Preferential reduction of quadriceps over respiratory muscle strength and bulk after lung transplantation for cystic fibrosis.

BACKGROUND: In the absence of complications, recipients of lung transplants for cystic fibrosis have normal pulmonary function but the impact of the procedure on the strength and bulk of respiratory and limb muscles has not been studied. METHODS: Twelve stable patients who had undergone lung transplantation for cystic fibrosis 48 months earlier (range 8-95) and 12 normal subjects matched for age, height, and sex were studied. The following parameters were measured: standard lung function, peak oxygen uptake by cycle ergometry, diaphragm surface area by computed tomographic (CT) scanning, diaphragm and abdominal muscle thickness by ultrasonography, twitch transdiaphragmatic and gastric pressures, quadriceps isokinetic strength, and quadriceps cross section by CT scanning, and lean body mass. Diaphragm mass was computed from diaphragm surface area and thickness. RESULTS: Twitch transdiaphragmatic and gastric pressures, diaphragm mass, and abdominal muscle thickness were similar in the two groups but quadriceps strength and cross section were decreased by nearly 30% in the patients. Patients had preserved quadriceps strength per unit cross section but reduced quadriceps cross section per unit lean body mass. The cumulative dose of corticosteroids was an independent predictor of quadriceps atrophy. Peak oxygen uptake showed positive correlations with quadriceps strength and cross section in the two groups, but peak oxygen uptake per unit quadriceps strength or cross section was reduced in the patient group. CONCLUSIONS: The diaphragm and abdominal muscles have preserved strength and bulk in patients transplanted for cystic fibrosis but the quadriceps is weak due to muscle atrophy. This atrophy is caused in part by corticosteroid therapy and correlates with the reduction in exercise capacity.

Computed tomography assessment of lung structure and function in pulmonary edema.

By definition pulmonary edema is an abnormal accumulation of water in the lung. Consequently, the computed tomography (CT) appearance of pulmonary edema reflects the sequence of this accumulation. In early hydrostatic pulmonary edema, CT shows vascular engorgement and peribronchovascular cuffing that increases with the severity of edema and that is associate in late stage, with consolidations. In acute respiratory distress syndrome (ARDS), CT shows the proportion of injured parenchyma and depicts associated alterations as parenchymal infiltrate and consolidation, pleural effusion, pneumothorax. These merely morphological findings can be complemented with data from objective CT analysis of the lung parenchyma. Indeed CT can assess lung water noninvasively. Correlated with hydrodynamic parameter, these objective measurements show that the increase of lung density parallels parenchymal fluid overload. These data also show that the occurrence of ground glass opacities can precede the hemodynamic evidence of edema.

[Clinical and radiological aspects of ageing of the respiratory tract]. / Aspects cliniques et radiologiques du vieillissement de l'appareil respiratoire.

The effects of ageing on the macroscopic appearance of the lung were recognized by Laennec, Andral suggesting that dyspnoea might be its clinical manifestation. At about the same time physiologists demonstrated the negative effects of ageing on the vital capacity, whereas anatomists defined its impact on the lung and thoracic cage structure. The prevalence of dyspnoea increases with ageing but co-morbid disease should always be sought. The prevalence of cough is strongly associated with active and passive smoking. With regard to physical signs, barrel chest and crepitations heard over the dependent lung zones do not necessarily have pathological significance. The usefulness of measuring the forced expiratory time remains to be established in the elderly. There is no characteristic radiological feature of a senile lung. If an X-ray abnormality is discovered during a routine examination, it should be regarded as pathological, but in most cases its detection will not alter management of the patient.

[Primary pulmonary hemangiopericytoma: 2 new cases]. / L'hémangiopéricytome pulmonaire primitif: deux nouvelles observations.

