Lung findings on high resolution CT in early ankylosing spondylitis

OBJECTIVE: Ankylosing spondylitis (AS) is a chronic inflammatory disease mainly affecting the axial skeleton and pulmonary involvement is a well known feature of the disease. The aim of this study was to investigate the pulmonary high resolution computed tomography (HRCT) findings of patients with early AS. The relationship between pulmonary function tests (PFT) and HRCT findings was also determined. SUBJECTS AND METHODS: Twenty-eight patients with AS (mean age 30.8+/-7.4 and disease duration 7.0+/-2.6) were included in the study. Patients with a disease duration of >10 years or had other pulmonary diseases were excluded. All patients underwent plain chest radiography (posteroanterior and lateral views), thoracic HRCT and PFT. RESULTS: All chest radiographs were normal and HRCT revealed abnormalities in 18 patients. The most common abnormalities seen on HRCT were mosaic pattern (ten of 28), subpleural nodule (seven of 28) and parenchymal bands (five of 28). Seven of ten patients with mosaic pattern revealed air trapping areas on end expiratory scans. Twelve patients had abnormal PFT and all had restrictive type of involvement. Ten of these 12 patients had abnormal HRCT and the remaining two patients had normal HRCT. On the other hand, eight patients with normal PFT had abnormalities on HRCT. CONCLUSION: Patients with early AS frequently have abnormalities on HRCT, even though they have normal PFT and chest X-ray. Small airway involvement was found as frequent as interstitial lung disease in early AS.     

Computed tomography in pulmonary sarcoidosis

We studied the high resolution CT (HRCT) scans of 15 patients with biopsy-proven sarcoidosis and correlated the findings with pulmonary function tests (12 patients), 67Ga scans (10 patients), bronchoalveolar lavage (five patients), recent transbronchial biopsy (six patients), and recent open lung biopsy (three patients). The HRCT features included small nodules, thickened interlobular septa, patchy focal increase in lung density, honeycombing, and central conglomeration of vessels and bronchi. Active alveolitis was present by gallium scanning criteria in 5 of 10 cases. By bronchoalveolar lavage criteria, activity was present in three of five cases. Patchy increase in density may correlate with active alveolitis as seen on 67Ga scanning. High resolution CT was better than chest X-radiography for demonstration of patchy increase in density and for distinguishing nodules from septal thickening. Both nodules and patchy density were partly reversible following therapy. Nodular densities seen on CT correlated with the presence of granulomata on histology. Resting pulmonary function tests correlated poorly with presence and extent of lung disease on HRCT. The presence on HRCT of focal fine nodules, patchy focal increase in lung density, and central crowding of bronchi and vessels should suggest the diagnosis of sarcoidosis. In some patients, HRCT can identify unsuspected parenchymal lung disease and document the reversible components of sarcoid lung disease.     

Comparative accuracy of high resolution computed tomography and chest radiography in the diagnosis of chronic diffuse infiltrative lung disease

One hundred individuals who had undergone both high resolution computed tomography (HRCT) and chest radiography were studied to determine the accuracy of each technique in establishing the diagnosis of diffuse lung disease. The group consisted of 86 patients with a diagnosis of a chronic diffuse infiltrative lung disease and 14 normal subjects. Two independent observers assessed the HRCT examinations and chest radiographs and recorded the three most likely diagnoses. Overall a confident diagnosis was reached more often with HRCT (49%) than with chest radiography (41%). The diagnoses were correct in 82% of HRCT examinations and 69% of chest radiographs. Diagnoses made on HRCT, irrespective of the degree of certainty, were accurate more often than diagnoses made on chest radiography (56% and 47% respectively). Of the patients thought to have a normal chest radiograph, 42% had diffuse infiltrative lung disease (DILD). Of the patients thought to be normal on HRCT, 18% had DILD. Conversely, normal subjects were correctly identified as such in 82% of chest radiographs and in 96% of HRCT examinations. This study emphasizes the important role of CT in helping to confirm or refute the presence of abnormality when the chest radiograph is normal or questionably abnormal, and underlines the superior diagnostic accuracy of HRCT compared with conventional chest radiography in DILD.     

