Idiopathic Pulmonary Fibrosis: Spectrum of High-Resolution CT Findings

Objective / Aim The aim of our article is to present our early experience to evaluate High Resolution CT (HRCT) findings in Idiopathic Pulmonary Fibrosis (IPF) and to stress upon its clinical utility. Materials & Methods A prospective study of ten patients was done at and tertiary care government hospital. Study population comprises seven women and three men. Patients with chronic respiratory symptoms, chest radiograph showing typical reticular pattern or with clinical suspicion of IPF were selected. All patients underwent HRCT examination. Chest radiograph findings were compared with the HRCT findings in all patients. HRCT findings of our study were compared with the other studies. Results From the study it was seen that IPF is most commonly manifested by the combination of HRCT findings, which includes peripheral (100%) and lower lobe predominance (80%) of the distribution of the lesions, evidences of intralobular septal thickening (100%), honeycombing (90%), traction bronchiectasis (90%) and parenchymal distortion (100%). Conclusion In conclusion, HRCT is accurate and superior in the confident diagnosis of IPF. HRCT findings in advance stage of IPF are characteristic. HRCT determines the disease activity and extent of IPF better than chest radiograph. When HRCT findings are characteristic in appropriate clinical settings, HRCT may obviate a need for open lung biopsy.

BACKGROUND AND OBJECTIVES:Radiological and histological evaluations are affected by subjective interpretation. This study determined the level of inter- and intraobserver variation among radiologists for detection of abnormal parenchymal lung changes on high resolution computed tomography (HRCT).METHODS:HRCT images of 65 patients known to have systemic lupus erythematosus (with clinical pulmonary involvement) were retrospectively reviewed by four nonthoracic radiologists (two with expertise in magnetic resonance [MR] and two general radiologists). Each radiologist read the scans twice, with an interval between readings of at least 6 months. The interobserver variation among the first and second readings of the four radiologists and the intraobserver variation of each radiologist's two readings were assessed by the kappa statistic.RESULTS:There was good agreement between the first and second readings of each radiologist. There was moderate agreement between the two readings of one MR radiologist (kappa=0.482); the other three radiologists had kappa values that were good to excellent (0.716, 0.691, and 0.829). There was a clinically acceptable level of interobserver variability between all radiologists. The agreement was fair to moderate between the MR radiologist and the other observers (kappa range: 0.362-0.519) and moderate to good between the other three radiologists (0.508-0.730).CONCLUSION:The interpretation of imaging findings of abnormal parenchymal lung changes on HRCT is reproducible and the agreement between general radiologists is clinically acceptable. There is reduced agreement when the radiologist is not involved on a regular basis with thoracic imaging. Difficult or indeterminate cases may benefit from review by a chest radiologist.

Radiologic diagnosis of chronic hypersensitivity pneumonitis (CHP) presenting a usual interstitial pneumonia (UIP) pattern is challenging. The aim of this study was to identify the high-resolution CT (HRCT) findings which are useful to discriminate CHP-UIP from idiopathic pulmonary fibrosis (IPF). This study included 49 patients with well-established bird-related CHP-UIP, histologically confirmed, and 49 patients with IPF. Two groups of observers independently assessed HRCT, evaluated the extent of each abnormal HRCT finding. When their radiological diagnosis was CHP-UIP, they noted the HRCT findings inconsistent with IPF. Correct CT diagnoses were made in 79% of CHP-UIP and 53% of IPF. Although no apparent difference was seen in the extent of each HRCT finding, upper or mid-lung predominance, extensive ground-glass abnormality, and profuse micronodules were more frequently pointed out as inconsistent findings in CHP-UIP than IPF (p = 0.007, 0.010, 0.001, respectively). On regression analysis, profuse micronodules [OR 13.34 (2.85-62.37); p = 0.001] and upper or mid-lung predominance of findings [OR 2.86 (1.16-7.01); p = 0.022] remained as variables in the equation. In this cohort, some IPF cases were misdiagnosed as CHP-UIP. Profuse micronodules and upper or mid-lung predominance are important clues for the differentiation of CHP-UIP from IPF.

