Tahreema Nihad Hashmi Matin MBBS, Presenter: Nothing to Disclose

Xiaojun Xu MSc, DPhil, Abstract Co-Author: Nothing to Disclose

Tom Doel DPhil, Abstract Co-Author: Nothing to Disclose

Jennifer Lee, Abstract Co-Author: Nothing to Disclose

Najib Rahman MSc, DPhil, Abstract Co-Author: Nothing to Disclose

Jim M. Wild PhD, Abstract Co-Author: Nothing to Disclose

Vicente Grau PhD, Abstract Co-Author: Nothing to Disclose

Annabel Nickol, Abstract Co-Author: Nothing to Disclose

Fergus Vincent Gleeson MBBS, Abstract Co-Author: Alliance Medical Ltd Consultant

To correlate hyperpolarised xenon MR lung imaging (Xe-MRI) and quantitative computed tomography (QCT) with pulmonary function tests (PFTs) and a patient-centred outcome measure (Dyspnoea-12 score) in subjects with chronic obstructive pulmonary disease (COPD).

Fifteen patients with COPD (stage II – IV GOLD criteria classification) underwent Xe-MRI at 1.5T, QCT, PFTs and dyspnoea-12 breathlessness questionnaire. Whole lung percentage ventilated volume was obtained using automated segmentation of Xe-MRI ventilation images and average whole lung apparent diffusion coefficients (ADCs) calculated from Xe-MRI diffusion-weighted images (b=20.855sec/cm2). Percentage predicted forced expiratory volume in one second (FEV1), FEV1/forced vital capacity (FVC) ratio and transfer factor of the lung for carbon monoxide (TLCO) was established for each participant. Dyspnoea-12 was analysed according to standard methodology. QCT-derived metrics for emphysema and bronchial wall thickness were calculated from percentage of lung tissue with density of <-950HU and Pi10 (the square root of wall area for an airway with lumen perimeter of 10mm). Pearson’s correlation coefficients were used to evaluate the relationship between imaging measures, PFTs and dyspnoea-12 scores.

Xe-MRI whole lung average ADC showed significant correlation with: QCT percentage emphysema (r= 0.79, P= 0.001), Pi10 (r= 0.68, P<0.05), and also demonstrated significant negative correlation with percentage predicted TLCO (r= -0.81, P<0.001). QCT percentage emphysema showed a similar significant negative correlation with percentage predicted TLCO (r= -0.80, P<0.001). The QCT-derived metrics, percentage emphysema and Pi10 demonstrated near significant correlation (r= 0.29, P<0.015). There was no correlation between imaging parameters and spirometric indices (FEV1, FEV1/FVC) or dyspnoea-12 scores.

This study correlates the non-ionising, functional imaging technique, Xe-MRI with QCT-derived metrics including Pi10 and clinical outcomes. The findings provide evidence to support the role of Xe-MRI and QCT for comprehensive structural and functional evaluation of the lungs in COPD.

The excellent correlation of Xe-MRI whole lung average ADC with structural QCT-derived measures of COPD and TLCO, suggest it may be of value in the investigation, management, and trialing of new therapies in these patients.

Matin, T, Xu, X, Doel, T, Lee, J, Rahman, N, Wild, J, Grau, V, Nickol, A, Gleeson, F, Demonstrating the Utility of Hyperpolarised Xenon MRI (Xe-MRI) and Quantitative Computed Tomography (QCT) in Chronic Obstructive Pulmonary Disease (COPD).  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045604.html