[The contribution of artificial intelligence (AI) subsequent to the processing of thoracic imaging]. / Apport de l'intelligence artificielle dans le post-traitement de l'imagerie thoracique.

The contribution of artificial intelligence (AI) to medical imaging is currently the object of widespread experimentation. The development of deep learning (DL) methods, particularly convolution neural networks (CNNs), has led to performance gains often superior to those achieved by conventional methods such as machine learning. Radiomics is an approach aimed at extracting quantitative data not accessible to the human eye from images expressing a disease. The data subsequently feed machine learning models and produce diagnostic or prognostic probabilities. As for the multiple applications of AI methods in thoracic imaging, they are undergoing evaluation. Chest radiography is a practically ideal field for the development of DL algorithms able to automatically interpret X-rays. Current algorithms can detect up to 14 different abnormalities present either in isolation or in combination. Chest CT is another area offering numerous AI applications. Various algorithms have been specifically formed and validated for the detection and characterization of pulmonary nodules and pulmonary embolism, as well as segmentation and quantitative analysis of the extent of diffuse lung diseases (emphysema, infectious pneumonias, interstitial lung disease). In addition, the analysis of medical images can be associated with clinical, biological, and functional data (multi-omics analysis), the objective being to construct predictive approaches regarding disease prognosis and response to treatment.

Integrated diagnostics: proceedings from the 9th biennial symposium of the International Society for Strategic Studies in Radiology.

The International Society for Strategic Studies in Radiology held its 9th biennial meeting in August 2011. The focus of the programme was integrated diagnostics and massive computing. Participants discussed the opportunities, challenges, and consequences for the discipline of radiology that will likely arise from the integration of diagnostic technologies. Diagnostic technologies are increasing in scope, including advanced imaging techniques, new molecular imaging agents, and sophisticated point-of-use devices. Advanced information technology (IT), which is increasingly influencing the practice of medicine, will aid clinical communication and the development of "population images" that represent the phenotype of particular diseases, which will aid the development of diagnostic algorithms. Integrated diagnostics offer increased operational efficiency and benefits to patients through quicker and more accurate diagnoses. As physicians with the most expertise in IT, radiologists are well placed to take the lead in introducing IT solutions and cloud computing to promote integrated diagnostics. To achieve this, radiologists must adapt to include quantitative data on biomarkers in their reports. Radiologists must also increase their role as participating physicians, collaborating with other medical specialties, not only to avoid being sidelined by other specialties but also to better prepare as leaders in the selection and sequence of diagnostic procedures. Key Points • New diagnostic technologies are yielding unprecedented amounts of diagnostic information.• Advanced IT/cloud computing will aid integration and analysis of diagnostic data.• Better diagnostic algorithms will lead to faster diagnosis and more rapid treatment.

[Imaging of the postsurgical liver]. / Imagerie du foie opéré

The appearance of the normal postsurgical liver and of potential complications specific to the type of liver resection performed (partial hepatectomy, cyst fenestration, RF ablation) must be well known by radiologists for early detection and treatment of postoperative complications. Early postoperative imaging of the liver aims at detecting vascular, biliary and extrahepatic complications and relies mainly on Doppler US and CT.

[Bronchial diseases: CT imaging features]. / Sémiologie de l'atteinte bronchique en scanner.

Multidetector row computed tomography (MDCT) is the imaging modality of reference for the diagnosis of bronchiectasis. MDCT may also detect a focal stenosis, a tumor or multiple morphologic abnormalities of the bronchial tree. It may orient the endoscopist towards the abnormal bronchi, and in all cases assess the extent of the bronchial lesions. The CT findings of bronchial abnormalities include anomalies of bronchial division and origin, bronchial stenosis, bronchial wall thickening, lumen dilatation, and mucoid impaction. The main CT features of bronchiectasis are increased bronchoarterial ratio, lack of bronchial tapering, and visibility of peripheral airways. Other bronchial abnormalities include excessive bronchial collapse at expiration, outpouchings and diverticula, dehiscence, fistulas, and calcifications.

