非特异性间质性肺炎患者的高分辨率CT表现及其病理学特点

目的探讨非特异性间质性肺炎（NSIP）的高分辨率CT（HRCT）影像学特点及其病理学改变。方法对9例经开胸肺活组织检查（简称肺活检）证实为NSIP患者的HRCT与病理表现进行回顾性分析。结果9例NSIP患者HRCT主要表现为两侧斑片状磨玻璃影、实变影、伴或不伴不规则线影和牵拉性支气管和细支气管扩张，分布在中、下肺的外周，但未见蜂窝影。HRCT表现为磨玻璃影伴或不伴不规则线影和牵拉性支气管和细支气管扩张的区域，其相应的病理改变为不同程度的炎性细胞浸润和纤维化引起的肺间质增厚，病变时相基本一致；在HRCT表现为实变影的区域，其病理改变表现为间质纤维化病变程度重于间质炎症；也可表现为闭塞性细支气管炎伴机化性肺炎样改变，肺泡腔内泡沫状细胞聚集，镜下可见蜂窝肺内有黏液潴留等病理改变。结论NSIP患者的HRCT表现有一定的特征性；根据病理特点并结合临床资料及HRCT表现可初步诊断为NSIP。     

Adenoviral bronchopneumonia in an immunocompetent adult: computed tomography and pathologic correlations

Acute febrile lung disease associated with "patchy ground-glass pattern" on high-resolution computed tomography (HRCT) of the lung in an immunocompromised patient is suggestive of Pneumocystis carinii pneumonia; however, in an immunocompetent young person, it is suggestive of an atypical pneumonia, including viral bronchopneumonia. We studied a 31-year-old man who presented with fever, cough and hypoxemia. HRCT showed bilateral patchy ground-glass opacification. HIV test was negative and lung biopsy specimen grew adenovirus on viral culture. Histopathology of the lung was compatible with bronchopneumonia. In patients without HIV who present with acute lower respiratory infections and patchy ground-glass opacification on HRCT, adenoviral bronchopneumonia should be included in the differential diagnosis.     

Imaging of unusual diffuse lung diseases

PURPOSE OF REVIEW: Computed tomography scans are commonly used in imaging lung diseases. As more information accumulates, patterns of rare or new diseases on CT scans are being increasingly reported. Several pulmonary diseases have distinguishing features, which are better delineated on high resolution CT scans than plain chest radiographs. The radiographic features of unusual diffuse lung diseases published in the past two years are described. RECENT FINDINGS: Severe acute respiratory syndrome generally manifests as focal or diffuse bilateral areas of consolidation on chest radiography and reticulation with ground-glass attenuation commonly seen on CT scans. A normal HRCT rules out the diagnosis of Pneumocystis carinii pneumonia while a normal chest radiograph does not. Immunocompromised patients without AIDS, who have CMV pneumonia, generally demonstrate a combination of ground-glass attenuation, air-space consolidation, and small nodules on HRCT. Nodules less than 10 mm in size in immunocompromised patients are highly suggestive of viral infections. Bronchial wall thickening on HRCT associated with cavitating nodules is suggestive of Wegner granulomatosis in the appropriate clinical setting. Small cysts may be seen in a minority of patients with subacute hypersensitivity pneumonitis and centrilobular emphysema in chronic farmer's lung. Reversed halo sign has a high specificity for cryptogenic organizing pneumonia. The triad of ground-glass opacities, ill-defined centrilobular nodules and cysts and focal areas of air trapping is highly suggestive of subacute hypersensitivity pneumonitis. SUMMARY: Familiarizing with radiographic and CT scan patterns may help the clinician to exclude certain diagnoses and narrow the differential diagnosis for others.     

