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Honeycombing on CT is the clue for the diagnosis of usual interstitial pneumonia (UIP) and its hallmark. According to the ATS-ERS-JRS-ALAT 2010 guideline, the patients with honeycombing on CT can be diagnosed as UIP without surgical biopsy. On CT scans, it is defined as clustered cystic airspaces, typically of comparable diameters of the order of 3-10mm, which are usually subpleural and have well-defined walls. Pathologically, honeycombing consists of both collapsing of multiple fibrotic alveoli and dilation of alveolar duct and lumen Although the definition of honeycombing seems to be strict, recognition of honeycombing on CT is various among each observer Because typical honeycombing is frequently observed in the patients with UIP, we should judge clustered cysts as honeycombing when a diagnosis of UIP is suspected.

Purpose: To quantify observer agreement and analyze causes of disagreement in identifying honeycombing at chest computed tomography (CT). Materials and Methods: The institutional review board approved this multi-institutional HIPAA-compliant retrospective study, and informed patient consent was not required. Five core study members scored 80 CT images with a five-point scale (5 = definitely yes to 1 = definitely no) to establish a reference standard for the identification of honeycombing. Forty-three observers from various subspecialties and geographic regions scored the CT images by using the same scoring system. Weighted kappa values of honeycombing scores compared with the reference standard were analyzed to investigate intergroup differences. Images were divided into four groups to allow analysis of imaging features of cases in which there was disagreement: agreement on the presence of honeycombing, agreement on the absence of honeycombing, disagreement on the presence of honeycombing, and other (none of the preceding three groups applied). Results: Agreement of scores of honeycombing presence by 43 observers with the reference standard was moderate (Cohen weighted kappa values: 0.40-0.58). There were no significant differences in kappa values among groups defined by either subspecialty or geographic region (Tukey-Kramer test, P = .38 to >.99). In 29% of cases, there was disagreement on identification of honeycombing. These cases included honeycombing mixed with traction bronchiectasis, large cysts, and superimposed pulmonary emphysema. Conclusion: Identification of honeycombing at CT is subjective, and disagreement is largely caused by conditions that mimic honeycombing. (C) RSNA, 2012

Sarcoidosis is a systemic granulomatous disease of unknown etiology with characteristic pulmonary lesions, which are often distributed in the upper lung fields. We describe a unique case of sarcoidosis with lower lung field-dominant reticular shadows. Three years after the diagnosis of sarcoidosis based on histologic findings of the mediastinal lymph nodes and transbronchial lung biopsy specimens, the patient developed acute respiratory failure and died. The autopsy showed usual interstitial pneumonia (UIP), with honeycombing and superimposed diffuse alveolar damage of the lungs. The findings suggest that the patient had both sarcoidosis and UIP, and that the UIP later progressed to acute exacerbation.

Purpose International experts developed a guideline on reading CT images of malignant pleural mesothelioma for radiologists and physicians. It is intended that it act as a supplement to the current International Classification of HRCT for Occupational and Environmental Respiratory Diseases. Methods The research literatures on mesothelioma CT features were systematically reviewed. Ten mesothelioma CT features were adopted into the guideline prepared according to experts’ opinion. The terminology of mesothelioma CT features and mesothelioma probability were agreed by consensus of experts. The CT reference films for each mesothelioma feature were selected based on agreement by experts from 22 definite mesothelioma cases confirmed pathologically and immunohistochemically. To support the validity of the mesothelioma probability, 4 experts’ readings of CT films from 57 cases with or without mesothelioma were analyzed by kappa statistics between the experts; sensitivity and specificity for mesothelioma were also assessed. Results The mesothelioma CT Guideline was developed, providing the terminology of CT features and the mesothelioma probability, the judgement of severity, the distribution of mesothelioma, and the revised CT reading sheet including mesothelioma items. The CT reference films with ten mesothelioma typical features were selected. The average linearly and quadratically weighted kappa of the agreement on the 4-point scale mesothelioma probability were 0.58 and 0.71, respectively. The average sensitivity and specificity for mesothelioma were 93.2% and 65.6%, respectively. Conclusion The evidence-based mesothelioma CT Guideline developed may serve as a good educational tool to facilitate physicians in recognising mesothelioma and improve their proficiency in diagnosis of mesothelioma.

29 physicians (A1-Group) and 24 physicians (A2-Group) attending the 1st and 2nd "Asian Intensive Reader of Pneumoconiosis" (AIR Pneumo) training course, respectively, and 22 physicians (B-Group) attending the Brazilian training course took the examination of reading the 60-film set. The objective of the study was firstly to investigate the factor structure of physicians' proficiency of reading pneumoconiosis chest X-ray, and secondly to examine differences in factor scores between groups. Reading results in terms of the 8-index of all examinees (Examinee Group) were subjected to the exploratory factor analysis. A 4-factor was analyzed to structure the 8-index: the specificity for pneumoconiosis, specificity for large opacities, specificity for pleural plaque and shape differentiation for small opacities loaded on the Factor 1; the sensitivity for pneumoconiosis and sensitivity for large opacities loaded on the Factor 2; the sensitivity for pleural plaque loaded on the Factor 3; the profusion increment consistency loaded on the Factor 4. 4-Factor scores were compared between each other of the three groups. The Factor 2 scores in A1 and A2 groups were significantly higher than in B-Group. Four factors could reflect four aspects of reading proficiency of pneumoconiosis X-ray, and it was suggested that 4-factor scores could also assess the attained skills appropriately.

