Expiratory CT scan in patients with normal inspiratory CT scan: a finding of obliterative bronchiolitis and other causes of bronchiolar obstruction

Abstract

Expiratory CT scan is usually obtained as supplement to normal inspiratory CT scan to recognize air-trapping, which is expression of small airways obstruction. In some patients the air-trapping may be the only sign of an early-stage small airways disease in an otherwise normal lung.The purpose of this article is to illustrate pathologic conditions, namely obliterative bronchiolitis, in which expiratory CT scan can be abnormal despite normal inspiratory CT examination, and to highlight indications for this technique in patients with clinical and functional suspect of bronchiolar obstruction.

Comparison of magnetic resonance imaging and computed tomography to measure preoperative parameters of children with pectus excavatum

“…In addition, for the mDIXON sequence measurements, cardiac parameters were unaffected by the respiratory phase, although the pulmonary parameters were of course higher in the end‐inspiratory phase than in the end‐expiratory phase. These results are supported by previous studies; indeed, it has been demonstrated that both inspiratory and expiratory CT have great impacts on the evaluation of thoracic movements . Albertal et al showed that assessment of PE at end‐expiration led to an additional number of surgical candidates compared with end‐inspiration assessment.…”

“…These results are supported by previous studies; indeed, it has been demonstrated that both inspiratory and expiratory CT have great impacts on the evaluation of thoracic movements. 10 Although the findings of the present study are encouraging, there are still several limitations to this study. First, the sample size was relatively small, and the children were all of school age (> 6 years old).…”

“…Conventional pulmonary function tests (PFT) do not meet the requirements for appropriate management of PE; therefore, clinicians now use computed tomography (CT) volume reconstruction as the gold standard for obtaining more detailed data on pulmonary functions . It has been demonstrated that both inspiratory and expiratory CT have great impacts on the evaluation of thoracic movement . Albertal et al showed that assessment of PE at end‐expiration led to an additional number of surgical candidates compared with end‐inspiration assessment only.…”

“…8,9 It has been demonstrated that both inspiratory and expiratory CT have great impacts on the evaluation of thoracic movement. 10,11 Albertal et al 12 showed that assessment of PE at endexpiration led to an additional number of surgical candidates compared with end-inspiration assessment only.…”

Use of expiratory CT images in the diagnosis and localisation of airway complications following lung transplantation

“…While many conditions involve a combination of large and small airways disease, the lung transplant population is distinct in that large airway (anastomotic) or small airway (bronchiolar) complications may occur in isolation of each other; therefore, the inclusion of expiratory views on a CT scan is of particular value in diagnosing and differentiating between these conditions. In bronchiolitis obliterans, expiratory obstruction appears patchy with scattered mosaic air trapping 1. Air trapping confined to certain lobes of the lung without a diffuse nature, as in this case is indicative of an anastomotic complication.…”