Thomas Semple

The radiology of diffuse interstitial pulmonary disease in children: pearls, pitfalls and new kids on the block in 2015.

Diffuse interstitial lung disease in children differs markedly from interstitial lung disease in adults and is a distinct entity. The childhood interstitial lung disease (ChILD) classification, devised in 2010 separates conditions into those occurring in infancy, and those not specific to infants, the later group containing many conditions related to systemic diseases (including connective tissue diseases and depositional/storage disorders), and conditions occurring in immunocompromised children. In this article, we briefly review normal lung growth and development. We discuss our preferred technique for imaging the lungs with computed tomography in children, and review the recent literature regarding the radiological appearance of various ChILD. We illustrate this with cases from our institution and emphasize the more recently recognised conditions including pleuroparenchymal fibroelastosis and filamin A deficiency-related lung disease.

Filamin A (FLNA) mutation—A newcomer to the childhood interstitial lung disease (ChILD) classification

Interstitial lung disease (ILD) in infants represents a rare and heterogenous group of disorders, distinct from those occurring in adults. In recent years a new entity within this category is being recognized, namely filamin A (FLNA) mutation related lung disease. Our aims are to describe the clinical and radiological course of patients with this disease entity to aid clinicians in the prognostic counseling and management of similar patients they may encounter.

Development of a congenital cardiovascular computed tomography imaging registry: Rationale and implementation

BACKGROUND The cumulative exposure and risk of anesthesia, vascular access, contrast agents and radiation is emerging as a significant lifelong burden in patients with congenital heart disease (CHD). Latest generation computerized tomographic (CT) scanners are increasingly used for high resolution cardiovascular imaging and have both hardware and post processing radiation dose reduction strategies that can be implemented. Currently, these dose reduction strategies are not uniformly applied and there is a large variability in radiation dose used for the performance of CT in CHD. METHODS We propose the development and implementation of a prospective, multi-center and multi-specialty consortium to measure the variability of use, risk and image quality of CT scans in patients of all ages with CHD. The primary goals of this collaboration are 1) define variability of use, diagnostic quality, and risk of cardiac CT 2) establish best practice guidelines designed to optimize diagnostic image quality with appropriate use of radiation and anesthesia exposure 3) provide institution specific feedback compared with the group norm across participating centers 4) improve the level of evidence for the use of CT in CHD through the collection of prospective and multi-institutional data. CONCLUSIONS Prospective multi-institutional data is needed to inform risk estimates of CT in CHD using current generation scanners and aggressive dose optimization techniques. This registry will provide a platform for future collaboration establishing a multi-modality risk assessment tool specific to patients with CHD.

Left circumflex coronary artery from the pulmonary artery in scimitar syndrome

BackgroundScimitar syndrome is a rare combination of cardiopulmonary abnormalities found in 1–3 per 1000 live births. Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is only found in 1 in 250–400 congenital heart disease patients.ObjectiveWe aimed to investigate the incidence of left circumflex ALCAPA within our referral center’s cohort of scimitar syndrome patients.Materials and methodsA review of medical records, cardiac imaging and operative notes from all patients diagnosed with scimitar syndrome at our center between 1992 and 2016 was undertaken and all imaging reviewed.ResultsFifty-four patients with scimitar syndrome and imaging were identified. Of these, 3 patients (1 male and 2 female) with ALCAPA were identified, representing an incidence of 5.5% (95% confidence interval [CI] 0–11.67%). In all three cases, the anomalous coronary arising from the pulmonary artery was the left circumflex coronary artery (LCx) and the point of origin was close to the pulmonary arterial bifurcation.ConclusionWe hypothesize that the prevalence of LCx-ALCAPA, in the setting of scimitar syndrome, may be greater than previously thought. We suggest that any patient with scimitar syndrome, especially with evidence of ischaemia, should be investigated for ALCAPA. Given its noninvasive nature and simultaneous imaging of the lungs, we suggest that cardiovascular CT is the most appropriate first-line investigation for these patients.

Accuracy of computed tomography in detection of great vessel stenosis or hypoplasia before superior bidirectional cavopulmonary connection: Comparison with cardiac catheterization and surgical findings

BACKGROUND Cardiac catheterization is the gold-standard modality for investigation of cardiovascular morphology before bidirectional cavopulmonary connection, but requires general anaesthesia and is associated with procedural risk. AIMS To assess the diagnostic accuracy and safety of computed tomography in diagnosing great vessel stenosis/hypoplasia compared with cardiac catheterization and surgical findings. METHODS Twenty-seven patients (10 after Norwood stage I) underwent computed tomography before surgery between January 2010 and June 2016; 16 of these patients also underwent cardiac catheterization. Proximal and distal pulmonary artery, aortic isthmus and descending aorta measurements, radiation dose and complications were compared via Bland-Altman analyses and correlation coefficients. RESULTS The accuracy of computed tomography in detecting stenosis/hypoplasia of either pulmonary artery was 96.1% compared with surgical findings. For absolute vessel measurements and Z-scores, there was high correlation between computed tomography and angiography at catheterization (r=0.98 for both) and a low mean bias (0.71mm and 0.48; respectively). The magnitude of intertechnique differences observed for individual patients was low (95% of the values ranged between -0.9 and 2.3mm and between -0.7 and 1.7, respectively). Four patients (25%) experienced minor complications from cardiac catheterization, whereas there were no complications from computed tomography. Patients tended to receive a higher radiation dose with cardiac catheterization than with computed tomography, even after exclusion of interventional catheterization procedures (median 2.5 mSv [interquartile range 1.3 to 3.4 mSv] versus median 1.3 mSv [interquartile range 0.9 to 2.6 mSv], respectively; P=0.13). All computed tomography scans were performed without sedation. CONCLUSIONS Computed tomography may replace cardiac catheterization in identification of great vessel stenosis/hypoplasia before bidirectional cavopulmonary connection when no intervention before surgery is required. Computed tomography carries lower morbidity, can be performed without sedation and may be associated with less radiation.

