WEEK 1: Imaging of the lung Flashcards
What does darker and lighter mean on x-ray?
Darker = less dense (attenuation)
Lighter = more dense (attenuation)
Arrange the following Attenuation scale in the body from more to less attenuation.
Air
Water
Soft tissue
Fat
Metal
Blood clot
Bone
IV contrast
air < fat < water < soft tissue < blood clot < IV contrast < bone < metal
Describe where we look when studying the Chest x-ray. 6 things.
- Scan Lungs:
*Lung Fields: Assess for abnormalities such as infiltrates, consolidations, nodules, masses, or cavitations.
*Apices: Check for any signs of apical lung disease, such as tuberculosis or pneumothorax.
*Behind Heart: Examine for lung pathology obscured by the heart shadow, such as masses or effusions.
- Costophrenic Angles:
Evaluate the costophrenic angles for blunting or obliteration, which may indicate pleural effusion or pleural thickening. - Heart:
*Size: Measure the cardiothoracic ratio to assess heart size relative to the thoracic cavity. A cardiothoracic ratio greater than 0.5 may suggest cardiomegaly.
*Shape: Examine for abnormalities in heart contour or silhouette, which could indicate cardiomegaly, pericardial effusion, or cardiac chamber enlargement.
- Mediastinal Borders:
Aorta: Assess the aortic arch and descending aorta for abnormalities, such as widening, aneurysms, or dissections.
*Pulmonary Artery (PA): Evaluate the size and contour of the pulmonary artery, looking for signs of pulmonary hypertension or embolism.
- Below the Diaphragm:
Look for abnormalities in the lower lung fields, including diaphragmatic hernias, liver pathology, or free air under the diaphragm indicating pneumoperitoneum. - Bones:
Assess for fractures, lytic lesions, or bony abnormalities, such as rib fractures, vertebral compression fractures, or evidence of metastatic disease.
Describe the technique on how to Use an X-ray for Diagnosis.
- Identify the location of the abnormality
- If in the lung:
- Decide is the abnormality focal (a single place in the lung?) or diffuse (affects both lungs uniformly)?
- Decide is the abnormality in the interstitium (small lines, dots or circles) or the airspaces (increased opacity, “patchy”, “fluffy”)?
- What shape? Location in the lung?
- Learn the causes for your imaging pattern (radiographic differential diagnosis)
- Using the imaging features, differential, clinical history, frequency of disease and demographics decide on the most likely cause(s)
Distribution
* Focal
* Multifocal
* Diffuse
Part effected
* Interstitium
* Airspace
If focal
* Where?
* Apex a special place
What shape?
* Irregular
* Round
Outline the 5 causes of Focal Airspace Opacities.
- Pneumonia
- Atelectasis
- Contusion
- Neoplasm
- Infarction
- Pneumonia:
Chest X-ray may reveal focal or diffuse areas of consolidation, which appear as opacities in the affected lung parenchyma.
Consolidation typically presents as fluffy or patchy opacities with air bronchograms (air-filled bronchi surrounded by consolidated lung tissue).
Other findings may include lobar or segmental atelectasis, pleural effusion, or cavitation in certain cases.
- Atelectasis:
Atelectasis refers to collapse or incomplete expansion of a lung or part of a lung.
On chest X-ray, atelectasis may present as opacities that are linear or plate-like and may involve an entire lobe, segment, or smaller portion of the lung.
The affected area may appear denser or darker than the surrounding lung tissue, and there may be associated mediastinal shift towards the affected side.
- Contusion:
Pulmonary contusion results from blunt chest trauma and is characterized by localized lung injury and hemorrhage.
On chest X-ray, contusions may initially appear as patchy areas of consolidation or opacities, often involving the lower lobes or areas of maximal impact.
Over time, contusions may evolve with areas of consolidation becoming more prominent, and air bronchograms may develop as surrounding lung tissue clears.
- Neoplasm:
Neoplasms, such as lung cancer or metastatic lesions, may present as focal or diffuse opacities on chest X-ray.
These opacities may vary in size, shape, and density, ranging from nodules or masses to ill-defined infiltrates.
Features suggestive of malignancy may include spiculated margins, irregular shape, rapid growth, or associated findings such as mediastinal lymphadenopathy or pleural effusion.
- Infarction:
Pulmonary infarction occurs when a segment of lung tissue becomes ischemic due to obstruction of pulmonary blood flow, commonly by a pulmonary embolism.
On chest X-ray, infarctions may appear as wedge-shaped opacities with the base of the wedge facing the pleural surface.
