Deep Learning Models for Gastric Signet Ring Cell Carcinoma Classification in Whole Slide Images

Signet ring cell carcinoma (SRCC) of the stomach is a rare type of cancer with a slowly rising incidence. It tends to be more difficult to detect by pathologists, mainly due to its cellular morphology and diffuse invasion manner, and it has poor prognosis when detected at an advanced stage. Computational pathology tools that can assist pathologists in detecting SRCC would be of a massive benefit. In this paper, we trained deep learning models using transfer learning, fully-supervised learning, and weakly-supervised learning to predict SRCC in Whole Slide Images (WSIs) using a training set of 1,765 WSIs. We evaluated the models on two different test sets (n = 999, n = 455). The best model achieved a ROC-AUC of at least 0.99 on all two test sets, setting a top baseline performance for SRCC WSI classification.

Weakly-supervised learning for lung carcinoma classification using deep learning

Lung cancer is one of the major causes of cancer-related deaths in many countries around the world, and its histopathological diagnosis is crucial for deciding on optimum treatment strategies. Recently, Artificial Intelligence (AI) deep learning models have been widely shown to be useful in various medical fields, particularly image and pathological diagnoses; however, AI models for the pathological diagnosis of pulmonary lesions that have been validated on large-scale test sets are yet to be seen. We trained a Convolution Neural Network (CNN) based on the EfficientNet-B3 architecture, using transfer learning and weakly-supervised learning, to predict carcinoma in Whole Slide Images (WSIs) using a training dataset of 3,554 WSIs. We obtained highly promising results for differentiating between lung carcinoma and non-neoplastic with high Receiver Operator Curve (ROC) area under the curves (AUCs) on four independent test sets (ROC AUCs of 0.975, 0.974, 0.988, and 0.981, respectively). Development and validation of algorithms such as ours are important initial steps in the development of software suites that could be adopted in routine pathological practices and potentially help reduce the burden on pathologists.

Reliable detection of the presence of pulmonary carcinoma on whole-slide images by a deep learning model

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Background: Lung cancer is one of the leading causes of cancer-related death worldwide, and its histopathological diagnosis is crucial for deciding on optimum treatment strategies. Recently, artificial intelligence (AI) models have been widely shown to be useful in various medical fields, particularly image and pathological diagnoses; however, AI models for the pathological diagnosis of pulmonary lesions that have been validated in large-scale test sets are yet to be seen. Methods: We trained a convolution neural network based on the Efficient Net B3 architecture to classify carcinoma from whole slide images (WSIs) using a training dataset of 3640 images. WSI diagnoses were available. We used a transfer learning approach, in which the starting weights were obtained from a pre-trained model on ImageNet. The model was then trained on our dataset using multiple instance learning, a semi-supervised learning approach. To classify a WSI, the model was applied in a sliding window fashion with an input tile size of 512x512 and a stride of 256. The maximum probability was then used as a WSI diagnosis. Results: We evaluated our model on a total of 2680 WSIs originating from five independent sources (two hospitals in Japan and three public datasets from around the world). The model achieved a Receiver Operator Curve Area Under the Curves (ROC AUCs) of 0.974, 0.974, 0.996, 0.988, and 0.981, respectively. Conclusions: We successfully established a reliable AI model for differentiating between lung carcinoma and non-neoplasm with a high ROC AUC on five independent test sets. If used in clinical practice, our model could help reduce the burden on pathologists and be useful for diagnosing pulmonary lesions in areas in which there are shortages of pathologists. Further prospective multicenter studies are warranted in order to validate the results obtained in the current study.