We describe two new resected cases of primary pulmonary hemangiopericytoma and the review of cases published in the period 1954-2002. The first patient has a large pulmonary mass of the right apex revealed by scapular pain. The right upper lobectomy with free margins reveals hemangiopericytoma. Pelvic and pulmonary metastases appear two years after surgery, treated by two series of chemotherapy without clinical response. After acute nephrotoxicity controlled by hemodialysis, the patient dies with distant metastases three years and an half after thoracotomy. The second patient develops dry cough and thoracic pain with discovery of a cavitary mass in the right pulmonary field. Fine needle aspiration cytology suggests a mesenchymatous lesion. Three months after extended pneumonectomy, the intrathoracic tumour relapses and regresses partially under chemotherapy. Femoral and brain metastases are irradiated. The patient dies 22 months after thoracotomy. Histology and immunohistochemistry of both tumours closely related to solitary fibrous tumour confirm malignant hemangiopericytoma. Primary pulmonary hemangiopericytoma is rare and may be benign or malignant. Radical resection is the best treatment. Chemotherapy and radiotherapy may improve the prognosis. Compared with lung cancer, the tumour is a slow growing mass, often voluminous, with delayed symptoms, very few lymph node dissemination, rare brain metastasis, more frequent cutaneous or retroperitoneal dissemination, often after long-term and requiring indeed a 10 to 20 years follow-up.

[Clinical and radiological aspects of ageing of the respiratory tract]. / Aspects cliniques et radiologiques du vieillissement de l'appareil respiratoire.

The effects of ageing on the macroscopic appearance of the lung were recognized by Laennec, Andral suggesting that dyspnoea might be its clinical manifestation. At about the same time physiologists demonstrated the negative effects of ageing on the vital capacity, whereas anatomists defined its impact on the lung and thoracic cage structure. The prevalence of dyspnoea increases with ageing but co-morbid disease should always be sought. The prevalence of cough is strongly associated with active and passive smoking. With regard to physical signs, barrel chest and crepitations heard over the dependent lung zones do not necessarily have pathological significance. The usefulness of measuring the forced expiratory time remains to be established in the elderly. There is no characteristic radiological feature of a senile lung. If an X-ray abnormality is discovered during a routine examination, it should be regarded as pathological, but in most cases its detection will not alter management of the patient.

[The medical imaging and radiology department]. / Le Service d'Imagerie Médicale et de Radiologie Interventionnelle.

Technological developments arising from research have affected the whole wide spectrum of medical endeavor and have made a very significant impact on clinical practice and especially on imaging sciences. Ultrasonography brought spectacular advances, but CT and MRI became important landmark techniques. A further important development, which greatly increased the involvement of radiologists in direct patient management, was the growth of interventional and therapeutic techniques, called interventional radiology. Some statistics: approximately 155,000 patients per year including 19,000 CT Scans, 10,000 MRI exams, 21,000 ultrasound examinations and 1,000 therapeutic procedures. Some research activities: CT quantification of pulmonary emphysema, respiratory mechanics, MR and CT angiography, antenatal diagnosis of congenital and genetic diseases of the fetus, quantification of portal haemodynamics, MR imaging of bile and pancreatic ducts, morphologic and functional imaging of the brain, radiology of bone trauma, MR characterization in hepatic lesions.

Oleic acid-induced lung injury: thin-section CT evaluation in dogs.

PURPOSE: To validate lung attenuation measurements for quantifying extravascular lung water in oleic acid-induced pulmonary edema, compare subjective assessment with attenuation measurements, and compare this permeability-type pulmonary edema with hydrostatic-type pulmonary edema. MATERIALS AND METHODS: Thin-section computed tomography (CT) and pulmonary hemodynamic examinations were performed sequentially in six dogs before and after intravenous administration of 0.08 mg of oleic acid per kilogram of body weight. Extravascular lung water and pulmonary capillary pressure were measured. Results were compared with those reported in a canine model of hydrostatic edema. RESULTS: Oleic acid induced a progressive increase in extravascular lung water without a change in capillary pressure, which indicated pure permeability-type edema. Ground-glass opacification was detected as soon as extravascular lung water increased. Lung attenuation was highly correlated to extravascular lung water (r = 0.76, P<.001), as in hydrostatic edema, but was characterized by an almost absent gravitational gradient. CONCLUSION: Thin-section CT is sensitive for early detection and quantification of oleic acid-induced pulmonary edema in a canine model. Different from early canine hydrostatic edema, which is characterized by a gravitational gradient, early oleic acid-induced pulmonary edema in a supine dog is characterized by nearly homogeneous distribution, except for ventral sparing.

Hydrostatic pulmonary edema: evaluation with thin-section CT in dogs.

