Irregular Linear Opacities Research Articles

Evaluation of high-resolution computed tomography findings and associated factors in hypersensitivity pneumonitis

Background/Aim: Hypersensitivity pneumonitis (HP) is a lung disease from inhaling diverse environmental and occupational organic substances, such as fungi, bacteria, birds, and occasionally nonorganic materials. An immune response triggers this condition. A high-resolution chest computed tomography (HRCT) scan is typically performed as part of the initial diagnostic assessment. This study assesses HRCT findings in HP patients and examines associated factors between fibrotic and non-fibrotic patient groups. Methods: This retrospective cross-sectional study encompassed all HP patients monitored between 2010 and 2022. The analysis included data from 117 patients. HRCT findings from the patients were categorized based on fibrosis presence, leading to the division of patients into fibrotic and non-fibrotic groups. Comparative analyses were conducted between these groups. Results: Among the 117 subjects analyzed, 59 (50.4%) were male, and 58 (49.6%) were female. The mean age at diagnosis was 52.1 (13.6) years, ranging from 20 to 81. The non-fibrotic HP group comprised 70 (59.8%) patients, while the fibrotic HP group comprised 47 (40.2%). The most prevalent HRCT findings were ground-glass opacity (90.6%), mosaic attenuation (87.2%), and traction bronchiectasis (50.4%). Statistically significant disparities were observed between non-fibrotic and fibrotic HP groups in terms of HRCT findings: ground-glass opacity, irregular linear opacities, reticulation, traction bronchiectasis, honeycombing, and fibrosis (P=0.024, P<0.001). In contrast, the lymphocyte ratio in bronchoalveolar lavage fluid was 28.78 (16.2) in the non-fibrotic HP group and 14.66 (10.3) in the fibrotic HP group. The fibrotic HP group exhibited a statistically significant lower lymphocyte ratio in bronchoalveolar lavage fluid (P<0.001). Conclusion: HRCT findings are pivotal in HP diagnosis and classification. Computed tomography also assists in delineating the HP classification. This study identified ground-glass opacity and mosaic attenuation as the most prevalent HRCT findings in HP patients. Investigating the connection between fibrosis and prognosis is vital for determining patient outcomes, as fibrosis appears to be the principal determinant.

Long-Term Follow-Up Study of COVID-19: Evaluation on Thin-Slice CT.

PurposeTo retrospectively analyse the CT imaging during the long-term follow-up of COVID-19 patients after discharge.Patients and MethodsA total of 122 patients entered the study group. All patients underwent CT examinations. The CT images, which included distribution and imaging signs, were evaluated by two chest radiologists. Laboratory examinations included routine blood work, biochemical testing, and SARS-CoV-2 antibody screening. Statistical methods include chi-square, Fisher’s exact test, one-way analysis of variance, rank sum test and logistic regression by SPSS 17.0.ResultsThere were 22 (18.0%) patients in the mild group, 74 (60.7%) patients in the moderate group, and 26 (21.3%) patients in the severe–critical group. The median follow-up interval was 405 days (378.0 days, 462.8 days). Only monocytes, prothrombin activity, and γ-glutamyltransferase showed significant differences among the three groups. We found that the more severe the patient’s condition, the more SARS-CoV-2 IgG antibodies existed. Only 11 patients (11.0%) showed residual lesions on CT. The CT manifestations included irregular linear opacities in nine cases (9.0%), reticular patterns in six cases (6.0%), and GGOs in five cases (5.0%).ConclusionThe proportion of residual lesions on CT in COVID-19 patients was significantly reduced after long-term follow-up. The patients’ age and disease conditions were positively correlated with residual lesions.

Plasma exchange therapy in refractory inflammatory myopathy with anti-signal recognition particle antibody: a case series.

