Costal pleura: appearances at high-resolution CT

Area of Science:

• Radiology
• Thoracic Imaging
• Pulmonary Medicine

Background:

• The visualization of the costal pleura is crucial for diagnosing pleural abnormalities.
• Distinguishing normal pleural structures from pathological thickening can be challenging on CT scans.

Purpose of the Study:

• To evaluate the appearance of the costal pleura using high-resolution computed tomography (CT).
• To compare high-resolution CT with standard CT in detecting mild pleural thickening, particularly in asbestos-exposed patients.

Main Methods:

• High-resolution CT scans were performed on a cadaver and 25 normal subjects.
• The imaging findings were contrasted with 15 patients exhibiting mild pleural thickening, including 13 with asbestos exposure.
• Normal pleural anatomy and potential mimics of thickening were identified.

Main Results:

• On high-resolution CT, normal costal pleura appears as a 1-2 mm soft-tissue line.
• In paravertebral regions, the innermost intercostal muscle is absent, altering the pleural line appearance.
• Mild pleural thickening (1-3 mm) was identifiable and often separated from intercostal muscles by extrapleural fat.
• High-resolution CT demonstrated superior sensitivity compared to standard CT (1-cm collimation) for subtle pleural changes.

Conclusions:

• High-resolution CT provides detailed visualization of the costal pleura.
• This technique is effective in differentiating normal pleura from mild thickening and identifying asbestos-related pleural changes.