Deep Learning Models for Histopathological Classification of Gastric and Colonic Epithelial Tumours

Histopathological classification of gastric and colonic epithelial tumours is one of the routine pathological diagnosis tasks for pathologists. Computational pathology techniques based on Artificial intelligence (AI) would be of high benefit in easing the ever increasing workloads on pathologists, especially in regions that have shortages in access to pathological diagnosis services. In this study, we trained convolutional neural networks (CNNs) and recurrent neural networks (RNNs) on biopsy histopathology whole-slide images (WSIs) of stomach and colon. The models were trained to classify WSI into adenocarcinoma, adenoma, and non-neoplastic. We evaluated our models on three independent test sets each, achieving area under the curves (AUCs) up to 0.97 and 0.99 for gastric adenocarcinoma and adenoma, respectively, and 0.96 and 0.99 for colonic adenocarcinoma and adenoma respectively. The results demonstrate the generalisation ability of our models and the high promising potential of deployment in a practical histopathological diagnostic workflow system.

Effect of daily versus twice weekly long-term iron supplementation on iron absorption and status in iron-deficient women: A stable isotope study

OBJECTIVES

This work aims at studying the effect of daily versus twice weekly long-term Fe supplementation on Fe absorption and status in Fe-deficient women.

DESIGN AND METHODS

The study design is a randomized controlled open study carried out in the Internal Medicine Department, CHU de Clermont-Ferrand, France. Twenty-four young women participated in this study and were randomized into two groups: Group 1 received 50 mg Fe daily, and group 2 received 50 mg Fe twice weekly for 3 months. On day 10 (D10) and on day 90 (D90) of Fe supplementation, blood samples were obtained, and women received orally about 5 mg of 57Fe, and blood was sampled at different times over 24 h. The 57Fe absorption was evaluated by calculating the areas under the curves (AUC). Fe and oxidative stress status were also assessed.

RESULTS

57Fe absorption was similar in both groups on D10 but was greatly decreased in Group 1 and remained high in Group 2 on D90. Fe status was more improved in Group 1 than in Group 2. Oxidative stress status remained statistically unchanged.

CONCLUSIONS

Our study shows that daily Fe supplementation is able to correct an Fe deficiency much more than twice weekly Fe supplementation in young women.

[Severe asthma due to an esophageal foreign body in a child]

A 4-year-old boy had infantile bronchial asthma resistant to treatment. He was referred for a febrile respiratory distress which led to the diagnosis of periesophagus mediastinis mass with erosion of both contiguous vertebral discs. The oesophagogram showed a foreign body in an esophageal diverticulum. After its extraction, all pulmonary symptoms disappeared.

Endoscopie interventionnelle dans les pancréatites de l'enfant

Authors report on 3 cases of children treated by therapeutic endoscopic retrograde cholangiopancreatography for pancreatitis (ERCP). The first child presented with familial pancreatitis: he was treated by sphincterotomy and lithiasis extraction. The second child presented with pancreatitis secondary to pancreas divisum: she was treated by sphincterotomy and stunt of small caroncula. The third child presented with severe pancreatitis with pseudocyst: after drainage she was treated by sphincterotomy, Wirsung dilatation and lithiasis extraction. ERCP is a beneficial treatment and may be alternative to surgery in complicated pancreatitis.

Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach

Literature data on the bioavailability of various Mg forms provide scarce information on the best Mg salt to be used in animal and human supplementation. This study aimed to investigate the bioavailability of different forms of Mg in rats using Mg stable isotopes. Eighty male Wistar rats aged 6 weeks were fed a semi-purified Mg-depleted diet for three weeks. The rats were then randomised into ten groups and received, for two more weeks, the same diet repleted with Mg (550 mg Mg/kg) as: oxide, chloride, sulphate, carbonate, acetate, pidolate, citrate, gluconate, lactate or aspartate. After 10 days of Mg-repleted diet, the rats received orally 1.8 mg of an enriched 26Mg. Faeces and urine were then collected for 4 consecutive days. Isotope ratios in faeces and urine were determined. The Mg absorption values obtained varied from 50% to 67%. Organic Mg salts were slightly more available than inorganic Mg salts. Mg gluconate exhibited the highest Mg bioavailability of the ten Mg salts studied. Urinary 26Mg excretion varied from 0.20 mg to 0.33 mg, and feeding with the organic pidolate, citrate, gluconate and aspartate salts resulted in higher urinary 26Mg excretion than with inorganic salts. Ultimately, 26Mg retention was higher in the rats receiving the organic salts such as gluconate, lactate and aspartate than in those receiving the inorganic salts. Taken together, these results indicate that 26Mg is sufficiently bioavailable from the ten different Mg salts studied in the present experiment, although Mg gluconate exhibited the highest bioavailability under these experimental conditions.

