Radiology of diffuse interstitial pulmonary disease in children

Chronic lung disease in paediatric patients: Does magnetic resonance imaging has a role?

Background

Pediatric chronic lung disease (CLD) refers to a range of distinct clinical and pathological disorders that affect children. High-resolution CT (HRCT) is critical for detecting and characterizing parenchymal abnormalities as well as determining their nature and distribution. Although magnetic resonance imaging (MRI) shows promising results, however, due to its poor spatial resolution and signal-to-noise ratio, imaging of the lung parenchyma remains a challenge. As a result, in addition to the initial CT, a follow-up MRI is required. The goal of this paper is to highlight the main imaging features of children with CLD and to evaluate the efficacy of MRI lungs in the diagnosis and monitoring of pediatric CLD.

Results

There was a strong positive correlation between CT and MRI, with a significant P-value. Findings of HRCT and MRI showed a qualitative agreement of 78% complete agreement. MRI helped primary diagnosis in 54% of cases compared to CT in 91% of cases.

Conclusion

MRI lungs are an equivalent technique to HRCT in assessing pediatric CLD; using the modified Helbich–Bhalla score, a strong correlation is obvious between both in the overall assessment. MRI is beneficial for case surveillance rather than primary diagnosis.

Interstitial lung disease in infancy and early childhood: a clinicopathological primer

Children's interstitial lung disease (chILD) encompasses a wide and heterogeneous spectrum of diseases substantially different from that of adults. Established classification systems divide chILD into conditions more prevalent in infancy and other conditions occurring at any age. This categorisation is based on a multidisciplinary approach including clinical, radiological, genetic and histological findings. The diagnostic evaluation may include lung biopsies if other diagnostic approaches failed to identify a precise chILD entity, or if severe or refractory respiratory distress of unknown cause is present. As the majority of children will be evaluated and diagnosed outside of specialist centres, this review summarises relevant clinical, genetic and histological findings of chILD to provide assistance in clinical assessment and rational diagnostics.

ILD of childhood is comparable by name only to lung disease in adults. A dedicated interdisciplinary team is required to achieve the best possible outcome. This review summarises the current clinicopathological criteria and associated genetic alterations.https://bit.ly/3mpxI3b

An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy

BACKGROUND

There is growing recognition and understanding of the entities that cause interstitial lung disease (ILD) in infants. These entities are distinct from those that cause ILD in older children and adults.

METHODS

A multidisciplinary panel was convened to develop evidence-based guidelines on the classification, diagnosis, and management of ILD in children, focusing on neonates and infants under 2 years of age. Recommendations were formulated using a systematic approach. Outcomes considered important included the accuracy of the diagnostic evaluation, complications of delayed or incorrect diagnosis, psychosocial complications affecting the patient's or family's quality of life, and death.

RESULTS

No controlled clinical trials were identified. Therefore, observational evidence and clinical experience informed judgments. These guidelines: (1) describe the clinical characteristics of neonates and infants (<2 yr of age) with diffuse lung disease (DLD); (2) list the common causes of DLD that should be eliminated during the evaluation of neonates and infants with DLD; (3) recommend methods for further clinical investigation of the remaining infants, who are regarded as having "childhood ILD syndrome"; (4) describe a new pathologic classification scheme of DLD in infants; (5) outline supportive and continuing care; and (6) suggest areas for future research.

CONCLUSIONS

After common causes of DLD are excluded, neonates and infants with childhood ILD syndrome should be evaluated by a knowledgeable subspecialist. The evaluation may include echocardiography, controlled ventilation high-resolution computed tomography, infant pulmonary function testing, bronchoscopy with bronchoalveolar lavage, genetic testing, and/or lung biopsy. Preventive care, family education, and support are essential.

Hypersensitivity pneumonitis: lessons for diagnosis and treatment of a rare entity in children

Hypersensitivity pneumonitis (HP) also called exogenous allergic alveolitis = extrinsic allergic alveolitis in children is an uncommon condition and may not be recognized and treated appropriately.

To assess current means of diagnosis and therapy and compare this to recommendations, we used the Surveillance Unit for Rare Paediatric Disorders (ESPED) to identify incident cases of HP in Germany during 2005/6. In addition, cases of HP reported for reference from all over Germany to our center in the consecutive year were included.

