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Biomedical subjects

D M Hansell

Publications and source records attributed to D M Hansell.

At least 91 records · Page 5Linked to original sources
PubMed1997

Fibrosing alveolitis in systemic sclerosis: indices of lung function in relation to extent of disease on computed tomography.

OBJECTIVE: Thin-section computed tomography (CT) provides a sensitive and reproducible method of quantifying the morphologic extent of disease in the clinical management of fibrosing alveolitis associated with systemic sclerosis (FASSc). The aim of this study was to determine which indices of lung function best reflect the extent of disease on CT in FASSc, and to determine the independent influences of smoking history, extent of fibrosing alveolitis, demographic features, and concurrent treatment upon functional impairment in FASSc. METHODS: Sixty-four patients with FASSc were studied using CT and static and exercise lung function testing. Statistical relationships were determined by multiple regression analyses. RESULTS: Five patients with overt pulmonary hypertension were characterized by severe impairment in 3 indices of lung function: diffusing capacity for carbon monoxide (DLCO), DLCO adjusted for alveolar volume (KCO), and arterial partial pressure of oxygen. On multiple regression analysis, the major determinant of functional impairment was the extent of fibrosing alveolitis on CT. A history of smoking was independently associated with preservation of total lung capacity and depression of KCO, but did not otherwise influence functional-morphologic correlations. The percent predicted DLCO correlated better with extent of disease on CT (r = -0.70) than did oxygen desaturation on exercise (r = 0.55), the physiologic component of the clinical-radiographic-physiologic score (CRP index) (r = 0.52), or other indices of lung function. Lung volume measures correlated poorly with disease extent on CT. CONCLUSION: The percent predicted DLCO best reflects the extent of fibrosing alveolitis in FASSc, and therefore should be measured in routine evaluations. Exercise testing may also have a useful role in staging the severity of pulmonary fibrosis, but the CRP index offers no additional advantage over the DLCO and exercise testing.

Carbon Monoxide↗
PubMed1997

Non-breath-hold lung magnetic resonance imaging with real-time navigation.

Magnetic resonance imaging (MRI) with navigating techniques based on consecutive breath-holds demand a level of respiratory control that is often beyond the capability of patients with lung disease. The objectives of this investigation were to develop and evaluate a navigating technique for lung MRI that does not rely on patient cooperation. Navigating techniques were implemented at 0.5 T using conventional imaging techniques of short echo-time and imaging during normal breathing in the diastolic phase of the cardiac cycle. A column of spins, orthogonal to the diaphragm, was excited both immediately before and after the imaging segment. These signals were processed in real time to provide the position of the lung-diaphragm interface. An imaging segment was considered correctly acquired only when the interface position was within the acceptance window both before and after the acquisition of the segment. A distribution of lung-diaphragm interface positions obtained during normal respiration was employed to define the acceptance window. In the case of multislice techniques, the position of the lung-diaphragm interface immediately before the imaging segment was also employed to decide which phase-encoding step to acquire next, therefore reducing the apparent frequency of the respiratory motion. A distribution of interface positions, updated in real time, served as a reference for the allocation of phase-encoding steps according to diaphragm position. The lung images obtained represent a significant advance in image quality, improving further the ability of MR to detect and monitor pulmonary disease. Motion artifacts were reduced, and images reliably demonstrated smaller vessels, which are not normally visible without navigation.

Computer Systems↗
PubMed1997

Three-dimensional computed tomography bronchoscopy using clinical datasets: a comparison with fibreoptic bronchoscopy.

