[CT imaging of chronic interstitial lung diseases: from diagnosis to automated quantification]. / Imagerie des pneumopathies infiltratives diffuses chroniques en tomodensitométrie : du diagnostic à la quantification automatisée.

Computed tomography is important for the diagnosis and follow-up of chronic diffuse interstitial lung diseases. Image quality has improved from each generation of scanner to the next and this continues to allow a better characterization of extent of pathology, or even the nature of the pathological process (potentially reversible inflammatory lesions compared to fibrotic lesions). The diagnostic imaging approach has evolved at the same time as technological developments. We initially thought in terms of the predominant lesions (nodular, alveolar consolidation, ground-glass opacity), and then moved to reasoning based on patterns, which are a combination of several elementary lesions (typically for the diagnosis of idiopathic pulmonary fibrosis). Nowadays, studies are focused on building models characterizing a specific disease and which combine several distinct patterns (typically for ground-glass opacity analysis). CT also allows a quantification of the extent of lung disease, which is linked to the prognosis of the disease and helps to monitor its progression. This quantification is usually based on visual criteria, the principles of which are summarized here. The development of automated quantification software could in the near future, be a support for the radiologist.

[Pulmonary sarcoidosis imaging]. / Imagerie de la sarcoïdose pulmonaire.

Sarcoidosis is a juvenile systemic granulomatosis. Its polymorphic clinical presentation depends on its different localisations, thoracic and extrathoracic. The role of imaging is very important for all localisations; but for mediastinopulmonary involvement, which is the most frequent (>90% of cases), it plays a major role in detecting the disease, diagnosing it, its prognosis, decision-making regarding treatment of it and in the monitoring of its development. Standard radiography, which sometimes detects the disease, forms the basis for its four-stage prognostic classification. CT scanning enables the study of mediastinal and hilar lymphadenopathy and the study of parenchyma, making it possible to identify micronodules of lymphatic distributions, alveolar opacities, septal lines, ground-glass hyperintensities, nodules surrounded by a ring of satellite micronodules, peribronchovascular thickening; all potentially reversible lesions. Elsewhere, it highlights irreversible fibrous lesions: hilar peripheral linear opacities; septal linear opacities; bronchial distortion, honeycomb destruction or even perihilar fibrotic masses. Less frequently we can visualise bronchiolar or cystic involvement. Benign in most cases, the sarcoidosis prognosis becomes bleaker in the event of hemoptysis, Aspergillus colonisation or before the onset of pulmonary hypertension.

[CT imaging features of pulmonary involvement in connective tissue disorders]. / Sémiologie tomodensitométrique de l'atteinte pulmonaire des connectivites.

Connective tissue disorders correspond to a heterogeneous group of inflammatory diseases characterized by abnormal immune system activity leading to connective tissue alterations in multiple parts of the body. In adults, connective tissue disorders include rheumatoid arthritis, progressive systemic sclerosis, Sjögren syndrome, systemic lupus erythematosus, dermatomyositis and polymyositis, ankylosing spondylitis, and mixed connective tissue disease. Broncho-pulmonary involvement may be variable with involvement of all anatomical components of the lung. Involvement of other intrathoracic structures (pleura, respiratory muscles, heart, rib cage) is frequent. The most specific manifestations include interstitial lung diseases and pulmonary hypertension. During follow-up, progressive respiratory diseases may occur due to the treatment, infections, pulmonary embolism or neoplasms.

[Combined apical emphysema and basal fibrosis syndrome (emphysema/fibrosis syndrome): CT imaging features and pulmonary function tests]. / Syndrome emphysème des sommets et fibrose pulmonaire des bases combinés (syndrome emphysème/fibrose): aspects tomodensitométriques et fonctionnels.

PURPOSE: To describe the high resolution CT (HRCT) imaging and functional features of the emphysema/fibrosis syndrome. PATIENTS AND METHODS: A total of 61 patients were included based on HRCT. We have quantified the extent of fibrosis and emphysema lesions and a combined score was calculated. The scores were correlated to pulmonary function test parameters and specific HRCT features were described. RESULTS: The emphysema and fibrosis scores correlated with functional parameters of obstruction and restriction respectively. The combined score correlated with the reduction in DLCO and degree of pulmonary hypertension. Three HRCT patterns were identified: progressive transition (n=23, 38%) with diffuse emphysema (centrilobular and/or bullous) and zone of transition between bullae and honeycombing; paraseptal emphysema (n=13, 21%) with predominant subpleural bullae of enlarging size at the bases; separate processes (n=14, 23%) with independent areas of fibrosis and emphysema. Eleven patients (18%) could not be classified. The HRCT imaging features changed based on TLC (p=0.04) and FEV1/FVC (p=0.01). CONCLUSION: The emphysema/fibrosis syndrome may be associated with different patterns on HRCT corresponding to specific profiles on pulmonary function tests.