To explore the efficacy of plasma exchange (PE) therapy in refractory idiopathic inflammatory myopathy (IIM) patients with positive anti-signal recognition particle (SRP) antibody. Nine refractory IIM patients with positive anti-SRP antibody were enrolled, who received PE therapy at Ruijin Hospital from October 2017 to December 2020. The clinical manifestations, laboratory tests, chest CT and lower extremity MRI images before and after PE therapy were compared. The treatment response was evaluated by the 2016 ACR/EULAR myositis response criteria. A total of 88.9% (8/9) of subjects had achieved improvement by 3 weeks after PE therapy, with 55.6% (5/9) minimal improvement and 33.3% (3/9) moderate improvement. There were statistically significant improvements between baseline and after PE therapy at 3 weeks on the core set measures: physician global activity, patient global activity, HAQ, manual muscle testing (MMT), extramuscular disease activity, and muscle enzymes activity including creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST), except for alanine transaminase (ALT). Moreover, the chest CT showed regression of ground glass opacities and irregular linear opacities after PE therapy in four patients with interstitial lung disease. The MRI images of lower extremity in four patients showed reduction of muscle oedema after the therapy. PE therapy is effective for refractory IIM patients with positive anti-SRP antibody. It should be considered as an alternative treatment for those patients who are resistant to the combined therapy of glucocorticoids and immunosuppressive agents.

High-Resolution CT Features of the COVID-19 Infection During Short-Term Follow-Up

Objective: To estimate the short-term follow-up chest HRCT manifestation in patients with COVID-19 who have left hospitals. Methods: Retrospective analysis was executed on the chest HRCT manifestation of 49 cases with RT-PCR confirmed COVID-19 pneumonia patients diagnosed in Beijing You’An hospital affiliated to capital medical university between 20 January 2020 to April 10, 2020. The study including 21 males and 28 females, and the median age was 59.5 years age ranged from 21 years to 80 years. The evolution characteristics of chest HRCT in short-term follow-up after discharge were analyzed. Results: Forty-nine patients were divided into two groups according to Diagnosis and Treatment Protocol of 2019 New Coronavirus Pneumonia (trial version 7) of National Health Commission of China. Severe group included 23 cases (46.9%) and 26 cases of ordinary (53.1%). The HRCT findings of patients in the 2 groups were analyzed on median follow-up time was 30 day (range, 14 to 46 days) after discharge. The follow-up chest HRCT were normal in 19 of 49 (38.8%) patients, abnormal HRCT findings were detected in 30 of 49 (61.2%) patients. The most frequent abnormality found on follow-up HRCT in COVID-19 patients who recovered from pneumonia was GGO which was seen in 26 of 49 (53.1%) patients, reticular pattern was in 9 of 49 (18.4%), traction bronchiectasis was in 3 of 49 (6.1%), small nodular consolidation was in 6 of 49 (12.2%), other findings including curved line in the subpleural area and irregular linear opacities were in 15 of 49 (30.6%). In the study, 3 of 49 (6.1%) patients were diagnosed with pulmonary fibrosis according to HRCT findings. Three cases were severe patients, aged from 65 to 80 years. Pulmonary fibrosis occurred within 30–50 days of onset. Conclusion: Pulmonary fibrosis may develop in 6.1% of COVID-19 patients, which was lower than that of SARS and MERS, suggesting that the lung damage caused by SARS-COV-2 in the recovered patients was lower than that of SARS and MERS.

Clinical profiles of SS-ILD compared with SS-NILD in a Chinese population: a retrospective analysis of 735 patients

