Pleural effusion volume calculator (CT)

Note to first time users: This calculator requires a single measurement (effusion depth), which also means that inaccuracies in measuring this parameter can lead to gross over- or underestimation of effusion volume. Please make sure to go through the detailed ‘Notes’ section below.

Notes

• The calculator uses the following formula originally published by Hazlinger et al.:
  • Volume = 0.365 × b³ – 4.529 × b² + 159.723 × b – 88.377
  • where b = maximum effusion depth measured in the axial (transverse) imaging plane.
• Effusion depth should be measured perpendicular to the parietal pleura.
• Note that if any structure (collapsed lung, diaphragm) interrupts the maximal depth it should be omitted from the calculation (see illustration below).
  • ^{Hazlinger M, Ctvrtlik F, Langova K, Herman M. Quantification of pleural effusion on CT by simple measurement. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2014;158(1):107-11. doi: 10.5507/bp.2012.042. Epub 2012 Jun 1. PMID: 23073526.}

Last updated: 2021-09-21