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Abstract

Quantitative CT is used to estimate LD but is not always available. We hypothesized that non-radiological parameters gathered in clinical practice may predict LD. 136 COPD subjects from a respirology practice completed PRO (mMRC and COPD Assessment Tests), PFT (Jaeger or Vmax22, Carefusion, Germany), OS (tremoFlo C-100, Thorasys, Canada) and a non-research CT scan within 1 year. LD (at 15th percentile) was determined from CT scans using AirwayInspector (airwayinspector.acil-bwh.org). Multiple linear regressions were performed (Stata, USA) using LD vs. BM, PRO, ln transformed OS parameters and PFT from a derivation group (DG) of 68 subjects. The resulting model was applied to data from a validation group (VG) of the remaining 68 subjects. With significance set at p<0.05 after Bonferroni correction, Student t-tests were used to determine differences in BM, PRO, OS and PFT between the 2 groups and none were observed (p=0.56-1.00).

LDmodel=0.37(CAT)-3.91(mMRC)+0.27(BMI)+0.19(FEV1/FVC)+0.72(lnAX)-0.32(TLC %predicted)+ 0.03(FRC %predicted)+0.32(Kco %predicted)+50.17 resulted in a strong correlation (r=0.75, p<0.0001) using DG data. LDmodel vs. LD using VG data showed a strong correlation (r=0.76, p<0.0001). A reasonable estimate of LD, and hence emphysema, is possible by means of non-radiologic parameters. Further work improving such models is warranted.

The articles include uses of tremoflo products or describes research devices that may not have been cleared by FD
Keywords
COPD diagnosis, imaging, Physiology
Source

Dandurand R, Dandurand M, San Jose Estepar R, Bourbeau J, Eidelman D. A statistical model to estimate lung density (LD) utilizing oscillometry (OS), biometrics (BM), patient reported outcomes (PRO) and pulmonary function tests (PFT). Eur Respir J [Internet]. 2016 Sep 8 [cited 2018 Jun 28];48(suppl 60):PA4408