Hypersensitivity pneumonitis: sensitivity of high-resolution CT in a population-based study.

OBJECTIVE. Hypersensitivity pneumonitis refers to a group of pulmonary disorders caused by inhalation of organic or inorganic particulates by sensitized persons. The diagnosis relies on a constellation of findings: exposure to an offending antigen, characteristic signs and symptoms, abnormal chest findings on physical examination, and abnormalities on pulmonary function tests and radiographic evaluation. In population-based studies, the sensitivity of chest radiography for detection of this disease is relatively low. The aim of this study was to determine the sensitivity of high-resolution CT (HRCT) for detection of hypersensitivity pneumonitis diagnosed in a population of swimming-pool employees. SUBJECTS AND METHODS. Thirty-one symptomatic employees of a recreation center who were referred because of possible hypersensitivity pneumonitis were examined by using chest radiography, HRCT, and fiberoptic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. Hypersensitivity pneumonitis was diagnosed in subjects who had two or more work-related signs or symptoms, abnormal results on transbronchial biopsies, and abnormal lymphocytosis as shown by examination of bronchoalveolar lavage fluid. The chest radiographs and HRCT scans were interpreted by consensus by two observers who were unaware of the clinical diagnosis. RESULTS. Only one of 11 subjects with a diagnosis of hypersensitivity pneumonitis had abnormal findings on a chest radiograph. Five had abnormal HRCT findings. The abnormality in each case consisted of small, poorly defined centrilobular nodules with variable profusion. No subject without the disease had abnormal HRCT findings. Those who had granulomas shown by lung biopsy were more likely to have abnormal HRCT findings than were those who had more subtle histologic abnormalities. CONCLUSION. The sensitivity of HRCT for the detection of hypersensitivity pneumonitis in a population-based study is greater than that of chest radiography. The finding of poorly defined centrilobular nodules on HRCT scans should prompt consideration of this disease.     

高分辨力CT在肾移植术后疑似肺炎患者中的应用价值

目的:评价高分辨率CT(HRCT)在诊断肾移植术后疑似肺炎中的应用价值。方法:33例肾移植术后疑似肺炎患者行胸片、胸部HRCT检查。所有患者均经影像学、实验室检查及临床随访而明确诊断。对33例患者的胸片和HRCT图像进行回顾性对比分析。结果:33例中10例(30.3%)胸片未见异常,其中9例HRCT提示肺炎并最终证实;23例胸片和HRCT均见异常,22例最终证实为肺炎,其中18例HRCT可提供更多更准确的信息,仅4例(12.1%)胸片与HRCT及最终诊断结果基本一致。结论:HRCT较胸片更敏感,有助于早期确诊肺炎,所有疑似肺炎的肾移植患者均应行HRCT检查,肾移植术后肺炎常见HRCT改变为磨玻璃样改变、小结节影和小片状实变。     

Interobserver variation in the diagnosis of bronchiectasis on high-resolution computed tomography

The purpose of our study was to determine interobserver variation in the analysis of high-resolution computed tomography (HRCT) in the lungs of patients with clinically suspected bronchiectasis. HRCT scans of 88 patients were analysed independently by three radiologists with variable experience in thoracic radiology using a subjective scoring system to record bronchi as normal, mildly abnormal or severely abnormal. The presence, severity and distribution of bronchial dilatation and bronchial wall thickening were recorded. Kappa values were calculated for assessment of interobserver agreement. Agreement between the three readers was good for the detection of bronchiectasis (kappa 0.78) and assessment of its severity (0.68), detection of bronchial wall thickening (0.64) and moderately good for the assessment of its severity (0.58) on a per-patient basis. When individual lobes were analysed, agreement was moderately good for the detection of abnormal bronchi (0.59). Agreement on the extent of abnormal bronchi using five categories was only fair (0.39), but was good when differences of one category were ignored (0.63). Interobserver variation with HRCT in suspected bronchiectasis appears satisfactory for comparative studies.     