Short- and long-term response to corticosteroid therapy in chronic beryllium disease.

Chronic beryllium disease (CBD) is a granulomatous disorder that affects the lung after exposure to beryllium. The present study reports short- and long-term evolution of granulomatous and fibrotic components in eight patients with severe CBD receiving corticosteroid therapy. Eight patients with confirmed CBD were studied at baseline, after initial corticosteroid treatment (4-12 months), at relapse and at the final visit. Beryllium exposure, Glu(69) (HLA-DPB1 genes coding for glutamate at position beta69) polymorphism, symptoms, pulmonary function tests (PFT), serum angiotensin-converting enzyme (SACE) and high-resolution computed tomography (HRCT) quantification of pulmonary lesions were analysed. The CBD patients were observed for a median (range) of 69 (20-180) months. After stopping beryllium exposure, corticosteroids improved symptoms and PFT (vital capacity +26%, diffusing capacity of the lung for carbon monoxide +15%), and decreased SACE level and active lesion HRCT score. In total, 18 clinical relapses occurred after the treatment was tapered and these were associated with SACE and active lesion HRCT score impairment. At the final visit, corticosteroids had completely stabilised all parameters including both HRCT scores of active lesions and fibrotic lesions in six out of eight patients. Corticosteroids were beneficial in chronic beryllium disease. They were effective in suppressing granulomatosis lesions in all cases and in stopping the evolution to pulmonary fibrosis in six out of eight patients.

Sarcoidosis with pulmonary fibrosis: CT patterns and correlation with pulmonary function.

OBJECTIVE: The purpose of our study was to identify CT patterns of pulmonary fibrosis in patients with sarcoidosis and to correlate these patterns with pulmonary function tests. MATERIALS AND METHODS: We conducted a retrospective review of CT scans of 80 patients with proven sarcoidosis and evidence of fibrotic changes on chest radiographs. RESULTS: Three main CT patterns were identified: bronchial distortion (n = 38, 47%), mainly central; honeycombing (n = 23, 29%), mainly peripheral; and linear (n = 19, 24%), mainly diffuse. In most cases, a pattern was clearly identified as shown by the good agreement between observers (kappa = 0.87). Nodules were significantly associated with the linear (87%) and distorted (71%) patterns, but not with the honeycomb pattern (35%). The honeycomb pattern was most often associated with restriction and decreased lung diffusing capacity for carbon monoxide. Patients with bronchial distortion had lower expiratory airflow rates. The linear pattern was generally associated with the least functional impairment. CONCLUSION: CT may be a useful tool for defining subgroups of patients with fibrotic pulmonary sarcoidosis. CT reveals three main patterns that may reflect different distributions of fibrotic lesions in the lung with different functional pulmonary impairments. The persistence of active pulmonary lesions suggested by the presence of nodular lesions was often associated with linear and distorted patterns.

[The respective role and limitations of pulmonary angiography, thoracic computed tomography, and MRI in the diagnosis of pulmonary embolism]. / Places respectives et limites de l'angiographie pulmonaire, de la tomodensitométrie thoracique, et de l'IRM dans le diagnostic de l'embolie pulmonaire.

Spiral or helical angioscanography for the positive or differential diagnosis of pulmonary emboli has become an emerging technique but remains poorly practised and has been little assessed scientifically. The optimal conditions to perform the test should be understood. The physician should appreciate in view of a large choice of parameters, the diagnostic value of the result and its reliability proximally and distally. Pulmonary angiography is only indicated when the angioscanography is negative according to the degree of clinical and paraclinical suspicion. Angiography magnetic resonance imaging is a diagnostic test full of promise which does not yet have its place in routine practice.

Pulmonary Wegener's granulomatosis: changes at follow-up CT.