We treated 8 cases of autoimmune pulmonary alveolar proteinosis (APAP) with whole lung lavage (WLL) in our hospital and evaluated the disease severity of APAP before and after WLL, adverse events (AEs) and recurrence-free survival in those cases who improved. In all cases, unilateral WLL was performed in both lungs. The median of total lavage volume in unilateral WLL was 17.9 L, and the median procedure time of unilateral WLL was 105 min. Fever was the most frequently observed AE (87.5% of all procedures). Pulmonary function tests (percentage of predicted value of VC, FEV1 and diffusing capacity of carbon monoxide), serum markers (KL-6, surfactant apoprotein (SP)-D, SP-A and carcinoembryonic antigens), arterial blood gas analyses (PaO2, AaDO2) and disease severity score all significantly improved after WLL. The serum levels of anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody temporarily decreased after unilateral WLL, but returned to previous levels (before WLL) in 7 cases. The radiological findings improved in 6 cases. In the 7 improved cases in whom AaDO2 decreased more than 10 Torr, the median recurrence-free survival of APAP after WLL was 17.5 months. We concluded that WLL is an effective and safe method for the treatment of APAP, and all parameters except for anti GM-CSF antibody are useful to evaluate the effect of WLL.

PURPOSE: The authors reviewed serial computed tomographic (CT) scans obtained in 19 patients with diffuse panbronchiolitis (DPB) to evaluate changes in disease pattern over time. MATERIALS AND METHODS: Nineteen patients with DPB were entered into the study. After initial CT examination, 12 patients were randomly assigned to receive long-term low-dose (200 mg three times daily) erythromycin therapy; seven patients received no treatment. RESULTS: Follow-up CT scans revealed that centrilobular areas of high attenuation observed initially had progressed to dilatation of the proximal airway in some patients in the untreated group. In the treated group, the centrilobular and branched linear areas of high attenuation were decreased in number and size, although the airway dilatation and decreased lung attenuation in the peripheral areas remained unchanged or were slightly increased. CONCLUSION: CT scans are valuable in the study of the disease process and response to therapy in DPB.

Background The aims of this study were to retrospectively assess the change in findings on follow-up CT scans of patients with non-specific interstitial pneumonia (NSIP; median, 72 months; range, 3–216 months) and to clarify the correlation between the baseline CT findings and mortality. Methods The study included 50 patients with a histologic diagnosis of NSIP. Two observers evaluated the high-resolution CT (HRCT) findings independently and classified each case into one of the following three categories: (1) compatible with NSIP, (2) compatible with UIP or (3) suggestive of alternative diagnosis. The correlation between the HRCT findings and mortality was evaluated using the Kaplan–Meier method and the log-rank test, as well as Cox proportional hazards regression models. Results Ground-glass opacity and consolidation decreased, whereas coarseness of fibrosis and traction bronchiectasis increased on the follow-up HRCT scans, however, in 78% of cases the overall extent of parenchymal abnormalities had no change or decreased. Patients with HRCT diagnosed compatible with NSIP had a longer survival than those with HRCT findings more compatible UIP or an alternative diagnosis. On multivariate analysis, the coarseness of fibrosis alone was associated with prognosis (HR: 1.480; 95% CIs 1.100 to 1.990). Conclusions The HRCT patterns seen in patients with a histopathologic diagnosis of NSIP progress in a variable manner. Overall disease extent may decrease over time in some, while fibrosis may progress in others. The initial HRCT diagnosis may impact survival in this group of patients.

Objective: Occupational lung diseases have specific radiographic manifestations not always well known by physicians. In Japan, asbestos-related diseases became a public health concern after the "Kubota Shock", when a number of workers and residents living nearby a manufacturer of asbestos-made ducts developed mesothelioma caused by asbestos exposure. This preliminary intervention trial evaluated the effect of two-hour training on inexperienced physicians' skill in interpreting pneumoconiotic chest radiographs. Methods: One hundred-two Japanese physicians participated in two reading-tests, using 12 radiographs, before and after the two-hour training with ILO/ICRP and Japan Pneumoconioses Study Group (JPSG) reading materials. Physicians had to check for the presence or absence of small opacity and pleural plaque consistent with pneumoconiosis. Sensitivity and specificity equal or greater than 70% were considered good, 50 to 69% acceptable and less than 50%, poor. Results: Post-training improvements in physicians' skills were seen. For small opacity, there was an increase in the proportion of physicians with good specificity, from 42% to 60%. For pleural plaque, the proportion of physicians with good specificity and good sensitivity increased, from 60% to 67% and from 18% to 25%, respectively. Also, significant improvements were observed in overall sensitivity for pleural plaque, from 46% to 60% (p

To determine the specific high resolution CT (HRCT) features for "pseudoalveolar" sarcoidosis, we reviewed HRCT of 10 patients with pathologically proven sarcoidosis. On HRCT the lesions of pseudoalveolar sarcoidosis were shown as homogeneous or inhomogeneous opacities 1-4 cm in diameter located either along the bronchovascular bundles or in the lung periphery adjacent to the pleural surface. The margin was irregular, and numerous nodules 1-2 mm in diameter were observed in the surrounding lung. Air bronchograms were observed in 6 patients. In addition to these lesions, other CT abnormalities such as nodules, groundglass opacities, thickened bronchovascular bundles, and interlobular septa were found in all 10 cases. Good response of pseudoalveolar sarcoid lesions to administration of corticosteroid was observed in all three cases in which follow-up CT was available.