Imaging findings of pulmonary vascular disorders in portal hypertension

PURPOSE: The purpose of this study was to demonstrate and compare the imaging findings of hepatopulmonary syndrome and portopulmonary hypertension. MATERIALS AND METHODS: We retrospectively reviewed the imaging findings of five patients with hepatopulmonary syndrome and four patients with portopulmonary hypertension. We evaluated chest radiographs, chest and abdominal computed tomography (CT) scans, 99mTc-macroaggregated albumin (MAA) lung perfusion scans, and pulmonary angiograms. RESULTS: In patients with hepatopulmonary syndrome, the presence of peripheral pulmonary vascular dilatation was detected by chest radiograph, chest CT scan, and pulmonary angiogram, especially the basilar segment. 99mTc-MAA lung perfusion scan showed extrapulmonary tracer distribution (brain, thyroid, and kidney), which revealed pulmonary R-L shunting. In patients with portopulmonary hypertension, chest radiographs and chest CT scans showed the classic findings of primary pulmonary hypertension. In patients with both disorders, extrahepatic features of portal hypertension including ascites, splenomegaly, and portosystemic collateral vessels were seen on abdominal CT. CONCLUSION: In conclusion, chest radiographs and CT in hepatopulmonary syndrome usually showed peripheral pulmonary vascular dilatation, whereas those in portopulmonary hypertension showed central pulmonary artery dilatation. The extrahepatic features of portal hypertension might be helpful for the diagnosis of both disorders.     

Diagnosis of bronchiolitis obliterans in heart-lung transplantation patients: importance of bronchial dilatation on CT.

OBJECTIVE. The purpose of this study was to evaluate the significance of bronchial dilatation identified on high-resolution CT scans obtained after heart-lung transplantation. Bronchial dilatation has been identified on pathologic specimens and on high-resolution CT scans of patients with severe bronchiolitis obliterans after lung transplantation, but this finding has not previously been systematically studied as a manifestation of this complication. MATERIALS AND METHODS. We studied the high-resolution CT scans of 16 patients who had had heart and lung transplantation at least 1 year before, and compared the percentage of dilated bronchi with evidence of small airways disease shown on pulmonary function tests. RESULTS. We found a close correlation between the percentage of bronchi in the lower lobes that were dilated and the percent predicted forced expiratory volume in 1 sec, forced vital capacity, and forced expiratory flow between 25% and 75% of vital capacity. No other feature identified on high-resolution CT scans correlated with pulmonary function abnormalities. CONCLUSION. We conclude that dilatation of the lower lobe bronchi is a good indicator of bronchiolitis obliterans in this population, and that the percentage of dilated bronchi generally increases with increasing pulmonary dysfunction.     

Pulmonary lymphangioleiomyomatosis: CT findings

Lymphangioleiomyomatosis, a rare disease occurring in women of childbearing age, is characterized by proliferation of smooth muscle in pulmonary lymphatic channels and mediastinal and abdominal lymph nodes. Chest radiographs typically reveal interstitial disease with normal lung volume. Pneumothorax and pleural effusions may be present. CT scans in eight patients with biopsy-proved pulmonary lymphangioleiomyomatosis were reviewed. The prominent feature of the disease was multiple thin-walled cysts throughout the lungs, best visualized on scans made with 1.5-mm collimation. Mediastinal and/or retrocrural lymphadenopathy, often not appreciated on the chest radiograph, was present in four of eight patients. CT can suggest a diagnosis of lymphangioleiomyomatosis when diagnosis by clinical presentation and chest radiographs is uncertain.     