Impact of micronutrient dietary intake and status on intestinal zinc absorption in late middle-aged men: the ZENITH study

BACKGROUND

Adjustments in intestinal absorption and losses of zinc (Zn) are thought to maintain Zn homeostasis when dietary intake levels are altered. Zn status may also influence efficiency of intestinal Zn absorption.

OBJECTIVES

To determine the impact of dietary intake and status of some micronutrients on Zn absorption in late middle-aged men.

DESIGN AND PARTICIPANTS

Dietary intake and status of Zn, Cu, Fe, vitamin A, C and fibre, and absorption of Zn were measured in 48 men, aged 58-68 y, confined to a metabolic unit and consuming a typical French diet. Dietary intake was estimated using 4-day food-intake records (including the weekend) and the GENI program. To assess Zn status, serum, erythrocyte, urine Zn levels and serum alkaline phosphatase activity were determined. Zn absorption was determined using the isotope double-labelling method. Zn stable isotopic ratios were measured in plasma samples collected before and 48 h after isotope administration using ICP/MS.

RESULTS

Zn intake within the group of men varied from 5.7 to 20.5 mg/day and averaged 12.9 mg/day. Serum Zn level varied from 10 to 18 micromol/l and averaged 12.9 micromol/l. Zn absorption varied from 12 to 46% and averaged 29.7%. Zn absorption was not significantly (P > 0.05) correlated with Zn intake or with any of the Zn status parameters. Zn absorption was only slightly negatively correlated with serum and erythrocyte Zn levels and with serum Fe and ferritin levels in this study.

CONCLUSION

Zn dietary intake and Zn absorption were satisfactory and led to an adequate Zn status in this population.

Erythrocyte magnesium fluxes in mice with nutritionally and genetically low magnesium status

Low intracellular magnesium (Mg) contents may be observed in case of severe Mg insufficient intake or because of genetic regulation. This work was conducted to investigate the influence of intracellular Mg content on erythrocyte Mg(2+) influx and efflux in mice with low nutritionally and genetically (MGL and MGH mice) Mg status. C57BL6 mice were fed for 2 wks a diet containing 1000 mg Mg/kg diet Mg (control group), 100 mg Mg/kg diet (Mg-marginal group) or 30 mg Mg/kg diet (Mg deficient group), while mice with low (MGL) and high (MGH) Mg levels were fed a control diet for 2 wks. The quantification of erythrocyte Mg(2+) influx and efflux was performed using a stable isotope of Mg. Our results showed that erythrocyte Mg(2+) influx and efflux were respectively increased and decreased in nutritional Mg deficiency; while in genetically determined Mg status Mg(2+) fluxes were lower in MGL mice compared to MGH mice. Moreover Mg(2+) efflux was significantly correlated to Mg level in erythrocytes in all the mice studied (p < 0.001). In conclusion, erythrocyte Mg(2+) influx and efflux are modulated by low Mg status, namely decreased Mg(2+) efflux compensate for nutritional Mg deficiency, while the genetic regulation of erythrocyte Mg(2+) content depends on modification of Mg(2+) influx.

