Update on the application of chest computed tomography scanning to cystic fibrosis

PURPOSE OF REVIEW: To summarize the role of chest computed tomography as a tool to evaluate cystic fibrosis lung disease, and to describe what abnormalities can be detected using computed tomography and how computed tomography can be used in clinical practice. RECENT FINDINGS: Pulmonary function tests are only an indirect measure of lung structure, and are insensitive to localized and early structural abnormalities. Computed tomography is able to detect small areas with localized severe damage. The differentiation between normal and abnormal on computed tomography is relatively easy. In half of cystic fibrosis patients, the information obtained from pulmonary function tests is discordant with the information obtained from computed tomography. SUMMARY: Cystic fibrosis patients show lung inflammation and infection starting early in life. This leads to irreversible structural lung damage such as bronchiectasis and air trapping. Cystic fibrosis lung disease varies widely between patients. The primary aim of therapy is to prevent structural damage and to conserve lung function. Adequate monitoring of cystic fibrosis lung disease is paramount to tailor treatment to a patient's need. Computed tomography is currently the best tool to monitor lung structure, and pulmonary function tests are the best to monitor lung function.     

Laryngeal involvement in rheumatoid arthritis. A clinical, laryngoscopic, and computerized tomographic study

Laryngeal involvement was evaluated in 45 patients with moderately severe rheumatoid arthritis (RA). RA duration and severity, prior laryngeal symptoms, and abnormalities detected by concurrent indirect laryngoscopy (IL) and computerized tomography (CT) were noted and correlated with changes of basilar interstitial fibrosis (BPF) found by chest radiograph. Thirty-two percent had abnormalities detected by IL, 54% had abnormalities by CT, and 36% had BPF on chest radiographs. Comparison of these groups revealed: only two symptoms (sore throat and difficulty during inspiration) were predictive of abnormalities detected by IL; no symptoms predicted abnormalities on percentage of RA patients even in the absence of symptoms; IL tends to detect mucosal and gross functional abnormalities while CT detects structural lesions; BPF shown on chest radiographs in RA patients does not appear to be correlated with cricoarytenoid arthritis as defined by IL and CT.     

Laryngeal involvement in rheumatoid arthritis

Laryngeal involvement was evaluated in 45 patients with moderately severe rheumatoid arthritis (RA). RA duration and severity, prior laryngeal symptoms, and abnormalities detected by concurrent indirect laryngoscopy (IL) and computerized tomography (CT) were noted and correlated with changes of basilar interstitial fibrosis (BPF) found by chest radiograph. Thirty-two percent had abnormalities detected by IL, 54% had abnormalities by CT, and 36% had BPF on chest radiographs. Comparison of these groups revealed: only two symptoms (sore throat and difficulty during inspiration) were predictive of abnormalities detected by IL; no symptoms predicted abnormalities on CT; IL and CT may show abnormalities in a large percentage of RA patients even in the absence of symptoms; IL tends to detect mucosal and gross functional abnormalities while CT detects structural lesions; BPF shown on chest radiographs in RA patients does not appear to be correlated with cricoarytenoid arthritis as defined by IL and CT.     

High‐resolution CT pulmonary findings in idiopathic ankylosing spondylitis: correlations with clinical assessment,plain chest X‐ray and pulmonary function tests

Aim: The aim of this study is to evaluate pulmonary manifestations of ankylosing spondylitis on high‐resolution computed tomography (CT) scan and to correlate these findings with clinical assessment, plain chest X‐ray and pulmonary function tests. Methods: The study comprised 32 patients (26 males [81.3%], 6 females [18.8%]) who met the modified New York criteria for diagnosis of idiopathic ankylosing spondylitis; in addition 10 normal subjects not complaining of any respiratory symptoms and matched for age and sex served as a control group. All patients were subjected to full history‐taking, full clinical examination, chest X‐ray, high‐resolution computed tomography (HRCT) chest and pulmonary function tests. Results: The abnormalities on HRCT included evidence of apical lung fibrosis in two patients (6.3%), interstitial lung disease in six (18.8%), minor interstitial abnormalities in eight (25%), bronchiectasis in four (12.5%), lung nodules in three (6.3%) and pleural thickening in five patients (6.3%). Nine patients (28.1%) showed negative findings by chest X‐ray which revealed positive findings on HRCT. Five patients (15.6%) showed positive findings on both HRCT and plain chest X‐ray, and 18 patients (56.3%) showed no findings on both HRCT and chest X‐ray. Four patients (12.5%) showed normal pulmonary function tests, 25 (78.13%) showed restrictive pattern, 17 (53.13%) had obstructive pattern and 26 patients (81.3%) had diffusion defects. Conclsuion: The identification of non‐apical minor basal interstitial lung disease in our study which was previously reported in other studies, raises a possible association to ankylosing spondylitis. High‐resolution CT scan is more sensitive than chest X‐rays in detection of such minor interstitial lung disease (ILD), and other parenchymal lung changes.     