The objective of this study was to assess the reversibility of pulmonary lesions in Wegener's granulomatosis using serial CT. We reviewed the follow-up CT scans of ten treated patients with confirmed Wegener's granulomatosis. The delay between the first evaluation before treatment and the second, on patients in clinical and biological remission, ranged from 6 to 54 months (mean 20.5 months). Follow-up CT showed a decrease in the extent of disease in all cases. Lesions disappeared completely, without scarring, in 4 of 4 ground-glass opacities, 25 of 36 nodules, and 4 of 9 pulmonary consolidations; they disappeared with residual scarring in 8 of 8 masses, 3 of 9 pulmonary consolidations, and 2 of 36 nodules. The majority of lesions disappear without scarring. Residual fibrosis may follow the occurence of masses and pulmonary consolidation. Computed tomography permits assessment of cicatricial lesions.

Sarcoidosis activity: correlation of HRCT findings with those of 67Ga scanning, bronchoalveolar lavage, and serum angiotensin-converting enzyme assay.

PURPOSE: The objective of this study was to correlate the findings of sarcoidosis on high resolution CT (HRCT) with indexes of disease activity as measured with 67Ga scan, bronchoalveolar lavage (BAL), and serum angiotensin-converting enzyme (SACE) assay. METHOD: Twenty-nine patients with proven sarcoidosis underwent HRCT scan, 67Ga scan, BAL, and SACE assay within a 1 month period. The extent of parenchymal involvement by nodules, consolidation, ground-glass attenuation, and linear opacities was quantified to the nearest 10% of surface area affected on the CT examination. Whole-lung gallium uptake was quantified and the percentage of BAL-recovered lymphocytes (BAL-%LC) and SACE levels obtained by chart review. CT scores of disease extent were correlated with measured indexes of activity using the Spearman rank correlation coefficient. RESULTS: The mean extent of nodules, consolidation, ground-glass attenuation, and linear opacities on HRCT images was 15.1 +/- 16.6, 1.6 +/- 4.0, 17.5 +/- 25.4, and 7.6 +/- 9.6%, respectively. The extent of nodules and consolidation correlated with the intensity of lung gallium uptake (r = 0.46, p < 0.02), BAL-%LC (r = 0.50, p < 0.01), and SACE levels (r = 0.38, p < 0.05). No significant correlation was found between extent of ground-glass attenuation or linear opacities with any indexes of disease activity. CONCLUSION: On HRCT scan, nodules and consolidation in sarcoidosis reflect disease activity as measured by 67Ga scan, BAL, and SACE assay.

[The contribution x-ray computed tomography in chronic diffuse infiltrative lung disease]. / Apport de la tomodensitométrie dans les pneumopathies chroniques infiltrantes diffuses (PCID).

Computed tomography (CT) may be useful at all stages of management of chronic infiltrative lung disease. It contributes to diagnosis and evaluation of inflammation and fibrosis, helping the therapeutic decision and appreciating the response to treatment. It contributes to follow-up in the course of the disease. Some further works are necessary to know the indications of CT and the frequency of examinations.

Pulmonary Langerhans cell histiocytosis: evolution of lesions on CT scans.

PURPOSE: To document the evolution of pulmonary lesions of Langerhans cell histiocytosis (LCH) with sequential computed tomography (CT). MATERIALS AND METHODS: Initial and final CT scans of 21 patients with LCH and CT evidence of pulmonary disease were compared retrospectively. Histologic confirmation of pulmonary involvement was available in 11 patients. RESULTS: On initial CT images, a nodular pattern (n = 14) was seen more frequently than a cystic pattern (n = 7). On final CT images, a cystic pattern (n = 14) was seen more often than a nodular one (n = 6). There was complete resolution of parenchymal abnormality in one case. Nodular opacities, thick-walled cysts, and ground-glass opacities underwent regression. Thin-walled cysts, linear opacities, and emphysematous lesions remained unchanged or progressed. CONCLUSION: Pulmonary CT allows good assessment of the evolution of LCH lesions. Nodular lesions probably represent active disease and often undergo regression or transform into cysts.

Pulmonary tuberculosis: comparison of CT findings in HIV-seropositive and HIV-seronegative patients.

