对严重急性呼吸综合征的再认识——胸部影像特点结合临床资料对早期诊断严重急性呼吸综合征的意义

目的:分析2004年在北京发生的严重急性呼吸综合征(SARS)早期胸部影像特点及相对应的临床表现,并对比2003年资料,探讨其早期的表现,为临床提供借鉴。方法:对2004年在北京地坛医院住院的7例SARS患者的临床、化验、胸片及高分辨CT(HRCT)资料进行回顾性分析。结果:6例均急性起病,体温>38℃,无上呼吸道卡他症状,发热第1周出现肺部局灶或多段分布的阴影,阴影常呈类圆型,多表现为磨玻璃影,其内可见小叶间隔增厚,部分表现肺实变影,病灶内可见支气管气像,无坏死或空洞病灶,无肺门及纵隔淋巴结肿大,无胸腔积液。发热的第2周,肺部阴影迅速扩大,或发展至对侧,出现呼吸困难,在出现肺部阴影进展时,给予糖皮质激素,阴影在2~3d内明显吸收,临床症状改善。病程早期,白细胞不增高,淋巴细胞和血小板偏低,血乳酸脱氢酶(LDH)在第2周明显增高,丙氨酸氨基转移酶(ALT)和天冬氨酸氨基转移酶(AST)在第2或第3周开始增高。结论:对于急性起病、发热、白细胞不高、胸部HRCT表现类圆型磨玻璃阴影伴小叶间隔增厚或肺实变、短期抗生素治疗无效的患者应提高警惕,注意排除SARS。     

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.     

Imaging in sarcoidosis

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology that may involve virtually any organ. Pulmonary involvement predominates, but sarcoidosis can involve multiple organs, with or without concomitant lung involvement. Aberrations on chest radiographs are present in more than 90% of patients with sarcoidosis. Bilateral hilar lymphadenopathy, with or without lung parenchymal infiltrates, is typical but a wide range of chest radiographic patterns may be observed. This article discusses the characteristic chest radiographic features of sarcoidosis and the prognostic value of the radiographic staging classification as espoused by Scadding more than 4 decades ago. Thin-section high-resolution computed tomographic (HRCT) scans more clearly elucidate the intrathoracic lesions observed in sarcoidosis and may discriminate active inflammation from end-stage fibrosis. Although HRCT is not necessary to manage all cases of sarcoidosis, HRCT may be invaluable in SELECTED patients with stage II or III sarcoidosis to discriminate alveolitis (which may be amenable to therapy) from fibrosis. Additionally, radionuclide techniques may have a role in extrapulmonary sarcoidosis (particularly when central nervous system or cardiac involvement is suspected). We review the salient features and role of magnetic resonance imaging and diverse radionuclide techniques to diagnose or follow selected cases of extrapulmonary sarcoidosis.     

High resolution computed tomography in systemic sclerosis. Real diagnostic utilities in the assessment of pulmonary involvement and comparison with other modalities of lung investigation

Summary The real utility of high resolution computed tomography (HRCT) for early detection of lung involvement was investigated in eighteen patients affected with systemic sclerosis (SSc). The results obtained from HRCT have been compared with traditional (chest radiographs, pulmonary function tests (PFT)) and nontraditional (ventilation and perfusion scintiscan) modalities of lung investigation. A significant statistical correlation (p<0.001) between HRCT scans and chest radiographs was observed. Moreover, HRCT was more sensitive in the detection of early pulmonary interstitial involvement and more accurate in the assessment of interstitial fibrosis in cases with severe lung involvement. A statistical correlation (P<0.001) between HRCT and the modalities of investigation of alveolo-capillary membrane — as PFT and ventilation scintiscan — was also observed. These results indicate that in SSc HRCT may be a useful technique for assessing early pulmonary involvement and for complementing other methodologies of investigation of lung function.     

Radiographic features of Legionnaires' disease.