Background Interstitial lung disease (ILD) is a serious complication in patients with Sjögren’s syndrome (SS). Most studies on primary SS (pSS) with ILD are limited in sample size, and studies on secondary SS (sSS) with ILD are rare. This study aimed to elucidate both primary and secondary SS-associated ILD (SS-ILD) based on a large cohort. Methods The medical records of hospitalized patients diagnosed with SS at the Second Xiangya Hospital of Central South University from January 2010 to May 2020 were retrospectively reviewed. Clinical manifestations, medical history, biological results and imaging data were collected. Results Of the 735 SS patients enrolled in this study, 563 (76.6%) were diagnosed with pSS, 172 (23.4%) were diagnosed with sSS. Additionally, 316 (43.0%) were diagnosed with SS-ILD. No significant difference was found between the pSS and sSS groups concerning the incidence of ILD (p = .718). Factors associated with SS-ILD were older age (p < .001), male sex (p = .032), female sex at menopause (p = .002), Raynaud’s phenomenon (p < .001), low levels of albumin (p = .010) and respiratory symptoms (p < .001). The SS-ILD group showed higher counts of platelets (p < .001). The three most frequent high-resolution CT (HRCT) findings of SS-ILD were irregular linear opacities (42.7%), grid shadows (30.7%) and pleural thickening (28.5%). NSIP (56.3%) was the most frequent HRCT pattern. Compared with pSS patients with ILD (pSS-ILD) patients, sSS patients with ILD (sSS-ILD) patients had a higher incidence of proteinuria (p < .001) and hypercreatinaemia (p = .013), a higher level of erythrocyte sedimentation rate (ESR) (p = .003), low levels of complement 3 (C3) (p = .013), lymphocytes (p = .009) and leukocytes (p = .024), and worse DLCO (%Pred) (p = .035). Conclusions ILD is a common pulmonary involvement in both pSS patients and sSS patients. Older age, male sex, female sex at menopause, Raynaud’s phenomenon, low albumin levels and respiratory symptoms are risk factors associated with SS-ILD. NSIP is important HRCT feature of SS-ILD. sSS-ILD patients showed worse laboratory results and pulmonary function. KEY MESSAGE Older age, male sex, female sex at menopause, Raynaud’s phenomenon, low albumin levels and respiratory symptoms are risk factors associated with SS-ILD. SS-ILD patients show higher counts of platelets and less purpura. sSS-ILD patients have worse laboratory results and pulmonary function.

Temporal Changes of CT Findings in 90 Patients with COVID-19 Pneumonia: A Longitudinal Study.

BackgroundCT may play a central role in the diagnosis and management of COVID-19 pneumonia.PurposeTo perform a longitudinal study to analyze the serial CT findings over time in patients with COVID-19 pneumonia.Materials and MethodsDuring January 16 to February 17, 2020, 90 patients (male:female, 33:57; mean age, 45 years) with COVID-19 pneumonia were prospectively enrolled and followed up until they were discharged or died, or until the end of the study. A total of 366 CT scans were acquired and reviewed by 2 groups of radiologists for the patterns and distribution of lung abnormalities, total CT scores and number of zones involved. Those features were analyzed for temporal change.ResultsCT scores and number of zones involved progressed rapidly, peaked during illness days 6-11 (median: 5 and 5), and followed by persistence of high levels. The predominant pattern of abnormalities after symptom onset was ground-glass opacity (35/78 [45%] to 49/79 [62%] in different periods). The percentage of mixed pattern peaked (30/78 [38%]) on illness days 12-17, and became the second most predominant pattern thereafter. Pure ground-glass opacity was the most prevalent sub-type of ground-glass opacity after symptom onset (20/50 [40%] to 20/28 [71%]). The percentage of ground-glass opacity with irregular linear opacity peaked on illness days 6-11 (14/50 [28%)]) and became the second most prevalent subtype thereafter. The distribution of lesions was predominantly bilateral and subpleural. 66/70 (94%) patients discharged had residual disease on final CT scans (median CT scores and zones involved: 4 and 4), with ground-glass opacity (42/70 [60%]) and pure ground-glass opacity (31/42 [74%]) the most common pattern and subtype.ConclusionThe extent of lung abnormalities on CT peaked during illness days 6-11. The temporal changes of the diverse CT manifestations followed a specific pattern, which might indicate the progression and recovery of the illness.

