Assessment Of Interstitial Lung Disease Research Articles

The six‐minute walk test using forehead oximetry is reliable in the assessment of scleroderma lung disease

The six-minute walk test (6MWT) is a validated field test in the assessment of interstitial lung disease but may not be so useful in scleroderma (SSc) lung disease. The aim of this study was to determine the reliability of the 6MWT in patients with SSc and correlate results with morphological and functional measures of disease severity. Thirty patients (24 female, mean age 47, mean diffusing capacity of carbon monoxide 65%, vital capacity 77% predicted) with American College of Rheumatology classification of SSc performed two 6MWT using various oximetry sites, 1 week apart, and underwent SSc-specific disease severity and quality-of-life measurements, lung function, high-resolution computed tomography and echocardiography. There was good reliability between the two 6MWT (distance; intraclass correlation coefficient 0.95, r = 0.89, Borg; intraclass correlation coefficient 0.85, r = 0.91, both P < 0.00 for r), and Bland Altman plots demonstrate good agreement between measures 1 week apart. Forehead and finger oximetry were more reliable than earlobe (intraclass correlation coefficient 0.64, 0.60, 0.24; r = 0.46, 0.47, 0.14; n = 22, 17, 7, respectively). Forehead desaturation correlated with forced expiratory volume in 1 s (r = 0.55, P = 0.01) and forced vital capacity (r = 0.59, P = 0.01). Distance correlated with all physiological measures: forced expiratory volume in 1 s (r = 0.55, P = 0.01), forced vital capacity (r = 0.61, P = 0.01) and diffusing capacity of carbon monoxide (r = 0.42, P = 0.05). Computed tomography extent and patterns of disease correlated poorly with 6MWT measures, and global measures of SSc correlated only with post-test Borg score. The 6MWT is feasible and reliable in SSc lung disease, but forehead oximetry should be used. The test measurements correlate reasonably but variably with functional and morphological measures of disease severity.

Lung Morphology Assessment with Balanced Steady-State Free Precession MR Imaging Compared with CT

To evaluate the utility of 1.5-T noncontrast magnetic resonance (MR) imaging of the lung parenchyma and to compare it with computed tomography (CT) in the assessment of interstitial lung disease and other morphologic lung abnormalities. Institutional review board approval was obtained for retrospective image analysis. A total of 236 patients who underwent MR imaging and CT as part of their assessment for suspected pulmonary hypertension were included in this study. Lung MR imaging was performed with a 1.5-T system as a stack of axial two-dimensional balanced steady-state free precession (bSSFP) acquisitions. Two radiologists independently evaluated CT and MR images for various morphologic abnormalities, such as pulmonary fibrosis, pleural and mediastinal disease, solid lesions, bronchial disease, and emphysema. Κ statistics were used to measure interobserver agreement. Sensitivity and specificity of MR imaging in the identification of pulmonary fibrosis (n = 46) were 89% (95% confidence interval: 77%, 96%) and 91% (95% confidence interval: 76%, 98%), respectively, when compared with CT. In comparison to CT, MR imaging depicted 75% of ground-glass opacities. Nine of the 12 noncalcified nodules were identified on MR images. Lung nodules (75%, κ = 0.71) and effusions (100%, κ = 0.89) were also well visualized on MR images. MR imaging was however less effective in depicting emphysema (16%, κ = 0.60) and minor fibrosis (67%, κ = 0.79). This study shows bSSFP MR imaging is inferior to CT in imaging parenchymal lung disease; however, this study does demonstrate for the first time a potential role for the bSSFP sequence as an alternative radiation-free noncontrast imaging modality for use in patients with pulmonary fibrosis.

Sonographic Assessment of Interstitial Lung Disease in Patients with Rheumatoid Arthritis, Systemic Sclerosis and Systemic Lupus Erythematodes

Introduction/Aims: The usefulness of transthoracic ultrasound in the evaluation of lung diseases has been highlighted in the past decades. We describe variable lung ultrasound patterns in an observational series of patients with RA, SLE and SSc.

Desaturation – distance ratio: a new concept for a functional assessment of interstitial lung diseases

INTRODUCTION:The functional evaluation has become increasingly important in the understanding and management of patients with interstitial lung diseases. The cardiopulmonary exercise test and the six‐minute walk test (6MWT), through their isolated variables, have been used to do this evaluation, with some limitations.OBJECTIVES:We proposed a new composite index (desaturation distance ratio using continuous peripheral oxygen saturation (SpO2) and the distance walked as a more reliable tool for doing a functional evaluation of these patients.METHODS:6MWT was performed by interstitial lung diseases patients and controls. Analyzed parameters were walked distance and desaturation area (DAO2), obtained by taking the difference between maximal SpO2 possible (100%) and patient's SpO2 every 2 seconds. desaturation distance ratio was calculated using the ratio between DAO2 and distance walked.RESULTS:Forty‐nine interstitial lung diseases patients and 11 control subjects completed the protocol. The mean (SD) age was 60 (12) years and 65 (9) years, respectively (p:NS). Data obtained from 6MWT showed a significant statistical difference between interstitial lung diseases patients and controls: mean walked distance (430 and 602 meters, respectively); SpO2 minimal maintained at least 10 seconds ‐ SpO2 min (85% and 94%, respectively), and median desaturation distance ratio (10 and 2.5, respectively). A correlation analysis, considering interstitial lung diseases patients, revealed the best correlation between desaturation distance ratio and DLco (r = ‐ 0.72; p<0.001), being the correlation between SpO2 min and DLco of 0.61 (p<0.001) and among walked distance and DLco of 0.58 (p<0.05).CONCLUSION:Desaturation distance ratio is a promising concept and a more reliable physiologic tool to assess pulmonary diseases characterized by involvement of the alveolar‐capillary membrane, such as interstitial lung diseases.

