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The aim of this study was to determine whether the speed of technetium-labelled diethylene-triamine-pentacetate (99mTc-DTPA) clearance from the lung is predictive of disease progression in fibrosing alveolitis, as judged by changes in respiratory function tests. 82 nonsmoking patients with fibrosing alveolitis were studied (progressive systemic sclerosis, n = 53; lone cryptogenic fibrosing alveolitis, n = 29). Normal 99mTc-DTPA clearance at initial measurement predicted stable disease; rapid 99mTc-DTPA clearance identified patients at risk of deterioration. Repeat measurement of clearance, approximately 12 months later, enabled the definition of a subgroup at higher risk, with persistently abnormal 99mTc-DTPA clearance, and a smaller subgroup in whom reversion of clearance to normal was associated with a sustained improvement in respiratory function indices. These findings were not attributable to differences in treatment between subgroups. We conclude that the speed of 99mTc-DTPA clearance discriminates between stable and progressive disease in fibrosing alveolitis.

Background: Open lung biopsy is often performed to confirm the diagnosis in patients with suspected fibrosing alveolitis. The superior sensitivity and specificity of high resolution computed tomography (CT) over chest radiography in various diffuse lung diseases suggest that the characteristic appearance of fibrosing alveolitis on high resolution CT might render biopsy confirmation unnecessary., Methods: The chest radiographs and high resolution CT scans of 86 patients (41 with fibrosing alveolitis and 45 with various other diffuse lung diseases) were examined individually and independently by two observers. No clinical information was given and the observers gave a level of confidence when the diagnosis was thought to be fibrosing alveolitis., Results: The observers correctly and confidently discriminated between fibrosing alveolitis and other diffuse lung diseases on high resolution CT with an accuracy of 88% and on chest radiography with an accuracy of 76%. The false negative rate for fibrosing alveolitis diminished from 29% on chest radiography to 11% on high resolution CT. The false positive rate on chest radiography was 19% and on high resolution CT 13%; the false positive diagnoses on CT were the result of a few conditions (extrinsic allergic alveolitis, sarcoidosis, cryptogenic organising pneumonia, and pulmonary eosinophilia) which mimicked some of the CT features of fibrosing alveolitis. The superficial similarity of the CT patterns of these conditions are discussed., Conclusions: High resolution CT is superior to chest radiography in establishing the diagnosis of fibrosing alveolitis and the typical CT appearances are virtually pathognomonic. The diagnostic advantages of CT over chest radiography should further reduce the need for open lung biopsy in this condition.

In order to characterize the appearances of bronchiolitis obliterans on high-resolution CT (HRCT) and to relate the extent of HRCT abnormalities to pulmonary function tests, the HRCT scans of 18 patients with bronchiolitis obliterans were examined by two independent observers. The underlying causes for the development of bronchiolitis obliterans were penicillamine therapy (n = 5), previous infection (n = 4), graft-vs-host disease (n = 3), and miscellaneous causes (n = 6). Abnormal HRCT findings were present in all cases. The commonest HRCT abnormalities consisted of patchy areas of decreased parenchymal attenuation (n = 15), subsegmental (n = 12) and segmental (n = 6) bronchial dilatation and centrilobular branching structures (n = 5). There was no significant correlation between the extent of abnormalities and the static lung volumes or the impairment in gas transfer (all P values > 0.05). The only significant correlation was between the number of segments with subsegmental bronchial dilatation and the forced expiratory volume in one second (Wilcoxon r = 0.61, P < 0.01). We conclude that the great majority of patients with bronchiolitis obliterans have HRCT abnormalities. However, there is poor correlation between the extent of abnormalities on HRCT and functional impairment.

Apart from projectional and plain radiographs, all images in a radiology department are obtained in a digital format and handled by computers. It is now technically possible to acquire a digital chest radiograph without the use of conventional film. There are advantages in the image processing of digital chest radiographs but the cost remains a compelling obstacle.