Serial chest radiographs of 35 patients with confirmed Legionnaires' disease were evaluated. A unilateral, unilobar alveolar infiltrate was, in general, the initial radiographic finding. Progression to consolidation or to new areas of involvement was typical. Every lobe was involved, but lower lobe involvement was most common. Pleural effusion was often present. Cavitation was not seen. Radiographic progression for several days following institution of therapy, and despite clinical response, was noted. In patients who survived, radiographic improvement of abnormalities was usually apparent within two weeks of therapy. Aradiographic spectrum exists and, although many features are typical, no single feature is pathognomonic.     

High resolution computed tomography in early scleroderma lung disease.

Seventeen patients with early systemic sclerosis (SSc) underwent high resolution computed tomography (HRCT) of the chest to evaluate dyspnea and/or abnormal pulmonary function tests (PFT). All patients were assigned a dyspnea score and each had routine chest radiography (CXR). Bronchoalveolar lavage (BAL) was performed on 10 patients. HRCT was abnormal in 15 patients (88%), while CXR was abnormal in only 10 patients (59%). Mediastinal lymphadenopathy was detected in 7 patients (41%). Disease duration, dyspnea score, and forced vital capacity (FVC) did not correlate with HRCT score. However, trends toward higher total BAL cell counts and higher BAL neutrophil counts were noted in patients with ground glass opacities on HRCT, and BAL lymphocyte counts were significantly higher in such cases. HRCT is superior to CXR for detecting early interstitial lung disease in SSc, but patient history and FVC correlate poorly with HRCT findings. Ground glass opacities on HRCT may reflect active alveolitis, and mediastinal lymphadenopathy associated with SSc lung disease may be a consequence of pulmonary inflammation.     

Diagnostic imaging of diffuse infiltrative disease of the lung

Plain chest radiography remains the first diagnostic approach to diffuse infiltrative lung disease but has limited diagnostic sensitivity and specificity. Many diseases remain occult or are not correctly assessed using chest X-ray, appearing as a nonspecific 'reticulonodular pattern'. High-resolution CT (HRCT) is actually the recommended imaging technique in the diagnosis, assessment, and follow-up of these diseases, allowing also the evaluation of the effectiveness of the medical therapy and the selection of the type and the location of the biopsy when required. Appropriate techniques must be used to acquire high-quality HRCT scans, with the thin collimation and high spatial reconstruction algorithm being the most important factors. A nodular pattern, linear and reticular opacities, cystic lesions, ground-glass opacities and consolidations are the most common HRCT patterns of diffuse infiltrative lung disease. This article reviews the role of chest radiography and HRCT in the diagnosis and assessment of these diseases, the technical aspects of HRCT, its clinical indications and the radiological pattern of the most common types of chronic diffuse infiltrative lung disease.     

Chest radiographic findings in cystic fibrosis.

Radiographic imaging modalities that have been applied to the staging and prognostication of the lung lesion in cystic fibrosis (CF) include conventional chest radiographs, computed tomography (CT), and magnetic resonance imaging (MRI). Conventional chest radiographs are usually adequate to detect the salient radiographic features of CF and provide objective parameters for longitudinal disease progression. Although the lung manifestations of CF can be highly variable most patients with CF demonstrate some of the classic chest radiographic findings that reflect chronic bronchiectasis: hyperinflation, bronchial thickening and dilatation, peribronchial cuffing, mucoid impaction, cystic radiolucencies, an increase in interstitial markings, and scattered nodular densities. Complications of advanced CF include atelectasis, mucoid impaction, pneumothorax, pneumomediastinum, pulmonary hemorrhage, cardiomegaly, and enlargement of the pulmonary artery with cor pulmonale. Scoring systems have been developed to grade the chest radiograph in CF and to more accurately quantitate the severity of disease. Currently, the Brasfield system is in widest use. These radiographic scoring systems correlate well with pulmonary function data in both the pediatric and adult CF populations. High-resolution computed tomography (HRCT) is clearly more sensitive and accurate than conventional chest radiography in delineating the extent and severity of bronchiectasis and other parenchymal and airway lesions in CF. Quantifiable scoring systems using HRCT have been developed to assess disease severity in CF. The use of MRI in the clinical management of CF has been limited. MRI may be helpful in determining the cause of linear lung markings, differentiating mucous plugging, and peribronchial thickening from normal pulmonary blood vessels. MRI is an excellent imaging modality to differentiate hilar or mediastinal adenopathy from blood vessels or mediastinal fat.     