OBJECTIVE: To assess three-dimensional computed tomography 'bronchoscopic' (3-DCTB) reconstruction of routine CT data as a non-invasive method of airway visualization, and compare it with fibreoptic bronchoscopy (FOB). METHODS: Fourteen datasets were acquired from 13 patients undergoing both FOB and CT examination of the chest. Standard continuous volume CT using 6 mm collimation and clinical FOB techniques were employed. Images were obtained from 3-DCTB reconstructions by segmentation and surface recognition algorithms generating surface rendered 'bronchoscopic views'. These were scored for technical quality and anatomical detail. The most distal bronchi seen in left upper and right lower lobes were recorded for FOB and 3-DCTB. RESULTS: On FOB, the subsegmental bronchi were seen in right lower and in left upper lobe in 10/14 cases and 4/14 cases, respectively. Visualization of the subsegmental airways was not achieved with 3-DCTB, as they could not be identified with confidence. 3-DCTB never achieved a more distal view than obtained by FOB. Using 3-DCT, the right, lower lobe segmental bronchi were seen in 10/14 cases, and lobar bronchus in 14/14 cases (two occluded). In the left upper lobe, 3-DCT showed segmental bronchi in 6/14 cases, lobar bronchus in 11/14 cases (one occluded) and the left main bronchus appeared occluded in 3/14 cases. Overall, technical quality and anatomical detail scores of the carina and proximal bronchi ranked significantly higher than views of segmental bronchi. CONCLUSIONS: 3-DCTB cannot routinely replace FOB for inspection of major and segmental bronchi. Subsegmental bronchi cannot be adequately demonstrated by 3-DCTB using 6 mm collimation datasets.

Adult↗
PubMed1997

Primary epithelioid angiosarcoma of the lung presenting as pulmonary hemorrhage.

Pulmonary angiosarcomas are usually secondary tumors, and only a few primary cases have been described. We report a unique case of epithelioid angiosarcoma arising in the lungs as a bilateral multinodular infiltrate and presenting as pulmonary hemorrhage. Because of its epithelioid histology, this tumor may resemble a carcinoma, also staining positively for keratin markers. Therefore, unless the diagnosis of epithelioid angiosarcoma is considered and endothelial markers used, the diagnosis of epithelioid angiosarcoma may be overlooked at this site.

Aged↗
PubMed1997

CT image enhancement with wavelet analysis for the detection of small airways disease.

Bronchiolar obstruction is commonly manifested in computed tomography (CT) images as areas of decreased attenuation relative to adjacent normal lung parenchyma. The certain identification of such areas is difficult in practice, particularly if they are poorly marginated. This paper presents a novel approach to the enhancement of feature differences between normal and diseased lung parenchyma so that reliable visual assessment can be made. The method relies on a hybrid structural filtering technique which removes pulmonary vessels appearing in the CT cross-sectional images without affecting intrinsic subtle intensity details of the lung parenchyma. In order to restore possible structural distortions introduced by the hybrid filter, a feature localization process based on wavelet reconstruction of feature extrema is used. After contrast enhancement the resultant images are used to delineate region borders of the diseased areas and quantification is made with regard to the extent of the disease.

Bronchiolitis Obliterans↗
PubMed1997

Effects of airway infection by Pseudomonas aeruginosa: a computed tomographic study.

BACKGROUND: Pseudomonas aeruginosa commonly infects the airways of patients with bronchiectasis. A study was undertaken to examine the relationship between infection of the airways with this pathogen, the morphological pattern of bronchiectasis on thin section computed tomographic (CT) scanning, symptom duration, smoking habits of the patients, and the presence of airflow obstruction. METHODS: Thin section CT scans of 22 adult patients with bronchiectasis and concurrent sputum infected by P aeruginosa (Pa +ve) and those of 45 randomly selected patients not infected by P aeruginosa (Pa -ve) were analysed independently by two thoracic radiologists. Patients with cystic fibrosis were excluded. Each scan was scored at a lobar level for extent of bronchiectasis, severity of bronchial wall thickening and dilatation, predominant pattern of bronchiectasis, presence of mucus plugging, and degree of decreased attenuation of the lung parenchyma. RESULTS: The Pa +ve group had more extensive bronchiectasis and a greater degree of bronchial wall thickening and dilatation on the CT scan than the Pa -ve group; more extensive decreased attenuation was seen in the Pa +ve group. These findings were robust on multivariate analysis; decreased attenuation was also independently related to the duration of sputum production. CONCLUSION: Patients with bronchiectasis infected by P aeruginosa have more extensive and severe bronchiectasis on thin section CT scanning than those without P aeruginosa infection. The bronchi and small airways are both involved, reflecting the end result of complex interactions between host airways and the numerous virulence factors produced by P aeruginosa.