Twenty-three children with confirmed pediatric HP were identified. All (age 9.4 y (4.4-15.1) presented with dyspnoea at rest or with exercise, mean FVC was 39% of predicted, seven of the 23 children already had a chronic disease state at presentation. IgG against bird was elevated in 20, and against fungi in 15. Bronchoalveolar lavage was done in 18 subjects (41% lymphocytes, CD4/CD8 1.99), and lung biopsy in 6. Except 2, all children were treated with prolonged courses of systemic steroids. Outcome was not favourable in all cases.

Late diagnosis in up to a quarter of the children with HP and inappropriate steroid treatment must be overcome to improve management of HP. Inclusion of children with HP into international, web-based registry studies will help to study and follow up such rare lung diseases.

Paediatric multi-detector row chest CT: what you really need to know

Background

The emergence of multi-detector row CT (MDCT) has established and extended the role of CT especially in paediatric chest imaging. This has altered the way in which data is acquired and is perceived as the 'gold standard' in the detection of certain chest pathologies. The range of available post-processing tools provide alternative ways in which CT images can be manipulated for review and interpretation in order to enhance diagnostic accuracy.

Methodology

Paediatric imaging technique/protocol together with radiation dose reduction is discussed in detail. The use of different post-processing tools to best demonstrate the wide range of important congenital anomalies and thoracic pathologies is outlined and presented pictorially.

Conclusion

MDCT with its isotropic resolution and fast imaging acquisition times reduces the need for invasive diagnostic investigations. However, users must be vigilant in their imaging techniques to minimise radiation burden, whilst maintaining good image quality.

Main Messages

• CT examinations should be clinically justified by the referring clinician and radiologist.

• MDCT is invaluable for evaluating the central airway, mediastinal structures and lung parenchyma.

• MDCT is more sensitive than plain radiographs in detection of structural changes within the lungs.

Chronic diseases of lung parenchyma in children: the role of imaging

Chronic diseases of the lung parenchyma (CDoLP) in children encompass a vast number of distinct clinico-pathological conditions. The prevalence of CDoLP has continued to increase in the last 10-15 years and the paediatric radiologist will therefore have to become more familiar with the imaging appearances of CDoLP. This review highlights some of the key imaging appearances of CDoLP, focussing mainly on airways disease. We also explore issues around technique optimisation and dose minimisation that remain of paramount importance in children.

HRCT and pulmonary function tests in monitoring of lung involvement in juvenile systemic sclerosis

OBJECTIVE

To investigate the role of high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) in staging pulmonary involvement in juvenile systemic sclerosis (JSS).

METHODS

Clinical charts of 17 JSS patients (pts) were reviewed and high-resolution CT (HRCT) scans and PFTs performed at first and last visit were examined. Forced expiratory volume in 1 sec (FEV(1)), forced vital capacity (FVC) and carbon monoxide diffusing capacity [DL(CO)] were measured (% pred. values) while HRCT changes were graded according to the Schurawitzki method (min-max score: 0-18).

RESULTS

At initial assessment, 10 pts (58.8%) had pulmonary involvement (HRCT score >0 and/or PFTs <80% pred. values). PTFs abnormalities were consistent with a restrictive defect, with low FEV(1), FVC and DL(CO) values and normal FEV(1)/FVC ratio. At first visit HRCT scores were inversely correlated with FEV(1) (r = -0.75; P = 0.02), FVC (r = -0.685; P = 0.035), and DL(CO) values (r = -0.71; P = 0.03), but not with the FEV(1)/FVC ratio (r = -0.36; P = 0.31). Stronger inverse correlations were detected at last visit (median time interval: 4.3 years; min-max: 1-10 years) between HRCT and FEV(1) (r = -0.86; P = 0.002), FVC (r = -0.79; P = 0.009) and DL(CO) (r = -0.79; P = 0.009), but not with the FEV(1)/FVC ratio (r = -0.33; P = 0.35). Changes in HRCT scores between first and last visit were correlated with changes in FEV(1) (r = -0.74; P = 0.02), FVC (r = -0.81; P = 0.007), but not in DL(CO) values (r = 0.07;P = 0.84). At the last visit, of the 10 pts with pulmonary involvement at initial assessment 5 showed worsening of lung involvement and 5 either no significant changes in PFTs and HRCT or mild improvement.