Posterior wall of the bronchus intermedius: radiographic-CT correlation

The posterior wall of the bronchus intermedius (PWBI) is visible on lateral chest radiographs and computed tomographic (CT) scans and can become abnormally thickened in the presence of right hilar disease. The appearances of the PWBI on plain radiographs and CT were correlated in groups of 20 normal patients and 20 patients with a right hilar abnormality. Among 10 patients with an abnormal hilum who had thickening of the PWBI on CT, the lateral radiograph showed thickening of similar degrees in seven. However, in two of the 10, the lateral chest radiograph significantly underestimated the degree of thickening of the PWBI, and in one the PWBI was not visible. Among 10 patients with an abnormal right hilum who had no thickening of the PWBI on CT, the PWBI appeared to be abnormal on lateral chest radiographs in four because of adenopathy in the lateral or medial hilum. One other finding of note was the presence in one patient of an anomalous pulmonary vein passing posterior to the bronchus intermedius, simulating a small posterior hilar mass.     

Comparison between conventional interrupted high-resolution CT and volume multidetector CT acquisition in the assessment of bronchiectasis

The aim of this study was to determine whether there is superior diagnostic accuracy for the detection and exclusion of bronchiectasis using 16-slice CT of the chest (1 mm) compared with conventional high-resolution CT (HRCT) of the chest (10 mm). A prospective study was carried out in patients who were referred for chest CT by a chest physician for the investigation of bronchiectasis over a 1-year period. All scans were performed using a 16-slice CT scanner. In addition to contiguous 1 mm slices, conventional HRCT images (1 mm slice every 10 mm) were prepared. Both datasets were dual read. There were 53 patients with a median age of 62 years (range, 51.5–71.5 years), comprising 14 males and 39 females. 10 of 53 scans had no bronchiectasis in either dataset. 36 patients had bronchiectasis diagnosed on both HRCT and 1 mm scans. Two patients had tubular bronchiectasis on the HRCT scans, which was not confirmed on the 1 mm scans. Five patients had confirmed tubular bronchiectasis on the 1 mm scans, which was not identified on HRCT scans. 40 extra lobes demonstrated bronchiectasis on the 1 mm vs the HRCT scans; of these, half were labelled as definite bronchiectasis on the 1 mm scan. There was a 32% increased confidence with the 1 mm scans compared with conventional HRCT of the chest in the diagnosis of bronchiectasis (p < 0.001). In conclusion, there is improved diagnostic accuracy and confidence for diagnosis and exclusion of bronchiectasis using 16-slice chest CT (1 mm cuts) compared with conventional HRCT of the chest.Bronchiectasis is a chronic disabling lung disease affecting between 1 in 1000 and 1 in 5000 of the general population. Pathologically, patients have irreversibly dilated and damaged bronchi. This leads to patients having a daily productive cough and recurrent chest infections.High-resolution computed tomography (HRCT) of the chest is the gold standard for the diagnosis of bronchiectasis. For diagnosis, patients should have bronchial dilatation at least greater than the associated arterial vessel [1–5]. There may be associated bronchial wall thickening and mucus plugging. The extent of bronchiectasis is determined by the number of lobes involved and the severity of bronchiectasis, varying from mild tubular bronchiectasis to severe cystic bronchiectasis. There has been shown to be good interobserver agreement for the detection and assessment of the severity of bronchiectasis using HRCT [6], with good pathological correlation [7].The aim of this study was to assess whether there is any difference in determining the extent and severity of bronchiectasis, and also if there is an improvement in the degree of confidence in diagnosis, using 16-slice CT of the chest using 1 mm contiguous slices compared with conventional HRCT using 1 mm slices every 10 mm.     

Radiology of diffuse interstitial pulmonary disease in children

Diffuse interstitial lung disease (DILD) represents a heterogeneous group of disorders characterised by restrictive lung function and impaired gas exchange. As these diseases occur on a background of the developing lungs and immune system, the clinical presentation and disease progression is modified by comparison with their adult equivalents; thus, often differs markedly in presentation, clinical features and progress from ILD in adults, and it is not safe to extrapolate from adults to children. It is important to understand the normal growth and development of the lungs in children to understand the development of interstitial lung disease. As the chest radiograph is often non-specific, HRCT has been shown in adults and children to increase the accuracy at diagnosis of diffuse lung disease. The trade-off in sensitivity and specificity of HRCT over chest X-ray is related to radiation dose which is significantly higher with conventional spiral or volumetric CT; however, the use of low-dose (50 mA, 0.75 s) limited (1-mm slices every 15-20 mm) HRCT in inspiration with three expiratory supplementary scans allows accurate assessment of the presence and extent of diffuse lung disease at a dose equivalent to approximately ten chest radiographs. Images are reconstructed on a high spatial resolution algorithm and displayed with a wide window setting, at a width of 1500 Hounsfield units (HU) and at a level of -500 HU.     