[CT imaging features of bronchiolitis]. / Aspect TDM des bronchiolites.

Bronchiolitis may be encountered in numerous clinical circumstances. Previous history of smoking, infections, toxic exposure, immunodeficiency, chronic inflammatory disorders or transplantation must be known. CT findings consist in centrilobular micronodules with sharp or ill borders of various density and/or a mosaic attenuation with expiratory air trapping. Tree-in-bud pattern suggest an inflammatory or infectious bronchiolitis. The associated presence of bronchiectasis and bronchiolectasis must be considered. Imaging-pathologic correlations will be presented for inflammatory bronchiolitis (infectious bronchiolitis, hypersensitivity pneumonitis, respiratory bronchiolitis, follicular bronchiolitis, diffuse panbronchiolitis) and fibrosing bronchiolitis (constrictive bronchiolitis, post-infectious bronchiolitis, toxic fume exposure, transplant-related bronchiolitis).

[Chest trauma: spectrum of lesions]. / Traumatismes du thorax: lésions élémentaires.

Blunt chest trauma typically occurs as part of polytrauma, usually secondary to motor vehicle accidents, sports related injuries or defenestration in Western Europe. Each chest compartment may be responsible for immediate and/or delayed complications, thus requiring a dedicated systematic and comprehensive analysis. The use of image post-processing is mandatory in order to not overlook a potentially severe injury. The purpose of this paper is to review the technical considerations of multidetector CT, and the imaging features and interpretation method for each chest compartment, in order to generate an adapted report.

Pharmacokinetic evaluation of oral fenofibrate nanosuspensions and SLN in comparison to conventional suspensions of micronized drug.

An increasing number of newly developed drugs show bioavailability problems due to poor water solubility. Formulating the drugs as nanosuspensions may help to overcome these problems by increasing saturation solubility and dissolution velocity. In the present study the bioavailability of the poorly soluble fenofibrate following oral administration was investigated in rats. Four formulations were tested: a nanosuspension type DissoCube(R), one solid lipid nanoparticle (SLN) preparation and two suspensions of micronized fenofibrate as reference formulations, one suspension in sirupus simplex and a second in a solution of hydroxyethy-cellulose in physiological saline. Both colloidal drug delivery systems showed approximately two-fold bioavailability enhancements in terms of rate and extent compared to the reference formulations. No significant differences were found in AUC(0-22 h) as well as in C(max) and t(max) between the two colloidal delivery systems. In conclusion, nanosuspensions may be a suitable delivery system to improve the bioavailability of drugs with low water solubility.

Matrices containing NaCMC and HPMC 1. Dissolution performance characterization.

In this study hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) were used as polymeric carriers to improve controlled release performances of matrix tablets containing a soluble drug. The drug release behaviour of the systems containing these two polymers mixture and each material separately was investigated. To evaluate the effect of the dissolution medium pH, on the drug release performance, release tests were conducted at pH 1, 4.5 and 6.8. In vitro release studies demonstrated that the mixture of the two cellulose derivatives enables a better control of the drug release profiles at pH 4.5 and at 6.8 both in term of rate and mechanism. Texture analysis on the swollen tablets helps to understand drug release kinetic and mechanism. In fact, the results obtained confirm that a gel, which is characterized by high strength and consistence is less susceptible to erosion and chains disentanglement and the drug release mechanism is mainly governed by diffusion. On the contrary, gels, which show a low strength and texture, have low resistance to the fluid erosion action and the release of the active molecule is manly due to polymer relaxation and chains disentanglement moving the drug delivery kinetic towards an erosion/relaxation mechanism.

Matrices containing NaCMC and HPMC 2. Swelling and release mechanism study.

