[CT Scan in early detection of lung cancer in patients with chronic obstructive pulmonary disease : a retrospective monocentric study]. / Apport de la tomodensitométrie à la détection précoce du cancer pulmonaire associé à la bronchopneumopathie chronique obstructive : étude rétrospective monocentrique.

OBJECTIVE: To explore the possible benefit of detecting lung cancer in COPD patients and to assess the pulmonologist's compliance with the Fleischner Society guidelines for management of pulmonary nodules. METHODS: This monocentric retrospective study was approved by the institutional ethical Committee. Patients with COPD undergoing a CT scan between January 2010 and March 2017 were included. Depending on CT indication (respectively screening or other indications), patients were divided into Group 1 and 2. Follow-up intervals were compared to those recommended in the Fleischner Society guidelines. Data were compared between groups using Chisquared test, Student test, or Wilcoxon test when appropriate. RESULTS: 254 patients were included (134 in Group 1 and 120 in Group 2). 235 opacities were found in 119 patients (47 %). 13 among 254 patients had a lung cancer; 9 in Group 1 (6.7 %) and 4 in Group 2 (3.3 %). The median follow-up by CT after nodule detection was six months regardless of their diameter or attenuation. No statistical significance was found between the observed follow-up and recommendations (P = 0.058). CONCLUSION: COPD in patients with a history of smoking is associated with a higher CT detection rate of lung cancer. This finding may be useful when evaluating selection criteria in lung screening programs. In contrast with the recommendations, CT detected nodules are followed-up regardless of their diameter and attenuation.

INTRODUCTION: Evaluer la tomodensitométrie (TDM) dans la détection des cancers pulmonaires chez les patients BPCO et l'adhésion aux recommandations quant au suivi des nodules détectés. Matériel et méthodes : Les patients BPCO qui ont eu une TDM entre janvier 2010 et mars 2017 prescrite par un des trois pneumologues du Service de Pneumologie impliqués dans la BPCO ont été identifiés et séparés en deux groupes selon l'indication de la TDM - dépistage (Groupe 1) ou une autre indication (Groupe 2). L'intervalle de suivi des nodules a été comparé aux recommandations de la Fleischner Society. En fonction des conditions, les comparaisons ont été effectuées par des tests Chicarré, de Student ou de Wilcoxon. Résultats : 254 patients ont été inclus (134 dans le Groupe 1 et 120 dans le Groupe 2) et 235 opacités décrites chez 119 d'entre eux (47 %). Parmi ces 254 patients, 13 étaient porteurs d'une tumeur pulmonaire maligne (5,1 %) dont 9 dans le Groupe 1 (6,7 %) et 4 dans le Groupe 2 (3,3 %). La médiane de suivi des opacités était de 6 mois indépendamment de leur atténuation ou de leur taille. Ce délai n'était statistiquement pas différent (P = 0,058) des recommandations. CONCLUSION: Chez des sujets tabagiques, la BPCO est associée à une détection par TDM plus fréquente de tumeurs pulmonaires malignes. Ce résultat suggère que la BPCO est un critère de sélection dans les programmes de dépistage. Contrairement aux recommandations, le suivi des opacités est indépendant de leur atténuation ou de leur taille.

Value of the "spine sign" on lateral chest views.

OBJECTIVE: To determine the performance of the spine sign in detecting lower chest abnormalities in the lateral view. METHODS: This retrospective study included 200 patients who had undergone lateral view and CT scans of the chest within 1 week. Two radiologists independently read the lateral views, and a third radiologist, blinded to the aim of the study, read the scans. The spine sign was considered as positive if the progressive increase in lucency of the vertebral bodies was altered. Interreader agreement was calculated through k-statistics. Sensitivity, specificity, positive- and negative-predictive values, and accuracy were calculated compared with CT. RESULTS: Agreements between readers ranged from 0.12 to 0.68. Positive spine sign could appear in two ways: absent or inversed progressive increase in lucency of the vertebral bodies. Sensitivity, specificity, positive- and negative-predictive values, and accuracy were, respectively, 60% and 70%; 64% and 84%; 91% and 97%; 19% and 29%; and 61% and 72% for each reader (p-value ranging from 0.026 to 0.196). Abnormalities most frequently associated with positive spine sign were plate-like atelectasis, ground-glass opacity, pleural effusion and consolidation. CONCLUSION: The spine sign can present as an absent or inversed progressive increase in lucency of the vertebral bodies. It has a moderate sensitivity but a good positive-predictive value, so it can be useful especially when it appears as inversed progressive increase in lucency of the vertebral bodies to detect various abnormalities usually identifiable on chest radiographs. ADVANCES IN KNOWLEDGE: On lateral chest radiographs, the spine sign is useful to detect lower chest abnormalities and is related to various underlying abnormalities and is, per se, non-specific.