Interstitial Lung Disease in Children Made Easier…Well, Almost

Interstitial lung disease (ILD) in pediatric patients is different from that in adults, with a vast array of pathologic conditions unique to childhood, varied modes of presentation, and a different range of radiologic appearances. Although rare, childhood ILD (chILD) is associated with significant morbidity and mortality, most notably in conditions of disordered surfactant function, with respiratory failure in 100% of neonates with surfactant protein B dysfunction and 100% mortality without lung transplantation. The authors present a summary of lung development and anatomy, followed by an organized approach, using the structure and nomenclature of the 2013 update to the chILD Research Network classification system, to aid radiologic diagnosis of chILD. Index radiologic cases with contemporaneous histopathologic findings illustrate a summary of recent imaging studies covering the full spectrum of chILD. chILD is best grouped by age at presentation from infancy (diffuse developmental disorders, lung growth abnormalities, specific conditions of unknown origin, surfactant dysfunction mutations) to later childhood (disorders of the normal host, disorders related to systemic disease processes, disorders related to immunocompromise). Appreciation of the temporal division of chILD into infant and later childhood onset, along with a sound understanding of pulmonary organogenesis and surfactant homeostasis, will aid in providing useful insight into this important group of pediatric conditions. Application of secondary lobular anatomy to interpretation of thin-section computed tomographic images is pivotal to understanding patterns of ILD and will aid in selecting and narrowing a differential diagnosis. ©RSNA, 2017.

12 Left circumflex alcapa in scimitar syndrome – an under-recognised association?

Introduction Scimitar syndrome is a well-known, but exceedingly rare condition, characterised by anomalous pulmonary venous return of all or part of the right lung to the IVC, normally in association with right lung hypoplasia, dextroposition of the heart and right pulmonary artery hypoplasia. Anomalous coronary anatomy is not, however, a well-described association. We reviewed the coronary anatomy of all patients diagnosed with scimitar syndrome, at a single institution, over a 24-year period. Methods Retrospective review of medical records, cardiac imaging and operative notes of all patients diagnosed with scimitar syndrome at a single institution between 1992 and 2016. Results 54 patients were identified. Within this cohort 3 patients (5.5%, 1 male, 2 female) had anomalous origin of the left circumflex coronary artery from the pulmonary artery (ALCAPA), all arising close to the pulmonary bifurcation. Conclusions There are many common and uncommon variants of scimitar syndrome. The relatively high incidence (5.5%) of anomalous origin of the left circumflex coronary from the pulmonary artery is not well described and should be borne in mind when reviewing cross-sectional imaging of these patients, particularly during the neonatal period, when coronary anatomy is often particularly difficult to assess.

13 Paediatric cardiac CT – current state of play and room for improvement

Introduction Despite significant technologic advancements, application of cardiac CT techniques to paediatric imaging continues to push technology to its limit. We examined indications for paediatric cardiac CT and the impact of advances in technology on dose and use of ECG-gating techniques between 1st, 2nd and 3rd generation dual-source scanners. Methods Retrospective collection of indications from a radiology information system. Comparison of cardiac, high-pitch ?spiral acquisitions during 6-month periods in 2014 (Definition DS), 2015 (Flash) and 2016 (Force) across 2 institutions. Whole-study DLP (32 cm phantom) used for simple comparison of dose. Proportion of scans performed as spiral, prospective and retrospective ECG-gated compared across generations of scanner. Results The majority of CTs were for complex congenital heart disease assessment (shunts, pulmonary vessels and aortic anatomy including major aortopulmonary collateral arteries). In the 6-months’ examined, 12 protocols were used on the definition DS, 17 on the Flash and 4 on the Force. 14.3% of cardiac scans were acquired with retrospective and 20% with prospective ECG-gating on the 1st generation machine with all examinations performed as high pitch spiral acquisitions on the 3rd generation machine. Moving from a 1st to a 3rd generation dual source scanner resulted in 72, 72 and 73% decreases in DLP in 0–2, 2–5 and 5–10 year-olds respectively. Conclusions CT is capable of non-invasive complex anatomic assessment in neonates and children. As technology advances, application of cardiac CT in this hard to image population becomes simpler with fewer protocols, less need for multiphase acquisitions and lower ionising radiation doses.

Imaging Bronchopulmonary Dysplasia—A Multimodality Update

Bronchopulmonary dysplasia is the most common form of infantile chronic lung disease and results in significant health-care expenditure. The roles of chest radiography and computed tomography (CT) are well documented but numerous recent advances in imaging technology have paved the way for newer imaging techniques including structural pulmonary assessment via lung magnetic resonance imaging (MRI), functional assessment via ventilation, and perfusion MRI and quantitative imaging techniques using both CT and MRI. New applications for ultrasound have also been suggested. With the increasing array of complex technologies available, it is becoming increasingly important to have a deeper knowledge of the technological advances of the past 5–10 years and particularly the limitations of some newer techniques currently undergoing intense research. This review article aims to cover the most salient advances relevant to BPD imaging, particularly advances within CT technology, postprocessing and quantitative CT; structural MRI assessment, ventilation and perfusion imaging using gas contrast agents and Fourier decomposition techniques and lung ultrasound.