These opacities are typically located peripherally and may show a pleural-based or subpleural distribution, often involving the lower lobes.
60 old woman with cough, fever, chills & leukocytosis.
Focal airspace lesion in the lungs.
What is the diagnosis?
Legionella Pneumonia
*Legionnaires’ disease is a serious type of pneumonia you get when Legionella bacteria infect your lungs.
*Symptoms include high fever, cough, diarrhea and confusion.
*You can get Legionnaires’ disease from water or cooling systems in large buildings, like hospitals or hotels. Legionnaires’ disease can be life-threatening.
Legionella pneumonia, also known as Legionnaires’ disease, is a severe form of pneumonia caused by the bacterium Legionella pneumophila. Here’s how Legionella pneumonia may present on a chest X-ray:
Patchy Infiltrates: Legionella pneumonia typically presents with bilateral, patchy infiltrates on chest X-ray. These infiltrates may involve one or more lobes of the lungs and can be distributed in a perihilar or diffuse pattern.
Consolidation: In some cases, Legionella pneumonia can cause areas of consolidation, particularly in the lower lobes of the lungs. Consolidation appears as dense opacities that may obscure the lung markings.
Ground-Glass Opacities: Ground-glass opacities, which appear hazy or milky on chest X-ray, can be seen in Legionella pneumonia. These opacities reflect partial filling of the alveoli with fluid or inflammatory exudate.
Cavitary Lesions: In severe cases or immunocompromised individuals, Legionella pneumonia may lead to the formation of cavitary lesions in the lungs. These cavities appear as lucent areas within the lung parenchyma surrounded by denser consolidative or ground-glass opacities.
Pleural Effusion: Occasionally, Legionella pneumonia may be associated with pleural effusion, which appears as blunting of the costophrenic angles or opacification of the pleural spaces on chest X-ray.
Mediastinal Adenopathy: While less common, Legionella pneumonia can cause mediastinal lymphadenopathy, which may be visible as enlarged lymph nodes on chest X-ray, particularly in severe or complicated cases.
30 years old Male with persistent intermittent fever and cough.
Focal and airspace lesions on the apical aspect of the lungs with lucent center.
Reactivation TB
- Most common
apical lung disease! - Cavitation frequent
- Fibrosis frequent
– Fibroproductive
– Fibrocavitary
– Fibronodular
Outline causes of Apical Predominant Opacities on the lungs.
- Reactivation (post primary) Tuberculosis
- Bronchogenic CA (“Pancoast tumor”)
- Pneumonia
- Noninvasive aspergillosis
- Radiation fibrosis
- TB Mimics
- Nontuberculous mycobacteria
- Cryptococcosis
- Histoplasmosis
- Coccidioidomycosis
- Other
- Chronic eosinophilic pneumonia
- Ankylosing Spondylitis
39-year-old HIV positive woman had a long smoking history.
*Focal airspace mass at the diaphragm.
*R hilar lymphadenopathy
What is the diagnosis?
Adenocarcinoma of the Lung with
Hilar Metastasis
- Lung ca. is most common lung mass
~ 60 -70% - Look for evidence of metastasis
–Lymphadenopathy
–Pleural, lung and bone metastasis
State the causes of Pulmonary Masses.
- Neoplasm
* Bronchogenic CA
* Lymphoma
* Carcinoid - Infection
* Lung abscess/round
pneumonia
* Granulomatous infection
– TB
* Echinococcus - Congenital
* CPAM/Sequestration
* AVM - Other inflammatory mass
* GPA (Wegener’s)
* Organizing pneumonia
* Rheumatoid nodule
* Lipoid pneumonia - Trauma
* Hematoma - Other
* Rounded atelectasis
* Amyloidosis
* Conglomerate masses of silicosis
35 M with chronic cough, dyspnea and hemoptysis.
-Multifocal airspace lung lesions with cavitation most severe at the apex.
What is the diagnosis?
Reactivation of TB.
Most common cause of apical lung disease
* Cavitation frequent
– Need to recognize cavitation to diagnose TB!
36m cough, dyspnea and fever. Pt is HIV negative.
Focal irregular airspace lesions in the lung.
What is the diagnosis?
Left Lower Lobe Bacterial Pneumonia
Most common cause of focal airspace disease
* Typical clinical presentation
68-year-old M with a chronic cough.
Rounded and chronic focal airspace lesion.
Diagnosis?
Bronchogenic Carcinoma
What are the 3 main findings on reactivation of TB?
- Apical lung disease
- Cavitation frequent - learn to see the lucency
- Fibrosis frequent - distorts adjacent structures
Visitslides for practice!!!!