The aim of the present study is an investigation of the swelling behaviour of matrix systems containing a mixture of hydroxypropylmethylcellulose (HPMC) and sodium carboxymethylcellulose (NaCMC) with a model soluble drug to find the correlation between the morphological behaviour and the drug release performance. The swelling study was conducted on tablets containing only the drug and the two polymers mixture (MB) and on reference tablets containing each polymer and the same drug, at three different pHs. MB matrices show a similar swelling trend at pH 4.5 and 6.8, while they have different behaviour in acidic fluid. At pH 1 the gel layer formed by NaCMC is characterized by a rigid structure of a partially chemically crosslinked hydrogel while HPMC and MB matrices form a physical not crosslinked gel. At pH 4.5 and 6.8, all the systems show the typical morphological behaviour of a swellable matrix in which the macromolecular chains in the gel network are held together by weak bondings (physical gel). In these buffers, MB systems maintain a constant drug release rate coupling diffusion and erosion mechanism: the gel and infiltrated layers thicknesses are maintained constant and a zero-order release kinetics can be achieved.

[Computer-aided detection of lung nodules on thin collimation MDCT: impact on radiologists' performance]. / Evaluation de l'impact d'un système CAD sur la performance des radiologues pour la détection des nodules pulmonaires sur des examens scanographiques multicoupes du thorax.

OBJECTIVES: Evaluate the improvement in detecting lung nodules when using multidetector CT (MDCT) computer-assisted diagnosis (CAD). MATERIAL AND METHODS: Three radiologists (R1, R2, R3) with different levels of experience independently interpreted 30 MDCT examinations of the thorax taken for screening purposes, first without and then with CAD. The diagnosis was established by two of the three radiologists interpreting the images together, assisted by the CAD. RESULTS: The consensus reading identified 133 nodules, 61 (46%) of which were 4 mm or larger. The sensitivity values in the detection of nodules before and after using the CAD were 54% and 80% (R1), 38% and 71% (R2), and 70% and 88% (R3), respectively. When considering only the nodules that were 4 mm or larger, the sensitivity values varied before and after using the CAD, from 62% to 95% (R1), from 41% to 84% (R2), and from 74% to 92% (R3). By combining two by two the three radiologists' results obtained without the CAD, the sensitivity values were 65%, 83%, and 77%, respectively, for all the nodules, and 70%, 85%, and 77% for the nodules that were 4 mm or larger. The CAD induced a total of 105 false-positive results, with a mean of 3.5 per examination. CONCLUSION: The lung nodules missed by the radiologist can be detected if the CAD is used as a second reader. The CAD can be at least as beneficial as the use of a second independent reader.

THORACIC INVOLVEMENT IN CONNECTIVE TISSUE DISEASES: RADIOLOGICAL PATTERNS AND FOLLOW-UP.

Connective tissue diseases (CTDs) are a heterogeneous group of idiopathic inflammatory diseases involving various organs. A thoracic involvement is frequent, and chest-CT represents the imaging technique of reference in its assessment. Pulmonary abnormalities related to CTDs are various; although several disease-specific aspects have been described, the two most clinically relevant complications are represented by interstitial lung disease and pulmonary arterial hypertension. The early identification of a thoracic involvement, with the adoption of specific therapies, can significantly change patient's prognosis. The aim of this article is to review the most common typical and atypical CT features of thoracic involvement occurring in CT, especially focusing on interstitial lung disease.

Endobronchial hamartoma associated with bronchioloalveolar cell carcinoma.

Computed tomographic findings in a 60-year-old man with lobar bronchioloalveolar cell carcinoma distal to endobronchial hamartoma are described.

Regional distribution of gas and tissue in acute respiratory distress syndrome. I. Consequences for lung morphology. CT Scan ARDS Study Group.

