Dynamic pulmonary computed tomography angiography: a new standard for evaluation of combined airway and vascular abnormalities in infants

Abstract

Airway abnormalities are frequently associated with congenital heart disease in infants and children. Respiratory distress in these children frequently requires prolonged respiratory support. Wide-detector dynamic pulmonary computed tomography angiography (DP-CTA) is a non-invasive technique that completely evaluates vascular and airway abnormalities during a single breathe. Our purpose was to evaluate the efficacy of DP-CTA to provide unique actionable information for patient care in newborns and infants with congenital heart disease and persistent respiratory distress. 23 infants with congenital heart disease and persistent respiratory distress underwent DP-CTA. All were intubated at the time of the examinations. The most common cardiac anomalies were tetralogy of Fallot (6) and hypoplastic left heart syndrome variants (5). The most common cardiac surgeries prior to DP-CTA were Norwood (4) and hybrid (3) procedures. The protocol for DP-CTA for intubated infants is four gantry rotations in 1.4 s after intravenous contrast injection. 3D and multiplanar reconstruction with cine loops were created for combined cardiopulmonary imaging. Tracheobronchomalacia was present in 17 children. Lobar bronchomalacia was identified in six children. Branch pulmonary artery stenosis was the most common vascular finding (10 children). Medical management was changed or a surgical procedure performed based on the information resulting from DP-CTA in 16 of the 23 patients (70 %). DP-CTA is non-invasive, fast and provides unique information for the management of infants with congenital heart disease and persistent respiratory distress. DP-CTA is uniquely suited for comprehensive and simultaneous evaluation of airway and vascular abnormalities in infants.

Paediatric tracheomalacia - A review of clinical features and comparison of diagnostic imaging techniques

“…Flexible bronchoscopy can allow assessment of a more natural airway, as airway stenting does not occur, and it can be used to assess for distal pathologies [13]. result of a dynamic cine pulmonary CT [27]. Gaarfar concludes that CTA is necessary in children with a high level of suspicion of vascular anomaly [28] and the current study would support this recommendation.…”

ERS statement on tracheomalacia and bronchomalacia in children

“…However, patients included in that study suffered from very severe TBM in whom surgery was required, so this was a biased population and the accuracy of the MDCT scan may have been overestimated [9]. Free-breathing cine-MDCT is an alternative technique in young children as it does not require general anaesthesia and controlled ventilation, and radiation exposure is low (mean effective dose <2 mSv, with the minimum ever reported 0.19-0.8 mSv) [11][12][13]. Reported sensitivity (96.3%) and specificity (97.2%) are high compared with bronchoscopic evaluation [11].…”

“…Another concern is the need for sedation and intubation in younger children, which can distort the airway and change the tracheal dynamics [7,9,11,12,28]. This problem can be partially solved by using free-breathing cine-MDCT [11][12][13].…”

“…Malacia is defined in this European Respiratory Society (ERS) Task Force report as an arbitrary >50% expiratory reduction in the cross-sectional luminal area during quiet respiration [7][8][9][10][11][12][13]. There is no universally agreed "gold standard" diagnostic test, although flexible bronchoscopy is the most commonly used modality by respiratory paediatricians.…”

High-pitch CT, decreasing need for sedation and its potential side effects: some practical considerations and future directions

“…Aided by sedation or anesthesia, we are now able to routinely acquire motionless images of the tracheobronchial tree at full inspiration and end-expiration [42] in a cross-sectional format [17][18][19]43]; however these acquisitions do not truly investigate the dynamic nature of tracheo-bronchomalacia. To address this, others have developed free-breathing cine chest CT [44,45] and "four-dimensional" CT on a scanner with enough detectors to cover the relevant anatomy without need for table motion [9,[46][47][48][49]. Yet, I have found that my results with these techniques usually did not affect the clinical management of dynamic airway collapse because most children eventually outgrow this condition and bronchoscopy has remained the diagnostic gold standard for this condition at my hospital [50].…”