Computed tomographic scanning in sarcoidosis

Sarcoidosis is a granulomatous disease of unknown etiology that involves the lungs or intrathoracic lymph nodes in more than 90% of patients. The clinical spectrum of sarcoidosis is protean, but pulmonary manifestations often dominate. Chest radiographs are abnormal in 90 to 95% of patients with sarcoidosis; the most characteristic feature is bilateral hilar lymphadenopathy (BHL), present in 50 to 80% of patients. Pulmonary parenchymal infiltrates are present in 25 to 50% of patients. In this article, we review the radiographic features of sarcoidosis (both typical and atypical), and the impact of chest radiographic stage on long-term prognosis. Computed tomographic (CT) scans are more sensitive than chest radiographs in delineating parenchymal, mediastinal, and hilar structures, and distinctive CT patterns may be virtually pathognomonic for sarcoidosis in some patients. Routine CT scan is not appropriate to diagnose or manage sarcoidosis, but CT may be invaluable in patients with atypical clinical or chest radiographic findings or specific complications of sarcoidosis (pulmonary or extrapulmonary), or to assess prognosis. High-resolution thin-section CT scans (HRCT) may be helpful in selected patients with stage II or III sarcoidosis to discriminate active inflammation from irreversible fibrosis. This article discusses the salient HRCT features of sarcoidosis, accuracy of CT in the differential diagnosis, and correlations of HRCT with disease extent and activity, pulmonary function, and lesion reversibility.     

SARS的影像学诊断

目的 探讨严重的急性呼吸综合征(SARS)的影像学特征。方法 回顾临床诊断的50例SARS的影像学检查方法与诊断价值。结果 50例均行胸片(后前位和右侧位或左侧位)检查，其中12例患多次摄床边胸片，11例患行HRCT检查，未行MRI检查。50例胸片均发现阴影，双侧肺内片状密度增高影27例(54％)和／或磨玻璃样影22例(44％)，一侧肺内片状密度增高影19例(38％)，双侧肺内间质改变呈网状阴影4例f病变短期内呈游走性和进展。吸收慢并且恢复后部分病例肺内纤维化；1例经胸部透视对肺内和胸膜病变进行了鉴别；11例经HRCT检查进一步了解肺内和纵隔病变。结论 凡临床诊断或疑似SARS病例短期内应进行影像学检查，并进行短期拍胸片动态观察。     

北京地区患严重急性呼吸综合征医务人员的胸部高分辨率CT与肺功能随访分析

目的分析医务人员患严重急性呼吸综合征(SAILS)后肺部恢复情况。方法对北京地区2003年在医疗工作岗位上感染SAILS病毒发病的456例医务人员，于2003年12月至2004年2月进行胸部高分辨率CT(HRCT)和肺功能测定。结果在406例进行肺通气功能检测的患者中，31例(7．64％)异常；404例进行肺弥散功能检测，其中165例(40．84％)异常；434例进行胸部HRCT检查，151例(34．79％)异常，表现为磨玻璃密度阴影、网格状阴影和胸膜下弧线影等；395例同时接受肺弥散功能检测和胸部HRCT检查，55例(13．92％)两项均异常，且HRCT显示双肺病变典型者的肺弥散功能较HRCT正常者有显著的下降，两组差异有统计学意义。结论SAILS病毒感染的医务人员在康复出院后尚有部分患者遗留肺功能降低、胸部HRCT异常等问题，提示肺部损伤为慢性改变，应对此类患者继续随访。     