RELAPSING CRYPTOGENIC ORGANIZING PNEUMONIA

SESSION TITLE: Wednesday Fellows Case Report Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Organizing pneumonia is a form of Interstitial lung disease. It has equal prevalence in men and women. Adults 40-60 years are most commonly affected. It can be idiopathic, called cryptogenic organizing pneumonia(COP), or secondary to other factors; secondary organizing pneumonia. CASE PRESENTATION: 77-year-old female with history of hypertension, CHF, COPD presented with 3 weeks of dyspnea. She was hospitalized 3 weeks prior and treated for CAP.CXR at that time demonstrated b/l upper lobe consolidations. She was discharged on 4L O2 and PO cefpodoxime. Pt reported subjective improvement, however she was not back to her baseline. CT chest revealed patchy consolidation in the b/l upper lobes, and multiple nodular opacities in lower lobes. On initial evaluation patient was afebrile, hypoxic, with PaO2:91 on non-rebreather saturating at 95%. WBC count of 8.9. Bronchoscopy was performed. BAL revealed WBC: 693, lymphocytes: 35%, cultures: negative. BAL analysis was supportive of a diagnosis of COP. Biopsy not done due to high FiO2 requirements and unstable condition. Patient was started on prednisone 40 mg x 4 weeks followed by 20 mg x 4 weeks. Patient was lost to follow up, and steroids stopped by PCP. 3 months later she was re hospitalized for hypoxia. CXR showed worsening opacities and she required 5 L O2 via NC. A tapering course of Prednisone was started. Patient seen on follow up at 3 months with resolution of symptoms. DISCUSSION: COP has an insidious onset. Risk factors include infections, connective tissue disease, malignancies, chronic recurrent aspiration, radiation, cocaine etc. The radiographic appearance of COP is variable. On chest CT scan patchy consolidation, is seen in 90% of patients. Nodules and irregular linear opacities or ground-glass attenuation may be seen. Diagnosis is made on history, Imaging, PFTs, Bronchoscopy with BAL and biopsy findings. PFTs may show obstructive vs restrictive defect. DLCO is usually decreased. Typical BAL findings include increases in lymphocytes (20 to 40 percent), neutrophils (5 to 10 percent), and eosinophils (5 to 25 percent). Foamy macrophages, mast cells, and a decreased CD4/CD8 T cell ratio may be seen. BAL neutrophilia (>10%) tends to correlate with relapse. Transbronchial/surgical lung biopsy provides a definitive diagnosis. Patients with minimal symptoms can be monitored without therapy as spontaneous remission may occur. For patients with severe disease: Long term course of steroids: 0.75-1 mg/kg/day for 4-8 weeks then 0.5 mg/kg/day for 4-8 weeks. Most patients respond to therapy with recovery usually occurring in two-thirds of patients. Approximately one-third of patients experience persistent symptoms, abnormalities on pulmonary function testing, and radiographic disease. CONCLUSIONS: Close monitoring is essential to ensure response and completion of therapy, as early discontinuation of steroids may result in recurrence of symptoms. Reference #1: 1. Cordier, J. F. "Cryptogenic organising pneumonia." European Respiratory Journal 28, no. 2 (2006): 422-446. Reference #2: 2. Drakopanagiotakis, Fotios, Koralia Paschalaki, Muhanned Abu-Hijleh, Bassam Aswad, Napoleon Karagianidis, Emmanouil Kastanakis, Sidney S. Braman, and Vlasis Polychronopoulos. "Cryptogenic and secondary organizing pneumonia: clinical presentation, radiographic findings, treatment response, and prognosis." Chest 139, no. 4 (2011): 893-900 Reference #3: 3. Epler, Gary R. "Bronchiolitis obliterans organizing pneumonia: definition and clinical features." Chest 102, no. 1 (1992): 2-6. DISCLOSURES: No relevant relationships by Siddique Chaudhary, source=Web Response No relevant relationships by Bhavna Sharma, source=Web Response No relevant relationships by Paul Kristan Valestra, source=Web Response

Interstitial Pneumonia in Psoriasis.

ObjectiveTo investigate the relationship between psoriasis and interstitial pneumonia (IP).Patients and MethodsWe analyzed the clinical data of patients with psoriasis treated with biologic agents from June 1, 2008, to June 30, 2017, retrospectively. Chest computed tomography was performed in 392 patients before treatment. The clinical characteristics and radiographic findings of these patients were evaluated.ResultsOf the 392 patients with psoriasis, IP was detected in 8 patients (2%). Bilateral ground-glass and/or irregular linear (reticular) opacity in the lower lung zone was the most common chest computed tomography finding. Five of the 8 patients with IP were treated with anti–interleukin (IL) 12/IL-23 or IL-17 antibodies, leading to decreased or stable IP activity.ConclusionInterstitial pneumonia was detected in 2% of patients with psoriasis who needed systemic treatments. Ground-glass and/or irregular linear (reticular) opacity in the bilateral lower lobes was characteristic of IP with psoriasis. The IL-23/IL-17 axis may play important roles in the pathogenesis of IP in psoriasis.

Interstitial lung disease in clinically amyopathic dermatomyositis with and without anti-MDA-5 antibody: to lump or split?