PURPOSE: To identify the hemodynamic determinants of ground-glass opacification on thin-section computed tomographic (CT) scans of hydrostatic pulmonary edema and to compare attenuation and subjective assessments of ground-glass opacification with extravascular lung water. MATERIALS AND METHODS: Left atrial pressure, pulmonary arterial pressure, effective pulmonary capillary pressure, and extravascular lung water were measured in six dogs before and during progressive increase of effective pulmonary capillary pressure. A thin-section CT scan was obtained at each step. Lung attenuation and subjective assessments of ground-glass opacification were compared with hemodynamic variables and extravascular lung water. RESULTS: Ground-glass opacification was identified when effective pulmonary capillary pressure equaled critical pulmonary capillary pressure. Extravascular lung water increased, and the distribution curve of lung attenuation coefficients shifted to higher attenuation from the second measurement at an effective pulmonary capillary pressure greater than the critical pulmonary capillary pressure. Attenuation was highly correlated (r = 0.98, P < .001) with extravascular lung water; ground-glass opacification was detected before a significant (P = .615, analysis of variance) increase in extravascular lung water. CONCLUSION: Thin-section CT depicts ground-glass opacification when effective pulmonary capillary pressure equals critical pulmonary capillary pressure and before a detectable increase in extravascular lung water. Attenuation reflects extravascular lung water.

The effects of age, sex, lung size, and hyperinflation on CT lung densitometry.

OBJECTIVE: To test our proposal that, on high-resolution CT scans, the relative area of the lung with attenuation values lower than -950 H (RA950) can be a measurement of pulmonary emphysema, we examine the possible influences of sex, age, lung size, and hyperinflation on CT lung densitometry. SUBJECTS AND METHODS: The RA950 and the mean lung density (MLD) were measured in 42 healthy subjects (21 men, 21 women) from 23 to 71 years old, in 10 patients with asthma before and after a bronchial challenge test, and in seven patients with asthma who have irreversible hyperinflation (defined as an increased total lung capacity). RESULTS: In the healthy subjects, we found no significant difference between sexes and no significant correlation between age and the MLD, but we found a significant correlation between age and the RA950. In addition, we found a significant correlation between the total lung capacity expressed as absolute values and both the RA950 and the MLD. We did not observe any effect of acute airflow limitation either on the MLD or on the RA950 in the asthmatic subjects after the bronchial challenge test. Likewise, we observed no change in either the MLD or the RA950 in the asthmatic subjects with chronic hyperinflation. CONCLUSION: This study shows that CT lung densitometry is influenced by total lung capacity and, to a lesser degree, by age. Thus, this study suggests that normal CT attenuation values for the lung should be established.

Pulmonary emphysema: quantitative CT during expiration.

PURPOSE: To determine whether measurement of the relative area of lung with attenuation coefficients lower than a certain threshold on thin-section computed tomographic (CT) scans obtained during expiration is a valuable method of quantifying the extent of pulmonary emphysema. MATERIALS AND METHODS: Eighty-nine patients underwent CT (with 1-mm collimation) preoperatively during inspiration and expiration. Relative areas of lung with attenuation coefficients lower than various thresholds were calculated. These relative areas were compared with areas found macroscopically to have emphysema (59 patients [51 men, eight women; aged 40-77 years]) and with two microscopic indices (35 patients [29 men, six women; aged 42-77 years]) assessed on the resected specimens. RESULTS: The valid expiratory CT thresholds were found to be -820 and 910 HU for microscopic and macroscopic emphysema, respectively. However, results of stepwise multiple regression analyses showed that the inspiratory threshold of -950 HU was superior for both macroscopically and microscopically quantified emphysema. The correlation coefficients in expiratory CT were higher for the pulmonary volumes but similar for the diffusing capacity. CONCLUSION: Expiratory quantitative CT is not as accurate as inspiratory CT for quantifying pulmonary emphysema and probably reflects air trapping more than reduction in the alveolar wall surface.

[Clinical role of spiral tomodensitometry in pulmonary disorders]. / Apport clinique de la tomodensitométrie hélicoïdale dans les affections pulmonaires.

Spiral CT of the lungs has taken the place of conventional CT in most indications. Until now, some specific indications, concerning the detection of lung nodules, the detection of central pulmonary thromboembolism and the description of the angioarchitecture of pulmonary arteriovenous malformations have been reported. This paper provides an overview of the clinical utility of this new technique.