PURPOSE: To determine the differences in the computed tomographic (CT) appearance of pulmonary tuberculosis (TB) between patients with and patients without human immunodeficiency virus (HIV) infection. MATERIALS AND METHODS: CT scans and chest radiographs of 42 HIV-seropositive and 42 HIV-seronegative patients with pulmonary TB were reviewed. CD4 T-lymphocyte counts, measured in 40 seropositive patients, were at least 200 cells per microliter in 10 patients and were less that 200 cells per microliter in 30. RESULTS: Seropositive patients had a higher prevalence of lymphadenopathy at chest radiography (P< .05). The seropositive patients had a lower prevalence of consolidation (P< .05), cavitation (P< .01), and postprimary pattern (P< .05) at CT. HIV-seropositive patients had a higher frequency of miliary (P< .01) and extrapulmonary disease (P< .001). Similar features of pulmonary TB were observed in seropositive patients with mild and severe immunosuppression. CONCLUSION: HIV-seropositive patients had a lower prevalence of localized parenchymal disease and a higher prevalence of disseminated disease at CT.

Abnormalities of the airways and lung parenchyma in asthmatics: CT observations in 50 patients and inter- and intraobserver variability.

The purpose of the study was to evaluate the CT abnormalities of airways and lung parenchyma in asthmatic patients and to assess inter- and intraobserver variability for these abnormalities. The CT scans of 50 asthmatic patients and 10 healthy volunteers were assessed independently by four independent chest radiologists who were masked with respect to the clinical information. Bronchiectasis involving mostly subsegmental and distal bronchi was noted in 28.5% of the asthmatic subjects and none of the non-asthmatics. Bronchial wall thickening, small centrilobular opacities and decreased lung attenuation were observed in 82%, 21% and 31% of asthmatic patients respectively, compared with 7%, 5% and 7% of healthy subjects. The intra- and inter-observer agreements for these four CT abnormalities were measured by the kappa statistic and ranged from 0.60 to 0.79 and from 0.40 to 0.64, respectively. It is concluded that asthmatic patients may exhibit bronchial wall thickening, bronchiectasis and morphological abnormalities suggestive of distal airways disease that can be assessed on CT scans with a clinically acceptable observer variability.

CT assessment of bronchi in sarcoidosis: endoscopic and pathologic correlations.

PURPOSE: To evaluate the computed tomographic (CT) appearance of bronchi in patients with sarcoidosis and to correlate CT, endoscopy, and bronchial biopsy findings. MATERIALS AND METHODS: Sixty patients with sarcoidosis underwent CT and tracheobronchial endoscopy. CT findings of abnormalities of the bronchial walls and lumina were compared with endoscopic and biopsy findings. RESULTS: CT scans showed bronchial abnormalities in 39 patients (65%). CT and endoscopic findings were concordant in only 35 cases. However, CT showed abnormal lumina in 14 patients and endoscopy showed mucosal thickening in 12 of these 14 patients. CT findings of bronchial abnormalities were associated with the presence of bronchial granulomas (P < .0001). CT scans showed that, of the 37 patients with biopsy results of granulomatosis, 84% had thickened bronchial walls and 35% had luminal abnormalities. Eight CT findings were false-positive, and six were false-negative for the presence of granulomas. CONCLUSION: Bronchial involvement in sarcoidosis was detected at CT in 65% of cases. CT can help predict whether bronchial granulomas will be found in cases of sarcoidosis.

[Thoracic imaging in the diagnosis and surveillance of sarcoidosis]. / Imagerie thoracique dans le diagnostic et la surveillance de la sarcoïdose.

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.

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.

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.

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.

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.

Pulmonary sarcoidosis: evaluation with high-resolution CT.

Forty-four patients with histologically confirmed sarcoidosis were prospectively studied with high-resolution computed tomography (CT). Nodules were seen in all cases. They were isolated in 19 cases and associated with other lesions in 25 cases. Other abnormalities were irregular interfaces (n = 18, 41%), linear network (n = 14, 32%), thickening of the pleural surface (n = 9, 20%), ground-glass opacities (n = 7, 16%), lung distortion (n = 11, 25%), traction bronchiectasis (n = 3, 7%), and network of air-filled cavities (n = 3, 7%). Predominant sites of lesions were the upper and middle zones (n = 30, 68%) and posterior zones (n = 13, 30%). Nodular abnormalities were noted at CT in six cases in which the pulmonary parenchyma appeared normal on radiographs. Lung distortion was noted at CT in eight cases without visible fibrosis on chest radiographs. The majority of patients with lung distortion (nine of 11, 82%) had disease of greater than a years duration. CT improved sensitivity for the detection of all types of lesions, mainly lung distortion. Low but significant correlations were found between visual score at CT and total lung capacity, vital capacity, forced expiratory volume in 1 second, and diffusing capacity.