The purpose of this study is to assess the differences of high-resolution CT (HRCT) findings in patients with idiopathic pulmonary fibrosis (IPF) and pulmonary involvement of collagen vascular disease (CVD). We analyzed the HRCT findings of 33 patients with IPF and 23 patients with CVD in terms of predominant pattern, site of involvement, mediastinal lymph node enlargement, pleural change, and pulmonary volume loss. The predominant HRCT pattern was honeycombing for IPF (58%), and ground-glass opacity for CVD (57%). Predominantly subpleural involvement was seen in 90% of IPF and 83% of CVD patients. Mediastinal lymph node enlargement was seen in 61% of the patients with IPF and 13% with CVD (p = 0.0004). Pleural thickening was seen in 97% of the patients with IPF and 35% with CVD and the severity of pleural thickening is statistically significant (p = 0.00001). Pleural effusion was seen in 6% of the patients with IPF and 26% with CVD (p = 0.0351). The hilar height ratio was more than 1.5 in 52% of the patients with IPF and 30% with CVD (p = 0.2620). Although HRCT findings of IPF and pulmonary involvement of CVD are similar and overlap considerably, but patients with IPF showed a tendency to more progressed fibrosis than patients with CVD.

Some patients with idiopathic pulmonary fibrosis (IPF) do not have honeycombing on high-resolution computed tomography (HRCT) at their initial evaluation. The clinical course and sequential changes in HRCT findings in these patients are not fully understood. We reviewed the cases of 43 patients with IPF without honeycombing on initial HRCT from institutions throughout Japan. All patients were diagnosed with IPF based on a surgical lung biopsy. Multidisciplinary discussions were held five times between 2011 and 2014, to exclude alternative etiologies. We evaluated the sequential changes in HRCT findings in 30 patients with IPF. We classified these 30 patients into three groups based on their HRCT patterns and clarified the clinical characteristics and prognosis among the groups. The patterns of all 30 patients on initial HRCT corresponded to a possible usual interstitial pneumonia (UIP) pattern which was described in the 2011 International Statement. On long-term follow-up (71.0±38.7 standard deviation [SD] months), honeycombing was seen in 16 patients (53%, the HoneyCo group); traction bronchiectasis or cysts without honeycombing was observed in 12 patients (40%, the NoHoneyCo group), and two patients showed no interval change (7%, the NoChange group) on HRCT. The mean survival periods of the HoneyCo and NoHoneyCo groups were 67.1 and 61.2 months, respectively (p = 0.76). There are some patients with IPF whose conditions chronically progress without honeycombing on HRCT. The appearance of honeycombing on HRCT during the follow-up might not be related to prognosis.

We studied high-resolution CT of asbestosis and idiopathic pulmonary fibrosis to determine whether differences-other than the frequency of associated pleural changes-could be discerned between the two diseases. High-resolution CT scans of 80 patients with asbestosis and 80 patients with idiopathic pulmonary fibrosis were retrospectively reviewed. Two chest radiologists assessed the type and distribution of parenchymal and pleural abnormalities on high-resolution CT. Subpleural dotlike or branching opacities (65/80), subpleural curvilinear lines (55/80), mosaic perfusion (39/80), and parenchymal bands (38/80) were more common in patients with asbestosis (p < 0.0001). Visible intralobular bronchioles (62/80), bronchiolectasis within fibrotic consolidations (47/80), and honeycombing (61/80) were more common in patients with idiopathic pulmonary fibrosis (p < 0.0001). The frequencies of interlobular septal thickening, ground-glass opacities, fibrotic consolidation, and emphysema were similar in both groups. Parenchymal bands and fibrotic consolidation were more commonly seen (p < 0. 05) in patients with asbestosis associated with pleural disease (n = 66) than in patients with asbestosis without pleural disease (n = 14). Also, statistically significant differences were noted between high-resolution CT findings of patients with asbestosis without pleural disease and those of patients with idiopathic pulmonary fibrosis, except for parenchymal bands. Specific combinations of high-resolution CT findings strongly suggest either asbestosis or idiopathic pulmonary fibrosis. We found that CT findings that might have represented bronchiolar obstruction in the subpleural region were more prominent in patients with asbestosis than in those with idiopathic pulmonary fibrosis, whereas bronchiolar dilatation was more prominent in patients with idiopathic pulmonary fibrosis than in those with asbestosis.