Lung manifestation in asymptomatic patients with primary Sj?gren syndrome: assessment with high resolution CT and pulmonary function tests.

The authors studied 37 consecutive patients with primary Sj?gren syndrome and normal chest radiographs. Thin-section CT images were analyzed using a semiquantitative grading system. The presence, distribution, and severity of 9 morphologic parameters were assessed. In 34 patients, CT findings were correlated to pulmonary function tests (PFTs). Abnormal high resolution CT (HRCT) findings were seen in 24 of 37 patients (65%): interlobular septal thickening, n = 9; micronodules, n = 9; ground glass attenuation n = 4; parenchymal cysts, n = 5. Intralobular opacities, honey combing, bronchial wall thickening, bronchiectasis, and pleural irregularities were less frequent. Both HRCT and PFTs were normal in 10 patients. Computed tomography was normal in four patients with PFTs that indicated the presence of small airway disease. High resolution CT abnormalities were found in seven patients with normal PFT. The overall correlation between HRCT and PFTs was poor. High resolution CT and PFTs appear to be sensitive for both the early detection of parenchymal abnormalities and a decreases in lung function in asymptomatic patients with primary Sj?gren syndrome. However, abnormal HRCT findings do not necessarily indicate a substantial alteration in PFTs.     

强直性脊柱炎患者肺部表现的高分辨CT特征及临床

目的研究强直性脊柱炎(anky losing spondy litis,A S)患者肺部高分辨CT(HRCT)表现及其临床特征。方法43例确诊A S患者分别进行肺HRCT、肺部X线平片、肺功能检查,并结合临床特征对比分析。结果43例A S患者中28例(65%)发现有肺HRCT异常,最常见的表现为非特异性间质改变20/43(46.5%),4例(9.3%)为间质性肺病(ILD),3例(7.0%)为上叶纤维化,每例患者可有1种以上病变表现。肺功能有16/43(23.3%)表现轻度限制性通气功能障碍,无DLCO下降。肺HRCT异常与不同病程、骶髂关节炎严重度、肺功能均无统计学相关。结论A S病人的肺部表现不少见,通过肺HRCT可以早期发现。     

Bronchoalveolar lavage--a sensitive tool for early diagnosis of pulmonary involvement in rheumatoid arthritis

Bronchoalveolar lavage (BAL) was performed to assess the nature of pulmonary involvement in 12 asymptomatic nonsmoking patients with rheumatoid arthritis (RA). All 12 patients had normal lung function tests, including diffuse capacity for carbon monoxide and normal blood gases. Four patients (33%) had mild basilar interstitial changes on chest radiographs. In these 4 patients an elevated lymphocytic count in BAL fluid (30.7 +/- 8.3%) was found, as compared to the 8 patients with normal chest roentgenograms (7.2 +/- 1.9%; p less than 0.001). We suggest that BAL may be used as a sensitive tool for early diagnosis of pulmonary involvement in patients with RA.     

Lack of evidence for an association between neurofibromatosis and pulmonary fibrosis

STUDY OBJECTIVES: To reassess the association between neurofibromatosis and pulmonary fibrosis. DESIGN: Retrospective single-center study with analysis of patients' chest radiographs, CT scans, and medical records. SETTING: Tertiary care, referral medical center. PATIENTS: One hundred fifty-six adult patients with neurofibromatosis seen over a 6-year period between 1997 and 2002. RESULTS: A review of chest radiographs revealed abnormal findings in 70 patients (44.9%). The most common radiographic abnormalities were extrapulmonary nodules or masses seen in 22 patients (14.1%), followed by skeletal abnormalities in 16 patients (10.3%). Bilateral interstitial infiltrates were noted in only three patients (1.9%), all of whom had potential causes other than neurofibromatosis for their lung infiltrates, including smoking-related interstitial lung disease, rheumatoid lung disease, recurrent pneumonias, and a history of ARDS. CT scans were available in two of these patients and revealed nonspecific patterns of abnormalities with no honeycombing. Six patients had bullae or cystic airspaces demonstrated on chest radiography or CT scan; all of these findings occurred in the context of smoking-related emphysema. Combined together, bilateral interstitial lung infiltrates or cystic airspaces were demonstrated in five patients (3.2%) by chest radiography, and in eight patients (5.1%) by chest radiography or CT scanning; one patient had both findings on the CT scan. CONCLUSIONS: We found little evidence to support an association between neurofibromatosis and pulmonary fibrosis or any other form of parenchymal lung disease. Interstitial lung disease and bullae described in association with neurofibromatosis in previous reports may have, in part, represented smoking-induced manifestations.     