Desquamative interstitial pneumonia may progress to lung fibrosis as characterized radiologically

Background and objective: In some patients, desquamative interstitial pneumonia may progress to lung fibrosis. The aim of this study was to assess the long‐term radiological follow‐up results in patients with desquamative interstitial pneumonia. Methods: Among 75 patients suspected of having desquamative interstitial pneumonia, 31 who fulfilled the criteria were included in this study. Clinical characteristics at presentation, responses to treatment and long‐term follow‐up were evaluated. Results: The 31 patients were predominantly males (94%), and the mean age was 55 years; 93% (28/30) had a history of smoking. The clinical findings included high serum levels of lactate dehydrogenase and immunoglobulin G. Bronchoalveolar lavage (26 patients, 84% of cases) frequently showed an increased percentage of eosinophils (mean 17%). Computed tomography (CT) or high resolution (HR) CT at presentation showed ground glass opacities and/or consolidation in all patients, with one third of patients also showing thin‐walled cysts within the ground glass opacities. There was no honeycombing on CT or HRCT scans at presentation. Corticosteroid therapy was effective early in the course of the disease; long‐term follow‐up (mean 99 months) of 31 patients showed only one death due to progression of the disease, but long‐term follow‐up of 14 patients (mean 125 months) by HRCT showed the development of new thin‐walled cysts and honeycombing in five and lung cancer in four patients, respectively. Conclusions: In a proportion of patients, desquamative interstitial pneumonia may progress to lung fibrosis with honeycombing on HRCT, despite therapy.     

Measles pneumonia presenting with multiple nodular opacities on chest radiographs]

A 22-year-old woman presented with fever, cough, and maculopapular erythematous rash on hands and feet. These symptoms developed 14 days after the onset of natural measles in the patient's daughter. Chest radiographs obtained on the first examination showed multiple nodular opacities and infiltrates in the left and right lung fields. Serological examinations disclosed elevated levels of the specific IgM antibody and a remarkably elevated hemagglutination inhibition (HI) titer, indicating a recent measles infection. The patient's symptoms, skin eruptions, and abnormal chest radiograph findings disappeared after several days. However, chest computed tomographic scans taken 8 months after the initial examination revealed small, residual nodular opacities. Other than the fact that the patient had received attenuated measles virus vaccine, these findings were typical of the clinical course for atypical pneumonia. We concluded that in the differential diagnosis of multiple nodular opacities on chest radiographs, adequate attention should be given to pulmonary involvement of measles infection.     

Radiological and clinical findings in acute and chronic exogenous lipoid pneumonia

PURPOSE: To describe the radiologic and clinical findings in a group of patients with exogenous lipoid pneumonia focusing on features that differentiate the acute and chronic presentations. MATERIALS AND METHODS: We retrospectively identified 15 patients from a single institution with exogenous lipoid pneumonia 1992-2001. Inclusion criteria were: imaging with chest CT and either CT features diagnostic of lipoid pneumonia or intrapulmonary lipids on pathologic examination. Each chart was reviewed for the clinical presentation, history of ingestion/exposure, predisposing factors, treatment and response to therapy. Initial (n = 13) and follow-up (n = 11) chest radiographs were reviewed for the patterns and distribution of lung parenchymal abnormalities and pleural effusion. Initial (n = 15) and follow-up (n = 7) CT scans were reviewed for lung parenchymal abnormalities (consolidation, ground glass opacities, linear/nodular opacities, masses, and crazy paving), presence or absence of fat attenuation, and pleural effusion. The groups were compared using the Fischer exact test. RESULTS: Nine patients had acute lipoid pneumonia, 7 males and 2 females with a mean age of 45 (range 4.5-81) years. Six patients had chronic lipoid pneumonia, 4 men and 2 women with a mean age of 63 (range 37-83) years. 78% (7/9) of patients with acute and all of the patients with chronic presentations had a known ingestion and/or a predisposing condition associated with lipoid pneumonia. On chest radiographs, consolidation and lower lobe involvement were present in the majority of patients with acute and none of the patients with chronic presentations. On CT, consolidation and fat attenuation were present in the majority of patients with each presentation. However, masses were present in 67% (4/6) of patients with chronic and none of the patients with acute presentation (P < 0.05). 86% (6/7) of patients with acute presentation had improvement on follow-up chest radiograph in contrast to none of the patients with chronic presentation (P < 0.05). 75% (3/4) of patients with acute lipoid pneumonia had improvement on follow-up CT in contrast with 67% (2/3) of patients with chronic lipoid pneumonia who had progression on follow-up CT. CONCLUSIONS: The imaging features of acute and chronic lipoid pneumonia overlap with consolidation and lower lobe involvement present in both groups. However, only the patients with acute lipoid pneumonia had pleural effusions and improvement on follow-up. Only the patients with chronic lipoid pneumonia had pulmonary masses.     