Adult↗
PubMed1997

Cryptogenic fibrosing alveolitis and the fibrosing alveolitis of systemic sclerosis: morphological differences on computed tomographic scans.

BACKGROUND: The purpose of this study was to identify morphological differences on the computed tomographic (CT) scan between cryptogenic fibrosing alveolitis (CFA) and the fibrosing alveolitis associated with systemic sclerosis (FASSc), and to examine their biological relevance. METHODS: One hundred and seven patients with CFA (n = 55) or FASSc (n = 52) who had undergone thin section CT scanning were included. Multivariate analysis was used to identify morphological differences on the CT scans between lone CFA and FASSc, and to determine whether the pattern and distribution of disease on the CT scans were functionally significant (as judged by the lung transfer factor (TLCO), forced vital capacity (FVC), and arterial oxygen tension (PaO2)) or predictive of survival (independent of the type and extent of fibrosing alveolitis, age, sex, and smoking history). RESULTS: Increasingly extensive disease on CT scans was associated with a coarser reticular pattern (increase in reticular score per percentage increase in disease extent = 0.06, 95% confidence interval (CI) 0.03 to 0.09, p < 0.0005) and increasing upper zone involvement (increase in ratio of upper zone to total disease per percentage increase in disease extent = 0.002, 95% CI 0.000 to 0.003, p < 0.04). Patients with CFA were characterised by a higher upper zone ratio (difference = 0.08, 95% CI 0.02 to 0.13, p < 0.004) and a weak trend towards a coarser reticular pattern (p = 0.09), independent of disease extent. Smokers with CFA had more upper zone involvement (difference = 0.11, 95% CI 0.05 to 0.16, p < 0.0005) and a coarser reticular pattern (difference in reticular score = 1.92, 95% CI 0.27 to 3.55, p < 0.02) than smokers with FASSc. The extent of disease on the CT scan was predictive of lung function impairment and survival but the pattern and distribution of disease were not. CONCLUSIONS: Patients with CFA have relatively more upper zone involvement than those with FASSc independent of the extent of disease on the CT scan. This finding may result from smoking related damage but is not functionally significant.

Diagnosis, Differential↗
PubMed1997

Obliterative bronchiolitis: individual CT signs of small airways disease and functional correlation.

PURPOSE: Individual features of small airways disease depicted at computed tomography (CT) were correlated with functional indexes in patients with obliterative bronchiolitis. MATERIALS AND METHODS: Fifteen patients (all women) who fulfilled the strict criteria for diagnosis of obliterative bronchiolitis underwent thin-section CT at full inspiration and at end expiration. The CT scans were scored by two observers for extent of decreased attenuation of the lung parenchyma; end-expiration CT signs of air trapping; and bronchial dilation, wall thickening, and mucous plugging. The functional importance of each CT sign was evaluated. RESULTS: Areas of decreased attenuation were present in all patients (median score at end expiration, 61%; range, 21%-83%). Bronchial wall thickening was identified in 13 of the 15 patients. Correlations of the extent of decreased attenuation and measures of air-flow obstruction were strongest between decreased attenuation at end expiration and air flow at low lung volumes (r(s) = -.70, P < .005). This relationship remained intact after correction for the severity of bronchial wall thickening. CONCLUSION: In patients with obliterative bronchiolitis, the extent of decreased attenuation at CT was most strongly related to depression of pulmonary function tests of the small airways. Decreased attenuation is the cardinal sign for further quantitative studies of obliterative bronchiolitis.

Adult↗
PubMed1997

Mosaic attenuation pattern on thin-section CT scans of the lung: differentiation among infiltrative lung, airway, and vascular diseases as a cause.