Recent advances in radiology of the interstitial lung disease

Idiopathic interstitial pneumonias are currently classified into four categories of disease: usual, desquamative, and acute interstitial pneumonia, and nonspecific interstitial pneumonia and fibrosis. Usual interstitial pneumonia appears on high-resolution CT (HRCT) as patchy subpleural areas of ground-glass opacity, irregular lines, and honeycombing. Desquamative interstitial pneumonia presents as patchy subpleural areas of ground-glass opacity in middle and lower lung zones. Acute interstitial pneumonia presents as extensive bilateral airspace consolidation and patchy or diffuse bilateral areas of ground-glass opacity. Nonspecific interstitial pneumonia and fibrosis appears as patchy or diffuse areas of ground-glass opacity with associated areas of consolidation and irregular lines. In a subset of patients with diffuse lung disease (especially in those with chronic interstitial lung disease), accurate diagnosis can be made with HRCT findings only, without surgical biopsy. However, HRCT provides a lower level of confidence in the diagnosis of acute or subacute interstitial lung disease such as infection, diffuse alveolar damage, drug reaction, or hemorrhage. Additional expiratory HRCT scans and scans with patients prone help to narrow the differential diagnosis among various diseases and help diagnose or exclude subtle disease in the posterior part of the lung, respectively. HRCT provides a reproducible method for evaluating the global extent of disease. It also discriminates between fibrotic and reversible inflammatory diseases.     

High-resolution CT findings in mild pulmonary fat embolism

OBJECTIVE: The aim of this article is to describe the high-resolution CT (HRCT) findings in mild cases of fat embolism syndrome (FES). MATERIAL AND METHODS: Nine patients with FES were examined with HRCT of the lungs (collimation, 1 mm/edge-enhancement algorithm). The median age of the patients was 26 years (range, 17 to 35 years). Five cases were included prospectively, and four cases were reviewed retrospectively. Of the major clinical criteria for FES, respiratory signs were present in six patients, CNS signs were present in two patients, and petechiae was present in six patients. HRCT patterns were recorded and analyzed. The type of injury and FES-associated clinical findings were also recorded. RESULTS: HRCT findings included ground-glass opacities in seven patients, associated with thickened interlobular septa in five patients and a patchy distribution resulting in a geographic appearance in four patients. A nodular pattern was observed in two patients. Resolution of the abnormalities occurred within 16.4 days (range, 7 to 25 days). CONCLUSION: The HRCT findings of mild fat embolism consist of bilateral ground-glass opacities and thickening of the interlobular septa. Centrilobular nodular opacities are present in some patients.     

SARS: radiological features

Air-space disease is typical in severe acute respiratory syndrome (SARS) and may be indistinguishable from pneumonia of other causes. In the majority of patients, ground glass opacities on chest radiographs progress rapidly to focal, multifocal or diffuse consolidation. Unilateral involvement is common in the early acute phase, becoming bilateral at maximal lung involvement. Generally, radiographic opacities peak between 8 and 10 days after onset of illness, with radiographic scores reflecting temporal changes in clinical and laboratory parameters such as oxygen saturation (SaO₂) and liver transaminases. Pleural effusions, cavitating consolidation and mediastinal lymphadenopathy are not typical radiographic features. Pneumomediastinum and pneumothoraces are complications that are associated with extensive disease, with or without assisted ventilation.
The utility of high resolution computed tomography (HRCT) and CT scans lies in the confirmation of airspace opacities in cases with normal initial chest radiographs that have strong contact history and signs and symptoms highly suspicious of SARS during the outbreak, allowing early treatment and prompt isolation. The characteristic HRCT feature in the acute phase is ground-glass opacities with smooth interlobular septal thickening, sometimes with consolidation in a subpleural location, which progress rapidly to involve other areas of the lungs. Temporal lung changes documented on HRCT suggest that some residual opacities found may not be reversible.     

