Paediatric Thoracic Imaging in Cystic Fibrosis in the Era of Cystic Fibrosis Transmembrane Conductance Regulator Modulation

Abstract

Cystic fibrosis (CF) is one of the most common progressive life-shortening genetic conditions worldwide. Ground-breaking translational research has generated therapies that target the primary cystic fibrosis transmembrane conductance regulator (CFTR) defect, known as CFTR modulators. A crucial aspect of paediatric CF disease is the development and progression of irreversible respiratory disease in the absence of clinical symptoms. Accurate thoracic diagnostics have an important role to play in this regard. Chest radiographs are non-specific and insensitive in the context of subtle changes in early CF disease, with computed tomography (CT) providing increased sensitivity. Recent advancements in imaging hardware and software have allowed thoracic CTs to be acquired in paediatric patients at radiation doses approaching that of a chest radiograph. CFTR modulators slow the progression of CF, reduce the frequency of exacerbations and extend life expectancy. In conjunction with advances in CT imaging techniques, low-dose thorax CT will establish a central position in the routine care of children with CF. International guidelines regarding the choice of modality and timing of thoracic imaging in children with CF are lagging behind these rapid technological advances. The continued progress of personalised medicine in the form of CFTR modulators will promote the emergence of personalised radiological diagnostics.

Keywords: computed tomography; cystic fibrosis; cystic fibrosis transmembrane conductance regulator modulator; magnetic resonance imaging; paediatrics; radiography.

Figure 1

Conventional-dose CT of the thorax. Coronally (A,C) and axially reconstructed (B,D). Conventional-dose CT of the thorax images in soft tissue (A,B) and lung windows (C,D) in a paediatric male CF patient performed during an acute hospital admission. The dose length product (DLP) for this examination was 39.77 mGy*cm.

Figure 2

Ultra-low-dose CT of the thorax. Coronally (A,C) and axially (B,D) reconstructed ultra-low-dose CT thorax images in soft tissue (A,B) and lung windows (C,D) in the same paediatric male CF patient as Figure 1, performed during routine disease surveillance several years later. The DLP for this examination was 2.28 mGy*cm.