PURPOSE: To determine whether infiltrative lung, airway, or vascular disease can be differentiated as the cause of mosaic attenuation on thin-section computed tomographic (CT) scans of the lung. MATERIALS AND METHODS: Thin-section CT scans were reviewed in 70 patients examined at three institutions. A mosaic attenuation pattern and pathologic or clinical proof of a specific type of disease were demonstrated. Causes of the mosaic pattern included infiltrative lung disease (n = 37), airway disease (n = 22), and vascular disease (n = 11). Thin-section CT findings were assessed independently by two observers blinded to clinical findings. RESULTS: The type of disease was identified correctly at CT in 58 (83%) of 70 patients by observer 1 and 57 (81%) of 70 patients by observer 2. Infiltrative lung disease was diagnosed correctly by both observers in 34 (92%) of 37 cases. Observer 1 identified 21 (95%) of 22 cases of airway disease and three (27%) of 11 cases of vascular disease. Observer 2 identified 19 (86%) of 22 cases of airway disease and four (36%) of 11 cases of vascular disease. CONCLUSION: Infiltrative lung disease and airway disease may be differentiated reliably as the cause of mosaic attenuation on lung CT scans, whereas vascular disease is often misinterpreted as infiltrative lung disease or airway disease.

Adult↗
PubMed1997

Lone cryptogenic fibrosing alveolitis: a functional-morphologic correlation based on extent of disease on thin-section computed tomography.

In most clinical series of patients with cryptogenic fibrosing alveolitis (CFA), disease severity is staged using lung function indices. However, many physiologic indices are measured in routine clinical practice; the choice of variable to evaluate functional severity is contentious. Computed tomography (CT) provides a reproducible means of quantifying the morphologic extent of disease. The aim of this study was to evaluate the functional consequences of smoking-related lung damage in CFA and to identify functional measures best reflecting the extent of fibrosing alveolitis on CT. Sixty-eight patients with CFA were studied. Fourteen patients with emphysema on CT were characterized by relative preservation of FVC and TLC (p < 0.005) and relative depression of DLCO (p < 0.05) and KCO (p < 0.00005). On multivariate analysis, the extent of fibrosing alveolitis and the presence of emphysema were independent determinants of functional impairment; there was no independent relationship between smoking history and functional abnormalities. In patients without emphysema on CT, percent predicted DLCO (r = -0.68), oxygen desaturation on exercise (r = 0.64), and the physiologic component of the clinical-radiographic-physiologic (CRP) score (r = 0.62) correlated much better with the extent of disease on CT than spirometric and plethysmographic volumes. A composite functional index was generated against the extent of disease on CT, using multivariate analysis; comparison with the CRP score suggested that the relationship between morphologic disease extent and the CRP score would be improved by the inclusion of DLCO and by the use of negative weighting for depression of FEV1. These findings indicate that in CFA, the presence of concurrent emphysema on CT has a more profound influence upon functional measures than the smoking history, and underline the importance of both the measurements of DLCO and exercise testing in the assessment of the severity of CFA.

Case-Control Studies↗
PubMed1997

Functional impairment in lone cryptogenic fibrosing alveolitis and fibrosing alveolitis associated with systemic sclerosis: a comparison.

Lone cryptogenic fibrosing alveolitis (CFA) is histologically identical to fibrosing alveolitis associated with systemic sclerosis (FASSc), but it has a much worse prognosis after matching for disease severity at presentation. Thin-section CT scanning (CT) provides a reproducible method of quantifying the morphologic extent of fibrosing alveolitis. The aim of this study was to gain insights into contrasting pathophysiologic mechanisms in the two diseases by comparing patterns of functional impairment after matching for extent of disease on CT, demographic factors, smoking history, and concurrent treatment. Patients with emphysema on CT (n = 16) and patients with FASSc with overt pulmonary hypertension (n = 5) were excluded; 111 patients were studied (CFA, n = 54; FASSc, n = 57). Patients with CFA were distinguished by more severe functional impairment and more extensive disease on CT (40.1 versus 22.1%, p < 0.00005). On multivariate analysis, patients with CFA had greater reduction in arterial P(O2) (p < 0.0005), wider AaP(O2) (p < 0.0005), greater oxygen desaturation on maximal exercise (p < 0.03), and higher dyspnea scores (p < 0.02) than did patients with FASSc after controlling for extent of disease on CT and other covariates. Measures of lung volume and gas transfer did not differ independently between CFA and FASSc. These findings persisted in subanalyses of patients with limited disease, extensive disease, histologic confirmation of fibrosing alveolitis, and with the reinclusion of patients with emphysema and pulmonary hypertension. The patterns of functional impairment were indicative of more severe ventilation-perfusion mismatch or anatomic shunting in CFA after adjustment for disease extent; we speculate that perfusion of poorly ventilated lung parenchyma in CFA occurs through new vessels formed in areas of intense inflammation. This mechanism may contribute to the greater mortality of patients with CFA than of patients with FASSc because of the deleterious effects of hypoxia on concurrent cardiac disease.