OBJECTIVE: To compare the computed tomographic (CT) analysis of the distribution of gas and tissue in the lungs of patients with ARDS with that in healthy volunteers. DESIGN: Prospective study over a 53-month period. SETTING: Fourteen-bed surgical intensive care unit of a university hospital. PATIENTS AND PARTICIPANTS: Seventy-one consecutive patients with early ARDS and 11 healthy volunteers. MEASUREMENTS AND RESULTS: A lung CT was performed at end-expiration in patients with ARDS (at zero PEEP) and healthy volunteers. In patients with ARDS, end-expiratory lung volume (gas + tissue) and functional residual capacity (FRC) were reduced by 17% and 58% respectively, and an excess lung tissue of 701+/-321 ml was observed. The loss of gas was more pronounced in the lower than in the upper lobes. The lower lobes of 27% of the patients were characterized by "compression atelectasis," defined as a massive loss of aeration with no concomitant excess in lung tissue, and "inflammatory atelectasis," defined as a massive loss of aeration associated with an excess lung tissue, was observed in 73% of the patients. Three groups of patients were differentiated according to the appearance of their CT: 23% had diffuse attenuations evenly distributed in the two lungs, 36% had lobar attenuations predominating in the lower lobes, and 41% had patchy attenuations unevenly distributed in the two lungs. The three groups were similar regarding excess lung tissue in the upper and lower lobes and reduction in FRC in the lower lobes. In contrast, the FRC of the upper lobes was markedly lower in patients with diffuse or patchy attenuations than in healthy volunteers or patients with lobar attenuations. CONCLUSIONS: These results demonstrate that striking differences in lung morphology, corresponding to different distributions of gas within the lungs, are observed in patients whose respiratory condition fulfills the definition criteria of ARDS.

Regional distribution of gas and tissue in acute respiratory distress syndrome. II. Physiological correlations and definition of an ARDS Severity Score. CT Scan ARDS Study Group.

OBJECTIVES: (a) To assess whether differences in lung morphology observed in patients with adult respiratory distress syndrome (ARDS) are associated with differences in cardiorespiratory parameters, lung mechanics, and outcome. (b) To propose a new ARDS Severity Score to identify patients with a high mortality risk. DESIGN: Prospective study over a 53-month period. SETTING: Fourteen-bed surgical intensive care unit of a university hospital. PATIENTS AND PARTICIPANTS: Seventy-one consecutive patients with early ARDS. MEASUREMENTS AND RESULTS: Cardiorespiratory parameters were measured using a Swan-Ganz catheter, the pressure-volume (PV) curve was measured using the gross syringe method, and fast spiral computed tomography (CT) was performed. Patients with diffuse attenuations (n = 16) differed from patients with lobar attenuations (n = 26) regarding: (a) mortality rate (75% vs. 42%, p = 0.05), (b) incidence of primary ARDS (82% vs. 50%, p = 0.03), (c) respiratory compliance (47 +/- 12 vs. 64 +/- 16 ml per cmH2O(-1) p = 0.04), and (d) lower inflexion point (8.4 +/- 2.0 vs. 4.6 +/- 2.0 cmH2O, p = 0.001). A third group of patients with patchy attenuations (n = 29) had a mortality rate of 41 %, a respiratory compliance of 56 +/- 18 ml per cmH2O(-1) and a lower inflexion point of 6.3 +/- 2.7 cmH2O. The bedside chest radiograph accurately assessed lung morphology in only 42% of the patients. In contrast to the scores based on the bedside chest radiograph, a new ARDS Severity Score based on CT lung morphology and cardiorespiratory parameters identified a subgroup of patients with a high mortality rate (> or = 60%). CONCLUSIONS: In patients with ARDS, differences in lung morphology are associated with differences in outcome and lung mechanics. A new ARDS Severity Score based on CT lung morphology and cardiorespiratory parameters accurately identified patients with the most severe forms of ARDS and a mortality rate above 60%.

Validation of a software designed for computed tomographic (CT) measurement of lung water.