Tuning of automatic exposure control strength in lumbar spine CT.

OBJECTIVE: To investigate the impact of tuning the automatic exposure control (AEC) strength curve (specific to Care Dose 4D®; Siemens Healthcare, Forchheim, Germany) from "average" to "strong" on image quality, radiation dose and operator dependency during lumbar spine CT examinations. METHODS: Two hospitals (H1, H2), both using the same scanners, were considered for two time periods (P1 and P2). During P1, the AEC curve was "average" and radiographers had to select one of two protocols according to the body mass index (BMI): "standard" if BMI <30.0 kg m(-2) (120 kV-330 mAs) or "large" if BMI >30.0 kg m(-2) (140 kV-280 mAs). During P2, the AEC curve was changed to "strong", and all acquisitions were obtained with one protocol (120 kV and 270 mAs). Image quality was scored and patients' diameters calculated for both periods. RESULTS: 497 examinations were analysed. There was no significant difference in mean diameters according to hospitals and periods (p > 0.801) and in quality scores between periods (p > 0.172). There was a significant difference between hospitals regarding how often the "large" protocol was assigned [13 (10%)/132 patients in H1 vs 37 (28%)/133 in H2] (p < 0.001). During P1, volume CT dose index (CTDIvol) was higher in H2 (+13%; p = 0.050). In both hospitals, CTDIvol was reduced between periods (-19.2% in H1 and -29.4% in H2; p < 0.001). CONCLUSION: An operator dependency in protocol selection, unexplained by patient diameters or highlighted by image quality scores, has been observed. Tuning the AEC curve from average to strong enables suppression of the operator dependency in protocol selection and related dose increase, while preserving image quality. ADVANCES IN KNOWLEDGE: CT acquisition protocols based on weight are responsible for biases in protocol selection. Using an appropriate AEC strength curve reduces the number of protocols to one. Operator dependency of protocol selection is thereby eliminated.

Reduced z-axis coverage in multidetector-row CT pulmonary angiography decreases radiation dose and diagnostic accuracy of alternative diseases.

OBJECTIVE: To investigate the effect of a two-third reduction of the scanned length (i.e. 10 cm) on diagnosis of both pulmonary embolism (PE) and alternative diseases. METHODS: 247 consecutive patients suspected of acute PE had a CT pulmonary angiography (CTPA) of the thorax (standard length, L). Based on this acquisition, a second set of images was created to obtain a scan length of 10 cm caudally to the aortic arch (l). Images were anonymized, randomized and interpreted by two independent readers. The quality of enhancement, the presence of PE and the possible alternative and/or complementary diagnoses were recorded. A McNemar exact test investigated differences in discrepancies between readers and between scan lengths. RESULTS: 57 (23%) patients had an acute PE. Among l sets, PE was missed by both readers in one (1.8%) patient, because the unique clot was localized in a subsegmental artery out of the 10-cm range. There were discrepancies between L and l sets in 9 (3.6%) and 11 (4.5%) patients, by Readers 1 and 2 (p=0.820), respectively. Discrepancies between the readers of L sets and those between both sets were not different regardless of the reader (p>0.99). There were discrepancies between both sets for alternative and/or complementary diagnoses in 43 (17.2%) patients. CONCLUSION: Although its performance in diagnosing PE is maintained, CTPA should not be restricted to a range of 10 cm centred over the pulmonary hilum, because alternative and/or complementary diagnoses could be missed. ADVANCES IN KNOWLEDGE: (1) A 10-cm CTPA acquisition reduces the radiation dose by two-thirds as compared with a standard one, but does not impair the accuracy for the diagnosis of PE. (2) Significant alternative diagnoses are missed in 17.2% of patients when reducing the acquisition height to 10 cm.

Optimised z-axis coverage at multidetector-row CT in adults suspected of acute appendicitis.

