Info
🌱 來自: Huppert’s Notes
Chest CT🚧 施工中
Chest CT
• Types of Chest CT:
- Standard: Images may be obtained with or without contrast. Indications for use of contrast include malignancy workup and evaluation for infection of chest wall/mediastinum
- High resolution: Very thin cuts with outstanding spatial resolution that helps to detect interstitial lung disease (particularly honeycombing, which can be missed on standard chest CT). Expiratory views are useful to detect air trapping, which helps with diagnosis of certain interstitial lung diseases (e.g., hypersensitivity pneumonitis)
- CT angiography: Image with contrast; timing of image attainment can be optimized for detection of specific diagnoses, such as pulmonary emboli
- Low radiation dose CT (LDCT): Screening for lung cancer (National Lung Cancer Screening Trial, New Engl J Med 2011)
• Interpreting chest CT images:
- Images provide information about density: Dense = bright/white
• Air: Black
• Fluid/Soft tissue: Gray
• Blood: White
• Bone/Contrast: Dense white
- Windows adjust what densities are displayed in the image (can aid interpretation)
• Lung window: Lung, airways, lung parenchyma
• Soft tissue window: Mediastinal structures, heart, thyroid, muscles, lymph nodes
• Bone window: Bone
• Approach to interpretation of chest CT:
- Verify patient name and date
- Identify chest CT type, including whether contrast was administered
- Select appropriate window (often start with lung, then use soft tissue)
- Read systematically:
• Air: Airway, lung parenchyma
• Bone: Evaluate for fractures, metastases
• Cardiac/vessels: Assess for anatomy, clots, false lumen
• Digestive: Evaluate esophagus patency
• Extras: Tubes, foreign bodies
• Soft tissue: Muscles, fat
- The radiographic finding(s) can be used to help create a differential diagnosis (Table 2.2)
TABLE 2.2 • Differential Diagnoses of Pulmonary Processeses Based on Radiographic Findings