The aim of this study was to determine the prevalence of enlarged mediastinal lymph nodes in systemic sclerosis (SSc) and relate this to the extent of pulmonary disease and disease activity as judged by high resolution computed tomography (HRCT). The HRCT scans of 78 patients with SSc were reviewed. The extent of lung disease and HRCT pattern were analysed and CT scans examined on soft tissue window settings for evidence of mediastinal lymph node enlargement. Sixty six (85%) patients had evidence of lung involvement on CT. Enlarged mediastinal lymph nodes were present in 21 (32%) patients with lung involvement but in only 1 (8%) patient without. The prevalence of enlarged mediastinal nodes increased with more extensive lung involvement on CT (p < 0.025), but correlated poorly with the type of CT appearance and concurrent erythrocyte sedimentation rate. Mediastinal lymph node enlargement occurs frequently in patients with SSc, particularly if lung involvement is extensive.

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.

A prospective study was performed comparing computed and conventional radiography for the detection and visibility of cardiovascular devices in intensive care unit patients. Computed images were obtained using a commercially available 2K x 2K, 12-bit storage phosphor plate system. Image sets from 50 patients were assessed independently by three observers. A significant difference between the types of image was found for the detection of mediastinal drainage tubes and prosthetic valves. Computed images allowed greater confidence in the identification of courses and tips of lines. This advantage was most marked with edge-enhanced computed images.

The superiority of CT over chest radiography in the evaluation of diffuse lung disease is now acknowledged, and the role of high-resolution CT is becoming increasingly clearly defined. In many cases of suspected diffuse lung disease, open lung biopsy may be obviated as a result of the findings of high-resolution CT. Now that the high-resolution CT appearances of most diffuse lung diseases have been described, studies are being directed at characterizing the natural history of these conditions using serial high-resolution CT examinations. This work is of particular relevance to industrial and fibrosing lung disease. Faster image acquisition by the latest CT scanners has allowed dynamic studies that have provided unique functional information in a number of diffuse lung diseases.

Background: The relative proportions of fibrosis and inflammation seen by open lung biopsy examination is a predictor of disease outcome in fibrosing alveolitis. This study was designed to assess the ability of high resolution computed tomography to predict the histological appearance of open lung biopsy specimens from patients with systemic sclerosis., Methods: Twenty abnormal biopsy specimens from 12 patients were assessed; abnormalities were categorised as fibrotic (fibrosis exceeding inflammation) or inflammatory (inflammation equal to or exceeding fibrosis). Computed tomography appearances were scored for the lobe from which the biopsy specimen was taken; scans were graded from parenchymal opacification alone through to a reticular pattern alone., Results: Two lobar appearances were identified on computed tomograms: amorphous parenchymal opacification equal in extent to reticulation (grade 3) and a predominantly reticular pattern (grade 4). There was a significant association between a fibrotic histological appearance and a grade 4 computed tomogram, and between an inflammatory histological appearance and a grade 3 computed tomogram. Computed tomography grade 4 was associated with a fibrotic histological appearance in 12 out of 13 lobes, and grade 3 with an inflammatory histological appearance in four out of seven lobes., Conclusion: Computed tomography discriminated between biopsy specimens that were predominantly fibrotic and a smaller group with a larger amount of inflammation.

The clinical features, radiographic and computed tomographic findings of nine patients with histological proof of cryptogenic organizing pneumonia were analysed. Patients present with cough, dyspnoea and malaise and commonly have bilateral multifocal consolidation on chest radiography, which may show resolution or relapse with or without steroid treatment. A good response to steroids is the rule, usually with complete radiological resolution or minimal residual scarring. The relative merits of the terms cryptogenic organizing pneumonia and bronchiolitis obliterans organizing pneumonia, both currently used to describe this entity, are discussed.

Patients with cryptogenic fibrosing alveolitis have a higher prevalence of enlarged mediastinal lymph nodes compared with the normal population. To determine whether or not this observation applies to individuals with asbestos-induced pulmonary fibrosis the high resolution computed tomography (CT) scans of 14 patients with definite asbestosis and 11 age-matched cases with benign asbestos-induced pleural disease, but no lung disease, were re-imaged on soft tissue settings. The site, size and number of mediastinal lymph nodes equal to, or greater than, 1.2 cm were recorded. In the asbestosis group 14 out of 14 patients had at least one enlarged lymph node with an average number per individual of four (range 1-10). In the control group two out of 11 patients each had one minimally enlarged lymph node. We conclude that mediastinal lymph node enlargement occurs frequently in asbestosis: awareness of this is important in the investigation of malignant disease in patients with asbestosis.