OBJECTIVE: To compare diagnostic performances of two reduced z-axis coverages to full coverage of the abdomen and pelvis for the diagnosis of acute appendicitis and alternative diseases at unenhanced CT. METHODS: This study included 152 adults suspected of appendicitis who were enrolled in two ethical committee-approved previous prospective trials. Based on scans covering the entire abdomen and pelvis (set L), two additional sets of images were generated, each with reduced z-axis coverages: (1) from the top of the iliac crests to the pubis (set S) and (2) from the diaphragmatic crus to the pubis (set M). Two readers independently coded the visualisation of the appendix, measured its diameter and proposed a diagnosis (appendicitis or alternative). Final diagnosis was based on surgical findings or clinical follow-up. Fisher exact and McNemar tests and logistic regression were used. RESULTS: 46 patients had a definite diagnosis of appendicitis and 53 of alternative diseases. The frequency of appendix visualisation was lower for set S than set L for both readers (89% and 84% vs 95% and 91% by Readers A and B, respectively; p=0.021 and 0.022). The probability of giving a correct diagnosis was lower for set S (68%) than set L (78%; odds ratio, 0.611; p=0.008) for both readers, without significant difference between sets L and M (77%, p=0.771); z-axis coverage being reduced by 25% for set M. CONCLUSION: Coverage from diaphragmatic crus to pubis, but not focused on pelvis only, can be recommended in adults suspected of appendicitis. ADVANCES IN KNOWLEDGE: In suspected appendicitis, CT-coverage can be reduced from diaphragmatic crus to pubis.

[Asbestosis still exists ]. / L'asbestose existe encore

A diagnosis of asbestosis, lung fibrosis due to asbestos exposure, was proposed in 2003 in a 64-year-old woman on the basis of the history, computed tomography appearances, lung function studies, and biometric data. This diagnosis was confirmed by the pathological examination of a lung lobe resected surgically for bronchial carcinoma in 2010. The diagnosis of asbestosis is now rarely made as a result of a substantial decrease in dust exposure over the past decades and mainly because of the interdiction of asbestos use in western countries. Currently, the most frequent thoracic manifestations of asbestos exposure are benign pleural lesions and mesothelioma. It has also become exceptional to have pathological confirmation of the diagnosis, obtained in this woman thanks to the surgical treatment of another complication of her occupational exposure.

Relationship between the extent of deep venous thrombosis and the extent of acute pulmonary embolism as assessed by CT angiography.

The aim of our study is to investigate prospectively the quantitative relationship between deep venous thrombosis (DVT) and acute pulmonary embolism (PE). 110 patients clinically suspected of having venous thromboembolic disease underwent combined CT pulmonary angiography (CTPA) and venography of lower limb veins. 44 patients presented with clinical signs of DVT and positive ultrasonography or ascending venography, but no clinical sign of PE (Group 1). 66 patients presented with clinical signs of PE and positive CTPA (Group 2). Clot load in lower limb veins and pulmonary arteries were scored by two independent readers, each using two separate systems for DVT and two for PE. 27 (61%) patients in Group 1 also had PE, and 55 (83%) patients in Group 2 also had DVT. Correlations between PE and DVT scores were weak but statistically significant in Group 2 (r(s) ranging from 0.470-0.520; p< or =0.001), but only some were significant in Group 1 (r(s) ranging from 0.253-0.318; p-values ranging from 0.035-0.097). In conclusion, although PE occurs in a majority of patients with DVT, and vice versa, the amount/burden of clot load in one condition does not necessarily indicate - or indicates only weakly - the degree of burden in the other condition.

Assessment of progression of COPD: report of a workshop held in Leuven, 11-12 March 2004.

Recently performed long term trials have enhanced the insight into the assessment of progression of COPD. The present review focuses on the initial assessment of COPD in general practice and the assessment of disease progression. Several variables may be used to assess this progression, all of which are associated with significant methodological problems. Finding the appropriate mix of outcome measures to capture all aspects of disease progression is a significant challenge.

Radiation dose in computed tomography of the chest.

Since the beginning of the eighties, computed tomography (CT) has been more and more widely used as this technique provides precise anatomical details on the lungs, the mediastinum, and the chest wall. However, CT requires the use of ionizing radiations. The collective radiation from CT is therefore in constant increase. As evaluated on atomic bomb survivors, ionizing radiations increase the mortality by cancer. The risk is proportional to the dose and the dose related to CT is much higher than that related to a chest radiograph, both being in the field "of low-level radiations" a range of radiation dose from which no increase in cancer mortality could be demonstrated. This article outlines the risk estimation in the field of low-level radiations, the various methods to measure and estimate the radiation dose, the CT parameters influencing the radiation dose, dose comparisons between CT and most other imaging techniques of the chest, the newly developed so called "Low-Dose" CT techniques and highlights some of the unresolved questions related to radiation dose in clinical CT practice.

