin were used. Her lung function was stable and her quality of life significantly improved. (AU)

Evaluation of inter-observer variation for computed tomography identification of childhood interstitial lung disease.

Making chILD diagnoses on CT is poorly reproducible, even amongst sub-specialists. CT might best improve diagnostic confidence in a multidisciplinary team setting when augmented with clinical, functional and haematological results. http://bit.ly/327jRCw.

Ground-glass burden as a biomarker in neuroendocrine cell hyperplasia of infancy.

BACKGROUND: Neuroendocrine cell hyperplasia of infancy (NEHI) is a rare pediatric interstitial lung disease (ILD). Distinct chest computed tomography (CT) define its radiographic appearance-specifically, ground-glass (GG) opacities most prominent in the right middle lobe (RML) and lingula. We sought to quantitatively validate this description and correlate radiologic findings with clinical presentation. METHODS: Twenty-one children with NEHI were identified retrospectively, alongside 10 age-matched controls without lung disease. Clinical histories were reviewed for NEHI subjects. Semiautomated image analysis was used to measure lung volume and density. A patient-specific Hounsfield unit threshold defining GG was developed to quantify GG and assess its distribution in each subject. RESULTS: NEHI subjects had more GG than controls (37.9 ± 11.3% vs 14.0 ± 2.7%, P < 0.0001). The proportion of GG in the RML and lingula was greater in NEHI patients compared to controls (1.43 ± 0.37 vs 0.45 ± 0.21, P < 0.0001). GG preferentially involved the RML and lingula in 20/21 NEHI subjects. There was more GG distribution in NEHI subjects who were prescribed continuous oxygen compared with those using only nocturnal oxygen (45.7 ± 8.9% vs 29.3 ± 6.1%, P = 0.003). CONCLUSIONS: We confirm the previously reported finding that most patients with childhood ILD and a distinctive pattern of GG distribution on CT scan are likely to have NEHI. The amount of GG may be a biomarker for severity of respiratory disease.

Quantitative chest computerized tomography and FEV1 equally identify pulmonary exacerbation risk in children with cystic fibrosis.

BACKGROUND: Chest computerized tomography (CT) scores are associated with the frequency of future pulmonary exacerbations in people with cystic fibrosis (CF). However, cut-off values to identify children with mild lung disease with different risks for frequent future pulmonary exacerbations have not been identified. METHODS: Chest CT scans were assessed using the Brody score for participants of the Pulmozyme Early Intervention Trial (PEIT) and Wisconsin Randomized Clinical Trial of CF Newborn Screening (WI RCT). We determined the area under the receiver operating characteristic (ROC) curve for Brody scores and forced expiratory volume in 1 s (FEV1 ) to compare with the frequency of pulmonary exacerbations up to 10 years later. RESULTS: There were 60 participants in the PEIT with mean (SD) age 10.6 (1.7) years at the time of the CT and 81 participants in the WI RCT with mean age 11.5 (3.0) years. The Brody score cut-off that best identified children at-risk for ≥0.3 annual pulmonary exacerbations was 3.6 in the PEIT and 2.1 in the WI RCT. There were no statistical differences between ROC curves for the Brody CT score and FEV1 % predicted in either study (P ≥ 0.4). CONCLUSIONS: CT score cut-off values that identify children with CF with mild lung disease at different risks for frequent pulmonary exacerbations over an extended follow up period are similar in separate cohorts. Brody scores and FEV1 % predicted have similar abilities to identify these children, suggesting that FEV1 % predicted alone may be adequate for predicting future frequency of pulmonary exacerbations.

Assessment of pulmonary structure-function relationships in young children and adolescents with cystic fibrosis by multivolume proton-MRI and CT.