BackgroundInterstitial lung disease (ILD) associated with clinically amyopathic dermatomyositis (CADM-ILD) is often refractory and rapidly progressive. Although the anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibody is associated with rapidly progressive ILD (RP-ILD), differences in clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD remain unclear.MethodsTo clarify the differences in the clinical features and prognosis between anti-MDA-5 antibody-positive and -negative cases, we retrospectively reviewed the medical records of patients diagnosed with CADM-ILD with and without anti-MDA-5 antibody at Kurashiki Central Hospital from January 2005 to September 2014.ResultsAnti-MDA-5 antibody was found in 10 of 16 patients (63 %). The levels of Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) at the first visit were significantly lower in positive patients than in negative patients, whereas the levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP), and the CD4+/CD8+ ratio in the bronchoalveolar lavage (BAL) fluid were significantly higher in positive patients than negative patients. Subpleural ground-glass opacity (GGO) or irregular linear opacity was predominant in positive patients. Peribronchovascular consolidation was predominant in negative patients. Positive patients had significantly lower survival rates than negative patients, with all six fatal cases occurring in positive patients who died of refractory ILD within 92 days from the first visit despite intensive treatment.ConclusionsThere are clear differences in the clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD. Low serum KL-6 and SP-D levels, high serum AST and γ-GTP levels, high CD4+/CD8+ ratio in BAL fluid, and predominance of subpleural GGO or irregular linear opacity in HRCT may help to discriminate anti-MDA-5 antibody-positive CADM-ILD with poor prognosis.

Human infection with a novel avian-origin influenza A (H7N9) virus: serial chest radiographic and CT findings.

Rapidly progressive pneumonia infection with H7N9 virus is a novel disease, and limited information is available concerning serial chest radiographic and computed tomography (CT) findings. The aim of this study was to evaluate the changes in serial radiologic findings in patients with H7N9 pneumonia. The two institutional ethics review boards approved this retrospective study. This study included 10 patients with H7N9 pneumonia. All patients underwent chest radiologic examinations at different time points. Serial radiologic images were systematically analyzed. All patients showed abnormal results on initial chest radiography and CT. The initial radiographic abnormalities were unilateral (n = 9) and bilateral (n = 1), including ground-glass opacities (GGOs) (n = 5) and consolidation (n = 5). The initial CT findings consisted of unilateral (n = 6) and bilateral (n = 4), including consolidation (n = 10), GGOs (n = 10), reticular opacities (n = 2), and pleural effusion (n = 3). Follow-up radiologic findings showed rapid development of consolidation or GGOs within two weeks after illness onset. Pneumomediastinum with secondary subcutaneous emphysema and pneumothorax were noted in two patients. Follow-up high resolution computed tomography (HRCT) after two weeks showed slow improvement in both size and opacity of the lesions. On HRCT after discharge, patients had substantial residual lesions such as irregular linear opacities, reticular opacities, parenchymal bands, traction bronchiectasis, and cystic lesions. The most common radiologic findings at presentation are multifocal or diffuse areas of consolidation and GGOs in H7N9 pneumonia. HRCT in sequence can show more changes in rapid progression of disease and a slow decrease of both size and opacity of the lesions plays an important role in the evaluation of H7N9 pneumonia.

Radiological diagnosis of interstitial lung diseases

Introduction. Interstitial lung diseases include the entities of idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia, and lymphocytic interstitial pneumonia. Recent introduction of high-resolution computed tomography has made the diagnosis of interstitial lung disease much easier. Usual interstitial pneumonia A predominantly subpleural reticulation and honeycombing at the basal posterior part of the lung with a progression to anterior and superior parts are characteristic of usual interstitial pneumonia/ idiopathic pulmonary fibrosis. Nonspecific interstitial pneumonia Typical findings of nonspecific interstitial pneumonia are bilateral, relatively symmetrical subpleural ground glass opacifications and irregular linear opacities. Desquamative interstitial pneumonia is characterized by diffuse symmetrical ground glass opacifications. Respiratory bronchiolitisassociated interstitial lung disease Centrilobular nodules and irregular ground glass opacifications are present. Cryptogenic organizing pneumonia Subpleural and peribronchial consolidations are prominent findings that are not present in other idiopathic interstitial pneumonias. Acute interstitial pneumonia. Bilateral ground-glass opacifications are present and areas of peripheral consolidations may also be seen in acute interstitial pneumonia. Lymphocytic interstitial pneumonia. Diffuse or patchy areas of ground glass opacification with centrilobular nodules and occasionally well-defined cysts are seen. Conclusion. Imaging plays a crucial role in identifying interstitial lung diseases but precise diagnosis requires a dynamic interdisciplinary approach that correlates clinical, radiological and pathologic features.