Summer-type hypersensitivity pneumonitis is an immunologic disease that occurs only in Japan. It is a form of hypersensitivity pneumonitis in which the clinical symptoms appear in the summer and subside spontaneously in mid autumn. The purpose of our study was to determine the CT findings in this condition, to compare the CT findings with those on chest radiographs, and to assess the variations in the CT findings over time. Accordingly, high-resolution CT scans and chest radiographs of 15 patients with summer-type hypersensitivity pneumonitis were retrospectively studied. Seven patients had sequential CT examinations 18-37 days apart. The CT scans and chest radiographs were reviewed by two observers independently. CT findings included diffuse micronodules (n = 15), slightly elevated lung density (n = 13), and patchy air-space consolidation (n = 13). In one patient, the findings on a chest radiograph were normal, while CT showed parenchymal abnormalities. In two cases, follow-up CT showed micronodular abnormalities after findings on the chest radiograph had returned to normal. Our results show that high-resolution CT findings of summer-type hypersensitivity pneumonitis include pulmonary micronodules, increased lung density, and air-space consolidation. High-resolution CT appears to be more useful than plain chest radiographs in the evaluation of pulmonary parenchymal abnormalities in this condition.

The serial computed tomography findings and prognosis of the acute exacerbation of idiopathic pulmonary fibrosis (IPF) are not yet well defined in a larger number of cases.To evaluate the parenchymal abnormalities and prognosis using high-resolution computed tomography (HRCT) in acute exacerbation of IPF.The study consisted of clinical, laboratory, and HRCT data before and at the time of acute exacerbation in 64 episodes of 58 patients with IPF. A semiquantitative analysis of overall extent of parenchymal abnormalities, extent of alveolar opacity (ground-glass attenuation and consolidation), and extent of fibrotic opacity (reticulation and honeycombing) on CT was performed by two chest radiologists. The newly appeared parenchymal abnormalities were also classified into three patterns: peripheral, multifocal, and diffuse.In all patients, HRCT scans taken at the exacerbation showed typical signs of IPF and newly developing alveolar opacity. They included 34 patients of peripheral pattern, 8 of multifocal pattern, and 16 of diffuse pattern. Twenty-five patients died and 33 survived after the initial exacerbation. Worse survival was associated with patients with diffuse type compared with patients with multifocal and peripheral type. The CT patterns and overall CT extent were associated with an increased hazard of death after adjusting for age, sex, smoking, baseline diffusion capacity for carbon monoxide, baseline FVC, and disease extent on CT. On multivariate analysis, the strongest correlations were observed between CT patterns (combined diffuse and multifocal versus peripheral) and survival (odds ratio, 4.629; 95% confidence interval, 1.900-11.278; P = 0.001).HRCT extent and patterns are predictive of survival in acute exacerbation of IPF.

The chest radiograph is the basic tool for identifying occupational and environmental lung diseases; however, its sensitivity and specificity for the diagnosis of occupational and environmental lung diseases are low. High-resolution CT is the optimal method of recognizing parenchymal abnormalities in occupational and environmental disease. With the exception of pleural plaques, the CT findings of occupational and environmental lung diseases are nonspecific. Therefore, correlation of imaging features with history of exposure, other clinical features, and sometimes pathology is needed for the diagnosis of pneumoconiosis.

A 56-year-old female non-smoker complained of general fatigue and pyrexia. Laboratory examination revealed elevation of white blood cells (WBC) 10200/microl and C-reactive protein (CRP) 13.3mg/dl. Chest radiograph showed bilateral patchy and ring-shaped consolidations in both lungs. Chest computed tomography (CT) revealed multiple round ground glass opacities fringed with consolidation, namely the "reversed halo sign". Transbronchial lung biopsy specimens showed polypoid granulation tissue in terminal air spaces, consistent with an organizing pneumonia pattern. Clinical findings suggesting collagen vascular diseases and drug induced lung diseases were not recognized, thus cryptogenic organizing pneumonia (COP) was diagnosed. High dose methylprednisolone therapy improved her condition, and the ring-shaped opacities on chest CT resolved. She relapsed twice during approximately five years after the disease onset. Chest CT at the recurrences revealed subpleural patchy consolidations without formation of the "reversed halo sign". The sign was originally supposed to be specific for cryptogenic organizing pneumonia. However, other diseases like sarcoidosis and paracoccidioidomycosis have been reported to show this sign. The meaning of the "reversed halo sign" should be examined based on the accumulation of more cases.