Computed tomography and conventional radiographs of the craniocervical region in rheumatoid arthritis

Radiographs and computed tomography (CT) scans of 12 patients with rheumatoid arthritis of the cervical spine were reviewed to determine whether CT provides additional information to that obtained from conventional radiography and tomography. Modalities were compared with respect to determination of the extent of erosion, C1-C2 subluxation, atlantoaxial impact impaction, and soft tissue findings. CT showed greater extent of erosion in 9 of 12 patients. In 11 patients with C1-C2 subluxation, CT and plain radiographs were both useful because it was necessary to demonstrate both sagittal and axial relationships. In the 5 patients with atlantoaxial impaction both CT and plain radiographs demonstrated the abnormal relationships between the odontoid and the foramen magnum. CT showed attenuation of the transverse ligament and the presence or absence of spinal cord compression, whereas plain radiographs did not. Nevertheless, significant new information regarding the spinal cord was obtained by CT in only 1 of the 12 patients. Computed tomography provides additional information about the rheumatoid cervical spine that is unobtainable by conventional modalities. In particular, CT demonstrates bone changes in the axial projection and facilitates evaluation of soft tissue, ligament, and spinal cord involvement. However, CT should be reserved for those instances in which plain radiographs and tomograms do not explain clinical findings.     

Computed tomography of asbestos-related pulmonary parenchymal and pleural diseases

Computed tomography has acquired an increasingly central role in the evaluation of asbestos-exposed individuals. The advantages of increased contrast resolution and axial image display have extended our ability to interrogate areas of the pulmonary parenchyma and pleura that are inadequately seen on chest radiographs. The additional information to be gained from CT evaluation must be balanced by the additional expense and time required, particularly in view of the large numbers of asbestos-exposed individuals who will undergo screening over the coming decades. Ideally, imaging strategies that include CT should emphasize those problematic situations in which additional information will serve a differential or diagnostic function, alter the management or habits of the individuals, modify the working environment, or improve our understanding of asbestos-induced diseases. The chest radiograph is the mainstay in the imaging evaluation of asbestos-exposed individuals, providing an inexpensive and rapid appraisal of the presence of both focal and diffuse abnormalities of the pleura and lung parenchyma. Conventional (whole-thorax) CT may be an important adjunct in the following situations: (1) to clarify the presence of pleural thickening, particularly in distinguishing pleural disease from normal extrapleural soft tissues; (2) to stage and determine tumor extent in malignant pleural mesothelioma; (3) to identify optimal sites for biopsy of suspicious pleural changes; and (4) to detect and characterize lung cancers or other focal masses that may be obscured by extensive pleural or parenchymal fibrosis. Limited HRCT studies are roughly competitive in time and cost with four-view radiographic examinations. There is growing evidence that HRCT can detect interstitial disease in advance of conventional clinical or radiographic studies. However, the application of limited HRCT for large-scale screening is controversial. This issue will be resolved as we gain greater understanding of the specificity of HRCT and establish guidelines for standardizing the technique and image interpretation. At present, limited HRCT scans can supplement the evaluation of subjects in whom there is equivocal parenchymal or pleural disease on radiographs or unexplained abnormalities on pulmonary function tests. In individuals with significant pleural disease, HRCT can effectively define the presence and extent of interstitial fibrosis. In individuals with combined cigarette smoking-asbestos exposure in whom symptoms or functional abnormalities are present, HRCT may play a central role in distinguishing emphysematous lung destruction from the peripheral interstitial changes of asbestosis.     