High-Resolution CT Findings of Parenchymal Fibrosis Correlate With Prognosis in Hypersensitivity Pneumonitis*

Histopathologic evidence of fibrosis on surgical lung biopsy has been associated with reduced survival in patients with hypersensitivity pneumonitis (HP). Changes of pulmonary fibrosis detected on CT may also correlate with prognosis in patients with HP. We identified 69 consecutive patients with HP diagnosed between January 1997 and December 2002 at Mayo Clinic, Rochester, MN. Patients were stratified into fibrotic and nonfibrotic groups based on the CT findings. Fibrosis was defined by the presence of irregular linear opacities, traction bronchiectasis, or honeycombing. Of 69 patients, 26 were classified as fibrotic and 43 as nonfibrotic. Patients in the fibrotic group were older, had longer symptom duration, were more likely to have crackles on auscultation, more likely to be exposed to avian antigen, and had greater restrictive lung impairment (p<0.05 for all comparisons). There were 11 deaths in the fibrotic group and 1 death in the nonfibrotic group (p<0.0001). In the regression analysis, CT evidence of fibrosis, more severe pulmonary function abnormalities, and the presence of crackles on auscultation were predictive of reduced survival (p<0.05 for all). The presence as well as the extent of fibrosis on CT was associated with increased mortality. The age-adjusted hazard ratio for mortality in patients with fibrosis was 4.6 (95% confidence interval, 2.0 to 20.1; p<0.0001). CT findings of parenchymal fibrosis are associated with reduced survival in patients with HP and may serve as a useful prognostic indicator.

Chronic Nitrofurantoin-Induced Lung Disease

To reassess the clinical and radiological features of chronic nitrofurantoin-induced lung disease and eventual clinical outcome. We retrospectively reviewed the medical records of 18 patients with chronic nitrofurantoin-induced lung disease who were seen at the Mayo Clinic in Rochester, Minn, from January 1, 1997, to December 31, 2002. The median age of the 18 patients was 72 years (range, 47-90 years) at the time of diagnosis; 17 (94%) were women. Onset of symptoms occurred after a median interval of 23 months (range, 10-144 months) following the initiation of nitrofurantoin therapy for the prevention of recurrent urinary tract infections. All patients presented with persistent dyspnea and cough associated with lung infiltrates detected on chest radiography. Ten computed tomograms were available for review and revealed bilateral areas of ground-glass opacities in all cases and showed subpleural Irregular linear opacities and patchy consolidation in some cases. Nitrofurantoin therapy was discontinued in all patients, and most improved subsequently; 9 patients received corticosteroid therapy. Chronic nitrofurantoin-induced lung disease is seen predominantly in older women who present with respiratory symptoms after a year or more of nitrofurantoin therapy. Associated radiological features are relatively nonspecific but usually include bilateral areas of ground-glass opacities on computed tomography of the chest. Cessation of nitrofurantoin therapy leads to improvement and suffices in the management of some patients, although corticosteroid therapy may be helpful in those more severely affected.

Giant Cell Interstitial Pneumonia: High-Resolution CT and Pathologic Findings in Four Adult Patients

The purpose of our study was to describe the high-resolution CT and pathologic findings of giant cell interstitial pneumonia (GIP) in four adult patients. GIP appears on high-resolution CT as ground-glass and irregular linear opacities in both lungs. These CT findings correspond histopathologically to areas of interstitial thickening caused by fibrosis and inflammatory cell infiltration and to areas of intraalveolar accumulation of macrophages and multinucleated giant cells.

Severe acute respiratory syndrome: temporal lung changes at thin-section CT in 30 patients.

