Emphysema Quantification in Inflation-Fixed Lungs Using Low-Dose Computed Tomography and 3He Magnetic Resonance Imaging

Abstract

Objective-To evaluate the use of inflation-fixed lung tissue for emphysema quantification with CT and 3 He MR diffusion imaging.Methods-Fourteen subjects representing a range of chronic obstructive pulmonary disease severity who underwent complete or lobar lung resection were studied. CT measurements of lung attenuation and MR measurements of the hyperpolarized 3 He apparent diffusion coefficient (ADC) in resected specimens fixed in inflation with heated formalin vapor were compared with measurements obtained before fixation.Results-The mean CT emphysema index was 56% ± 17% before and 58% ± 19% after fixation (P=0.77; R=0.76). Index differences correlated with differences in lung volume (R 2 =0.47). The mean 3 He ADC was 0.40 ± 0.15 cm 2 /sec before and 0.39 ± 0.14 cm 2 /sec after fixation (P=0.03, R=0.98). The CT emphysema index and the 3 He ADC were correlated before (R=0.89) and after fixation (R=0.79).Conclusion-Concordance of CT and 3 He MR imaging measurements in unfixed and inflationfixed lungs supports the use of inflation-fixed lungs for quantitative imaging studies in emphysema.

Progress in Imaging COPD, 2004 - 2014

“…[72][73][74][75] On MRI following inhalation of this gas, its diffusivity can be used to estimate measures of the size of lung microstructure including alveolar ducts and alveoli. In cigarette smokers with absent or mild spirometric abnormality, this technique showed significant decrease in alveolar depth and enlargement of alveolar ducts.…”

A support vector machine classifier reduces interscanner variation in the HRCT classification of regional disease pattern in diffuse lung disease: Comparison to a Bayesian classifier

“…Two classifiers, a naive Bayesian classifier 8 and a support vector machine (SVM) classifier, 15 were used to classify each ROI into one of the five disease or normal regions. To investigate the effect of different scanners on the accuracy of the classification of regional disease patterns, three study designs were employed: intrascanner, interscanner, and integrated scanner.…”