OBJECTIVE: The in-vitro validation of a computed tomographic (CT) software specifically designed for quantifying the volume of water contained in the lung. DESIGN: An in-vitro, ex-vivo study. In 1993, a postmortem left pneumonectomy was performed in a patient who died from acute respiratory distress syndrome. The lung was fixed, inflated and dried according to a technique proposed by Markarian and Dailey in 1975 aimed at producing a lung specimen spongy in texture and suitable for radiography. MEASUREMENTS AND RESULTS: In 1999, 13 CT scans of this lung specimen were performed corresponding to different bronchial instillations of known volumes of water and albumin 4%. The different lung weights resulting from the successive bronchial instillations were calculated using a specially designed software, Lungview, adapted for CT measurements and compared with the actual lung weight measured by an electronic scale. The increase in lung weight measured by Lungview was closely correlated with the actual increase in lung weight resulting from bronchial instillation of water and albumin (y = 0.99x - 23, r = 1 for water and y = x - 17, r = 1 for albumin 4%) and the precision of the bias was 7 g for water and 3 g for albumin 4%. CONCLUSIONS: This study shows that the CT software Lungview accurately measured the volume of lung water present within an air-dried exsanguine human lung.

Long-term loss of Warren's shunt selectivity. Angiographic demonstration.

Fifteen patients with a patent shunt after distal splenorenal shunt with gastrosplenic disconnection were prospectively studied by angiography three to 36 months after operation. In all patients a collateral circulation from the portomesenteric to the gastrosplenic system was developed through enlarged venous channels. In all patients the portal flow decreased, as suggested by the angiographically assessed degradation of the portal perfusion of the liver and/or the diminution of the diameter of the portal vein. In two patients the portal vein was thrombotic. We conclude that three months after operation distal splenorenal shunt with gastrosplenic disconnection is not hemodynamically different than portacaval laterolateral shunt.

Caustic sclerosing cholangitis. A complication of the surgical treatment of hydatid disease of the liver.

In five patients, sclerosing cholangitis developed after the surgical treatment of hydatid cyst of the liver. The cyst communicated with the biliary tree, and a scolicidal solution (2% formaldehyde in two patients and 20% sodium chloride in three) was injected into the cyst. Cholangiography showed strictures affecting the intrahepatic biliary tree in two and both the intrahepatic and extrahepatic biliary tree in three. Sclerosing cholangitis in these patients was likely to result from the caustic effect of the scolicidal solution having diffused from the cyst into the biliary tree. We propose to designate this entity "caustic sclerosing cholangitis". Because of the risk of this complication, and the unproved efficacy of intracystic injection of a scolicidal solution in preventing the dissemination of the parasite, we recommend that this maneuver be abandoned in the surgical treatment of hydatid disease of the liver.

Computed tomography in the assessment of diffuse lung disease.

Computed tomography (CT) has a significant impact on the evaluation of patients suspected of having diffuse lung disease. The technique is based on thin-section scans and high-resolution reconstruction. CT interpretation is based on a recognition of the main pattern, associated findings, and distribution of the lesions assessed at the regional level as well as the level of the secondary pulmonary lobule. CT may demonstrate clinically suspected abnormalities undetected on the radiographs. It may have characteristic pictures in patients with non specific findings on the radiograph. It can be used to limit the differential diagnosis to a few possibilities. In selected cases, in the presence of the appropriate clinical setting, CT appearances can be diagnostic or so strongly suggestive that lung biopsy can be avoided. When a lung biopsy is indicated, CT has a considerable value in determining the most appropriate site for the biopsy. To a certain extent, CT may also provide information on disease activity and prognosis, particularly in the differentiation between inflammatory changes, potentially treatable or reversible, and irreversible lung fibrosis.

The subcarinal space revisited on a frontal chest radiography. An evaluation in subcarinal mass detection.

Subcarinal space lucency is visible on a routine frontal chest high kvp radiography because of a double density gradient (vertical and horizontal). Results obtained in the first part of the study concerning 300 normal subjects show that the vertical density gradient is visible in 83% of cases, the horizontal gradient in 93% and both gradients in 76%. The right internal bronchial stripe (RIBS) is inconstant and visible on the three segments of the right bronchial tree in only 31% of cases. Results obtained in the second part of the study concerning 30 cases of subcarinal pathology grant a good detecting value for subcarinal mass to the inversion of the vertical gradient and the disappearance of both gradients.

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.