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.

[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.

[The Erasme Foundation]. / La Fondation Erasme.

Created in 1982 to encourage the scientific research in the Erasme Hospital, the Erasme Foundation has founded 174 research grants, has financially supported the building of the Cellular and Molecular Therapy Unit, and has organized more than 60 lectures in various biomedical fields.

Quantitative computed tomography assessment of lung structure and function in pulmonary emphysema.

Accurate diagnosis and quantification of pulmonary emphysema during life is important to understand the natural history of the disease, to assess the extent of the disease, and to evaluate and follow-up therapeutic interventions. Since pulmonary emphysema is defined through pathological criteria, new methods of diagnosis and quantification should be validated by comparisons against histological references. Recent studies have addressed the capability of computed tomography (CT) to quantify pulmonary emphysema accurately. The studies reviewed in this article have been based on CT scans obtained after deep inspiration or expiration, on subjective visual grading and on objective measurements of attenuation values. Especially dedicated software was used for this purpose, which provided numerical data, on both two- and three-dimensional approaches, and compared CT data with pulmonary function tests. More recently, fractal and textural analyses were applied to computed tomography scans to assess the presence, the extent, and the types of emphysema. Quantitative computed tomography has already been used in patient selection for surgical treatment of pulmonary emphysema and in pharmacotherapeutical trials. However, despite numerous and extensive studies, this technique has not yet been standardized and important questions about how best to use computed tomography for the quantification of pulmonary emphysema are still unsolved.

[Bronchiolitis obliterans organizing pneumonia: eight cases and review of the literature]. / La bronchiolite oblitérante avec pneumopathie organisée: à propos de 8 cas et revue de la littérature.

Bronchiolitis obliterans and organizing pneumonia is characterized histologically by plugs of granulation tissue in terminal air spaces. Patients usually present with flu-like illness followed by cough, dyspnea and fever. The chest X-ray pattern is characterized by pneumonia like infiltrate which can migrate. Outcome is good with steroid treatment. The aim of this article is to define the clinical, biological, including bronchoalveolar lavage and radiological aspects of BOOP on the basis of 8 clinical cases. The pathophysiology, diagnosis methods and treatment of BOOP are also discussed.

Observer variation in computed tomography of pleural lesions in subjects exposed to indoor asbestos.

To assess the reliability of computed tomography (CT) in detecting discrete pleural lesions, the interobserver and intra-observer variability in reading the conventional and high-resolution CT (HRCT) scans of 100 volunteers, who had worked for > or = 10 yrs in a building with known asbestos contamination, was evaluated. In the first session, pleural abnormalities were detected by a single radiologist (A1) in 13 subjects. In the second session, the scans were read again independently by the same radiologist (A2) and two other experienced radiologists (B, C). The final decision for the presence of pleural lesions was made in a final consensus reading. This gave a diagnosis of pleural abnormalities in 18 subjects, of whom eight (44%) had been detected by all three readers, five (28%) by two readers and four (22%) by only one reader; one scan, rated normal by all readers during the second session, was reconsidered because pleural abnormalities had been noted at the first reading (A1). The intra-observer agreement for reader A was good (kappa (kappa) 0.68) but the interobserver agreement between the readers was only fair to moderate (weighted kappa: A2-B=0.43, A2-C = 0.45, B-C = 0.26) in the second reading session. In conclusion, when looking for the prevalence of pleural lesions in indoor asbestos exposed subjects, the potential lack of consistency in reporting the presence of small pleural abnormalities must be borne in mind and strict precautions must be taken.

Pulmonary lymphangiomyomatosis mimicking Langerhans cell histiocytosis.

The authors describe a patient with histologically confirmed pulmonary lymphangiomyomatosis and thin-section computed tomography findings mimicking Langerhans cell histioctytosis. The description emphasizes the nonspecificity of the computed tomography findings in this patient. This report also suggests that the computed tomography diagnosis of lymphangioleiomyomatosis can be difficult at an early stage of the disease and should be complemented by biopsy verification.

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.