Three cases of respiratory bronchiolitis-associated interstitial lung disease (RB-ILD): a study of HRCT-pathologic correlation]

Respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) is a clinicopathologic entity occurring rarely in smokers. We report three cases of RB-ILD diagnosed pathologically by surgical lung biopsy. Cough was observed in all cases, sputum in one case and dyspnea on exertion in another. Reduction of diffusing capacity was observed in all three cases. No abnormality was found in the chest radiographs of any case. However, in high-resolution computed tomography (HRCT), ground-glass opacities and centrilobular nodules were observed in all three cases, emphysema in one case, intralobular linear or reticular opacities in two cases, small subpleural cysts in two and emphysema in one. Histologic examination of lung biopsy specimens taken by thoracoscopy showed peribronchiolar fibrosis and centrilobular intraluminal accumulation of macrophages in all three cases, centrilobular emphysema, membranous bronchioles filled with mucus and macrophages, and focal microscopic honeycombing in subpleural lesions in one case each. RB-ILD should be included in the differential diagnosis of interstitial lung disease in smokers.     

传染性非典型肺炎的影像表现

目的 探讨传染性非典型肺炎(世界卫生组织又称其为严重呼吸综合征，SARS)的X线表现及变化规律。方法 回顾性分析临床诊断的61例SARS患，对发病后的一系列胸片和CT影像进行统计分析。结果 患均以发热为最早起病症状，88％患在起病1周内肺部出现局灶性斑片状模糊影，并迅速扩大。2周内病变达高峰，有57％患两肺大部分肺野受累，病情重。84％患在5周内肺部阴影逐渐消散。在16例恢复期患的CT扫描中，有13例显示肺部遗留纤维化病灶。有6例患合并感染，病期延长，4例死亡。结论 SARS早期出现肺部炎性改变，发展迅速，大部分两肺受累，重症比例高，易致肺纤维化。     

Neurofibromatosis-associated lung disease: a case series and literature review.

An association of neurofibromatosis with diffuse lung disease (NF-DLD) has been described, but its true prevalence and characteristics remain unclear. The objective of the present study was to define diffuse lung disease in patients with neurofibromatosis. A retrospective case series and literature review in a tertiary care academic medical centre is reported in which medical records, chest radiographs and high-resolution computed tomography (HRCT) scans were reviewed. A total of 55 adult patients with neurofibromatosis were identified, three of whom had NF-DLD. A literature review revealed 16 articles reporting 61 additional cases, yielding a total of 64 NF-DLD cases. The mean age of patients was 50 yrs. Males outnumbered females; most reported dyspnoea. Of the 16 subjects with documented smoking histories, 12 were ever-smokers. Eight patients had HRCT scan results demonstrating ground-glass opacities (37%), bibasilar reticular opacities (50%), bullae (50%), cysts (25%) and emphysema (25%); none had honeycombing. A group of 14 patients had surgical biopsy results that showed findings of interstitial fibrosis (100%) and interstitial inflammation (93%). In conclusion, neurofibromatosis with diffuse lung disease is a definable clinical entity, characterised by upper lobe cystic and bullous disease and lower lobe fibrosis. Its relationship to smoking remains unclear.     