To evaluate lung abnormalities on serial thin-section computed tomographic (CT) scans in patients with severe acute respiratory syndrome (SARS) during acute and convalescent periods. Serial thin-section CT scans in 30 patients (17 men, aged 42.5 years +/- 12.2 [SD]) with SARS were reviewed by two radiologists together for predominant patterns of lung abnormalities: ground-glass opacities, ground-glass opacities with superimposed linear opacities, consolidation, reticular pattern, and mixed pattern (consolidation, ground-glass opacities, and reticular pattern). Scans were classified according to duration in weeks after symptom onset. Longitudinal changes of specific abnormalities were documented in 17 patients with serial scans obtained during 3 weeks. Each lung was divided into three zones; each zone was evaluated for percentage of lung involvement. Summation of scores from all six lung zones provided overall CT score (maximal CT score, 24). Median CT scores increased from 1 in the 1st week to 12.5 in the 2nd week. Ground-glass opacities with or without smooth interlobular septal thickening and consolidation were predominant patterns found during the 1st week. Ground-glass opacities with superimposed irregular reticular opacities, mixed pattern, and reticular opacities were noted from the 2nd week and peaked at or after the 4th week. After the 4th week, 12 (55%) of 22 patients had irregular linear opacities with or without associated ground-glass opacities and CT scores greater than 5; five of these patients had bronchial dilatation. When specific opacities were analyzed in 17 patients, consolidation generally resolved completely (n = 4) or to minimal residual opacities; six (55%) of 11 patients with ground-glass opacities had substantial residual disease (CT scores > 5) on final scans. There is a temporal pattern of lung abnormalities at thin-section CT in SARS. Predominant findings at presentation are ground-glass opacities and consolidation. Reticulation is evident after the 2nd week and persists in half of all patients evaluated after 4 weeks. Long-term follow-up is required to determine whether the reticulation represents irreversible fibrosis.

The HRCT Features of Extrinsic Allergic Alveolitis

Exposure to organic dusts can produce an immune-mediated inflammatory response in sensitized individuals. The pulmonary disease caused by this response has been called extrinsic allergic alveolitis (EAA) or hypersensitivity pneumonitis. The clinical phases associated with this process have been termed acute, subacute, and chronic. There are corresponding imaging findings that are characteristic of each of these phases, although there is some overlap between the phases. The acute phase is characterized by confluent opacities that may mimic infection or edema. The subacute phase is characterized by centrilobular nodules, areas of ground-glass attenuation, a mosaic perfusion pattern, and air trapping on expiratory imaging. The chronic phase is characterized by subpleural irregular linear opacities with associated architectural distortion. Honeycombing may sometimes also be present. In the acute and subacute phases, the disease is predominantly in the lower lungs, whereas in chronic EAA the findings are predominant in the mid to upper lungs. Although the high-resolution computed tomography findings individually are nonspecific, the combination of the findings coupled with the distribution of the findings can often narrow the differential or allow a presumptive diagnosis of EAA to be made.

Steroid treatment based on the findings of transbronchial biopsy in idiopathic interstitial pneumonia.

This study was performed to find the rationale for administering steroids to patients with idiopathic interstitial pneumonia (IIP), which was unlikely to be usual interstitial pneumonia (UIP) but was not surgically biopsied. Among IIP patients in the file of the departments, nine patients who met the following criteria were selected for this study ("non-UIP" group): 1) transbronchial lung biopsy showed dense mononuclear cell infiltration in thickened alveolar septa; 2) chest radiograph and computed tomography showed irregular linear, reticular or ground-glass opacities with alveolar consolidation without honeycombing in the lung base; and 3) spirometry was performed before and after steroid therapy. Ten patients with pathologically confirmed nonspecific interstitial pneumonia ("NSIP" group) were also selected for the comparison. Baseline values and percentage increase of vital capacity (VC) after steroid therapy were plotted. Steroids improved VC in both groups of patients. After 1 yr of steroid therapy, percentage increase of VC in "non-UIP" was 28.8+/-7.7%, which was not significantly different from that in NSIP (30.0+/-11.7%). One "non-UIP" patient and one NSIP patient died after 6.4 and 4.3 yrs of follow-up, respectively. Patients with idiopathic interstitial pneumonia presenting cellular interstitial pneumonia in transbronchial lung biopsy, in addition to radiographic findings not typical for usual interstitial pneumonia, could expect a beneficial effect of steroids without undergoing surgical biopsy.