Pulmonary involvement in systemic sclerosis: the detection of early changes by thin section CT scan, bronchoalveolar lavage and 99mTc-DTPA clearance

Systemic sclerosis is frequently complicated by fibrosing alveolitis although clinical and radiological abnormalities are not usually apparent until the lung disease is well established. The aim of this study was to investigate pulmonary involvement in systemic sclerosis by thin section CT scan, bronchoalveolar lavage (BAL) and 99mTc-DTPA clearance studies, and assess the value of these tests in defining pulmonary abnormalities in patients with a normal chest radiograph. Patients were divided into those with an abnormal chest radiograph (Group I, n = 14) and those with a normal chest radiograph (Group II, n = 16). CT scans were abnormal in all patients in Group I and 7 of 16 (44%) in Group II. BAL inflammatory cell counts were raised in all 12 (100%) patients studied in Group I and 11 of 15 (73%) in Group II. There was no difference in the type of inflammatory cells observed between the two groups. 99mTc-DTPA clearance was faster than normal controls in ten of 14 patients (71%) in Group I and seven of 15 (47%) in Group II and correlated with carbon monoxide transfer factor (P less than 0.05). Lung biopsies were performed on nine patients in Group I and three in Group II all of whom had abnormal CT scans. Fibrosing alveolitis was confirmed in every case. Group II biopsies could not be distinguished from Group I biopsies; both showed fibrosis as well as inflammation suggesting that pulmonary fibrosis is an early abnormality in systemic sclerosis. Our results indicate that CT scans, BAL and 99mTc-DTPA are frequently abnormal in asymptomatic patients with systemic sclerosis who have normal chest radiographs. When the CT scan is normal abnormalities of BAL and/or 99mTc-DTPA (99mTechnetium diethylenetriamine pentacetate) clearance may indicate lung disease at a still earlier stage. This observation requires further investigation.     

Absence of pulmonary fibrosis in patients with psoriatic arthritis treated with weekly low-dose methotrexate.

OBJECTIVES: To analyse pulmonary toxicity in psoriatic arthritis patients treated with weekly low-dose methotrexate. METHODS: A transversal study was carried out to analyse the findings on chest x-rays and high resolution computed tomography, and the results of pulmonary function tests in 27 Caucasian psoriatic arthritis patients treated with weekly low-dose methotrexate. None of them had previous recognized interstitial lung disease. RESULTS: The median age of the patient cohort was 50 years (range 24-70 years) and the sex ratio was 20M/7F. 17 patients had previously used other disease-modifying antirheumatic drugs. The mean weekly dose of methotrexate was 8.46 mg (range 5-15 mg), the average treatment period was 52 months (range 3-240 months), and the median cumulative dose was 2241 mg (range 300-6520 mg). High resolution computed tomography failed to show alveolar or interstitial involvement in any patient. Diffusing lung capacity for carbon monoxide was mildly altered only in 2 cases. Pulmonary function tests did not show differences between patients with and without recognized risk factors for developing methotrexate-associated lung toxicity identified in rheumatoid arthritis patients (old age, diabetes, hypoalbuminemia, previous use of disease modifying antirheumatic drugs). CONCLUSION: In this cohort of 27 psoriatic arthritis patients methotrexate was not associated with pulmonary fibrosis evaluated by means of sensitive imaging findings and pulmonary function tests.     

Respiratory symptoms in rheumatoid arthritis: relation to pulmonary abnormalities detected by high-resolution CT and pulmonary functional testing

Pulmonary disease is the most frequent and among the most severe extra-articular manifestation of rheumatoid arthritis (RA). However, this issue has not been sufficiently studied in Egyptian patients. The objectives of the present study are to investigate the prevalence and types of pulmonary involvement using high-resolution computed tomography scan (HRCT) and pulmonary function tests (PFT) and evaluate the association between respiratory symptoms and RA-lung disease in a group of Egyptian RA patients. Thirty-six RA patients were recruited; 34 females (94.4%) and 2 males (5.6%) with median age of 48.5?years, and none of them was smoker. Detailed medical and drug histories were obtained. PFT, plain X-ray of the chest, and HRCT were performed to all subjects involved. Nearly 64% of RA patients demonstrated abnormalities in PFT and 47% in HRCT. Mixed restrictive and obstructive pattern was the commonest. Nearly two-thirds of our patients reported one or more pulmonary symptom whether dyspnea, cough, wheezing, or phlegm. Dyspnea was the most frequent symptom. Respiratory symptoms were statistically more common in patients with lung disease. The advanced age, high radiological score, and severity of rheumatoid disease were found to be predictive of lung involvement. Among respiratory symptoms, dyspnea and cough were associated with any pulmonary abnormalities. When specific pulmonary abnormalities were considered, only dyspnea was identified as predictor for restriction. For obstructive abnormality, both cough and wheezing provided valid prediction. We conclude that pulmonary involvement is a common manifestation in Egyptian RA patients, and the pattern of involvement is generally consistent with other studies that were performed worldwide. Specific respiratory symptoms could be used as practical, easy, and cost-effective method, especially in older and with more severe RA patients, to discriminate patients in need of subsequent PFT and HRCT imaging.     

