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Biomedical subjects

D M Hansell

Publications and source records attributed to D M Hansell.

At least 73 records · Page 4Linked to original sources
PubMed1999

Mechanism of mosaic attenuation of the lungs on computed tomography in induced bronchospasm.

The purpose of this study was to investigate whether hypoxic pulmonary vasoconstriction is the major determinant of the computed tomography (CT) pattern of mosaic attenuation in asthmatic patients with induced bronchoconstriction. Thin-section CT was performed at suspended full inspiration immediately and 30 min after methacholine bronchoprovocation in 22 asthmatic subjects, who were randomly assigned to breathe room air (group A, n = 8), oxygen via nasal prongs at 5 l/min (group B, n = 8), and oxygen via face mask at 12 l/min (group C, n = 6). CT changes were quantified in terms of global lung density and density in hypodense and hyperdense areas. Lung parenchymal density increases were greatest in group C and greater in group B than in group A, globally (P = 0.03) and in hypodense regions (P = 0.01). On bivariate analysis, the only change in cross-sectional area was related to change in global density. In hypodense regions, density change was related both to reduction in cross-sectional area (P < 0.0005) and to oxygen administration (P = 0.01). After correction for changes in global lung density, only oxygen was independently related to density increase in hypodense areas (P = 0.02). In induced bronchoconstriction, the CT appearance of mosaic attenuation can be largely ascribed to hypoxic vasoconstriction rather than to changes in lung inflation.

Adult↗
PubMed1999

A histologic pattern of nonspecific interstitial pneumonia is associated with a better prognosis than usual interstitial pneumonia in patients with cryptogenic fibrosing alveolitis.

This study aimed to investigate whether there was a difference in outcome related to histologic pattern in cryptogenic fibrosing alveolitis (CFA) and to see whether there were correlations between clinical and radiologic findings and histology. One hundred thirteen lung biopsies from consecutive patients taken for the diagnosis of diffuse lung disease were reviewed and reclassified using the Katzenstein and Myers criteria for interstitial pneumonias. Patients lacking full investigational data at presentation and those with conditions predisposing to lung fibrosis were excluded, leaving 15 patients diagnosed with nonspecific interstitial pneumonia (NSIP) and 15 with usual interstitial pneumonia (UIP). Clinical and radiologic findings at presentation and serial lung function information and survival status in November 1998 were compared for the two groups. Survival was found to be significantly greater in the NSIP group compared with the UIP group (p < 0.001). This could not be explained by differences in treatment. Patients with UIP showed a progressive deterioration in lung function whereas those with NSIP remained stable. CT scans of patients with UIP showed more fibrosis than those of patients with NSIP (p < 0.011). A histologic diagnosis of NSIP is associated with a better prognosis than UIP. This subclassification of CFA is clinically useful.

Adult↗
PubMed1999

Pericardial thickening or effusion in patients with pulmonary artery hypertension: a CT study.

OBJECTIVE: The aim of the study was to determine the prevalence of pericardial thickening or effusion revealed by CT in patients with pulmonary artery hypertension. MATERIALS AND METHODS: Forty-five patients underwent pulmonary artery catheterization and CT of the thorax. On CT, we measured the maximum pericardial thickness, total pericardial score (the sum of four measures of pericardial thickness), and thickness of the anterior pericardial recess. Patients were grouped according to mean pulmonary artery pressure: group 1, less than 21 mm Hg (n = 15); group 2, 21-35 mm Hg (n = 15); and group 3, greater than 35 mm Hg (n = 15). RESULTS: The prevalence of an increased pericardial score and increased maximum pericardial thickening was higher in group 3 than in group 1 or group 2 (p = .02 and < .001, respectively). Anterior pericardial recess thickening was markedly increased in group 3 (p < .0001). For all patients, significant correlations (Spearman's rank correlation coefficient = .44-.56, p < .005-.0001) were found between mean pulmonary artery pressure and all pericardial measures. CONCLUSION: On CT, pericardial thickening or effusion is a frequent finding in patients with severe pulmonary hypertension.