Objectives The aim of the present study was to determine how the pattern and extent of sarcoidosis changes over time on serial high-resolution CT (HRCT) scans and to identify CT scan findings that might be helpful in predicting the prognosis of patients with the disease. Methods The initial and last HRCT scan findings of 40 patients with pulmonary sarcoidosis during a mean follow-up period of 7.4 years (range, 3 to 18 years) were evaluated retrospectively. HRCT scan findings then were correlated with the pulmonary function tests. Results Parenchymal abnormalities in most patients with a predominant nodular pattern (18 patients) and multiple large nodular pattern (8 patients) disappeared or decreased in size on long-term follow-up CT scans. A conglomeration pattern (five patients) shrank and evolved into bronchial distortion. The shrinkage of the conglomeration pattern correlated with a decline of FEV1/FVC ratio, despite an improvement in FVC. A ground-glass opacity pattern (five patients) and a consolidation pattern (three patients) evolved into honeycombing. The evolution of the ground-glass opacity and consolidation patterns into honeycombing occurred along with a decline in FVC, although the parenchymal abnormalities became smaller. Conclusion Patients with a predominantly ground-glass opacity pattern and consolidation pattern seen on the initial CT scan had a worse prognosis and were susceptible to developing severe respiratory insufficiency. The predominant patterns seen on the initial HRCT scan may be helpful in predicting the outcomes of patients with sarcoidosis.

Bronchial artery embolization (BAE) is almost the only effective nonsurgical treatment for massive hemoptysis. Metallic coils with plastic fibers are widely used as embolic materials. We have introduced an interlocking detachable coil (IDC) for BAE. IDC is a mechanically detachable coil, allowing the operator to seek the ideal shape until its final release. We compared hemoptysis patients treated with conventional metallic coils (24 patients, non-IDC group) with those treated with conventional coils and IDCs (26 patients, IDC group). The hemoptysis rate after three months is significantly lower in the IDC group than in the non-IDC group (7.7% vs. 16.3%, p = 0.035 Fisher's exact method). Total procedure time (in staged or repetitive BAE cases, procedure times are added together) is significantly shorter in the IDC group than in the non-IDC group (3.4 +/- 1.4 hours vs. 4.4 +/- 2.5 hours, p = 0.040 unpaired t-test). IDC is a useful device for BAE. This is the first-ever report documenting the usefulness of IDC for BAE.

The purpose of this study was to establish the technique of multiplanar reconstruction (MPR) with multidetector-row (MDR) computed tomography (CT) guided needle biopsy for the diagnosis to access very difficult lesions. The CT guided percutaneous biopsy are well-established methods to obtain cytological and histological material such as the peripheral tumors in lung cancer. Occasionally, the conventional CT cannot permit planning a trajectory to avoid passage through bones, avoidance of bullae, fissures or vessels. In addition, some lesions are situated in less favorable locations such as those in the costophrenic recess or close to the mediastinum. Rarely can we diagnose them. MPR with MDR-CT has recently become widely available with applications for thoracic lesions. MPR images have been used to evaluate the location of small peripheral lung nodules to the relation of bullaes, vessels, and costophrenic recess. To diagnose these lesions, the usefulness of MPR were evaluated for an planning of an oblique approach of CT guided needle biopsy. MPR images were reconstructed as a line from the needle entry point to the target lesion. The first oblique image applied as the direction of posterior-anterior and cranio-caudal axis, and the second oblique image applied as the direction of posterior-anterior and left-right. Eleven out of 151 patients were required MPR technique to allow possible access to target, because of avoidance of bone and fissures in the needle pass or located in the costophrenic recess, between April 2001 and December 2002. The 5/11 patients were at the upper site (segment 1, 2 and 6) behind the scapula and ribs, 3/11 patients were at the lower lobe (segment 10) in the costophrenic recess, and 3/11 were middle lobe or segment 3 covered by the ribs and fissures. All the lesions except one were histologically diagnosed. Five patients were adenocarcinoma, and the other five patients were benign tumors. Pneumothorax occurred in one patient before we obtained the specimens. MPR guided needle biopsy with oblique approach was thought to be useful for diagnosis of very difficult thoracic lesions and would obviate an unnecessary surgical thoracoscopy.

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 (p0.0001). Visible intralobular bronchioles (62/80), bronchiolectasis within fibrotic consolidations (47/80), and honeycombing (61/80) were more common in patients with idiopathic pulmonary fibrosis (p0.0001). 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 (p0. 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.

The objective of this study was to determine whether the various chronic cystic lung diseases can be differentiated on the basis of the pattern and distribution of abnormalities on high-resolution CT.High-resolution CT scans in 92 patients with chronic cystic lung diseases (18 with pulmonary Langerhans cell histiocytosis, 18 with pulmonary lymphangioleiomyomatosis, 17 with usual interstitial pneumonia, 16 with lymphocytic interstitial pneumonia, 15 with emphysema, and eight with desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease) were retrospectively assessed by two independent observers without knowledge of the clinical or pathologic data. The observers recorded the abnormalities, the most likely diagnosis, and the degree of confidence in that diagnosis.The two observers made a correct first-choice diagnosis in 148 (80%) of 184 interpretations. The correct diagnosis was made in 100% of interpretations of usual interstitial pneumonia, 81% of desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease, 81% of lymphocytic interstitial pneumonia, 77% of emphysema, 72% of lymphangioleiomyomatosis, and 72% of Langerhans cell histiocytosis. The two observers made a diagnosis with a high degree of confidence in 105 (57%) of 184 interpretations. The confident diagnosis was correct in 98 (93%) of 105 interpretations.Although various chronic cystic lung diseases often have a characteristic appearance that allows their distinction on high-resolution CT, considerable overlap exists among the CT findings. Therefore, lung biopsy is often required for a definitive diagnosis.