Alpha-1-antitrypsin (AAT) deficiency is an inherited disorder associated with an increased prevalence of pulmonary emphysema. To date there has been no description of the appearances on CT of the emphysema associated with AAT deficiency. We have reviewed the CT scans of 17 patients with proven AAT deficiency. Eleven out of 17 were examined with HRCT. The CT features were correlated with those on chest radiography. Areas of low density corresponding to parenchymal destruction and reduced perfusion, and attenuation of the pulmonary vasculature were present in all cases. Frank bulla formation occurred in 7/17 patients and was not a major feature. A striking CT finding was bronchial wall thickening and/or dilatation in 7/17 patients with gross cystic bronchiectasis in one patient. In contrast to appearances on chest radiography the upper zones were affected in all cases (17/17) and fine section scanning was particularly valuable in demonstrating changes in these less severely affected regions. Estimation of the extent of disease correlated well with abnormal lung function tests.

Chest radiography gives a useful but imprecise indication of the extent of diffuse lung disease. The limitations in sensitivity and specificity of chest radiography in this context are well known and have been reinforced with the advent of computed tomography and its application to this difficult diagnostic area. High resolution computed tomography shows morphological detail invisible on chest radiography and both sensitivity and specificity in diffuse lung disease are greatly improved with this technique. Features of sarcoidosis and extrinsic allergic alveolitis revealed by high resolution computed tomography are examined in this review.

To evaluate the effects of scanning equalization radiography (SER) on the detection of diffuse lung disease a clinical comparison between an Advanced Multiple Beam Equalization Radiography (AMBER) unit and conventional chest radiography was performed. Even though the overall detection of focal pulmonary lesions with the AMBER unit has been shown to be significantly higher than with conventional radiography because of the improved demonstration of the costophrenic and retrocardiac regions, the utility of AMBER in the demonstration of diffuse lung disease has not been established. Twenty-one patients with diffuse lung disease (fibrosing alveolitis or sarcoidosis) and six patients with no pulmonary disease had high kVp frontal and lateral chest radiographs on both an AMBER unit and a conventional chest stand. The pooled results of five observers using Receiver Operating Characteristic (ROC) analysis indicate that there is a slight improvement but no statistically significant difference in observer performance between AMBER (Area under the ROC curve AZ = 0.934) and conventional radiography (AZ = 0.868) in the task of detecting diffuse 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.

The value of needle biopsy (NB) of pulmonary masses in patients unsuitable for surgery is well established. The presence of malignant cells confirms the diagnosis and thus aids management. We have reviewed 196 patients aged over 40 years with a solitary pulmonary mass suspected of being operable lung cancer to assess the effect of a negative NB result on the management. Malignant cells were discovered in 148 patients and diagnoses of infection were made in a further 10. In 38 patients no malignant cells were identified. Nineteen patients proceeded to thoracotomy and 13 of these had malignant disease. Nine others had further needle biopsies and eight of these had malignancy. Ten patients were followed up without any further intervention and four of these eventually proved to have malignancy. Thus of the 38 patients with no malignant cells on NB but no definite benign diagnosis, 25 had malignancy, six had benign disease and seven had presumed benign disease. In this series NB provided a definite benign diagnosis in 5.1% of patients. From this study it may be concluded that if a solitary pulmonary nodule has a high clinical suspicion of malignancy and the patient is a candidate for surgery, NB is of limited value in management.

With an increasing number of storage phosphor computed radiography units being installed worldwide, the evaluation of digital chest radiology is no longer being confined to experimental determinations of adequate imaging variables. There has been a substantial increase in the number of clinically based studies that have compared computed radiography with conventional film radiography. The applications of computed radiography are widening and further developments in dual-energy imaging and scanning equalization radiography have become possible through the use of phosphor storage computed radiography. Computer-assisted diagnosis applied to chest radiography may shortly be revolutionized by artificial intelligence, which is capable of assimilating both radiographic and clinical data.

Seventeen patients with extrinsic allergic alveolitis were examined with high-resolution computed tomography (CT). Increased attenuation of the lung parenchyma was present in eleven cases; the corresponding abnormality on chest radiography of ground-glass opacification was found in only five cases. The apparent upper zone sparing on chest radiography was not confirmed on CT which demonstrated a global increase in lung density. Several other abnormalities identified on CT in the subacute phase of extrinsic allergic alveolitis are described and correlated with chest radiographs. Whilst there is no single pathognomonic CT feature of extrinsic allergic alveolitis, there is a characteristic constellation of abnormalities which provide support for an otherwise uncertain clinical diagnosis.

