Evidence map›Paper›PMID 41422440›Full record

ArticleEuropean radiology2026

Comparison of Pi10 and PiSlope calculation methods and association with lung function.

Razieh Enjilela, Sukhraj Virdee, Jason Bartlett, Benjamin M Smith, Wan C Tan, James C Hogg, Jean Bourbeau, Miranda Kirby

Abstract readComparative Study
PubMed Publisher
In one paragraph

Article in European radiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Review
  2. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors.

Razieh EnjilelaPhysics Department, Toronto Metropolitan University, Toronto, ON, Canada.
Sukhraj VirdeePhysics Department, Toronto Metropolitan University, Toronto, ON, Canada.
Jason BartlettPhysics Department, Toronto Metropolitan University, Toronto, ON, Canada.
Benjamin M SmithDepartment of Medicine, McGill University, Montreal, QC, Canada.
Wan C TanCentre for Heart Lung Innovation, University of British Columbia, Vancouver, BC, Canada.
James C HoggCentre for Heart Lung Innovation, University of British Columbia, Vancouver, BC, Canada.
Jean BourbeauResearch Institute McGill University Health Centre, Montreal, QC, Canada.
Miranda KirbyPhysics Department, Toronto Metropolitan University, Toronto, ON, Canada. miranda.kirby@torontomu.ca.ORCID http://orcid.org/0000-0003-2951-784X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesThe average wall thickness of a theoretical airway with a lumen perimeter of 10 mm (Pi10) and the slope of the luminal perimeter of airways against their wall thickness (PiSlope) are CT-derived biomarkers of airway remodeling in chronic obstructive pulmonary disease (COPD). However, numerous calculation methods for Pi10 have been used across studies, leading to substantial variability in Pi10 values. This study evaluated reliability among 10 Pi10/PiSlope methodologies and their associations with lung function. MATERIALS AND

methodsCanCOLD participants underwent full-inspiration CT scans; CT airway segmentation was performed using VIDA software. Ten literature-based methods were used to calculate Pi10 (regression-derived wall thickness at 10 mm perimeter) and PiSlope (slope of wall area/perimeter plot). The 10 methods varied in their approaches: some focused on specific airway sizes (Patel, Van Tho, Nakano, Telenga), others limited measurements to certain airway generations (Gietema, Park, Dudurych) or covered broader airway size ranges and generations (Bhatt, Jobst, Smith). Reliability was assessed via intraclass correlation (ICC); lung function associations were assessed using regression.

resultsPi10 and PiSlope were calculated for 1351 participants (67 ± 10 years; 550 women). Pi10 and PiSlope  measurement methods with higher airway counts (Patel, Nakano, Smith, Jobst, Bhatt) showed excellent reliability (ICC > 0.90, p < 0.05). Compared to Pi10, PiSlope demonstrated stronger, consistent negative associations with FEV1, FEV1/FVC, and FEF

conclusionThese results provide insight into which Pi10/PiSlope calculation methods may generate more reliable findings and indicate PiSlope may provide a more comprehensive measure of airway remodeling in COPD. KEY POINTS: Question CT Pi10/PiSlope measures airway remodeling in COPD, but calculation methods vary. Are CT Pi10/PiSlope reliable and provide comparable associations with lung function across various methodologies? Findings Pi10/PiSlope calculation methods that included a higher number of CT airways were more reliable, and PiSlope showed stronger associations with lung function than Pi10. Clinical relevance These results provide insight into which methods may generate more reliable findings, aiding interpretation of results between studies, and support the potential of PiSlope as a reliable biomarker for monitoring airway remodeling in COPD.

Indexed as

Airway RemodelingLungPulmonary Disease, Chronic ObstructiveTomography, X-Ray ComputedAgedFemaleHumansMaleMiddle AgedReproducibility of ResultsRespiratory Function TestsAirway remodelingCOPDCTPi10PiSlope

Identifiers

PMID41422440

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.