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Biomedical subjects

P Grenier

Publications and source records attributed to P Grenier.

At least 73 records · Page 4Linked to original sources

[Thoracic imaging in the diagnosis and surveillance of sarcoidosis].

Imaging is useful at all stages of management of thoracic sarcoidosis. It contributes to diagnosis, prognosis, evaluation of lesions and follow-up in the course of the disease. Chest radiography is essential in initial work-up as well as during the course of well-tolerated forms of the disease. High resolution CT and gallium-67 scintigraphy are useful in severe lung involvement and in chronic forms of sarcoidosis.

Gallium Radioisotopes↗

Ultrasono-anatomy of the ankle ligaments.

The ligaments of the ankle are superficial and easily accessible at ultrasonography. Surprisingly, the reliability of this technique has never been proven. With this goal in mind, ten ankles were subjected to a ultrasono-anatomic comparison. The five principle ligamentous fascicles (three on the lateral side and two on the medial side) measured at ultrasonography and the values verified after dissection. This study shows that the ligaments of the ankle are analyzed with ultrasonography and that the measures done are valid and have a precision of 2 mm for the anterior fascicle and the lateral fascicle of the lateral ligamentous plane Due to its simplicity and its low price, ultrasonography appears to be an important method in evaluating the ligaments and the degree of seriousness of ankle sprains.

Ankle Joint↗

Chronic diffuse infiltrative lung disease: determination of the diagnostic value of clinical data, chest radiography, and CT and Bayesian analysis.

PURPOSE: To assess the value of clinical, chest radiographic, and computed tomographic (CT) findings in classifying chronic diffuse infiltrative lung disease (CDILD) MATERIALS AND METHODS: Two samples from the same population were consecutively studied: the training set (group A, n = 208) for the development of the decision aid and the test set (group B, n = 100) for validation. Computer-aided diagnoses were made with a Bayesian model that assigned to each patient diagnostic probabilities based on clinical, radiographic, or CT variables. RESULTS: In group A, a correct diagnosis based on clinical data was obtained in 29% of cases; radiography, 9%; and CT, 36%. This increased to 54% when clinical and radiographic variables were combined (P < .0001) and to 80% when data from all three were analyzed together (P < .0001). With prior and conditional probabilities determined from group A, the frequency of correct diagnosis in group B was 27% with clinical data, which increased to 53% (P < .0001) with radiographic findings and 61% after including CT data (P = .07). CONCLUSION: CT can help determine the specific diagnosis in patients with CDILD.

Bayes Theorem↗

[High resolution computed tomography in the study of the respiratory tract].

High resolution computed tomography (CT) is an imaging technique of choice for the evaluation of most lesions of the bronchial tree, particularly those affecting the small airways. This technique can confirm the diagnosis of bronchiectasis with a high degree of sensitivity and specificity and can contribute to the diagnosis of bronchiolitis (particularly diffuse panbronchiolitis and bronchiolitis obliterans) as well as other inflammatory diseases of the airways. CT can also reliably detect obstructive bronchial lesions such as tumours or broncholithiasis and can provide key information useful for the diagnosis of bronchial fistula, dehiscence or bronchial rupture, in addition to the study of numerous congenital pulmonary malformations. This article describes the computed tomography techniques recommended in each clinical situation and review the computed tomographic signs of all diseases of the airways.

Bronchial Diseases↗

High-resolution computed tomography of the airways.

High-resolution computed tomography (HRCT) is the imaging modality of choice to evaluate most bronchial tree lesions, especially those affecting small airways. It can confirm the diagnosis of bronchiectasis with high sensitivity and specificity and may contribute to the investigation of bronchiolitis (particularly diffuse panbronchiolitis and bronchiolitis obliterans) and other inflammatory disorders of the airways. HRCT can also reliably detect obstructing bronchial lesions such as tumors or broncholithiasis. It may also provide useful clues to the diagnosis of bronchial fistula, dehiscence, or rupture as well as permit the study of many pulmonary congenital abnormalities. This article describes the CT techniques recommended in each clinical situation and reviews the HRCT findings in diseases of the airway.

Bronchial Diseases↗

High-resolution CT for specific diagnosis of diffuse chronic infiltrative lung disease.

High-resolution CT is highly contributive for correctly diagnosing chronic infiltrative lung disease, as it enables better interobserver agreement, it reveals more discriminant findings, and it provides complementary information. High-resolution CT should be considered an excellent extension to chest radiography and should be included in the routine investigation strategy of chronic infiltrative lung disease.

Humans↗

High-resolution CT of parenchymal lung disease: precise correlation with histologic findings.

To provide a precise correlation between high-resolution computed tomographic (CT) findings and histologic studies of various parenchymal lung diseases, 20 fixed and inflated lungs were studied as follows: (a) Every lung was cut at the corresponding CT level into 1.5-mm-thick sections, (b) selected slices were cut into small blocks to prepare histologic slides, (c) each slide was photographed, and (d) the image of the entire lung section was reconstituted with the enlarged photographs (assembled as in a jigsaw puzzle). Results obtained in cases of normal lungs, pulmonary edema, alveolitis, hypersensitivity pneumonitis, emphysema, Pneumocystis carinii pneumonia, silicosis-asbestosis, and idiopathic pulmonary fibrosis demonstrated the method to be accurate in correlating high-resolution CT findings and the corresponding histologic data.

Alveolitis, Extrinsic Allergic↗

Pulmonary sarcoidosis: CT assessment of lesion reversibility.