A case of pulmonary hyalinizing granuloma (PHG) with Castleman's disease in a 43-year-old man is presented. He was asymptomatic, but the disease was recognized due to a routine chest roentgenographic study. Anemia, multiple lymphadenopathy, hypoalbuminemia and polyclonal hypergamma-globulinemia were observed. Histological examination of cervical lymph nodes revealed the plasma cell type of Castleman's disease. The diagnosis of PHG was confirmed by video-assisted thoracoscopical lung biopsy, and the immuno-histochemical staining of lamellar fibrosis for types I and III collagen was positive.

To describe thin-section computed tomographic (CT) findings in patients with drug-induced pneumonitis, to compare these CT findings, and to correlate them with arterial oxygen tension level.Thin-section CT scans obtained in 60 patients with drug-induced pneumonitis were evaluated retrospectively. The patients had 31 cases of antineoplastic agent-induced pneumonitis and 29 cases of nonneoplastic agent-induced pneumonitis (antibiotic agent, 20 cases; herbal medicine [sho-saiko-to], four cases; antirheumatic agent, three cases; phenytoin, one case; disodium cromoglycate, one case). CT scans were reviewed by two chest radiologists in consensus. Correlation between arterial oxygen tension level and the extent of disease at CT was available in 21 patients. These two factors were compared by using the Spearman rank correlation coefficient.The predominant findings in antineoplastic agent-induced pneumonitis were diffuse or multifocal ground-glass opacities with intralobular interstitial thickening. The predominant CT findings in antibiotic agent-induced pneumonitis were patchy ground-glass opacities with centrilobular opacities and interlobular septal lines. The predominant CT findings in herbal medicine-induced pneumonitis were diffuse ground-glass opacities with patchy consolidation. Interlobular septal lines and centrilobular opacities were observed more frequently in antibiotic agent-induced pneumonitis, and intralobular interstitial thickening was observed more frequently in antineoplastic agent-induced pneumonitis. A significant correlation was established between arterial oxygen tension level and extent of disease at CT (r = -0.84, P.05).In addition to ground-glass opacities and interlobular septal lines, the most common thin-section CT findings were intralobular interstitial thickening, observed in antineoplastic agent-induced pneumonitis, and centrilobular opacities, observed in antibiotic-induced pneumonitis.

In Japan, crocidolite had been used for asbestos cement pipe and spraying, and amosite had been used for building board and spraying. These two types of asbestos had stopped to use in Japan in the late 1970s. An extreme increase in imported asbestos (all 3 commercial types) was observed between 1960 and 1974. In 1960, 77,000 tons of asbestos were imported, and reached the peak as 352,316 tons in 1974. This extreme rise of asbestos imports corresponds with the recent rapid increase in mortality of malignant pleural mesothelioma. Between 1995 and 1999, an estimated mean annual death from pleural mesothelioma was about 500. The annual number of compensated occupational respiratory cancers due to asbestos exposure has also been increasing. Up to the end of March 2000, 162 cases with malignant mesothelioma and 197 cases with lung cancer were compensated. As for lung cancer, epidemiological studies are scanty in Japan. Limited environmental data of the working places in asbestos textile factories suggests that heavy asbestos exposure in the past made deaths from respiratory diseases. Less asbestos exposure will enable exposed workers to survive enough to reach cancer age. Even now smoking rate among males in Japan are over 50%. So lung cancer deaths caused by the interaction between smoking and asbestos exposure will be continuing.

Purpose: The purpose of this work was to compare the thin-section CT findings of acute respiratory distress syndrome (ARDS) with those of acute interstitial pneumonia (AIP). Method: The thin-section CT scans from 25 patients with ARDS and 25 with AIP were independently assessed by two observers without knowledge of clinical and pathologic data. The presence, extent, and distribution of various CT findings were independently analyzed. Results: Honeycombing was seen more frequently in lobes of patients with AIP (26%) than in lobes with ARDS (8%) (p < 0.001). Compared with patients with ARDS, a greater number of patients with AIP had a predominantly lower lung zone distribution (p < 0.05) and a symmetric distribution (p < 0.05) of the parenchymal abnormalities. Conclusion: Patients with AIP have a greater prevalence of honeycombing and are more likely to have a symmetric bilateral distribution and a lower lung zone predominance than patients with ARDS. However, significant overlap exists among the CT findings.