<b>Background:</b> Some idiopathic pulmonary fibrosis (IPF) patients are histologically diagnosed with usual interstitial pneumonia (UIP) pattern and show lack of honeycombing on high resolution computed tomography (HRCT) . Clinical course and the changes in HRCT findings of these IPF patients are unknown. <b>Aims and objectives:</b> The purpose of our study was to retrospectively assess the changes in HRCT pattern in IPF patients, who were diagnosed with UIP pattern by histology and show lack of honeycombing by HRCT in initial evaluation, and to clarify their clinical course and prognosis. <b>Methods:</b> We evaluated IPF patients without honeycombing on HRCT and who were histologically diagnosed with UIP pattern on the basis of surgical lung biopsy between 1991 and 2010. Multidisciplinary discussions were held 5 times between 2011 and 2014 to evaluate the disease changes as assessed by HRCT and clinical course of these patients. <b>Results:</b> Thirty patients were evaluated by 2014. Sixteen patients demonstrated emerging honeycombing (Group A) and 12 patients demonstrated emerging traction bronchiectasis or cyst without honeycombing (Group B) by HRCT. Two cases were considered as no change (Group C) by HRCT. The mean survival times of Groups A and B were 67.1 and 61.2 months which were not significantly different (p=0.76) . <b>Conclusions:</b> Some IPF patients may not demonstrate honeycombing on HRCT even if they have advanced stage IPF. Our study suggests that there is no difference in prognosis of IPF between cases with honeycombing on HRCT and those without.

To investigate the correlation of cluster of differentiation (CD)4 lymphocyte counts with high-resolution CT (HRCT) findings and distribution of pulmonary tuberculosis. Thirty-seven bacteriologically proven pulmonary tuberculosis, clinically non-AIDS, patients underwent HRCT and CD4 lymphocyte counts in peripheral blood cells were obtained within 3 days after the CT examinations. Patients were categorized into four groups according to CD4 lymphocyte counts (A >800; B 800-500; C 500-200; D <200). HRCT findings analyzed were as follows: typical, atypical, and mixed findings of post-primary tuberculosis, common, uncommon, and mixed distribution, and number of lobes involved. CD4 lymphocyte counts correlated with the degree of the mixture of atypical CT findings (rho=0.565, p<0.001) and the degree of the mixture of uncommon distribution (rho=0.431, p<0.01). Number of involved lobes showed no statistically significant correlation (rho=0.209, p=0.21). In patients with low CD4 levels, atypical HRCT findings co-exist with typical findings, and uncommon sites are involved in addition to common sites.

Pulmonary Alveolar Microlithiasis: High-Resolution CT Scan

High-resolution computed tomography (HRCT) is an integral aspect of the evaluation of patients with suspected idiopathic pulmonary fibrosis (IPF). However, few studies have evaluated its use in a large cohort. To describe HRCT features in patients with mild to moderate IPF, compare diagnostic evaluations by a radiology core (three thoracic radiologists) with those by study-site radiologists, correlate baseline clinical and physiologic variables with HRCT findings, and evaluate their association with mortality. We assessed HRCT scans from patients with IPF (n = 315) enrolled in a randomized controlled study evaluating IFN-gamma1b. There was concordance between study-site and core radiologists regarding the diagnosis of IPF in 86% of cases. Diffusing capacity of carbon monoxide (DLCO) was the physiologic characteristic most highly correlated with HRCT findings. Multivariate analysis identified three independent predictors of mortality: a higher extent of fibrosis score increased the risk of death (p < 0.0001), whereas a higher percent-predicted DLCO (p = 0.004) and treatment assignment to IFN-gamma1b rather than placebo (p = 0.04) reduced the risk of death. A study-site diagnosis of IPF on HRCT was regularly confirmed by core radiologists. Extent of reticulation and honeycombing on HRCT is an important independent predictor of mortality in patients with IPF.

BackgroundThe 2011 idiopathic pulmonary fibrosis (IPF) guidelines are based on the diagnosis of IPF using only high-resolution computed tomography (HRCT). However, few studies have thus far reviewed the usefulness of the HRCT scoring system based on the grading scale provided in the guidelines. We retrospectively studied 98 patients with respect to assess the prognostic value of changes in HRCT findings using a new HRCT scoring system based on the grading scale published in the guidelines.MethodsConsecutive patients with IPF who were diagnosed using HRCT alone between January 2008 and January 2012 were evaluated. HRCT examinations and pulmonary function tests were performed at six-month intervals for the first year after diagnosis. The HRCT findings were evaluated using the new HRCT scoring system (HRCT fibrosis score) over time. The findings and survival rates were analyzed using a Kaplan-Meier analysis.ResultsThe HRCT fibrosis scores at six and 12 months after diagnosis were significantly increased compared to those observed at the initial diagnosis (p < 0.001). The patients with an elevated HRCT fibrosis score at six months based on a receiver operating characteristic (ROC) curves analysis had a poor prognosis (log-rank, hazard ratio [HR] 2.435, 95% CI 1.196-4.962; p = 0.0142). Furthermore, among the patients without marked changes in %FVC, those with an elevated score above the cut-off value had a poor prognosis (HR 2.192, 95% CI 1.003-4.791; p = 0.0491).ConclusionsOur data demonstrate that the HRCT scoring system based on the grading scale is useful for predicting the clinical outcomes of IPF and identifying patients with an adverse prognosis when used in combination with spirometry.

