Test Details & Preparation
High-Resolution Computed Tomography (HRCT) is a widely used technique to image various lung pathologies. Compared to helical CT, HRCT uses a narrow beam collimation to take thin slice images of the lung parenchyma. This protocol produces extremely high definition images of lung alveoli, airways, interstitium, and pulmonary vasculature. Expiration images may assist in identifying air-trapping in patients with lung disease.
In patients with suspected chronic diffuse lung disease, HRCT is used for detection in patients with normal or equivocal plain CXR appearances who have symptoms or pulmonary function tests suggestive of diffuse lung disease where the symptoms or plain CXR findings are non-specific, to attempt a specific diagnosis to assess activity of disease and to select assess activity of disease.
In patients with suspected acute diffuse lung disease, HRCT is used for detection in patients with normal or equivocal plain CXR appearances who have symptoms or pulmonary function tests suggestive of acute lung disease for investigation of haemoptysis in selected patients and to select an optimal biopsy site.
HRCT may also be useful in industrial lung disease, idiopathic pulmonary fibrosis, connective tissue disease, radiation-induced lung disease, diffuse metastatic disease, sarcoidosis, bronchio-alveolar carcinoma, mycobacterial infection, infections in immunosuppressed patients, hypersensitivity pneumonitide, interstitial pneumonitis, bronchiolitis obliterans organising pneumonia (BOOP), cryptogenic organising pneumonia (COP), etc.