Question

What are the techniques used to image the lungs and pulmonary vasculature? Which techniques are of use when performing specialized procedures on the lungs such as bronchoscopy, lung biopsy, V/Q imaging, and pulmonary embolism diagnosis and why?

Answer 1

Techniques used to image the lungs and pulmonary vasculature are:

Chest radiography

Chest radiography (X-ray) is an essential part of the diagnostic (and monitoring) examination, and is the first step in the radiological evaluation of patients with suspected respiratory diseases.

Computed tomography

Computed tomography (CT) of the chest is the second most important radiological modality in respiratory medicine, allowing much more detailed visualisation of thoracic structures than radiography

Pulmonary angiography and bronchial angiography are invasive techniques for imaging vessels and are only used if less invasive techniques (contrast CT/magnetic resonance imaging (MRI)) fail or need to be confirmed.

Fluoroscopy

Fluoroscopy (an X-ray technique by which respiratory movement is visualised directly) is used mainly for guidance of biopsy of peripheral lung lesions and for differential diagnosis of an elevated diaphragm.

Magnetic resonance imaging

MRI has the advantage that radiation is avoided. It is also useful with suspected tumour invasion of the mediastinum and the chest wall.

Ultrasonography

Ultrasonography has become an important imaging technique. Its advantages are lack of radiation, low cost and mobility. It is mainly used in the investigation of pleural effusions (in which it also has a role in guiding thoracentesis) but also in pleural thickening, chest wall abnormalities, for the diagnosis of pneumothorax and for biopsies of lesions adjacent to the chest wall.

Nuclear medicine techniques

Nuclear medicine techniques include perfusion and ventilation scintigraphy, which are mainly indicated in the diagnosis of pulmonary embolism but also for regional lung function studies.

Techniques are of use when performing specialized procedures on the lungs such as bronchoscopy, lung biopsy, V/Q imaging, and pulmonary embolism diagnosis are:

Pulmonary health specialists use a wide range of minimally invasive procedures to visualize your internal structures, obtain tissue samples and diagnose lung disease, including:

Electromagnetic navigation guided (EMN) bronchoscopy. This outpatient procedure is like a GPS of our airways and gives the doctor a detailed map of our internal structures. The procedure also can be used to place objects, called fiducial markers, if having stereotactic radiation therapy to treat lung cancer.

Endobronchial ultrasound (EBUS). Doctor may use this procedure to take a sample of lymph node tissues. To perform the procedure, the doctor uses a bronchoscope with an ultrasound tip.

Confocal endomicroscopy. Your doctor may use this procedure for early diagnosis of lung cancer.

Medical thoracoscopy. This procedure is used to check for pleural lung disease. The doctor inserts a special instrument (pleuroscope) through the chest wall to obtain a tissue sample of pleura, the tissue outside the lungs and in chest cavity.

Robotic-assisted bronchoscopy. Doctor may use this minimally invasive approach to biopsy a lung nodule that’s difficult to reach.

Transbronchial cryobiopsy. This procedure can help the doctor diagnose interstitial lung disease, such as pulmonary fibrosis.

Bronchoalveolar lavage: Bronchoalveolar lavage (BAL) involves the instillation of saline via a bronchoscope in order to collect specimens for cytological or microbiological investigation.

Autofluorescence and narrow-band imaging: Autofluorescence or narrowband imaging may be helpful in the detection of precancerous lesions and early cancers located in the bronchial tree.

Percutaneous needle biopsy: Percutaneous (or transthoracic) needle biopsy is mainly performed to investigate peripheral lung lesions when bronchoscopy is negative.

Thoracentesis and pleuroscopy (medical thoracoscopy): Thoracentesis (pleural fluid aspiration or ‘tap’) is a frequently performed procedure in pleural effusions, preferably used under ultrasound guidance, at least when the effusion is small.