Adult↗
PubMed1999

Accuracy of CT in the diagnosis of allergic bronchopulmonary aspergillosis in asthmatic patients.

OBJECTIVE: The purpose of this study was to assess the accuracy of high-resolution CT in the diagnosis of allergic bronchopulmonary aspergillosis in asthmatic patients. MATERIALS AND METHODS: The high-resolution CT scans of 44 asthmatic patients with allergic bronchopulmonary aspergillosis and 38 asthmatic patients without allergic bronchopulmonary aspergillosis were analyzed retrospectively and randomly by two independent observers for these features: bronchial wall thickening, bronchiectasis, centrilobular nodules, mucoid impaction, mosaic perfusion, atelectasis, and consolidation. Each observer made a final diagnosis with a stated degree of confidence. The results are expressed as the average number of observations by the two observers. RESULTS: Findings seen more commonly in patients with allergic bronchopulmonary aspergillosis than in patients with asthma alone included bronchiectasis, centrilobular nodules, and mucoid impaction (p < .01, chi-square test). Bronchiectasis was present in 42 (95%) of 44 patients with allergic bronchopulmonary aspergillosis, centrilobular nodules in 41 (93%), and mucoid impaction in 29.5 (67%) (average of two observers). In the asthmatic control group, bronchiectasis was detected in 11 (29%) of 38 patients, centrilobular nodules in 10.5 (28%), and mucoid impaction in 4%. Bronchiectasis was seen in 184 (70%) of 264 lobes of patients with allergic bronchopulmonary aspergillosis compared with 19.5 (9%) of 228 lobes in asthmatic controls (p < .001, chi-square test). CONCLUSION: In asthmatic patients, bronchiectasis affecting three or more lobes, centrilobular nodules, and mucoid impaction are findings on high-resolution CT that are highly suggestive of allergic bronchopulmonary aspergillosis.

Adult↗
PubMed1998

The significance of bronchial dilatation on CT in patients with adult respiratory distress syndrome.

AIMS: Irreversible bronchial dilatation on computed tomography (CT) is seen in patients with interstitial pulmonary fibrosis whereas reversible dilatation of the bronchi is a feature of many conditions. The aim of this study was to determine whether airways dilatation, which is a frequent finding in adult respiratory distress syndrome (ARDS), is reversible and to establish whether persistent airways dilatation is accompanied by other CT signs of established interstitial fibrosis. METHOD: Thin section CT scans of 16 patients with ARDS were analysed at a lobar level in the acute phase of the disease and at follow-up (median interval 6.3 months) for the presence and extent of a ground-glass pattern, reticular or linear opacities and the presence or absence of bronchial dilatation. RESULTS: 95 out of 96 (99%) lobes on the initial CT scan showed ground-glass pattern. Airway dilatation was present in 65 of 95 (68%) of these lobes. On follow-up CT the airways remained dilated in 60 of 65 (92%) lobes and, in the majority of these, 53 of 60 (88%), a reticular and linear pattern with associated distortion had developed. A coexisting ground-glass pattern was present in 12 of 60 (20%) lobes on follow-up CT, but was the sole residual abnormality in only one lobe. CONCLUSION: In patients with ARDS, dilatation of the airways within areas of ground-glass pattern is a frequent observation in the acute phase of the condition and tends to persist at follow-up, usually accompanied by the CT features of supervening pulmonary fibrosis.

Acute Disease↗
PubMed1998

Imaging the 'dirty lung'--has high resolution computed tomography cleared the smoke?

The histopathological abnormalities that characterize cigarette smokers' lung damage have been widely studied, but these microscopic changes do not fully explain the radiographic features that have been loosely termed the 'dirty lung'. High resolution computed tomography is not only more sensitive for the detection of early emphysema, it has also provided the imaging correlates of subtle parenchymal changes of smokers, for example, respiratory bronchiolitis - interstitial lung disease. Nevertheless, some aspects of the radiographic 'dirty lung' remain enigmatic.