Leflunomide-related lung injury in patients with rheumatoid arthritis: imaging features

Imaging findings of 26 cases of leflunomide (Arava)-related acute lung injury were analyzed. Thirteen cases had pre-existing interstitial pulmonary disease on chest X-ray or computed tomography. The main features of clinically determined leflunomide-induced acute lung injury were similar to those caused by other drugs: diffuse or widespread patchy ground-glass opacities and/or consolidation, frequently accompanied by septal thickening and intralobular reticular opacities. We categorized these findings into four patterns: diffuse alveolar damage (DAD), acute eosinophilic pneumonia, hyperreaction, and cryptogenic organizing pneumonia. The DAD group had a higher mortality rate, but statistically not a significant one. It is impossible to exclude infectious disease such as pneumocystis carinii pneumonia based on imaging findings, and detailed correlation of imaging findings with clinical and laboratory findings is essential in order to make a correct diagnosis.     

A case of bacterial pneumonia caused by Streptococcus dysgalactiae subsp. equisimilis, showing patchy consolidations resembling organizing pneumonia]

In December, 2001, a 67-year-old woman was given a diagnosis of having systemic sclerosis and organizing pneumonia. Steroid treatment improved her condition, and she received no further medication for approximately three years thereafter. In October 2005, she visited Kurume University Hospital because of cough and fever. Chest X-ray film and high-resolution computed tomography (HRCT) showed bilateral patchy consolidation with air-bronchogram sign and ground-glass opacities, predominantly in the right lower lung field, suggesting relapse of organizing pneumonia. However, bronchoalveolar lavage fluid (BALF) analysis showed an increase of neutrophils (79%) and the CD4/CD8 ratio (4.04). Streptococcus dysgalactiae subsp. equisimilis (beta-hemolytic, Lancefield group G) was detected by bacterial culture of the BALF. Treatment with sulbactam sodium/ampicillin sodium (SBT/ ABPC) rapidly improved her symptoms. The patchy consolidations on chest X-ray and HRCT also disappeared after the treatment. On the basis of these clinical and bacteriological findings, we diagnosed the patient as having bacterial pneumonia caused by Streptococcus dysgalactiae subsp. equisimilis.     

Influenza A (H1N1) pneumonia: HRCT findings

OBJECTIVE:

To describe aspects found on HRCT scans of the chest in patients infected with the influenza A (H1N1) virus.

METHODS:

We retrospectively analyzed the HRCT scans of 71 patients (38 females and 33 males) with H1N1 infection, confirmed through laboratory tests, between July and September of 2009. The HRCT scans were interpreted by two thoracic radiologists independently, and in case of disagreement, the decisions were made by consensus.

RESULTS:

The most common HRCT findings were ground-glass opacities (85%), consolidation (64%), or a combination of ground-glass opacities and consolidation (58%). Other findings were airspace nodules (25%), bronchial wall thickening (25%), interlobular septal thickening (21%), crazy-paving pattern (15%), perilobular pattern (3%), and air trapping (3%). The findings were frequently bilateral (89%), with a random distribution (68%). Pleural effusion, when observed, was typically minimal. No lymphadenopathy was identified.

CONCLUSIONS:

The most common findings were ground-glass opacities and consolidations, or a combination of both. Involvement was commonly bilateral with no axial or craniocaudal predominance in the distribution. Although the major tomographic findings in H1N1 infection are nonspecific, it is important to recognize such findings in order to include infection with the H1N1 virus in the differential diagnosis of respiratory symptoms.     

Pulmonary findings in Churg–Strauss syndrome in chest X-rays and high resolution computed tomography at the time of initial diagnosis