Erythrocyte magnesium influx and efflux in solid tumor bearing mice

Mg metabolism is modified in tumors and tumor-bearing organisms. In particular cancer patients often display elevated erythrocyte Mg levels. For a better understanding of the increased erythrocyte Mg content, we attempted to determine Mg fluxes in erythrocytes from tumor-bearing mice by Mg stable isotopes, using a method developed in our laboratory. To characterize the animal Mg status, blood and tissue Mg levels and hematological parameters were assayed. Results showed that in tumor-bearing mice total erythrocyte Mg was about 46% higher than in controls, whereas plasma and tissues Mg levels were not modified; red blood cells and hemoglobin as well as hematocrits were significantly decreased, while mean corpuscular volume and mean corpuscular hemoglobin were slightly but significantly increased in tumor-bearing mice compared to controls (by 3% and 4%, respectively), a picture corresponding to a normochromic, slightly macrocytic anemia. Erythrocyte Mg efflux was about 20% higher (404 + 59 versus 330 + 45 micromol/L, respectively, p < 0.05) in tumor-bearing mice compared to controls, whereas influx was not significantly modified (130 + 11 versus 122 + 19 micromol/L, respectively). Our data therefore exclude that the increased Mg content observed in erythrocytes of tumor-bearing mice is due to decrease of Mg efflux, or to an increase of Mg influx. On the other hand, the increased Mg content observed in erythrocytes of tumor-bearing mice could simply result from an increase of young Mg-enriched erythrocytes produced by the enhanced erythropoiesis which follows tumor-induced anemia.

[CD-ROM burning of CT scan images: initial experience]

OBJECTIVES

To evaluate the cost, the functionment and the impact of the installation of a CD-ROM burning system of CT scan images.

MATERIALS AND METHODS

An automated CD-ROM burning system (e-patient*, TSI, Paris, France) allows to burn CDs for CT scan examinations containing more than 4 films. During a 3 month period, we have delivered for each examination a CD-ROM including images with a Dicom viewer and a selection of interesting images printed on one film. The system has been evaluated by the technologists, the radiologists and the referring physicians by means of a questionnaire. The costs and the technical problems have also been studied.

RESULTS

The benefits of our system are the increase of the diagnostic performances of the referring physicians who use the DICOM format and a reduction of the printing costs. All referring physicians pointed out major changes in their daily work including difficulties to visualize images in relation with a lack of computer infrastructure and the impossibility of simultaneous analysis of several examinations. Technologists encountered technical problems to bum examinations and radiologists had to do extra work to related to image selection.

CONCLUSION

The installation of an automated burning system requires the creation of a dedicated team to train all the users and adapt the presentation of results to the clinical constraints (i.e. performing and printing an image selection). This system will not replace the hospital network but will be complementary.

[Process management in a radiology department. Impact on the quality system]

The purpose of this work was the transition from a mode of management combining TQM (Total Quality Management) based on the European model "EFQM", and quality assurance based on the ISO 9001-1994 certification model, to the ISO 9001-2000 certification model which imposes process management and integrates both management and quality assurance. In order to visualize the inter-relation between processes, a processes-map was made. That is to say a representation of the organization in terms of inputs and outputs. Those processes were divided step by step, from general to final processes which were translated into an algorithmic approach. Subsequently, two external auditors were asked to evaluate the new quality system. They used three quality standards (IOS 9001-2000, MFQ and ANAES) in order to determine the adaptation score of the quality system. Finally, the implementation of the department documentation system on an intranet was evaluated by means of two questionnaires: a qualitative one, dealing with staff acceptability, and a quantitative one, dealing with research effectiveness.

Prevalence of Neospora caninum infection in dogs from beef-cattle farms, dairy farms, and from urban areas of Argentina

Prevalence of anti-Neospora caninum antibodies was determined in sera of 320 dogs from Argentina using the indirect fluorescent antibody test (IFAT). Antibodies to N. caninum were found in 121 of 320 (37.8%) sera with titers of 1:50 (21 dogs), 1:100 (23 dogs), 1:200 (23 dogs), 1:400 (17 dogs), 1:800 (23 dogs), and > or = 1:1.600 (14 dogs). The seropositivity (IFAT, > or = 1:50) was higher in dogs from dairy (48% of 125) and beef (54.2% of 35) farms than in dogs from urban areas (26.2% of 160). Prevalence of anti-N. caninum antibodies was higher in dogs more than 12 mo of age (47.7%, 105 of 222) versus in 12-mo-old or younger dogs (12.7% of 86), suggesting postnatal exposure of N. caninum infection in dogs.