Aged↗
PubMed1998

Bronchiectasis.

Imaging has a key role in the identification of bronchiectasis. Over the years, imaging tests have become increasingly accurate in depicting the features of early bronchiectasis. This article covers the clinical, pathologic, and functional features of bronchiectasis; high-resolution CT scan technique; the signs of bronchiectasis on chest radiography and high-resolution CT scan; and the causes of misdiagnosis of bronchiectasis.

Bronchi↗
PubMed1998

Pulmonary sarcoidosis: morphologic associations of airflow obstruction at thin-section CT.

PURPOSE: To identify relationships between the obstructive defects of pulmonary sarcoidosis and the computed tomographic (CT) patterns of disease. MATERIAL AND METHODS: CT scans obtained in 45 patients were scored semiquantitatively for extent of five CT patterns, and the functional importance of each pattern was evaluated. RESULTS: The most prevalent CT patterns were decreased attenuation (n = 40), a reticular pattern (n = 37), and a nodular pattern (n = 36). At univariate and multivariate analyses, a reticular pattern was the main determinant of functional impairment, particularly airflow obstruction. The extent of a reticular pattern was independently associated with airflow obstruction, as shown by the inverse relationships with the forced expiratory volume in 1 second (FEV1) (P < .001), FEV1-forced vital capacity ratio (P < .01), maximum expiratory flow at 25% above residual volume (P < .001), and maximum expiratory flow at 50% above residual volume (P < .001) and the positive relationship with the residual volume-total lung capacity ratio (P < .001). CONCLUSION: In sarcoidosis, CT features compatible with small airways disease are common but contribute little to airflow obstruction, particularly in more advanced disease, which is characterized by an extensive reticular pattern. A reticular pattern at CT is the major morphologic association of airflow obstruction.

Adult↗
PubMed1998

Bronchoalveolar lavage cellularity: lone cryptogenic fibrosing alveolitis compared with the fibrosing alveolitis of systemic sclerosis.

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. The aims of this study were to gain insights into possible pathogenetic mechanisms contributing to this prognostic difference, by comparing bronchoalveolar lavage (BAL) cellularity in the two diseases, and to evaluate the relationships between BAL findings and the regional and global extent of disease, quantified by thin-section computed tomography (CT) and lung function indices. Patients with CFA were distinguished by more extensive fibrosing alveolitis on CT (p < 0.02) and by higher counts of neutrophils (total per ml, p < 0.02; percentage p < 0.03) and eosinophils (total per ml, p < 0.002; percentages, p < 0.02) in BAL fluid. After adjustment for functional and morphologic measures of disease extent, eosinophil percentages and total counts were increased in CFA (p < 0.05 in all 12 multivariate models), but they were not independently related to regional or global disease severity. Neutrophil percentages and total counts were virtually identical in CFA and FASSc in disease of comparable severity, and they increased with increasingly extensive lobar disease and global disease, as judged by CT, p < 0.0005 in all analyses. Neutrophil levels were more closely linked to the extent of disease on CT than to the severity of functional impairment, on univariate and multivariate analysis. The higher BAL eosinophil levels seen in CFA, compared with those seen in FASSc, after adjustment for disease extent, indicate that an eosinophilic influx may be linked to the pathogenesis of fibrosing alveolitis. By contrast, BAL neutrophil levels increase with increasingly extensive disease on CT, but they do not differ independently between CFA and FASSc, suggesting that neutrophil degradation products are unlikely to account for the excess mortality in CFA, compared with that in FASSc.

Bronchoalveolar Lavage Fluid↗
PubMed1998

Systemic markers of inflammation in stable bronchiectasis.

