Lund-Mackay score

The Lund-Mackay score is a widely used method for radiologic staging of chronic rhinosinusitis ¹.

When reading a CT scan of the paranasal sinuses and ostiomeatal complex, the reader assigns each sinus a score of:

• 0 (no abnormality)

• 1 (partial opacification) or

• 2 (complete opacification)

The ostiomeatal complex is assigned a score of either 0 (not obstructed) or 2 (obstructed).

The sinuses are grouped into:

• frontal sinus

• anterior ethmoidal cells

• posterior ethmoidal cells

• maxillary sinus

• sphenoid sinus

• ostiomeatal complex

Each side is graded separately. A combined score of up to 24 is possible. Of note, an aplastic (absent) frontal sinus receives a score of 0.

The method is intentionally simplistic, for the sake of minimizing interobserver variability and expediting its application ².​ Thus, it lends itself to application by non-radiologists and in clinical studies ¹.​ Despite its simplicity, it correlates well with disease severity, extent of surgery, and complication rates, even independent of the extent of surgery ³.​

Modified Lund-Mackay (Zinreich) score

For a more accurate representation of disease burden modifications were proposed to the original system, further subdividing the assessment categories. In the modified staging system the reader assigns a score ranging from 0 to 5 based on the percentage of sinus opacification caused by mucosal thickening: 

• 0 (0%)

• 1 (<25%) 

• 2 (26-50%)

• 3 (51-75%)

• 4 (76-99%)

• 5 (100%)

The ostiomeatal complex is graded differently:

• 0 (normal)

• 1 (partially obstructed)

• 2 (completely obstructed)

Otherwise the assessment is the same, sides are graded separately, resulting in a maximum total score of 54. It has been shown that the modified system better represents disease burden than the original Lund-Mackay score ^4,5. 

History and etymology

It is named after its developers, British rhinologists Valerie J Lund and Ian S Mackay.