Female↗
PubMed1997

Functional impairment in fibrosing alveolitis: relationship to reversible disease on thin section computed tomography.

Thin-section computed tomography (CT) provides a reproducible method of quantifying global disease extent and can also discriminate between fibrotic disease, with predominance of reticular abnormalities, and reversible inflammatory cell infiltration, shown as ground-glass attenuation. The aim of this study was to determine whether functional impairment varied according to the presence of ground-glass attenuation on CT, independently of extent of disease on CT, demographic factors, smoking history, therapeutic status, and the type of fibrosing alveolitis (lone cryptogenic fibrosing alveolitis (CFA) versus fibrosing alveolitis associated with systemic sclerosis (FASSc)). Patients with concurrent emphysema on CT (n = 16) and FASSc patients with end-stage pulmonary hypertension (n = 5) were excluded. One hundred and eleven patients were studied (CFA, n = 54; FASSc, n = 57). The severity of functional impairment did not vary independently with the presence of predominant ground-glass attenuation, mixed appearance and predominant reticulation on CT. In 34 treated patients undergoing serial CT scanning, the severity of functional impairment did not differ independently between patients with and without regression of ground-glass attenuation at follow-up. We conclude that the severity of functional impairment does not discriminate between inflammatory and fibrotic disease in fibrosing alveolitis, as judged by initial and serial computed tomographic scanning, after adjustment for the morphological extent of disease on computed tomography.

Female↗
PubMed1997

Effect of sputum bacteriology on the quality of life of patients with bronchiectasis.

Bronchiectatic patients have impaired health-related quality of life (QoL) and are prone to chronic lower respiratory tract infections. We have investigated whether impaired QoL is related to sputum bacteriology. Eighty seven patients with non-cystic fibrosis (non-CF) bronchiectasis, in a stable phase of their illness, completed three QoL measures, underwent a computed tomography (CT) scan and lung function tests, and provided a fresh sputum sample for microscopy and culture. The QoL of patients colonized by Pseudomonas aeruginosa (Pa group) was significantly worse than all other patients grouped together (non-Pa group), and specifically those infected by Haemophilus influenzae (Hi group) or who had no bacterial growth (NG group) (p<0.05), but not those infected by other bacterial species (O group). The Pa group had worse lung function, but no significant differences were found between the groups for forced expiratory volume in one second (FEV1) and peak expiratory flow rate. The Pa group had significantly worse bronchiectasis scores than the O, NG and non-Pa groups, but not the Hi group. There were no significant differences between the groups with respect to the number of infective exacerbations in the last year, but the Pa group had significantly more hospital admissions. Patients infected by P. aeruginosa for more than 3 yrs had significantly worse FEV1 (p<0.03) and bronchiectasis scores (p<0.05) than those infected with P. aeruginosa for less time, but not significantly worse QoL. We conclude that, overall, patients infected with P. aeruginosa have worse quality of life, and that P. aeruginosa is associated with a greater extent of disease and worse lung function. Although patients infected with H. influenzae had extensive bronchiectasis their quality of life was better than the P. aeruginosa infected group.

Adult↗
PubMed1997

Thoracic imaging--then and now.

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.

Humans↗