Churg–Strauss syndrome (CSS) is a rare, systemic, necrotizing, small- and middle-sized vessel vasculitis which is accompanied by blood eosinophilia, eosinophil infiltration of various tissues, and bronchial asthma. The lungs are the organs most often involved in CSS. The aim of this study was a retrospective evaluation of the pulmonary findings in chest X-rays and high resolution computed tomography (HRCT) in CSS patients at the time of initial diagnosis and to determine their frequency, character, and location. Seventeen CSS patients were studied (12 women; 5 men; aged 29–56 years). In all patients at the time of initial diagnosis, chest X-rays were performed, and in 15 patients, HRCT was performed additionally. The radiological images were evaluated independently by two radiologists who reached a decision by consensus. Out of 17 patients studied, chest X-rays revealed parenchymal abnormalities in 11, pleural effusion in three, and bronchial wall thickening in one. In five patients, no abnormalities in chest X-rays were found. In HRCT, abnormalities were found in all patients (15 patients, 100%). Predominant HRCT findings consisted of: ground-glass opacities and consolidations found in 13 patients (86.7%). Additionally, in four patients, pulmonary micronodules were described; in ten, interlobular septal thickening; in three, linear opacities; in ten, bronchial wall thickening and/or bronchial dilatation; and in three, pleural effusions. Ground-glass opacities and consolidation abnormalities distribution pattern were peripheral in seven and random in six patients. In patients with CSS, the most common pulmonary radiological findings are parenchymal opacities, which may be peripheral or random in distribution. Pathologic changes were found in 70.6% of patient in chest X-rays, and in 100%, when HRCT was performed. These changes are nonspecific; however, they should be not overlooked, as they may help in establishing the diagnosis and suggest the prognosis.     

Case of drug-induced pneumonia possibly due to mefloquine (antimalarial drug)]

A 59-year-old man took mefloquine (antimalarial drug), total dose of 1,000 mg, to prevent malaria before and during traveling to South Africa. Three weeks after the first administration, he was admitted complaining of fever and dyspnea. Chest HRCT showed ground-glass opacities and consolidation in both lung fields. Withdrawal of mefloquine and treatment with corticosteroid resulted in improvement of the clinical findings. From the clinical course, we considered this case to be mefloquine-induced pneumonia. Mefloquine may have caused pulmonary toxicity.     

HRCT findings of proximal interruption of the right pulmonary artery

The purpose of this study is to present the characteristic HRCT findings of the lung parenchyma in patients with proximal interruption of the right main pulmonary artery. HRCT findings of proximal interruption of the right pulmonary artery demonstrated reticular opacities, septal thickening, subpleural consolidation, cystic lung changes, and pleural thickening in all 5 patients; bronchial dilation and bronchial wall thickening in 4 patients; and subpleural ground glass opacity (GGO) in 3 patients. The changes may be caused by absent pulmonary artery perfusion and development of systemic vessel collateralization.     

Ability of high-resolution computed tomography to distinguish Mycoplasma pneumoniae pneumonia from other bacterial pneumonia: Significance of lateral bronchial lesions,less air bronchogram,and no peripheral predominance

BackgroundNo study has investigated the capability of high-resolution computed tomography (HRCT) to detect a lateral bronchus abnormality, degree of air bronchogram, and distribution of affected lesions in the diagnosis of Mycoplasma pneumoniae pneumonia (MPP).MethodsWe prospectively enrolled patients with serologically-confirmed MPP or culture-confirmed other bacterial pneumonia (OBP). The distribution of affected areas, abnormalities in lateral bronchial lesions, the degree of air bronchogram, and previously reported findings on HRCT were evaluated for MPP and OBP. Predictive HRCT findings for MPP were determined by logistic regression analysis. We provisionally designed our HRCT criteria (negative, probable, or highly suspected) for diagnosing MPP and investigated the diagnostic yield of the HRCT criteria.ResultsSixty-three MPP and 126 OBP patients were included in this study. Logistic regression analysis showed that the absence of peripheral predominance, bronchial wall thickening, lateral bronchial wall thickening, intralobular or lobular ground-glass opacities, intralobular ground-glass opacities connected to a lateral bronchus, and less air bronchogram in infiltrates were significant predictors of MPP. Our HRCT criteria showed that the sensitivity and specificity in negative, probable, and highly suspected MPP were 0.0 and 0.33, 1.0 and 0.69, and 0.5 and 0.98, respectively.ConclusionsHRCT had considerable ability to detect a lateral bronchial abnormality and to diagnose or rule out MPP based on the distribution of affected areas, abnormalities in lateral bronchial lesions, and the degree of air bronchogram in the infiltrates.     