BACKGROUND: Lung disease is the most frequent cause of morbidity and mortality in patients with cystic fibrosis (CF), and there is a shortage of sensitive biomarkers able to regionally monitor disease progression and to assess early responses to therapy. PURPOSE: To determine the feasibility of noncontrast-enhanced multivolume MRI, which assesses intensity changes between expiratory and inspiratory breath-hold images, to detect and quantify regional ventilation abnormalities in CF lung disease, with a focus on the structure-function relationship. STUDY TYPE: Retrospective. POPULATION: Twenty-nine subjects, including healthy young children (n = 9, 7-37 months), healthy adolescents (n = 4, 14-22 years), young children with CF lung disease (n = 10, 7-47 months), and adolescents with CF lung disease (n = 6, 8-18 years) were studied. FIELD STRENGTH/SEQUENCE: 3D spoiled gradient-recalled sequence at 1.5T. ASSESSMENT: Subjects were scanned during breath-hold at functional residual capacity (FRC) and total lung capacity (TLC) through noncontrast-enhanced MRI and CT. Expiratory-inspiratory differences in MR signal-intensity (Δ1 H-MRI) and CT-density (ΔHU) were computed to estimate regional ventilation. MR and CT images were also evaluated using a CF-specific scoring system. STATISTICAL TESTS: Quadratic regression, Spearman's correlation, one-way analysis of variance (ANOVA). RESULTS: Δ1 H-MRI maps were sensitive to ventilation heterogeneity related to gravity dependence in healthy lung and to ventilation impairment in CF lung disease. A high correlation was found between MRI and CT ventilation maps (R2 = 0.79, P < 0.001). Globally, Δ1 H-MRI and ΔHU decrease with increasing morphological score (respectively, R2 = 0.56, P < 0.001 and R2 = 0.31, P < 0.001). Locally, Δ1 H-MRI was higher in healthy regions (median 15%) compared to regions with bronchiectasis, air trapping, consolidation, and to segments fed by airways with bronchial wall thickening (P < 0.001). DATA CONCLUSION: Multivolume noncontrast-enhanced MRI, as a nonionizing imaging modality that can be used on nearly any MRI scanner without specialized equipment or gaseous tracers, may be particularly valuable in CF care, providing a new imaging biomarker to detect early alterations in regional lung structure-function. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 3 J. MAGN. RESON. IMAGING 2018;48:531-542.

Quantitative CT scans of lung parenchymal pathology in premature infants ages 0-6 years.

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a common, heterogeneous disease in premature infants. We hypothesized that quantitative CT techniques could assess lung parenchymal heterogeneity in BPD patients across a broad age range and demonstrate how pathologies change over time. METHODS: A cross-sectional, retrospective study of children age 0-6 years with non-contrast chest CT scans was conducted. BPD subjects met NICHD/NHLBI diagnostic criteria for BPD and were excluded for congenital lung/airway abnormalities or other known/suspected pulmonary diagnoses; control subjects were not premature and had normal CT scan findings. Radiologic opacities, lucencies, and spatial heterogeneity were quantified via: 1) thresholding using CT-attenuation (HU); 2) manual segmentation; and 3) Ochiai reader-scoring system. Clinical outcomes included BPD severity by NICHD/NHLBI criteria, respiratory support at NICU discharge, wheezing, and respiratory exacerbations. RESULTS: Heterogeneity (standard deviation) of lung attenuation in BPD was significantly greater than in controls (difference 36.4 HU [26.1-46.7 HU], P < 0.001); the difference between the groups decreased 0.58 HU per month of age (0.08-1.07 HU per month, P = 0.02). BPD patients had greater amounts of opacities and lucencies than controls except with automated quantification of lucencies. Cross-sectionally, lucencies per Ochiai score and opacities per manual segmentation decreased with time. No approach measured a statistically significant relationship to BPD clinical severity. CONCLUSIONS: Opacities, lucencies, and overall heterogeneity of lungs via quantitative CT can distinguish BPD patients from healthy controls, and these abnormalities decrease with age across BPD patients. Defining BPD severity by clinical outcomes such as respiratory support at several time points (vs a single time point, per current guidelines) may be meaningful.

Clinical potential for imaging in patients with asthma and other lung disorders.

The ability of lung imaging to phenotype patients, determine prognosis, and predict response to treatment is expanding in clinical and translational research. The purpose of this perspective is to describe current imaging modalities that might be useful clinical tools in patients with asthma and other lung disorders and to explore some of the new developments in imaging modalities of the lung. These imaging modalities include chest radiography, computed tomography, lung magnetic resonance imaging, electrical impedance tomography, bronchoscopy, and others.

Constrictive Bronchiolitis in Cystic Fibrosis Adolescents with Refractory Pulmonary Decline.

