Search

Objective: To compare the performance of radiographers against that of radiologists for CT lung nodule detection in the UK Lung Cancer Screening (UKLS) pilot trial., Methods: Four radiographers, trained in CT nodule detection, and three radiologists were prospectively evaluated. 290 CTs performed for the UKLS were independently read by 2 radiologists and 2 radiographers. The reference standard comprised all radiologist-identified positive nodules after arbitration of discrepancies. For each radiographer and radiologist, relative sensitivity and average false positives (FPs) per case were compared for all cases read, as well as for subsets of cases read by each radiographer-radiologist combination (10 combinations)., Results: 599 nodules in 209/290 (72.1%) CT studies comprised the reference standard. The relative mean (±standard deviation) sensitivity of the four radiographers was 71.6 ± 8.5% compared with 83.3 ± 8.1% for the three radiologists. Radiographers were less sensitive and detected more FPs per case than radiologists in 7/10 and 8/10 radiographer-radiologist combinations, respectively (ranges of difference 11.2-33.8% and 0.4-2.6; p < 0.05). In 3/10 and 2/10 combinations, there was no difference in sensitivity and FPs per case between radiographers and radiologists. For nodules ≥100 mm(3) in volume or ≥5 mm in maximum diameter, radiographers were relatively less sensitive than radiologists in only 5/10 radiographer-radiologist combinations (range of difference 16.1-30.6%; p < 0.05) and not significantly different in the remaining 5/10 combinations., Conclusion: Although overall radiographer performance was lower than that of experienced radiologists in this study, some radiographer performances were comparable with that of radiologists., Advances in Knowledge: Overall, radiographers were less sensitive than radiologists reading the same CTs and also displayed higher average FP detections per case when compared with a reference standard derived from radiologist readings. However, some radiographers compared favourably with radiologists, especially when considering larger potentially clinically relevant nodules. Thus, while probably not sensitive enough to function as first readers, radiographers may still be able to fulfil the role of an assistant reader-that is, as a first or concurrent reader, who presents detected nodules for verification to a reading radiologist.

Idiopathic pulmonary fibrosis (IPF) has a more variable clinical course than has been traditionally recognised. Many patients will remain stable over time while others experience relatively rapid deterioration. The prognosis and clinical course of patients with other fibrosing lung diseases is also variable. A number of conditions may complicate the clinical course of the idiopathic fibrosing lung diseases, which results in morbidity and mortality, but also represents potentially treatable causes of worsening symptoms. Infection and malignancy have a long-recognised association with IPF while other conditions, particularly pulmonary hypertension and acute exacerbation of IPF, are being increasingly recognised in this patient population. Many of these patients have serial high-resolution CT (HRCT) examinations that may demonstrate one or more of these supervening conditions. In this article we review the more common conditions that may complicate the course of idiopathic fibrosing lung disease with an emphasis on the HRCT appearance, which the reporting radiologist should be aware of.

Lung cancer is the most common cause of cancer-related death in the UK. Despite aggressive primary prevention measures and improved medical care, the 5-year survival rate is less than 10% for patients in the UK who present with symptoms. The possibility of CT screening for lung cancer provides some hope of reducing mortality. However, the case for screening remains unproven. This article explores the issues surrounding lung cancer screening in the context of historical studies, trials in progress and tentative plans for a UK CT lung cancer screening trial.

Lung volume reduction surgery has recently been reintroduced as a palliative treatment for patients with severe emphysema. Selection criteria vary between centres and imaging is extensively used, but the exact role of individual techniques in the selection process is still emerging.

The data set of the thorax acquired by spiral CT is volumetric. Such data can be processed so that conventional axial sections are supplemented by reconstructed images, in an attempt to answer specific clinical questions. This review considers three reconstruction techniques: multiplanar reformation, three-dimensional rendering and sliding-thin slab reconstruction. Their relative benefits and limitations are considered, as are the implications of image processing in general.

Several pulmonary conditions are characterized by the finding of areas of decreased attenuation relative to adjacent normal lung parenchyma on computed tomography. In particular, the identification of areas of the lung affected by small airways disease is difficult as the reduction in lung density is subtle and the regions are poorly marginated. This paper presents a novel wavelet analysis technique which increases the conspicuity of differences between normal and abnormal lung parenchyma.

The chest radiograph has proved a robust diagnostic aid over the last century. The accumulation of knowledge about chest disease by radiography has been gained slowly during the last 90 years. New impetus has been given by the development of computed tomography and the recent refinements of high resolution and spiral computed tomography. The pathophysiological insights provided by these new techniques have been obtained in a remarkably short period, with the promise of more to come.

Objective measurement of bronchial damage in patients with bronchiectasis is needed to identify progressive disease. This study evaluates the inter- and intraobserver variation in computed tomography (CT) measurements of bronchial wall circumference and examines the precision with which CT measurements of the bronchi can be repeated in patients with bronchiectasis. Twelve patients were scanned and the circumferences of 61 subsegmental bronchi were measured independently on two occasions, by three observers, using a tracing facility on the CT console. To determine the accuracy with which previously acquired sections could be repeated, five patients were scanned on two separate occasions. The mean bronchial circumference measured by the three observers was 16.1 +/- 8.3 mm. The standard deviations of differences between first and second measurements of bronchial circumference for the three observers (intraobserver variability) were: 0.60 mm, 0.67 mm and 0.40 mm. The standard deviation of readings for interobserver variability was 0.71 mm. The standard deviations of differences (and coefficients of variation) for measurements of bronchial circumference following rescanning were: 1.82 mm, 1.40 mm and 1.74 mm (9.9%, 7.6% and 9.3%, respectively). The reproducibility of measurements of wall circumference, between and within observers and between examinations, indicates that such measurements may be clinically useful in demonstrating the progression of bronchiectasis.

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.

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 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.

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.