Organizing pneumonia: chest HRCT findings

OBJECTIVE:

To determine the frequency of HRCT findings and their distribution in the lung parenchyma of patients with organizing pneumonia.

METHODS:

This was a retrospective review of the HRCT scans of 36 adult patients (26 females and 10 males) with biopsy-proven organizing pneumonia. The patients were between 19 and 82 years of age (mean age, 56.2 years). The HRCT images were evaluated by two independent observers, discordant interpretations being resolved by consensus.

RESULTS:

The most common HRCT finding was that of ground-glass opacities, which were seen in 88.9% of the cases. The second most common finding was consolidation (in 83.3% of cases), followed by peribronchovascular opacities (in 52.8%), reticulation (in 38.9%), bronchiectasis (in 33.3%), interstitial nodules (in 27.8%), interlobular septal thickening (in 27.8%), perilobular pattern (in 22.2%), the reversed halo sign (in 16.7%), airspace nodules (in 11.1%), and the halo sign (in 8.3%). The lesions were predominantly bilateral, the middle and lower lung fields being the areas most commonly affected.

CONCLUSIONS:

Ground-glass opacities and consolidation were the most common findings, with a predominantly random distribution, although they were more common in the middle and lower thirds of the lungs.     

重症甲型H1N1流行性感冒肺炎高分辨率计算机X线断层扫描表现的动态变化

目的 探讨重症甲型H1N1流行性感冒(流感)肺炎高分辨率计算机X线断层扫描(HRCT)表现及动态变化.方法 回顾性分析36例临床确诊的重症甲型H1N1流感肺炎1个月内100次HRCT资料,分析其肺部病变出现、进展及吸收时间和影像学特点.结果 发病初期行HRCT检查(3d内)6例,小片磨玻璃密度影3例,小片实变影3例.病变进展期(发病3d后)36例患者均表现为双肺多发弥漫分布的磨玻璃密度影伴或不伴实变,其中主要呈弥漫磨玻璃密度影9例,占25.0％；弥漫磨玻璃密度影伴实变影20例,占55.6％;主要呈肺实变影7例,占19.4％；合并胸膜病变10例,占27.8％.在发病(8.0±2.6)d内病变进展最为明显,发病(16.0±4.8)d后为吸收期,36例病变均明显吸收,23例出现肺间质增生,占63.9％.病灶的动态变化分三型,包括先进展后吸收型、进展和吸收并存后吸收型和逐渐吸收型,以先进展后吸收型为主,占41.7％.结论 HRCT可准确显示重症甲型H1N1流感肺炎的病变形态和范围,监测其动态变化.     

Pulmonary involvement in sarcoidosis: CT findings at diagnosis and their changes at follow-up in cases without corticosteroid treatment]

To review the pulmonary CT findings in sarcoidosis at diagnosis, and to analyze the change in each finding at follow-up in cases without corticosteroid treatment. The study included 21 cases of pulmonary involvement of sarcoidosis. We analyzed the presence or absence and grade of each HRCT finding: bronchial wall thickening, enlargement of vascular shadows, pleural involvement, septal thickening, small nodules, ground-glass opacities, centrilobular opacities, consolidation, nodules, and volume loss. Afterwards, we compared the initial CT with the follow-up CT, and described the change of each finding as "improved" or "not improved". Furthermore, we decided if each case as a whole was improved or not after considering all of the pulmonary CT findings. Twelve of the 21 cases were improved. Small nodules, ground-glass opacities, centrilobular opacities, and nodules had improved in more than 50% of the cases since the initial CT. However, pleural involvement (10/11) and volume loss (6/9) were not improved. Pleural involvement and volume loss correlated the radiological irreversibility (p < 0.05). Of the several pulmonary CT findings in sarcoidosis, pleural involvement and volume loss show the highest rates of irreversible pulmonary changes.     