Navigator‐triggered oxygen‐enhanced MRI with simultaneous cardiac and respiratory synchronization for the assessment of interstitial lung disease.

To evaluate an optimized method for oxygen-enhanced MRI of the lung, using simultaneous electrocardiograph (ECG) and navigator triggering. To correlate oxygen-enhanced MRI with lung function tests assessing alveolar-capillary gas exchange. A total of 12 healthy volunteers (aged 20-32 years) and 10 patients (aged 37-87 years) with interstitial lung diseases (ILD) underwent oxygen-enhanced MRI and pulmonary functional tests (PFTs) assessing alveolar-capillary gas exchange. The paradigm room-air-oxygen-room-air was acquired with a nonselective inversion-recovery half-Fourier single-shot turbo spin-echo sequence (inversion time = 1200 msec; acquisition time = 134.5 msec; slice thickness = 20 mm; matrix size = 128 x 128), using simultaneous double triggering (navigator plus ECG trigger). Cross-correlation was performed in regions of interest (ROIs) encompassing both lungs. The number of oxygen-activated pixels over the total number of pixels in the ROIs (OAP%) of volunteers and patients was compared. OAP%s were correlated with PFTs. The mean OAP% of patients was significantly lower than that of volunteers (36.7 vs. 81.7, P = 0.001). OAP% correlated with the transfer lung factor for carbon monoxide (Tlco) (r = 0.64; P = 0.002), the transfer coefficient (Kco) (r = 0.75; P = 0.001), the arterial partial pressure (r = 0.77; P < 0.001), and the saturation (r = 0.70; P < 0.001) of oxygen. Navigator-triggered oxygen-enhanced MRI of the lung may have a potential role in the quantitative assessment of lung function in ILD.

Characterization of the interstitial lung diseases via density-based and texture-based analysis of computed tomography images of lung structure and function 1

Rationale and Objectives. Efforts to establish a quantitative approach to the computed tomography (CT)-based characterization of the lung parenchyma in interstitial lung disease (including emphysema) has been sought. The accuracy of these tools must be site independent. Multi-detector row CT has remained the gold standard for imaging the lung, and it provides the ability to image both lung structure as well as lung function. Material and Methods. Imaging is via multi-detector row CT and protocols include careful control of lung volume during scanning. Characterization includes not only anatomic-based measures but also functional measures including regional parameters derived from measures of pulmonary blood flow and ventilation. Image processing includes the automated detection of the lungs, lobes, and airways. The airways provide the road map to the lung parenchyma. Software automatically detects the airways, the airway centerlines, and the branch points, and then automatically labels the airway tree segments with a standardized set of labels, allowing for intersubject as well intrasubject comparisons across time. By warping all lungs to a common atlas, the atlas provides the range of normality for the various parameters provided by CT imaging. Results. Imaged density and textural changes mark underlying structural changes at the most peripheral regions of the lung. Additionally, texture-based alterations in the parameters of blood flow may provide early evidence of pathologic processes. Imaging of stable xenon gas provides a regional measure of ventilation which, when coupled with measures of flow, provide for a textural analysis regional of ventilation-perfusion matching. Conclusion. With the improved resolution and speed of CT imaging, the patchy nature of regional parenchymal pathology can be imaged as texture of structure and function. With careful control of imaging protocols and the use of objective image analysis methods it is possible to provide site-independent tools for the assessment of interstitial lung disease. There remains a need to validate these methods, which requires interdisciplinary and cross-institutional efforts to gather appropriate data bases of images along with a consensus on appropriate ground truths associated with the images. Furthermore, there is the growing need for scanner manufacturers to focus on not just visually pleasing images, but on quantitatifiably accurate images.

High-resolution computed tomography scanning in the assessment of interstitial lung diseases.

The development of high-resolution computed tomography (HRCT) has added a new dimension to the radiographic evaluation of interstitial lung diseases. The article reviews the techniques for HRCT, the normal anatomy seen by HRCT, and the HRCT findings of interstitial lung diseases.

New Concepts in Assessment of Interstitial Lung Disease

Dr. Lynch is Clinical Instructor, Department of Radiology, University of Colorado Health Sciences Center, 4200 E. 9th Avenue, Denver, CO 80262.

New Techniques for the Assessment of Interstitial Lung Disease

The authors succinctly describe the pathogenic mechanisms of this disease and the failures of the traditional diagnostic techniques in providing data about the extent of alveolitis and thus about disease activity and prognosis. The authors then show how the new methods of bronchoalveolar lavage and gallium-67 scanning may provide such information. Next in the discussion is how these techniques are applied to the understanding and management of sarcoidosis and idiopathic pulmonary fibrosis. And finally, the authors propose an integrated approach that uses both the new and traditional methods in the diagnosis and management of interstitial lung disease.