实验性正常人肺HRCT研究

本文收集３例新鲜尸体的胸部标本，经改良的Ｈｅｉｔｚｍａｎ方法处理，处理前后应用高分辨ＣＴ（ＨＲＣＴ）扫描。为了明确正常肺小叶ＨＲＣＴ表现，本文仅将标本处理前的ＨＲＣＴ像与相应的横断大体标本、组织学切片行对照观察。结果表明：ＨＲＣＴ能显示正常次级肺小叶结构中的部分小叶间隔、小叶肺动脉，但不能在同一层面显示次级肺小叶的完整结构，不能显示核心结构中的终末细支气管。然而，小叶间隔、小叶肺动脉是ＨＲＣＴ图上     

Radiology of diffuse interstitial pulmonary disease in children

Diffuse interstitial lung disease (DILD) represents a heterogeneous group of disorders characterised by restrictive lung function and impaired gas exchange. As these diseases occur on a background of the developing lungs and immune system, the clinical presentation and disease progression is modified by comparison with their adult equivalents; thus, often differs markedly in presentation, clinical features and progress from ILD in adults, and it is not safe to extrapolate from adults to children. It is important to understand the normal growth and development of the lungs in children to understand the development of interstitial lung disease. As the chest radiograph is often non-specific, HRCT has been shown in adults and children to increase the accuracy at diagnosis of diffuse lung disease. The trade-off in sensitivity and specificity of HRCT over chest X-ray is related to radiation dose which is significantly higher with conventional spiral or volumetric CT; however, the use of low-dose (50 mA, 0.75 s) limited (1-mm slices every 15–20 mm) HRCT in inspiration with three expiratory supplementary scans allows accurate assessment of the presence and extent of diffuse lung disease at a dose equivalent to approximately ten chest radiographs. Images are reconstructed on a high spatial resolution algorithm and displayed with a wide window setting, at a width of 1500 Hounsfield units (HU) and at a level of ?500 HU.     

Obliterative bronchiolitis following lung transplantation. Diagnostic utility of aerosol ventilation lung scanning and high resolution CT

A serious and often fatal complication of heart-lung transplantation is the development of obliterative bronchiolitis (OB). Currently the screening for OB is based on symptoms, pulmonary function tests, and transbronchial biopsies. The chest radiographs are often normal with OB. Obliterative bronchiolitis produces luminal narrowing of both bronchioles and bronchi resulting in areas of peripheral consolidation and occasional bronchiectasis. We report a patient in whom a chest film was normal, an aerosol ventilation lung scan was abnormal while a perfusion study was mildly abnormal. Simultaneously, routine CT was essentially normal while high resolution CT with 1 mm thick sections was clearly abnormal and demonstrated areas of consolidation. These imaging modalities detected clear-cut abnormalities at a time when the patient was symptomatic but prior to the development of demonstrable abnormality on chest radiograph.     

Do plain films of the chest and abdomen have a role in the diagnosis of acute pancreatitis?

Radiographs taken on the day of admission on 52 patients with acute pancreatitis have been compared with similar radiographs of 30 patients with acute cholecystitis and 22 patients with perforated duodenal ulcer. Two radiologists, who were unaware of the clinical features, looked specifically for the presence of 30 radiological signs. The only abdominal signs seen more frequently in acute pancreatitis were fluid levels in the stomach and duodenum, usually associated with dilatation. Duodenal abnormalities were seen in 42% of patients with acute pancreatitis and 21% of the controls (P less than 0.05) while gastric dilatation with a fluid level was seen in 29% of cases of acute pancreatitis compared with 12% of controls (P less than 0.05). Seventy per cent of the patients with severe acute pancreatitis had an abnormal chest radiograph on admission compared with 18% of those with mild disease. Left pleural effusion was the most common abnormality in severe pancreatitis (43%) and was seen significantly more often than in mild pancreatitis (P less than 0.01) and the control group (P less than 0.05). Therefore, consideration of the admission chest radiograph may help at an early stage to distinguish patients with severe pancreatitis from those with mild disease.     