[From accreditation to certification. Quality management in a radiology department]

The leaders of a radiology department started a quality process based on ISO 9001 certification and the total quality management program. The purpose of this work is to match the conformity of this quality system to ANAES recommendations. If the concordance is obvious, the advantages of using quality insurance to get an accreditation are important. In conclusion, a quality process is proposed, it includes a quality insurance manual of ISO 9001 norm, the total quality management in the first point of the norm and the ANAES recommendations spread over the 20 points of the norm.

[Web radiology servers: advices for users, their development and evaluation of the quality of sites]

Sites available on the Internet are constantly increasing and over 15,000 medical websites covering all medical sub-specialties are now available. Finding relevant information on the web may be time consuming and difficult. We suggest that new users begin by accessing servers where lists of available sites are grouped under headings such as medical sub-specialties. We will list a selection of useful radiological websites providing image databases, case reports, radiological anatomy and continuing medical education. While surfing on the web, an evaluation of the quality of the websites is necessary. We used the quality criteria proposed by Darmoni to rate the quality of ten websites. The overall quality was good, but the lack of help options and external links were the main pitfalls that we noted. All webmasters should pay attention to quality criteria and show the Darmoni criteria on their homepage. In order to evaluate which internet options should be developed, we evaluated our own website and submitted a questionnaire to our users. Clinical cases were the most requested feature, they could be used for continuing medical education.

[Optimization of a teleradiology system between two geriatric hospitals and a radiology department of a CHU]

The routine use of a 64 kb/sec Numeris network requires that a compromise be reached between image quality and time required for image transfer. Our goal was to present our experience and describe our choices when reporting examinations for two geriatric hospitals located at a short distance from our radiology department. Different digitization parameters were tested (resolution, compression) for 10 plain films corresponding to the usual clinical situations: abdominal X ray, chest X ray, wrist, spine and pelvis X rays. A subjective analysis of the global quality and of the quality of a region of interest enlarged twelve times has been performed. After result analysis, our choices were: digitization using 75 or 150 DPI and systematic use of a reversible compression format. This system proved satisfactory for both clinicians and radiologists; since its implementation, 1,800 files have been reviewed.

[Comparison of accreditation procedures, ISO 9000 certification procedures and total quality management. Personal experiences and application of quality assurance in a department of radiology and medical imaging]

Management of quality assurance protocols in a radiology department can be done by using several tools or models. Some are specific like accreditation manuals issued by some organizations, others like the ISO 9000 certification and the Total Quality management are more general and already well known by manufacturers. In order to implement a process of quality improvement, we have reviewed three models of quality assurance: evaluation in total quality based on the European model "EFQM", accreditation based on booklets from French cancer centers and Canadian radiology centers and, finally, accreditation based on the ISO 9002 certification model. Based on results of our comparative study, these three tools of quality management are not contradictory and may be complementary. However, they can be compared in terms of constraints they impose, of their historical background, of the criteria evaluated as well as the role of different teams. In conclusion, we suggest that directors of radiology department interested in implementing a quality assurance program first evaluate their department using the Canadian accreditation model issued in 1993 which is useful to become familiar with this new concept of quality. In a second step, a self assessment using the EFQM has to be done in collaboration with all members of the administration board in order to integrate all parameters and to share this protocol with all decision makers. The last step is to consolidate the organization of the quality assurance protocols by means of the ISO 9002 certification.

[The virtual university in medicine. Context, concepts, specifications, users' manual]

The widespread use of Web servers, with the emergence of interactive functions and the possibility of credit card payment via Internet, together with the requirement for continuing education and the subsequent need for a computer to link into the health care network have incited the development of a virtual university scheme on Internet. The Virtual University of Radiology is not only a computer-assisted teaching tool with a set of attractive features, but also a powerful engine allowing the organization, distribution and control of medical knowledge available in the www.server. The scheme provides patient access to general information, a secretary's office for enrollment and the Virtual University itself, with its library, image database, a forum for subspecialties and clinical case reports, an evaluation module and various guides and help tools for diagnosis, prescription and indexing. Currently the Virtual University of Radiology offers diagnostic imaging, but can also be used by other specialties and for general practice.