类风湿性关节炎的肺胸膜表现56例临床分析

目的了解并分析类风湿性关节炎（rheumatoid arthritis，an）对呼吸系统的影响。方法选择符合诊断标准的RA患者110例。对有肺部表现的56例根据其一般临床表现，呼吸系统症状和体征、胸部X线检查和肺功能检查进行分析。结果110例中56例有明显肺部表现，占50．9％。呼吸系统症状和体征主要为干咳、胸痛、呼吸困难、水泡音。可发生肺间质纤维化。肺功能损害为限制性通气障碍、弥散功能障碍和小气道通气障碍。胸部X线检查表现为肺间质纤维化、胸腔积液、胸膜肥厚、肺结节、肺纹理增多和肺部渗出性病变。结论RA对呼吸系统的影响较常见。应引起重视。     

Normal expiratory flow rate and lung volumes in patients with combined emphysema and interstitial lung disease: a case series and literature review

Pulmonary function tests in patients with idiopathic pulmonary fibrosis characteristically show a restrictive pattern including small lung volumes and increased expiratory flow rates resulting from a reduction in pulmonary compliance due to diffuse fibrosis. Conversely, an obstructive pattern with hyperinflation results in emphysema by loss of elastic recoil, expiratory collapse of the peripheral airways and air trapping. When the diseases coexist, pulmonary volumes are compensated, and a smaller than expected reduction or even normal lung volumes can be found. The present report describes 10 patients with progressive breathlessness, three of whom experienced severe limitation in their quality of life. All patients showed lung interstitial involvement and emphysema on computed tomography scan of the chest. The 10 patients showed normal spirometry and lung volumes with severe compromise of gas exchange. Normal lung volumes do not exclude diagnosis of idiopathic pulmonary fibrosis in patients with concomitant emphysema. The relatively preserved lung volumes may underestimate the severity of idiopathic pulmonary fibrosis and attenuate its effects on lung function parameters.     

Pulmonary involvement in ankylosing spondylitis

PURPOSE OF REVIEW: Anti-tumor necrosis factor-alpha agents have recently been approved and recommended as effective and relatively safe drug therapy for ankylosing spondylitis. In light of this major advance in the management of these patients, recent observations on the pulmonary manifestations of ankylosing spondylitis are reviewed. RECENT FINDINGS: High-resolution computed tomography abnormalities were found to be prevalent (range 50-85%) in ankylosing spondylitis even in patients with early disease, and in those with normal chest radiographs and without respiratory symptoms. The high-resolution computed tomography changes included apical fibrosis, interstitial lung disease, emphysema, bronchietasis and pleural thickening. In general, the high-resolution computed tomography changes were of mild degree, and no correlation was observed between high-resolution computed tomography abnormalities, pulmonary function test variables and indices of ankylosing spondylitis symptoms and disease structural severity. Spontaneous pneumothorax was reported to be a rare complication, but tended to occur in those patients with fibrobullous disease. SUMMARY: The clinical significance of the high-resolution computed tomography abnormalities remains to be determined. Most of the published studies are cross-sectional, and are limited by lack of control subjects matched for age, gender and tobacco use. Studies to correlate high-resolution computed tomography changes with bronchoalveolar lavage and lung biopsies as well as prospective studies on long-term evolution of these findings including those patients receiving anti-tumor necrosis factor-alpha agents are needed.     

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.     

High resolution computed tomography of the lung in lifelong non-smoking patients with rheumatoid arthritis.