Bronchoalveolar lavage (BAL) is a technique that is in use since the advent of the rigid bronchoscope and subsequently it was also utilized with the flexible bronchoscope. It was evolved as a therapeutic modality to drain purulent secretions and also for treatment of diseases like alveolar proteinosis.[1] However, much later low volume BAL was used to diagnose diseases such as malignancy, infection, and interstitial lung disease (ILD). ILD are a group of diseases that present with exertional dyspnea, dry cough, and infiltrates in bilateral lung fields, which are evident on chest radiography and high resolution computed tomography (HRCT) of the chest. There have been numerous tests to diagnose this perplexing disease. The gold standard for diagnosis is surgical lung biopsy.[2] However, with the advent of HRCT of the chest, it has been possible to identify and classify ILD's through these noninvasive means. In early disease, however, diagnosis is difficult and in such cases BAL may be helpful. The role of BAL in the diagnosis of ILD had been debatable until the American Thoracic Society (ATS) issued guidelines to define the methodology, processing, and use of BAL in the diagnosis of ILD in 2012.[3] The guidelines stated that BAL may be a useful adjunct to other diagnostic modalities rather than being a stand-alone diagnostic test. The site for BAL should be decided by the part of the lung involved with disease process on HRCT rather than the conventional BAL sites such as the right middle lobe or lingula. Differential cellular count should be performed on the BAL sample and should include measurement of lymphocytes, neutrophils, macrophages, and eosinophils. Lymphocyte subset analysis is not routinely recommended in all ILD cases. BAL analysis may also exclude diseases such as malignancy, infections, and certain rare diseases like pulmonary alveolar proteinosis. In the current issue of the journal, Palaniswamy et al.[4] diagnosed fifty cases of ILD on the basis of HRCT and then performed BAL in the same. The paper highlights few important issues. The first, BAL is a relatively safe test which can be performed in a suspected case of ILD. The BAL findings may not be pathogonomic for a certain type of ILD, but they may help confirm or exclude a certain disease diagnosis. For example, a patient who was suspected to have idiopathic pulmonary fibrosis (IPF) on HRCT underwent bronchoscopy and BAL analysis, which subsequently revealed histiocytes. Thus, the diagnosis was revised to chronic langerhan cell histiocytosis rather than IPF. This supports a previous study conducted by Ohshimo et al. in which they found that 8% of patients diagnosed as usual interstitial pneumonia pattern on HRCT thorax may have a different diagnosis when evaluated with BAL analysis.[5] The second issue that has been highlighted in the current paper is that BAL may help in identifying acute exacerbations and super-added infections. These may be treated with a systemic course of steroids and antibiotics, respectively. The study has certain limitations that including lack of gold standards such as surgical lung biopsies and non inclusion of ILD patients with inconclusive HRCT. The ATS recommends performing BAL in all patients of ILD with nondiagnostic HRCT and these may be the patients who may be candidates of surgical lung biopsy subsequently. A BAL lymphocyte count of >25% is suggestive of nonspecific interstitial pneumonia, hypersensitivity pneumonitis (HP), or sarcoidosis.[56] An eosinophil percentage of more than 25% is highly diagnostic of eosinophilic pneumonia.[6] Similarly, a BAL neutrophil level of >50% is suggestive of acute interstitial pneumonia or acute infection.[6] These BAL abnormalities may also be seen in other non-ILD conditions such as bronchiolitis, asthma, or allergic bronchopulmonary aspergillosis. Thus, BAL findings should be cautiously interpreted and correlated with clinical and HRCT findings. Furthermore, it has been shown that BAL findings may alter once fibrosis sets in diseases like HP.[7] In conclusion, BAL analysis subsequent to HRCT evaluation is a useful test to confirm the diagnosis, exclude acute exacerbation and super-added infections in cases of ILD. BAL findings should however be carefully interpreted in context to the clinical and radiological findings.

Magnetic resonance imaging in the evaluation of idiopathic pulmonary fibrosis: a real possibility, or an attractive challenge?

Pictorial Essay: Multinodular Disease

15 - Lung Cancer with Idiopathic Pulmonary Fibrosis: High-resolution Computed Tomography