[Multimodal approach to carotid bifurcation in atherosclerosis]

The cost of treatment of ischemic stroke (second cause of death for elderly patients) is increasing. carotid bifurcation surgery can change the prognosis (as proven by NASCET and ECST studies) for symptomatic patients with over 70% of carotid narrowing. Exploration of the carotid bifurcation is an important step in the diagnosis and must assess the degree of stenosis, the smoothness of the plaque and describe the collateral vessels. Duplex sonography is used to analyze the plaque and to measure the hemodynamic consequences beyond the stenosis. Transcranial Doppler is used to study the hemodynamic consequences at the circle of Willis. 3D TOF MR Angiography visualizes vessels using MIP but with a risk of overestimation of the degree of stenosis. A good morphological study of the circle of Willis can be achieved. With spiral CT, 3D data bases can be acquired with a single injection of contrast medium. Analysis is based on native, reformatted and MIP images. The image quality is generally good, but decreases in the case of huge calcifications. Brain examination can be performed in the same session, looking for rupture of the blood-brain barrier. Angiography remains the gold standard with a high complication rate. It allows excellent analysis from the aortic arch to distal cortical vessels. Isotope studies are only performed in difficult cases (vertebro-basilar lesions, differential diagnosis). Duplex ultrasound is performed first in all protocols. Until recently, angiography was performed before surgery, but the current tendency is to use a less invasive examination (MR angiography or CT angiography) and angiography is then only performed when necessary. A knowledge of the respective advantages of each technique is essential in order to adapt the protocols to each local team.

Lower limb angiography: a prospective study comparing carbon dioxide with iodinated contrast material in 30 patients

OBJECTIVE

We prospectively compared patients' tolerance for and the usefulness of carbon dioxide (CO2) with iodinated contrast material in the study of lower limb arteries in 30 patients.

SUBJECTS AND METHODS

We systematically performed digital subtraction angiography with electronic injection of CO2 (injection average, 330 ml) and digital subtraction angiography with iodinated contrast material in 30 patients (20 men and 10 women; mean age, 67.5 years) suffering from lower limb ischemia. Patients were monitored for vital signs and comfort. Four reviewers subjectively evaluated vessel visibility at five levels (pelvis, thigh, knee, calf, and ankle). We used the Student's t test to evaluate the tolerance and the global examination quality. The chi-square test was used to evaluate the stratified analysis of the observers and scores of the image quality according to the anatomic level studied. Bartlett's test of equality of variances was used to compare the variances between the readers.

RESULTS

CO2 was less well tolerated (p < .01) than iodine was. Fifty-three percent of patients reported CO2 was equally well tolerated (53%), 40% reported more discomfort than with iodine, and 4% reported less discomfort than with iodine. Both techniques were equivalent for imaging of the iliac arteries, but CO2 performed poorly in the arteries below the knee (p << .001).

CONCLUSION

CO2 angiography with electronic injection proved to be less comfortable than iodinated angiography. CO2 arteriography is equivalent to iodinated arteriography for imaging the iliac arteries but imaging performance progressively degrades in the more distal arteries of the legs.

[Evaluation of carboxy-angiography in the study of arteriopathy of the lower limbs]

PURPOSE

We prospectively compared the safety and the usefulness of CO2 with iodinated contrast material in the study of lower limb arteries.