Idiopathic Interstitial Pneumonias: Radiologic-Pathologic Correlation

Idiopathic interstitial pneumonias are at present classified as one of four types: usual, nonspecific, acute, or desquamative. The acute form has the worst prognosis, followed by the usual and the nonspecific form; it is in desquamative cases that prognosis is best. At high-resolution CT, usual interstitial pneumonia, the most frequent type, manifests as patchy subpleural areas of ground-glass attenuation, irregular linear opacity, and honeycombing, which the nonspecific type, the second most frequent, appears as subpleural patchy areas of ground-glass attenuation with associated areas of irregular linear opacity. Acute interstitial pneumonia demonstrates extensive bilateral airspace consolidation and patchy or diffuse bilateral areas of ground-glass attenuation in middle and lower lung zones.

Polymyositis-dermatomyositis-associated interstitial lung disease.

We report findings in 70 patients with both diffuse interstitial lung disease and either polymyositis (PM) or dermatomyositis (DM). Initial presentations were most commonly either musculoskeletal (arthralgias, myalgias, and weakness) or pulmonary (cough, dyspnea, and fever) symptoms alone; in only 15 patients (21.4%) did both occur simultaneously. Pulmonary disease usually took the form of acute to subacute antibiotic-resistant community-acquired pneumonia. Chest radiographs and computed tomography most commonly demonstrated bilateral irregular linear opacities involving the lung bases; occasionally consolidation was present. Jo-1 antibody was present in 19 (38%) of 50 patients tested. Synchronous associated malignancy was present in 4 of 70 patients (5.7%). Surgical lung biopsies disclosed nonspecific interstitial pneumonia (NSIP) in 18 of 22 patients (81.8%), organizing diffuse alveolar damage (DAD) in 2, bronchiolitis obliterans organizing pneumonia (BOOP) in 1, and usual interstitial pneumonia (UIP) in 1. Treatment usually included prednisone in 40-60 mg/d dosages for initial control, followed by lower dose prednisone plus an immunosuppressive agent such as azathioprine or methotrexate for disease suppression. Survival was significantly better than that observed for historical control subjects with idiopathic UIP, and was more consistent with survival previously reported in idiopathic NSIP. There was no difference in survival between Jo-1 positive and Jo-1 negative groups.

Interstitial pneumonia in progressive systemic sclerosis: serial high-resolution CT findings with functional correlation.

The aim of our study was to assess the serial high-resolution CT findings and their correlation with the results of pulmonary function tests in patients with progressive systemic sclerosis (PSS) and interstitial pneumonia. The study included 40 patients with symptoms or signs of PSS and interstitial pneumonia, who underwent serial high-resolution CT scans (mean follow-up period 39 months). Seventeen patients simultaneously had serial pulmonary function tests (mean follow-up period 40 months). On high-resolution CT, the pattern and extent of parenchymal abnormalities were retrospectively analyzed. Serial changes on high-resolution CT were correlated with the changes of pulmonary function tests. On initial CT, areas of ground-glass opacity (mean +/- SD extent 17.7 +/- 12.3% in all patients), irregular linear opacity (4.4 +/- 4.4% in 36 patients), small nodules (3.9 +/- 12.5% in 28), consolidation (1.9 +/- 4.2% in 13), and honeycombing (1.9 +/- 3.8% in 12) were seen. The total disease extent (p = 0.042) and extents of ground-glass opacity (18.9 +/- 15.5%; p = 0.04) and honeycombing (5.0 +/- 7.2%; p = 0.002) increased significantly on follow-up CT. Both forced vital capacity (from 2.4 +/- 0.4 to 2.0 +/- 0.4 L; p = 0.002) and forced expiratory volume in 1 s (from 2.0 +/- 0.4 to 1.6 +/- 0.3 L; p = 0.013) decreased significantly on follow-up examination. The increase in the extent of honeycombing on CT correlated significantly with the decrease in diffusing capacity for carbon monoxide (r = -0.411, p = 0.049). In patients with PSS and interstitial pneumonia, the overall extent of disease and extents of honeycombing and ground-glass opacity increase significantly on follow-up CT. Increase of honeycombing correlates well with decrease of diffusing capacity for carbon monoxide.