Qanadli CT Pulmonary Obstruction Index
Qanadli 2001 (AJR)Quantifies pulmonary arterial clot burden in acute PE as a percentage obstruction index. Each thrombus scores points equal to the number of segmental branches distal to it, weighted 1 for partial and 2 for total occlusion; the index is Σ(n·d)/40 × 100%.
Also searched as: pulmonary embolism · CTPA · clot burden
Information
Incomplete input
- Please provide: at least one thrombus entry (segmental counts or a proximal level) — enter zeros/"none" explicitly if no thrombus is present.
How this tool works
The Qanadli index models each lung as 10 segmental arteries (3 upper-lobe, 2 middle-lobe/lingular, 5 lower-lobe). A thrombus is scored by its most proximal level — 1 point for a segmental artery up to 20 for the pulmonary trunk — multiplied by an obstruction weighting (0 none, 1 partial, 2 total occlusion). The summed score is divided by the maximum of 40 and expressed as a percentage. In the derivation study the index correlated strongly with the angiographic Miller index (r = 0.867) with excellent interobserver agreement, and an index above 40% identified more than 90% of patients with right ventricular dilatation. The index is an anatomic burden descriptor, not a stand-alone prognostic tool.
References
- Qanadli SD et al. AJR Am J Roentgenol 2001;176:1415-20 (PubMed abstract)
- Schematic scoring-tree reproduction (J Korean Med Sci 2022)
- Radiopaedia: Qanadli score
Implemented from the cited published sources. Educational use only; confirm against current guidelines before clinical use.
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