Eight patients with the diagnosis of lymphangiomyomatosis were evaluated with computed tomography (CT), chest radiography, and pulmonary function tests to determine the relationship between the extent of disease seen on imaging studies and functional status. Chest radiographic assessment included the subjective determination of disease extent and measurements of lung length and the arc of the right hemidiaphragm. Disease extent on CT scans was scored as a percentage of lung that was abnormal on the basis of visual assessment of the degree of cystic replacement of the lung parenchyma. Significant correlations were observed between CT scores and percentages of predicted forced expiratory volume in 1 second/forced vital capacity (r = -.92, P less than .002) and diffusing capacity of the lungs for carbon monoxide (r = -.80, P less than .017). No significant correlations were observed between subjective chest radiographic scores and pulmonary function tests, although measurements of lung length and percentage of predicted total lung capacity were correlated (r = .76, P less than .045). CT was more accurate than chest radiography in defining the presence and extent of parenchymal cysts and provided for greater morphologic-physiologic correlation. CT, particularly high-resolution CT, may be useful in the diagnosis and longitudinal evaluation of patients with this disease and may be more sensitive than pulmonary function tests in the early stages of lung damage.

Refsum's disease is a rare inborn error of phytanic acid metabolism in which skeletal abnormalities are part of the clinical syndrome. The reported incidence of bone changes in patients with Refsum's disease varies widely and reflects the small series published to date. An analysis of the skeletal abnormalities of the largest series of patients in the world is presented.

The mammograms of 444 patients who had a breast biopsy leading to a definitive histological diagnosis were reviewed. In 21 cases (4.7%) grouped microcalcifications were identified as the only mammographic abnormality. These groups of microcalcifications were analysed to determine whether there was any quantitative difference between benign and malignant lesions with respect to a shape parameter of the group, the spatial frequency of the particles and neighbour-to-neighbour relationships of the particles. This analysis did not reveal any significant difference between the spatial relationships of the grouped microcalcifications found in benign and malignant breast disease.

Twenty-one patients with established cystic fibrosis were examined using high-resolution, narrow-section computed tomography. The bronchiectasis of cystic fibrosis is described and is shown to be characteristic in many respects. Computed tomography was found to be more accurate than standard radiography in locating the disease process and demonstrated pleural involvement which was not apparent on chest radiographs.

The accuracy of mammography alone and in combination with clinical examination and aspiration cytology was assessed in 402 patients who attended the Early Diagnostic Unit of the Royal Marsden Hospital, London. The sensitivities of mammography, clinical examination and cytology in identifying breast cancer were 76.9%, 81.7% and 63.5% respectively; the specificities of each test were 90.0%, 87.6% and 99.3%. The calculated sensitivity was increased to 96.2% if one positive test out of the three was regarded as an indication to undertake breast biopsy. If this approach was adopted the number of breast cancers missed would be two out of 104 and the yield of positive biopsies would be approximately one in four (27.6%). The implications of proceeding to breast biopsy on the basis of a single positive test are discussed.

It has been shown that raised intracapsular pressure causes avascular necrosis of the femoral head in experimental animals, but the relevance of this to clinical fractures of the femoral neck is controversial. We have studied 19 patients with intracapsular fractures of the femoral neck by pressure measurement and by ultrasonography to demonstrate capsular distension. The intra-articular pressure in Garden Grade I and II fractures averaged 66.4 mmHg with a maximum of 145 mmHg. In 10 Garden Grade III and IV fractures the average pressure was 28 mmHg with a maximum of 65 mmHg. Most of the recorded intracapsular pressures were high enough to have caused possible vascular embarrassment, and it is suggested that early decompression of the haemarthrosis should be considered.

The place of computed tomography (CT) scanning in the detection of pulmonary nodules is now well established. Due to the increasing spatial resolution of CT and shorter scan times, patients with diffuse lung disease can now be examined more effectively. Narrow section CT demonstrates the morphological detail of some diffuse lung diseases at an earlier stage than conventional radiography.