Temporal changes in cytokine/chemokine profiles and pulmonary involvement in severe acute respiratory syndrome

OBJECTIVE AND BACKGROUND: Pathological changes in severe acute respiratory syndrome (SARS) suggest that SARS sequelae are associated with dysregulation of cytokine and chemokine production. To improve understanding of the immuno-pathological processes involved in lung injury associated with SARS, the temporal changes in cytokine/chemokine profiles in the sera of SARS patients were compared with those of patients with community-acquired pneumonia (CAP), according to the degree of lung involvement. METHODS: Serum levels of 11 cytokines and chemokines, in 14 patients with SARS and 24 patients with CAP, were serially checked using a bead-based multiassay system. Sera from 12 healthy subjects were used as normal controls. RESULTS: The serum levels of interferon-gamma-inducible protein-10 (IP-10), IL-2 and IL-6 were significantly elevated during SARS infection. In patients with CAP, but not in those with SARS, the levels of interferon-gamma, IL-10, IL-8 and monokine induced by interferon-gamma (MIG) were significantly elevated compared with the levels in healthy controls. Among the chemokines/cytokines, IL-6 levels correlated most strongly with radiographic scores (r=0.62). The elevation of IP-10 and IL-2 antedated the development of chest involvement and reached peak levels earlier than the radiographic scores. In contrast, the dynamic changes in IL-6, C-reactive protein and neutrophils occurred synchronously with the changes in radiographic scores. The mean ratio of IL-6 to IL-10 in SARS patients (4.84; range 0.41-21) was significantly higher than that in CAP patients (2.95; range 0.02-10.57) (P=0.04). CONCLUSIONS: The early induction of IP-10 and IL-2, as well as the subsequent over-production of IL-6 and lack of IL-10 production, probably contribute to the main immuno-pathological processes involved in lung injury in SARS. These changes in cytokine/chemokine profile are remarkably different from those observed in CAP patients.     

High-resolution computed tomography of chronic interstitial lung disease

The absence of superimposition of parenchymal structures on HRCT permits better assessment of the pattern and distribution of disease than is possible on the radiograph. Several studies have shown that HRCT is superior to the chest radiograph in the diagnosis and management of patients with chronic interstitial lung disease. High-resolution studies may demonstrate extensive parenchymal disease when the radiograph is normal and allow for a confident diagnosis when the radiographic findings are nonspecific. It is superior to the chest radiograph in determining whether transbronchial or open lung biopsy is indicated, and it is essential in selecting the optimal biopsy site. Although further studies are required to determine the precise role of HRCT in interstitial lung disease, current indications for HRCT include: (1) assessment of patients with symptoms suggestive of infiltrative lung disease but normal or nonspecific findings on the radiograph; (2) further evaluation of the lung parenchyma in patients in whom the radiographic findings are not in keeping with the clinical history or symptomatology; (3) as a guide to the optimal biopsy site in all patients undergoing open or transbronchial biopsy; and (4) assessment of suspected complications (e.g., infection) in patients with diffuse lung disease.     

COPD影像学表型与肺癌关系的研究进展

COPD是一种可预防和治疗的呼吸系统疾病,以气流受限不完全可逆、进行性发展为特征,高分辨率CT能够定量显示早期的肺气肿并进行分级,且能先于肺功能检查发现肺部解剖结构异常。肺癌是最常见的恶性肿瘤之一,研究发现COPD影像学表型可能会增加肺癌的发病风险。该文就COPD影像学表型与肺癌的关系研究进展予以综述,为肺癌的早期预防、诊断提供帮助。