BS 2 - Lungs
1. To discuss current imaging techniques for evaluation of normal lung anatomy.
2. To learn and understand possible anatomical variants.
3. To describe the typical imaging features of the most common anatomical anomalies.
Imaging in lung anomalies is usually started off by plain film radiography. This projection technique gives a first overview of the anatomical situs and allows for a first assessment of expected anomaly. Depending on the individual setting an ultrasound of the chest can be added for further assessment of the vascular structures or cystic components. A more sophisticated imaging technique like computed tomography or magnetic resonance imaging will allow for definite classification of the anomaly. The different imaging techniques and especially CT and MRI protocols used will be covered. Anatomical variants are most often detected within the tracheobronchial tree, namely with anomalous branching pattern of the upper lobe bronchi. Congenital lung anomalies are a heterogeneous group of developmental disorders with a wide distribution in imaging appearance and clinical manifestations. The most frequent ones are: congenital pulmonary airway malformation (CPAM), congenital lobar hyperinflation, bronchial atresia, bronchiogenic cyst and pulmonary sequestration. For these anomalies, the embryologic background, clinical presentation and imaging findings will be demonstrated.
1. To recognise the most common imaging patterns of lung infections.
2. To understand the temporal relationship between the immune status and diverse lung infections.
3. To have a basic knowledge of CT-path correlation of some pulmonary infectious diseases.
Inflammation is a response of vascularised tissues to infections to eliminate the offending agents. Pneumonia occurs when the host mounts an inflammatory response, centred on the lung parenchyma, usually against a microorganism which has reached this normally sterile site. Bacteria are the most common causative microorganisms. Pneumococci usually spare alveolar walls and cause lobar pneumonia that resolves completely, whereas Staphylococci and Klebsiella species destroy alveolar walls and form abscesses that heal with scar formation. Combination of pattern recognition with knowledge of the clinical setting is the best approach to pulmonary infectious processes. When pulmonary infection is suspected, knowledge of the varied radiographic manifestations will narrow the differential diagnosis, helping to direct additional diagnostic measures, and serving as an ideal tool for follow-up examinations. Management of immunocompromised patients is challenging and difficult because of the diversity of causative organisms. Although diagnostic information may also be obtained by means of bronchoalveolar lavage and transbronchial needle aspiration, the radiologist plays an important role in the diagnosis and management of patients with suspected pneumonia.
1. To describe the typical imaging appearance of bronchogenic carcinoma.
2. To describe the typical imaging features of pulmonary metastases.
3. To describe the manifestations and the role of imaging in pulmonary lymphoma.
Non-small cell lung carcinoma (NSCLC) comprises the largest group of which the imaging appearance can be variable. It can present as centrally or peripherally located nodule or mass that may invade mediastinal structures or the chest wall. Tumour margins may be smooth, lobulated, ill defined, irregular or spiculated. Other findings include cavitation, consolidation and ground glass opacity (GGO). Accompanying post-obstructive pneumonia and/or lung collapse can be seen in central tumours. Small cell lung carcinoma (SCLC) is the most common primary pulmonary neuroendocrine tumour. Most SCLCs are a centrally located large mass invading or metastasising to regional lymph nodes. 5-10% of SCLCs present as a peripherally located spiculated nodule without associated lymphadenopathy. Pulmonary metastasis: the lung is frequently involved in metastatic disease. Typical radiological features include multiple round nodules with variable size, peripherally located (haematogenous metastasis) and diffuse thickening of the interstitium (lymphangitic carcinomatosis). Atypical features such as cavitation, calcification, air bronchogram and GGO are often encountered. Pulmonary lymphoma imaging findings of parenchymal disease in both primary (rare entity) and more frequently occurring secondary pulmonary lymphoma are variable and non-specific. They include single or multiple nodules, masses or consolidations, cavitation and air bronchogram. Ancillary findings include lymphadenopathy, bronchial wall thickening, interlobular septal thickening and pleural effusion. CT is the workhorse of imaging in bronchogenic carcinoma, metastasis and lymphoma, and plays together with PET/CT a crucial role in staging bronchogenic carcinoma and lymphoma. Due to the variety in CT imaging appearances, tissue confirmation is usually warranted to confirm the diagnosis.