Primary pulmonary cryptococcosis exhibiting the radiological characteristics of bronchiolitis obliterans organizing pneumonia

A 31-year-old male was admitted to Toranomon Hospital because of a cough and bilateral patchy infiltrates shown on the chest radiograph. He had been well prior to admission. Chest CT scan revealed patchy areas of air-space consolidation with air-bronchogram and adjacent ground-glass opacities, suggestive of bronchiolitis obliterans organizing pneumonia (BOOP). Transbronchial lung biopsy specimen confirmed the formation of epithelioid cell granulomas without necrosis and the coexistence of organizing pneumonia. The titer of serum cryptococcal antigen increased to 1:256. According to these findings, a diagnosis of primary pulmonary cryptococcosis was made, although cryptococci were neither recognized in the specimen nor cultured from the bronchial lavaged fluid. Chest radiograph showed spontaneous regression in a short period of time. However, itraconazole was administered for the prolonged cough, and the symptom disappeared. The titer of serum cryptococcal antigen decreased to 1:16 after the therapy. Pulmonary cryptococcosis should be considered as one of the differential diagnoses when chest CT scan shows combined air-space consolidation and ground-glass opacities.     

Respiratory bronchiolitis-associated interstitial lung disease

Respiratory bronchiolitis-associated interstitial lung disease (RBILD) can be viewed as an exaggerated respiratory bronchiolitic response to cigarette smoke. The histologic, high-resolution computed tomographic (HRCT) and bronchoalveolar lavage (BAL) features of RBILD overlap substantially with those of respiratory bronchiolitis, with the diagnosis of RBILD being based upon the severity of disease, as judged by symptoms, clinical signs, the severity of lung function impairment, and the extent of abnormalities on HRCT. Typical histologic appearances consist of an accumulation of pigmented macrophages within respiratory bronchioles, associated with peribronchial chronic inflammatory cell infiltration and, variably, peribronchial fibrotic alveolar septal thickening. Characteristic HRCT findings include poorly defined centrilobular micronodules, patchy limited ground-glass attenuation, bronchial wall thickening, and areas of regional hypoattenuation. The ventilatory defect is often mixed but is usually predominantly restrictive. The diagnosis of RBILD is often made on clinical and HRCT criteria, with BAL findings providing useful diagnostic support, but a thoracoscopic biopsy continues to be required when other features are atypical. RBILD may regress with discontinuation of smoking but often persists with no functional improvement despite smoking cessation and treatment. Nonetheless, the course tends to be benign, without inexorable deterioration. This article outlines the rationale for viewing RBILD and desquamative interstitial pneumonia as separate entities, rather than two ends of the same disease spectrum (based upon overlapping histologic and HRCT features).     

Four cases of respiratory infections caused by Legionella pneumophila serogroup 3

Legionella pneumonia tends to be severe and is known to be fatal. Introduction of the urinary Legionella antigen test and changes in the Infectious Disease Law have led to increased numbers of reports, and milder cases are now occasionally seen. We experienced three cases demonstrating mild respiratory infections and one case demonstrating nosocomial pneumonia associated by Legionella pneumophila serogroup 3. Case 1 showed multiple ground-glass opacities on HRCT and productive cough. Cases 2 and 3 showed abnormal findings on chest X-ray, and chest CT findings in both cases suggested chronic respiratory infection. Case 4 experienced fever and hypoxia, and pulmonary edema was noted on X-ray. All of them four cases were diagnosed with respiratory infections isolated L. pneumophila serogroup 3 by culture results, and three of them cases were treated in the outpatient clinic. Thus, milder cases of Legionella pneumonia may be encountered during routine care, and tests for Legionella should be performed in such cases.     

Leptospirosis of the lung: high-resolution computed tomography findings in five patients

The authors report the high-resolution computed tomography findings in five patients with diffuse pulmonary hemorrhage caused by serologically proven leptospirosis. The main findings consisted of extensive ground-glass opacities and patchy areas of airspace consolidation.