Lund-Mackay score

The Lund-Mackay score is a CT-based scoring system for chronic rhinosinusitis ¹ and is popular due to its simplicity and high inter and intra-observer reliability ^6,7.

Lund-Mackay score

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

• no abnormality: 0 points

• partial opacification: 1 point

• complete opacification: 2 points

N.B. ostiomeatal complex is scored differently:

• not obstructed: 0 points

• obstructed: 2 points

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 minimising 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 (higher scoress associated with worse symptoms ⁷), extent of surgery, treatment response (higher pre-FESS scores have better outcomes ⁷), 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%:

• <25%: 1 point

• 26-50%: 2 points

• 51-75%: 3 points

• 76-99%: 4 points

• 100%: 5 points

N.B. the ostiomeatal complex is scored 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

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