BACKGROUND—The purpose of this study was to describe findings on sequential high resolution computed tomographic (CT) scans of nine patients with non-specific interstitial pneumonia. METHODS—Thin section CT scans of nine patients with pathologically proven non-specific interstitial pneumonia were evaluated retrospectively. All patients underwent sequential CT scanning (mean follow up 3.1 years (range 1-8)). RESULTS—The predominant finding on the initial CT scans in seven patients was patchy areas of ground glass opacity in both the central and peripheral lung, with (n = 5) or without (n = 2) irregular areas of consolidation. In another two patients areas of consolidation in both the central and peripheral lung were seen as the predominant abnormality. The initial parenchymal abnormalities had resolved completely in four patients with predominant ground glass opacity without bronchiolectasis. Some of the bronchiectasis and bronchiolectasis resolved. In two patients bronchiectasis and bronchiolectasis occurred at one year and two years of follow up, respectively. In two patients with predominant consolidation the consolidation decreased but persisted, and in one patient the consolidation evolved into honeycombing. In the other patient bronchiectasis progressed over the course of seven years, forming varicoid bronchiectasis. CONCLUSION—Patients with non-specific interstitial pneumonia may recover completely after treatment with corticosteroids, but as many as half of these patients will have persistent pulmonary abnormalities on CT scans including bronchiectasis and honeycomb lung.

The aim of the present study was to assess the evolution of various computed tomographic (CT) findings of lymphocytic interstitial pneumonia (LIP) with determination of potentially reversible or irreversible features. The study included 14 patients with biopsy-proved LIP who had serial thin-section CT examination 4 to 82 months (median 13 months) apart. Initial and follow-up CT scans were evaluated independently and then directly compared with each other by two observers. The main parenchymal abnormalities on the initial CT scan consisted of ground-glass attenuation (n = 14), thickening of interlobular septa (n = 13), centrilobular nodules (n = 12), cystic airspaces (n = 10), and airspace consolidation (n = 4). On follow-up CT, nine patients improved, one showed no change, and four showed increased extent of disease. With the exception of cysts, the parenchymal opacities were reversible. On follow-up CT, new cysts were seen in three patients; these developed mainly in areas with centrilobular nodules on initial CT. Honeycombing was seen on follow-up CT in four patients; in three patients it developed in areas of airspace consolidation and in one patient it developed in an area with ground-glass attenuation on initial CT. The majority of patients with LIP improved on follow-up. However, airspace consolidation may progress to honeycombing and centrilobular nodules may precede cystic formation.

PURPOSE A study was undertaken to describe the thin-section CT features of transient radiographic progression during initial treatment of active pulmonary tuberculosis. METHOD The CT scans of 13 patients who developed transient radiographic progression during initial treatment of pulmonary tuberculosis were evaluated and compared with those of 10 patients with true progression of pulmonary tuberculosis. Two patients underwent transbronchial lung biopsy for pathologic evaluation of new lesion. RESULTS Eight patients had increased opacity at the site of their original lesion, whereas five had new opacities elsewhere: ipsilateral (n = 3) or contralateral (n = 1) to the original lesion or both (n = 1). Relatively extensive areas of ground-glass attenuation were concomitantly depicted in three of the eight patients with progression in the area of the original lesion. In those with progression ipsilateral or contralateral to the lesion, the character of the new lesions was ground-glass opacity and/or consolidation mainly in the subpleural region. Transbronchial lung biopsy specimens obtained from two patients showed intraluminal organizing exudates and thickened alveolar septa with lymphocyte infiltration, whereas the dominant CT findings of true progression of pulmonary tuberculosis were nodules (n = 8) or centrilobular nodules (n = 7). CONCLUSION Thin-section CT may be useful to differentiate transient radiographic progression from true progression of pulmonary tuberculosis.

The purpose of this study was to analyze the high-resolution CT features of diffuse bronchioloalveolar carcinoma and determine the useful findings in differential diagnosis.High-resolution CT scans of 38 patients with pathologically proven diffuse bronchioloalveolar carcinoma were reviewed. Sequential CT scans were obtained in 15 patients. The high-resolution CT findings were compared with those of eosinophilic pneumonia (n = 22), multiple pulmonary metastases (n = 12), and tuberculosis (bronchogenic: n = 22; miliary: n = 12).High-resolution CT findings of diffuse bronchioloalveolar carcinoma included ground-glass opacity (n = 29), consolidation (n = 29), nodules (n = 28), centrilobular nodules (n = 26), peripheral distribution (n = 19), and air bronchogram (n = 18). According to the major features, high-resolution CT findings of diffuse bronchioloalveolar carcinoma could be classified into three patterns: predominantly ground-glass (n = 4), consolidative (n = 22), and multinodular (n = 12). Most patients with diffuse bronchioloalveolar carcinoma had a mixture of these findings. The frequency of findings of diffuse bronchioloalveolar carcinoma on high-resolution CT was not different from that of tuberculosis, but the predominant distribution of the nodules and areas of ground-glass attenuation differed between the two. Difference in distribution between bronchioloalveolar carcinoma and bronchogenic tuberculosis included ground-glass opacity remote from the consolidation and a lower lung predominance.Although these high-resolution CT findings are not specific, the combination of consolidation and nodules and the coexistence of centrilobular nodules and remote areas of ground-glass attenuation are characteristic of diffuse bronchioloalveolar carcinoma.