CONCLUSIONS

PFTs, namely lung volumes, represent a reliable "monitoring" tool in children with JSS to identify pts that need to undergo an HRCT to rule out initial pulmonary involvement and to monitor the course of ILD over time. The weaker clinical value of DL(CO) may relate to poor lung function technique in some younger children.

Multidetector row CT for imaging the paediatric tracheobronchial tree

The introduction of multidetector row computed tomography (MDCT) scanners has altered the approach to imaging the paediatric thorax. In an environment where the rapid acquisition of CT data allows general hospitals to image children instead of referring them to specialist paediatric centres, it is vital that general radiologists have access to protocols appropriate for paediatric applications. Thus a dramatic reduction in the delivered radiation dose is ensured with optimal contrast bolus delivery and timing, and inappropriate repetition of the scans is avoided. This article focuses on the main principles of volumetric CT imaging that apply generically to all MDCT scanners. We describe the reconstruction techniques for imaging the paediatric thorax and the low-dose protocols used in our institution on a 16-slice detector CT scanner. Examples of the commonest clinical applications are also given.

Is there a role for CT in the neonate?

Choice of imaging modalities should be based on scientific proof and best practice guidelines. However, in the neonatal age group there is a paucity of medical evidence, and imaging is often guided by local experience, availability of equipment and expertise, and by logistical factors. This paper discusses possible indications for CT in the neonate, the associated radiation protection issues, common CT findings and potential pitfalls in technique and image interpretation. Due to the particular range of abnormalities in this age group, imaging must be tailored to the individual, and should in most cases be done in specialist units.

Pearls and pitfalls in HRCT in children

The aim of this talk is to discuss the role of thin slice high resolution CT in paediatric practice and to describe the various means by which these images can be acquired to a satisfactory [diagnostic] level in routine paediatric practice. It is also to highlight the utility of HRCT in paediatric practice to enable the various patterns of disease processes to be understood. The main role for HRCT is in the diagnosis and follow up of diffuse airways and interstitial lung diseases in children. We will focus on the utility of HRCT in diagnosis of paediatric diffuse interstitial lung disease [DILD] and the inherent strengths and weakness within the ultimate choices made to acquire images. We will emphasise and illustrate the specific conditions for which HRCT provides a powerful diagnostic tool.

Can HRCT be used as a marker of airway remodelling in children with difficult asthma?

Background

Whole airway wall thickening on high resolution computed tomography (HRCT) is reported to parallel thickening of the bronchial epithelial reticular basement membrane (RBM) in adult asthmatics. A similar relationship in children with difficult asthma (DA), in whom RBM thickening is a known feature, may allow the use of HRCT as a non-invasive marker of airway remodelling. We evaluated this relationship in children with DA.

Methods

27 children (median age 10.5 [range 4.1–16.7] years) with DA, underwent endobronchial biopsy from the right lower lobe and HRCT less than 4 months apart. HRCTs were assessed for bronchial wall thickening (BWT) of the right lower lobe using semi-quantitative and quantitative scoring techniques. The semi-quantitative score (grade 0–4) was an overall assessment of BWT of all clearly identifiable airways in HRCT scans. The quantitative score (BWT %; defined as [airway outer diameter – airway lumen diameter]/airway outer diameter ×100) was the average score of all airways visible and calculated using electronic endpoint callipers. RBM thickness in endobronchial biopsies was measured using image analysis. 23/27 subjects performed spirometry and the relationships between RBM thickness and BWT with airflow obstruction evaluated.

Results

Median RBM thickness in endobronchial biopsies was 6.7(range 4.6 – 10.0) μm. Median qualitative score for BWT of the right lower lobe was 1(range 0 – 1.5) and quantitative score was 54.3 (range 48.2 – 65.6)%. There was no relationship between RBM thickness and BWT in the right lower lobe using either scoring technique. No relationship was found between FEV₁ and BWT or RBM thickness.

Conclusion

Although a relationship between RBM thickness and BWT on HRCT has been found in adults with asthma, this relationship does not appear to hold true in children with DA.

Imaging evolution of airway disorders in children

This article discusses and illustrates the insights gained from CT imaging of the lungs in infants and young children who do not have respiratory motion and at end-inspiratory and resting end-expiratory lung volumes using noninvasive controlled ventilation CT technique. The potential role of noninvasive controlled ventilation CT in developing quantitative measures of airway disease is highlighted and clinical examples demonstrating the use of the technique are shown.