Learning Radiology xray montage

Incomplete Fissure Sign

    • Clear crescentric, concave lucency seen adjacent to heart on frontal radiograph usually better demarcated when there is fluid in the pleural space laterally
    • Called the “Incomplete Fissure Sign”
    • The curvilinear edge is caused by a major fissure which does not completely separate the upper and lower lobes (middle on the right)]
    • More common on the right side than the left
    • Overall, quite common: over 60% are incomplete on the right and 50% on the left
    • Incomplete fissures may allow for collateral air drift and the transmission of disease from one lobe to another

    Incomplete Fissure

    Incomplete Fissure. The black arrow points to a crescentric edge-like density that represents the medial border of an incomplete major fissure. The fissure is outlined by pleural fluid laterally.

    Signs in Imaging: The Incomplete Fissure Sign. Meghan G. Lubner, MD. Radiology: 247, Issue 2.