To assess the thin-section computed tomographic (CT) findings of lymphocytic interstitial pneumonia.The study included 22 patients (five men, 17 women; age range, 24-83 years; mean age, 50 years) with biopsy-proved lymphocytic interstitial pneumonia. The CT scans were obtained by using 1-3-mm collimation and reconstructed by using a high-spatial-frequency algorithm.The predominant abnormalities consisted of areas of ground-glass attenuation and poorly defined centrilobular nodules present in all 22 patients and subpleural small nodules seen in 19 patients. Other common findings included thickening of bronchovascular bundles (n - 19), interlobular septal thickening (n = 18), cystic airspaces (n = 15), and lymph node enlargement (n = 15). Less common findings included large nodules, emphysema, airspace consolidation, bronchiectasis, architectural distortion, honeycombing, and pleural thickening.Lymphocytic interstitial pneumonia is characterized by the presence of ground-glass attenuation, poorly defined centrilobular nodules, and thickening of the interstitium along the lymphatic vessels. Lymph node enlargement is more common than previously recognized; it was seen in 68% of patients.

To characterize the computed tomographic (CT) findings of acute interstitial pneumonia and to correlate the pattern and the extent of abnormalities with the time between symptom onset and CT.The study included 36 patients (20 men, 16 women; age range, 22-83 years; mean age, 61 years) with histopathologically proved acute interstitial pneumonia who were identified retrospectively. The time between symptom onset and CT was 2-90 days (mean, 22 days; median, 17 days). The presence, extent, and distribution of various CT findings were evaluated. Disease duration and extent of each finding were compared by using the Spearman rank correlation coefficient.Areas with ground-glass attenuation, traction bronchiectasis, and architectural distortion were present in all 36 patients. Airspace consolidation was present in 33 patients (92%). The extent of areas of ground-glass attenuation (r = 0.45, P.01) and the extent of traction bronchiectasis (r = 0.35, P.05) correlated with disease duration. No other significant correlation was found between the CT findings and disease duration.A combination of ground-glass attenuation, airspace consolidation, traction bronchiectasis, and architectural distortion is seen in the majority of patients with acute interstitial pneumonia. The extent of ground-glass attenuation and traction bronchiectasis increases with disease duration.

To determine the long-term follow-up computed tomographic (CT) findings of interstitial lung disease associated with polymyositis-dermatomyositis.CT scans in seven patients with interstitial lung disease and associated polymyositis-dermatomyositis were evaluated retrospectively. Six patients underwent sequential CT (follow-up range, 2-8 years; mean, 4.3 years). Histologic confirmation of pulmonary involvement was available in five patients.The predominant finding on the initial CT scans in four patients was subpleural consolidation, which corresponded to bronchiolitis obliterans organizing pneumonia with or without coexistent chronic eosinophilic pneumonia. In most cases, consolidation improved with use of corticosteroid and/or immunosuppressive therapy; in two patients, however, consolidation evolved into honeycombing. In one patient, diffuse areas of ground-glass opacity and consolidation appeared rapidly during illness; this patient died of sudden, rapid deterioration. In one patient with subpleural linear opacities, parenchymal abnormalities slowly progressed, and linear opacities had evolved into honeycombing at 8-year follow-up. In one patient with histologically proved organizing diffuse alveolar damage, bilateral patchy areas of ground-glass opacity and consolidation were seen. In one patient, subpleural bands changed to subpleural lines on sequential CT scans.CT provides an excellent demonstration of the lung changes in patients with interstitial lung disease and associated polymyositis-dermatomyositis.

To determine the spectrum of disease associated with a fine reticular pattern superimposed on areas of ground-glass opacity (i.e., "crazy-paving" appearance) at thin-section computed tomography (CT) and to determine the underlying pathologic features.In the in vivo study, the cases of 46 patients (21 male, 25 female; age range, 13-82 years) were retrospectively reviewed, with special attention paid to the size and extent of the reticular network. In the in vitro study, the thin-section CT findings in 20 inflated and fixed lungs were precisely correlated with the gross appearance, contact radiograph findings, stereomicroscopic views, and histologic findings.In the in vivo study, 15 different diseases were identified, including alveolar proteinosis, adult respiratory distress syndrome, acute interstitial pneumonia, diffuse alveolar damage superimposed on usual interstitial pneumonia, and drug-induced pneumonitis. In the in vitro study, the fine networks at pathologic analysis were due to an alveolar filling process (n = 10), an interstitial fibrotic process (n = 7), or a combination of interstitial and intraalveolar processes (n = 3). Twelve (60%) cases did not have thickening of the interlobular septa within the areas of the crazy-paving appearance.The crazy-paving appearance is a nonspecific finding seen in a variety of interstitial and airspace lung diseases.