Patients with bronchiectasis have an active local and systemic inflammatory response during infective exacerbations. Systemic markers of inflammation were investigated during a stable phase of their illness, because continued inflammation could affect their general health and be involved in disease progression. The relationship between levels of various systemic markers of inflammation and extent of disease on computed tomographic scan, lung function, sputum bacteriology and health related quality of life (HRQoL) was investigated in 87 noncystic fibrosis bronchiectasis patients. Several markers were elevated and correlated with the extent of disease and poor lung function. The total white cell count, neutrophil count and erythrocyte sedimentation rate correlated with both disease measures. Sputum bacteriology did not correlate with inflammation markers and patients with positive and negative cultures were similar. C-reactive protein and total white cell count correlated with some components of a disease-specific HRQoL questionnaire. In conclusion, patients with bronchiectasis in a stable phase have raised systemic markers of inflammation. Some markers, particularly the neutrophil count, correlate with disease severity. This result is in keeping with the hypothesis that the level of inflammation determines disease progression and health status.

Adult↗
PubMed1998

Enhancement of subtle density differences of the lung parenchyma on CT.

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.

Humans↗
PubMed1998

Image processing and spiral CT of the thorax.

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.

Humans↗
PubMed1998

Clinical correlates in acute lung injury: response to inhaled nitric oxide.

STUDY OBJECTIVES: The use of inhaled nitric oxide (NO) in the management of patients with ARDS has become widespread, although not all patients respond to this form of support. The aim of this study was to examine the relationship of responsiveness to inhaled NO and features of underlying disease. DESIGN: Prospective observational study. SETTING: The ICU of a university-affiliated, tertiary referral hospital. PATIENTS: Twenty-six adult patients with established ARDS. INTERVENTIONS: Conventional support for multiple organ failure, plus inhaled NO. MEASUREMENTS AND RESULTS: Response to inhaled NO was assessed, and ARDS was characterized in terms of pulmonary morphology (scoring of high-resolution CT); inflammation (BAL neutrophil count and plasma myeloperoxidase concentration); and markers of lung injury severity (oxygenation deficit and pulmonary vascular resistance [PVR]). Fourteen patients responded to NO and 12 did not. There were no differences between the two groups in terms of CT score, inflammatory status, baseline oxygenation deficit, lung injury score, or PVR. Additionally, there was no difference in survival between responders and nonresponders. Patients who developed ARDS after thoracic surgery were significantly more likely to die than other patients (relative risk 4.1, p < 0.01). The oxygenation deficit and lung injury score correlated better with the extent of ground-glass opacification than with the volume of consolidated lung tissue. CONCLUSION: We were unable to identify features of disease likely to be associated with a clinically useful response to inhaled NO therapy using the parameters studied.

Acute Disease↗
PubMed1998

Churg-Strauss syndrome: the spectrum of pulmonary CT findings in 17 patients.

OBJECTIVE: The aim of this study was to evaluate the pulmonary CT findings in patients with Churg-Strauss syndrome to determine the frequency and nature of parenchymal abnormalities. MATERIALS AND METHODS: CT examinations performed at the time of diagnosis in 17 patients with Churg-Strauss syndrome were retrospectively evaluated by two observers who reached a decision by consensus about the presence and nature of parenchymal abnormalities. High-resolution CT (1- to 3-mm collimation) was performed in 14 patients and conventional CT (6- to 10-mm collimation) was performed in three cases. RESULTS: Predominant CT findings consisted of parenchymal opacification (consolidation or ground-glass attenuation) (n = 10), pulmonary nodules (n = 2), bronchial wall thickening or dilatation (n = 2), interlobular septal thickening (n = 1), and normal anatomy (n = 2). Parenchymal opacification was predominantly peripheral (n = 6) or random in distribution (n = 4). CONCLUSION: The most common CT finding in patients with Churg-Strauss syndrome consists of areas of parenchymal opacification that may be random or peripheral in distribution. These findings are nonspecific.

Churg-Strauss Syndrome↗
PubMed1998

High resolution computed tomography of the lungs.

High resolution computed tomography has increased the certainty with which diffuse lung disease is detected and often allows a histospecific diagnosis to be made. The technique continues to be refined and further pathophysiological insights can be expected in this challenging area.

Humans↗