RATIONALE: Refractory lung function decline in association with recurrent pulmonary exacerbations is a common, yet poorly explained finding in cystic fibrosis (CF). To investigate the histopathologic mechanisms of pulmonary deterioration during adolescence and early adulthood, we reviewed clinically-indicated lung biopsy specimens obtained during a period of persistent decline. OBJECTIVES: To determine if peribronchiolar remodeling is prominent in lung biopsy specimens obtained in adolescents with CF refractory to conventional therapy. METHODS: Six adolescents with CF (mean age, 16.2 y; mean FEV1, 52% predicted at biopsy) with significant pulmonary deterioration over 12-24 months (mean FEV1 decline of 14% predicted/year) despite aggressive intervention underwent computed tomography imaging and ultimately lung biopsy to aid clinical management. In addition to routine clinical evaluation, histopathologic investigation included staining for transforming growth factor-ß (TGF-ß, a genetic modifier of CF lung disease), collagen deposition (a marker of fibrosis), elastin (to evaluate for bronchiectasis), and α-smooth muscle actin (to identify myofibroblasts). MEASUREMENTS AND MAIN RESULTS: All computed tomography scans demonstrated a mix of bronchiectasis and hyperinflation that was variable across lung regions and within patients. Lung biopsy revealed significant peribronchiolar remodeling, particularly in patients with more advanced disease, with near complete obliteration of the peribronchiolar lumen (constrictive bronchiolitis). Myofibroblast differentiation (a TGF-ß-dependent process) was prominent in specimens with significant airway remodeling. CONCLUSIONS: Constrictive bronchiolitis is widely present in the lung tissue of adolescents with CF with advanced disease and may contribute to impaired lung function that is refractory to conventional therapy (antibiotics, antiinflammatories, and mucolytics). TGF-ß-dependent myofibroblast differentiation is prominent in areas of active fibrogenesis and may foster small airway remodeling in CF lung disease.

Quantitative CT characterization of pediatric lung development using routine clinical imaging.

BACKGROUND: The use of quantitative CT analysis in children is limited by lack of normal values of lung parenchymal attenuation. These characteristics are important because normal lung development yields significant parenchymal attenuation changes as children age. OBJECTIVE: To perform quantitative characterization of normal pediatric lung parenchymal X-ray CT attenuation under routine clinical conditions in order to establish a baseline comparison to that seen in pathological lung conditions. MATERIALS AND METHODS: We conducted a retrospective query of normal CT chest examinations in children ages 0-7 years from 2004 to 2014 using standard clinical protocol. During these examinations semi-automated lung parenchymal segmentation was performed to measure lung volume and mean lung attenuation. RESULTS: We analyzed 42 CT examinations in 39 children, ages 3 days to 83 months (mean ± standard deviation [SD] = 42 ± 27 months). Lung volume ranged 0.10-1.72 liters (L). Mean lung attenuation was much higher in children younger than 12 months, with values as high as -380 Hounsfield units (HU) in neonates (lung volume 0.10 L). Lung volume decreased to approximately -650 HU by age 2 years (lung volume 0.47 L), with subsequently slower exponential decrease toward a relatively constant value of -860 HU as age and lung volume increased. CONCLUSION: Normal lung parenchymal X-ray CT attenuation decreases with increasing lung volume and age; lung attenuation decreases rapidly in the first 2 years of age and more slowly thereafter. This change in normal lung attenuation should be taken into account as quantitative CT methods are translated to pediatric pulmonary imaging.

Ultrashort Echo-Time Magnetic Resonance Imaging Is a Sensitive Method for the Evaluation of Early Cystic Fibrosis Lung Disease.

RATIONALE: Recent advancements that have been made in magnetic resonance imaging (MRI) improve our ability to assess pulmonary structure and function in patients with cystic fibrosis (CF). A nonionizing imaging modality that can be used as a serial monitoring tool throughout life can positively affect patient care and outcomes. OBJECTIVES: To compare an ultrashort echo-time MRI method with computed tomography (CT) as a biomarker of lung structure abnormalities in young children with early CF lung disease. METHODS: Eleven patients with CF (mean age, 31.8 ± 5.7 mo; median age, 33 mo; 7 male and 4 female) were imaged via CT and ultrashort echo-time MRI. Eleven healthy age-matched patients (mean age, 22.5 ± 10.2 mo; median age, 23 mo; 5 male and 6 female) were imaged via ultrashort echo-time MRI. CT scans of 13 additional patients obtained for clinical indications not affecting the heart or lungs and interpreted as normal provided a CT control group (mean age, 24.1 ± 11.7 mo; median age, 24 mo; 6 male and 7 female). Studies were scored by two experienced radiologists using a well-validated CF-specific scoring system for CF lung disease. MEASUREMENTS AND MAIN RESULTS: Correlations between CT and ultrashort echo-time MRI scores of patients with CF were very strong, with P values ≤0.001 for bronchiectasis (r = 0.96) and overall score (r = 0.90), and moderately strong for bronchial wall thickening (r = 0.62, P = 0.043). MRI easily differentiated CF and control groups via a reader CF-specific scoring system. CONCLUSIONS: Ultrashort echo-time MRI detected structural lung disease in very young patients with CF and provided imaging data that correlated well with CT. By quantifying early CF lung disease without using ionizing radiation, ultrashort echo-time MRI appears well suited for pediatric patients requiring longitudinal imaging for clinical care or research studies. Clinical Trial registered with www.clinicaltrials.gov (NCT01832519).