BACKGROUND: Desquamative interstitial pneumonia (DIP) may represent the early stage and usual interstitial pneumonia (UIP) the late stage of the same disease. The purpose of this study was to evaluate the computed tomographic (CT) features of DIP, to evaluate the changes in pattern and extent of disease over time, and to determine whether the appearances of DIP on the CT scan change to those of UIP during follow up. METHODS: Sequential CT evaluation was conducted on eight patients with DIP over a mean (SD) follow up period of 3.2 (1.3) years (range 1.6-6.5). The relative extents of ground glass and honeycombing were determined from serial CT scans. Changes in the extent and appearance of the disease were examined in paired anatomically comparable CT sections. RESULTS: Common features on the CT scans of patients with DIP were a homogeneous increase in lung attenuation (n = 5), linear areas of attenuation (n = 5), relatively well preserved lung architecture (n = 5), and the presence of small cysts (n = 6). Uncommon features were architectural distortion (n = 3), and traction bronchiectasis (n = 1). In six patients with DIP with cystic spaces these did not change with time in three cases, in two they regreased, and in one patient they increased. Open lung biopsy samples from patients with DIP with many cystic lesions showed dilated alveolar ducts and bronchioles and/or pulmonary cysts, as well as numerous macrophage-filled air spaces and mild fibrosis, but no typical honeycomb cysts were seen. CONCLUSIONS: Some of the microcysts in DIP are different from the honeycomb cysts seen in UIP, and some of the cysts seen in patients with DIP resolve with time. DIP does not progress to UIP in the short term.

Most patients with idiopathic pulmonary fibrosis (IPF) show slowly progressive deterioration. However, accelerated deterioration also occurs in patient with IPF who have previously shown slowly progressive deterioration. The purpose of this study was to evaluate the CT findings of accelerated deterioration in patients with IPF.We evaluated the CT findings of 17 patients with IPF who fulfilled all the following criteria for accelerated deterioration of IPF: exacerbation of dyspnea within 1 month, new diffuse pulmonary opacities on chest radiography, a decrease in arterial oxygen tension (PaO2) of more than 10 mm Hg under similar conditions, and absence of apparent infectious agents and heart failure. Seven patients underwent sequential CT examination. Pathologic specimens were obtained from nine patients.CT findings were classified as peripheral parenchymal opacification (n = 6), multifocal parenchymal opacification (n = 6), and diffuse parenchymal opacification (n = 5). Multifocal lesions developed diffusely in two of the seven patients who underwent sequential CT. These two patients both died. Three of the six patients with a multifocal pattern responded to corticosteroid therapy. All patients with a peripheral pattern showed various degrees of improvement following corticosteroid therapy. Multifocal and diffuse parenchymal opacification corresponded pathologically to acute diffuse alveolar damage. Peripheral parenchymal opacification corresponded pathologically to active fibroblastic foci.CT patterns seen during periods of rapid deterioration in patients with IPF may allow predictions of prognosis and of response to treatment.

The radiologic findings were reviewed in nine patients with biopsy- or autopsy-proved acute interstitial pneumonia (AIP). All patients had bilateral air-space opacification on radiographs and bilateral, symmetric areas of ground-glass attenuation on computed tomographic (CT) scans. The areas of ground-glass attenuation had a patchy distribution in six patients (67%) and were diffuse in three patients. Air-space consolidation was seen at CT in six patients (67%) and involved mainly the lower lung zones in three patients and upper lung zones in one patient and was diffuse in two patients. A predominantly subpleural distribution of the consolidation was present in two patients. Eight of the nine patients died within 3 months of presentation. The authors conclude that the radiographic and CT features of AIP are similar to those of adult respiratory distress syndrome and represent acute alveolar damage. AIP differs from the more chronic forms of interstitial pneumonia in clinical presentation and in pathologic and radiologic findings.

To determine the earliest stage at which lesions in asbestosis can be diagnosed and to assess their progression, 23 asbestos-exposed patients with minimal or no abnormalities at plain radiography were examined with high-resolution computed tomography (HRCT) twice, with an interval of 12-37 months between examinations. In 21 of the patients, parenchymal abnormalities were found. Major parenchymal features seen at CT included thickened intralobular and interlobular lines, subpleural curvilinear lines, pleural-based nodular irregularities, hazy patches of increased attenuation, small cystic spaces, and small areas of low attenuation. At paired serial CT, subpleural isolated dots or branching structures connected with the most peripheral branch of the pulmonary artery started to appear in lower subpleural zones and then became confluent to create pleural-based nodular irregularities. CT-pathologic correlation led to the conclusion that the confluence of subpleural peribronchiolar fibrosis creates subpleural fibrosis.

High-resolution computed tomography (HRCT) was performed in seven inflated and fixed postmortem lungs from seven asbestos-exposed patients with pathologically proved asbestosis. The parenchymal abnormalities seen at in vitro HRCT included thickened intralobular lines (n = 7), thickened interlobular lines (n = 7), pleural-based opacities (n = 7), parenchymal fibrous bands (n = 5), subpleural curvilinear shadows (n = 4), ground-glass appearance (n = 4), traction bronchiectasis (n = 4), and honeycombing (n = 2). The thickened intralobular lines were shown histologically to be due to peribronchiolar fibrosis. Thickened interlobular lines were due mainly to interlobular fibrotic thickening in four lungs and edema in three. The peribronchiolar fibrosis was most severe in the subpleural lung regions, creating curvilinear line shadows and pleural-based areas of opacity. Some subpleural fibrosis extended proximally along the bronchovascular sheath to create bandlike lesions. Areas of ground-glass appearance on HRCT scans were shown to be the result of mild alveolar wall and interlobular septal thickening due to fibrosis or edema. Postmortem HRCT findings were similar to premortem HRCT findings and correlated well with the pathologic findings of asbestosis.