Chest radiographic and computed tomographic manifestations in allergic bronchopulmonary aspergillosis

AIM:To investigate the chest radiographic and high resolution computed tomography(HRCT)chest manifestations in glucocorticoid-naive allergic bronchopulmonary aspergillosis(ABPA)patients.METHODS:This is a prospective observational study and includes 60 consecutive glucocorticoid-naive patients with ABPA who underwent chest radiography and HRCT of the chest(1.25 mm every 10 mm)in the routine diagnostic workup for ABPA.RESULTS:Chest radiographs were normal in 50%of cases.Of the remainder,most patients demonstrated permanent findings in the form of parallel line and ring shadows suggesting bronchiectasis.Consolidation was detected in 17 cases but in the majority,the corresponding HRCT chest scan showed mucus-filled bronchiectatic cavities.Chest HRCT was normal in 22 patients,while central bronchiectasis(CB)was demonstrated in the remaining 38 patients.Bronchiectasis extended to the periphery in 33%-43%depending on the criteria used for defining CB.The other findings observed on HRCT were mucoid impaction,centrilobular nodules and high-attenuation mucus in decreasing order of frequency.CONCLUSION:Patients with ABPA can present with normal HRCT chest scans.Central bronchiectasis cannot be considered a characteristic feature of ABPA as peripheral bronchiectasis is commonly observed.Consolidation is an uncommon finding in ABPA.     

异常体动脉供应正常左下肺基底段的胸部X线片和螺旋CT表现

目的 总结异常体动脉供应正常左下肺基底段在胸部X线片和螺旋CT上的特征性表现。方法 回顾分析5例异常体动脉供应正常左下肺基底段的胸部X线片和螺旋CT资料。结果 5例异常体动脉供应正常左下肺基底段在胸部X线片上均表现为心后区肿块，左下肺动脉纹理细小，受累左下肺区域无正常肺动脉分支影分布，但有异常增粗纹理。CT上5例均表现为受累肺组织体积轻度缩小，支气管通畅，2例肺实质呈磨玻璃状改变。5例均可见左下肺动脉在背段动脉起始远侧缺如，增粗扭曲的异常体动脉起自降主动脉，其扩张的分支分布于受累肺段。1例血管造影表现与CT相仿。结论 该病在胸部X线片上的表现有一定特征性。增强螺旋CT扫描可明确诊断，以避免创伤性的血管造影和致命的穿刺活检。     

High-resolution computed tomography of drug-induced lung disease.

In order to determine the potential clinical utility of high-resolution CT (HRCT) in the assessment of drug-induced lung disease, we reviewed the chest radiographs and HRCT scans of 23 patients and five normal controls. The radiographs and HRCT scans were reviewed separately in random order by two independent observers who were not aware of the relative numbers of patients and controls. Abnormal findings were detected in the affected patients in 17/23 radiographs compared to 23/23 HRCT scans. The patients included five cases of bleomycin toxicity, five cases of nitrofurantoin toxicity, two cases each of penicillamine, busulphan, BCNU and amiodarone toxicity, and one case each of cyclophosphamide, procainamide, mitomycin and methotrexate toxicity. The HRCT appearances could be grouped into four categories according to their dominant pattern and distribution of disease. These include fibrosis with or without consolidation (n = 12), ground-glass opacities (n = 7), widespread bilateral consolidation (n = 2), and bronchial wall thickening with areas of decreased attenuation (n = 2). The results of this study indicate that HRCT is more sensitive than the radiograph in the detection of drug-induced lung disease. The appearances demonstrated by HRCT reflect the pathological mechanisms of drug-induced lung disease.