By comparing serial computed tomographic (CT) scans obtained when sarcoidosis was clinically active and after the onset of remission, an attempt was made to differentiate inflammatory from fibrotic lesions in the lungs of patients with sarcoidosis. Twenty patients with pulmonary infiltration seen on their chest radiographs were studied. For each patient, lesions found on the first CT scan were assessed by two observers as being decreased or increased on the second CT scan. Nodules (n = 8), irregularly marginated nodules (n = 5), and alveolar or pseudoalveolar consolidation (n = 5) always disappeared or clearly decreased. Septal lines (n = 10), nonseptal lines (n = 9), and lung distortion (n = 7) remained unchanged or increased. Some findings varied among patients: Micronodules (n = 9) and subpleural thickening (n = 5) disappeared or decreased in sarcoidosis of recent origin. Many findings of pulmonary infiltration seen on the first CT scan can be considered expressions of either inflammatory (reversible CT findings) or fibrotic (irreversible CT findings) lesions.

Adolescent↗

[Contribution of imaging in the diagnosis of interstitial fibrosing lung diseases].

Standard radiography of the chest shows pulmonary infiltration and is determinant for the diagnosis of chronic diffuse infiltrative lung diseases. Since lung biopsy is an invasive exploratory technique, using computed tomography (CT) in the diagnostic approach is perfectly justified as a direct prolongation of plain radiography. CT identifies patients who, in spite of normal chest X-ray films, do have pulmonary infiltration. It is superior to radiography in suggesting the correct aetiological diagnosis, as it provides signs that are more discriminant than the radiographic signs. It also gives a better approach to the localization of lesions, thereby helping in guiding lung biopsies. Finally, once the diagnosis has been made CT remains useful in evaluating the effects of treatment of pulmonary lesions and in detecting possible complications.

Humans↗

Ventilatory effects of medical antishock trousers in healthy volunteers.

The ventilatory effects of medical antishock trousers (MAST) were investigated using 10 healthy volunteers. Use of the MAST (60-80 mm Hg) decreased forced expiratory volume (-8% +/- 4%, p less than 0.01), vital capacity (-8% +/- 5%, p less than 0.01), and functional residual capacity (-12% +/- 6%, p less than 0.01) and induced a significant decrease in tidal volume (-30% +/- 17%, p less than 0.05), but minute ventilation was unmodified because of a concomitant increase in respiratory rate (+17% +/- 8%, p less than 0.001). The MAST modified the breathing pattern: the abdominal contribution to ventilation was markedly decreased (-57% +/- 22%, p less than 0.001), suggesting a decrease in the diaphragmatic contribution to ventilation. The MAST increased both the end-expiratory (+131% +/- 115%, p less than 0.01) and inspiratory variation (delta Pgas: +42% +/- 40%, p less than 0.05) of gastric pressure, whereas the end-expiratory and inspiratory variation of esophageal pressure remained unchanged. Because of a higher delta Pgas, the dynamic compliance of the abdominal compartment markedly fell (-77% +/- 10%, p less than 0.001). Transdiaphragmatic pressure (Pdi: +28% +/- 30%, p less than 0.05) significantly increased and the pressure-time index of the diaphragm significantly increased (+32% +/- 32%, p less than 0.05) after inflation of the MAST, suggesting an increase in the diaphragmatic cost of breathing. Inspiratory activity of the parasternal intercostal muscles significantly increased after the MAST was inflated. Computerized tomography showed that the MAST induced a cephalad shift of the diaphragm, which reduced pulmonary height.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Chronic diffuse interstitial lung disease: diagnostic value of chest radiography and high-resolution CT.

The diagnostic value of chest radiography and high-resolution computed tomography (CT) in chronic diffuse interstitial lung disease (CDILD) was assessed in 140 consecutive patients with diffuse infiltration of the lung visible at radiography. Radiographs and CT scans were separately read by three independent observers without knowledge of clinical and pathologic data. The observers listed the three most likely diagnoses and recorded the degree of confidence they had in their choice on a 0%-100% probability scale. Findings at radiography and high-resolution CT were recorded by each observer and were used for a stepwise discriminant analysis between diagnoses. First-choice diagnoses of all three observers that were made with a high level of confidence (probability, greater than or equal to 75%) were more accurate with CT than with radiography (P less than .001). The superiority of high-resolution CT over radiography was most obvious for histiocytosis X and sarcoidosis; in cases of pulmonary fibrosis, CT was not significantly different from radiography. The interobserver agreement for the proposed diagnosis was significantly better with high-resolution CT (P less than .001). Twenty-one of 26 radiographic findings and 21 of 25 CT findings were discriminant. Stepwise discriminant analysis revealed the superiority of CT over radiography, since the ranking of all findings showed that the four most discriminant findings, and eight of the first 12 findings, were revealed with CT.

Adolescent↗

Pulmonary lymphangiomyomatosis and tuberous sclerosis: comparison of radiographic and thin-section CT findings.

Chest radiographs, thin-section computed tomographic (CT) scans, and results of pulmonary function tests in nine women with pulmonary lymphangiomyomatosis and two women with pulmonary tuberous sclerosis were retrospectively evaluated. In all patients, CT demonstrated thin-walled cysts less than 20 mm in diameter scattered at random in all parts of the lungs. In eight patients, cysts larger than 20 mm in diameter were also present. Lung tissue between cysts appeared normal in all 11 patients, except one with septal lines and dependent alveolar areas of attenuation. CT showed cysts in three patients whose radiographs were normal, and it demonstrated that many lesions that appeared reticular on plain radiographs were actually cysts. CT findings correlated better with the diffusion capacity of the lungs for carbon monoxide than did the plain radiographic findings. CT was more sensitive and more precise than radiography at showing the presence and morphology of lung abnormalities.

Adult↗