Quantitative Computed Tomography Imaging of Interstitial Lung Diseases

Abstract

Purpose High-Resolution chest CT (HRCT) is essential in the characterization of interstitial lung disease (ILD). The HRCT features of some diseases can be diagnostic. Longitudinal monitoring with HRCT can assess progression of ILD; however, subtle changes in the volume and character of abnormalities can be difficult to assess. Accuracy of diagnosis can be dependent on expertise and experience of the radiologist, pathologist or clinician. Quantitative analysis of thoracic HRCT has the potential to determine the extent of disease reproducibly, classify the types of abnormalities and automate the diagnostic process. Materials and Methods Novel software that utilizes histogram signatures to characterize pulmonary parenchyma was used to interrogate chest HRCT data, including retrospective processing of clinical CT scans and research data from the Lung Tissue Research Consortium (LTRC). Additional information including physiologic, pathologic and semi-quantitative radiologist assessment was available to allowcomparison of quantitative results with visual estimates of disease, physiologic parameters and measures of disease outcome. Results Quantitative analysis results were provided in regional volumetric quantities for statistical analysis as well as a graphical representation. Analysis suggests that quantitative HRCT analysis can serve as a biomarker with physiologic, pathologic and prognostic significance. Conclusion It is likely that quantitative analysis of HRCT can be used in clinical practice as a means to aid in identifying probable diagnosis, stratifying prognosis in early disease, and consistently determining progression of disease or response to therapy. Further optimization of quantitative techniques and longitudinal analysis of well-characterized subjects would be helpful to validate these methods.

Evaluation of computer-based computer tomography stratification against outcome models in connective tissue disease-related interstitial lung disease: a patient outcome study

“…The remaining computer-based studies have evaluated the lung according to its simple density characteristics, deriving metrics of histogram skewness and kurtosis [32–34]. Such metrics have been shown to correlate poorly with other markers of disease severity and with mortality in IPF [15] and are relatively unsophisticated compared to modern structural and textural analytic techniques [27]. Furthermore, only the studies by Marten et al [32, 33] evaluated computer scores against physiological indices whilst the remaining studies compared computer-based scores with visual CT scoring.…”

“…Visual CT parameters included ground glass opacity, reticular pattern, honeycombing, emphysema, consolidation, mosaicism (decreased attenuation component), and traction bronchiectasis as described in Additional file 1: Appendix. CALIPER evaluation of the lungs [13] is described in Additional file 1: Appendix and was pictorially expressed as a glyph [27] (Fig. 1).…”

Quantitative CT characterization of pediatric lung development using routine clinical imaging

“…Quantitative methods offer the advantage of objective, reproducible measurements that have been shown to correlate with pathological and clinical lung disease severity, thereby enabling longitudinal studies of disease pathogenesis and the effect of therapeutic intervention. Quantitative CT analysis methods have been employed in adult lung diseases to include chronic obstructive pulmonary disease (COPD) [1–6], lung cancer screening [7, 8], pulmonary fibrosis [9–14] and asthma [11, 15–18]. …”

Interstitial Lung Disease: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

“…The most common radiographic changes include ground-glass, reticular abnormalities, diffuse centrilobular nodularity, honeycombing, traction bronchiectasis, and nonemphysematous cysts (2). Alternative approaches quantify area of increased CT lung attenuation (high-attenuation areas [HAAs]) or use novel techniques to quantify structural abnormalities (5,6). The significance of these radiographic subtypes is unknown, but they may represent early stages of distinct idiopathic interstitial pneumonias (IIPs) or ILD associated with connective tissue disease (CTD), with differing rates of progression and/or prognosis.…”