PATIENTS AND METHOD

The study included 30 patients (20 men, 10 women, mean age 67) suffering from lower limb ischemia: stage II (3), stage III (13), stage IV (9), Leriche syndrome (1), post-operative (4). We systemically performed an aortic injection (L3), via a 4F catheter, of (1) CO2-DSA (5 to 6 injections of 75 ml at a flow rate of 20 ml/s) and (2) DSA with iodine contrast material (100 ml at a flow rate of 8 ml/s). Patients were monitored for pain and vital signs. Four reviewers did a subjective evaluation of the vessel visibility at five levels (pelvis, thigh, knee, calf, ankle).

RESULTS

No side effect was found. Concerning pain, the patients had the same sensation in 53%; pain was more disagreeable with CO2 in 40%, more disagreeable with iodine in 7%. Concerning vessel visualization, there was a good coherence between the readers and we found the same quality in 61%. CO2 was less informative in 35%, and more informative in 4%. Image quality decreased with fragmentation of the gas and remoteness of injection site.

CONCLUSION

CO2 angiography, with electronic injection, is a safe alternative to conventional angiography with iodinated contrast material. The disagreeable sensations can be reduced with explanations given before injection and reducing flow rate. Image stacking software could imitate the side effects of fragmentation of the CO2 bubble. This method appears to be a good alternative for patients with severe renal impairment or allergic problems.

[Preliminary evaluation of the performance of 3D morphometer and spiral scanner in carotid stenoses]

Carotid stenosis evaluation is now possible with 3D Imaging. We prospectively compared the diagnostic value of Spiral CT and 3D Morphometer with conventional intraarterial DSA considered as the gold standard. We studied 19 bifurcations in 10 patients. We evaluated the stenosis following the NASCET guidelines on the DSA, with common carotid injection, on the 3D databases of 3D morphometer and of spiral CT (using MIP display). There was a good correlation between the degree of stenosis calculated with the 3D morphometer and angiography even if severe stenoses were slightly overestimated with the former. For the spiral CT databases, accurate diameters were impossible to obtain in case of huge calcifications. There was no benefit of measuring the surfaces on reoriented axial views in comparison with native axial views and MIP images. With the 3D morphometer, post processing selective visualization of the carotid bifurcations is possible without selective injection. The 3D acquisition with 3D morphometer could be an additional acquisition of a standard DSA. It should replace selective injections and should reduce the side effects of angiography.

[Image data bases and multimedia works on server and CD-ROM in medical imaging. A French experience]

The CD-ROM technology allows the production of multimedia works which costs far less than books do. The creation of Internet and the servers World Wide Web has the advantage of distributing those works world wide, without the difficulties and the delays related to books and magazines distribution. The Teachers' Council of Radiology of France (CERF) and the French Society of Radiology (SFR) have opted to use these new media and these information highways to spread a part of their radiology teaching work. Iconocerf is a software program which allows to create, store, read and to exchange digitized radiological cases. It's available free of charge, within the CERF and SFR. The CD-ROMs Iconocerf-Medimag contain 3,500 radiological files with 15,000 images, previously on the videodisc Medimag. The Server of the French Radiology is a W3 server which includes: the CERF directory, a guide for the teachers, the research workers and the students in Radiology and Medical Imaging. It also contains the teaching works on Radiology, and some Iconocerf clinical cases translated onto HTML. The aim of this project is to create an evaluation system for radiology. By using key words, this system allows to consult: radiological clinical cases, located on the server or on CD-ROMs; reference texts; and to have access to the experts' addresses to be able to send them eventually a difficult case through electronic mail.

[Evaluation of the scanner and radiography in rheumatic pelvispondylitis]

We studied 20 normal subjects and 20 suffering from sacro-iliitis. The performance of the two techniques were compared in studying reports ROC curve from several readers. We assessed the performance of each technique and each sign: CT scan appears as a better technique than plain films. Some signs present a poor interest: osteophytes seen on CT or plain films, subchondral cysts seen on CT. In other respects, articular cartilage erosions, subchondral sclerosis are main signs as much on CT as on plain films. In conclusion, CT scan allowed an accurate analysis of sacro-iliitis. It has a better diagnostic value than plain films and, in case of doubt, should be performed to increase diagnosis sensibility and specificity.