OBJECTIVES--To define pulmonary involvement on high resolution computed tomography (HRCT) of the thorax in lifelong non-smoking rheumatoid arthritis patients and to relate the results to pulmonary function, bronchial reactivity, and a variety of clinical and serological factors. METHODS--Twenty lifelong non-smoking RA patients (mean age 59 years (range 44-72; 18 females) were studied. Detailed medical and drug histories were taken. Protease inhibitor phenotype (Pi) and HLA-DR4 status were assessed. Schirmer's tear tests were performed to detect keratoconjunctivitis sicca (KCS). Spirometry, flow volume loops, and gas transfer factor measurement were recorded. The degree of bronchial reactivity (PC20 FEV1) was measured by a methacholine inhalation test. Chest and hand radiographs and HRCT of the lung were performed in all patients. RESULTS--Thirteen patients were HLA-DR4 positive. Eighteen had the Pi MM and two the Pi MS phenotype. Eight patients had evidence of KCS on Schirmer's tear testing. Ten patients achieved PC20 FEV1 in the methacholine inhalation test. All the patients had normal chest radiographs and all showed evidence of erosive arthropathy on hand radiographs. Five patients (25%) showed basal bronchiectasis and one mild interstitial lung disease on HRCT. All five patients with bronchiectasis had the Pi MM phenotype, four had HLA-DR4, four had KCS and three achieved PC20 FEV1; these values were not significantly different (p > 0.05) from those in patients without bronchiectasis. CONCLUSION--Using the highly sensitive technique of HRCT, we found evidence to suggest that the incidence of bronchiectasis in lifelong non-smoking RA patients may be much higher than previously reported.     

Assessment of asbestos-induced pleural disease by computed tomography--correlation with chest radiograph and lung function

We compared computed tomography (CT) scanning with chest radiography in the assessment of asbestos-induced pleural disease (AIPD) in 20 patients (17 men and 3 women, mean age 55 years, range 43-74 years). Involved pleura was scored on plain chest radiographs according to the International Labour Office (ILO) method of evaluating AIPD. A CT score was calculated from the measurement, using a digital length probe, of the circumference of the chest wall involved by pleural disease in each slice. The maximum width of pleural disease was taken into account in a way analogous to the ILO method for the chest radiograph. The CT score correlated with the chest radiograph score (r = +0.82, P less than 0.0006). CT demonstrated discrete plaques in 95% of patients but these were identified only in 59% patients on the radiograph. Diffuse pleural thickening was evident on the CT scan in all patients and in 70% on the radiograph. There was more inter-reader agreement about the type of pleural disease on the CT scans than on the chest radiographs. CT and chest radiograph scores inversely correlated with all lung function measurements except KCO. We conclude that increasingly extensive pleural disease is associated with increasingly severe impairment of lung function. CT scanning demonstrates the type of AIPD better than plain chest radiography.     

Lung findings on thoracic high-resolution computed tomography in patients with ankylosing spondylitis. Correlations with disease duration,clinical findings and pulmonary function testing

The aim of this study was to identify the spectrum of abnormalities revealed on high-resolution computerized tomography (HRCT) in patients with ankylosing spondylitis (AS), to compare findings with those of plain radiography and pulmonary function testing (PFT), and to look for correlations between lung involvement and AS severity. We prospectively studied 55 consecutive patients with a diagnosis of AS according to the modified New York criteria who attended our department over a period of 2 years. All patients had a detailed rheumatological examination and underwent plain chest radiography, chest HRCT and PFT. HRCT revealed abnormalities in 29 patients (52.7%), whereas plain chest radiography was abnormal in only 2. Abnormalities consisted of interstitial lung disease (ILD) (n=4), apical fibrosis (n=5), emphysema (n=5), bronchiectasis (n=4), ground glass attenuation (n=2), and non-specific interstitial abnormalities (n=26). Only apical fibrosis and bronchiectasis were statistically more frequent with increasing disease duration (significant trend ²test, p=0.0029 and 0.028, respectively). PFT showed a restrictive process in 19 patients (34.5%). No correlation was noted between HRCT and PFT, nor with AS symptomatic and structural severity parameters. However, there was a statistically significant correlation between PFT and AS symptomatic and structural severity parameters. In conclusion,: this study confirms that the chest HRCT of patients with AS showed a great number of abnormalities undetectable by standard X-rays. The high incidence of lung abnormalities emphasizes the importance of excluding such a diagnosis in patients with AS even without respiratory symptoms.Abbreviations AF Apical fibrosis - AS Ankylosing spondylitis - FVC Forced vital capacity - FEV₁ Forced expiratory volume in 1 s - HRCT High-resolution computerized tomography - ILD Interstitial lung disease - PFT Pulmonary function tests - VC Vital capacity