Prompt regression of paravertebral and epidural abscesses in patients with pyogenic discitis. Sixteen cases evaluated using magnetic resonance imaging.

OBJECTIVE: To determine whether spinal magnetic resonance imaging performed one month into anti-microbial therapy for pyogenic discitis demonstrated changes of value for predicting outcomes and making therapeutic decisions. METHODS: Prospective study of 16 patients with discitis. A physical evaluation, laboratory tests for inflammation, plain radiographs centered on the affected vertebral level, and magnetic resonance imaging with gadolinium injection were performed at baseline and on day 30. All 16 patients were reevaluated after three months and 15 after six months. RESULTS: The 12 men and four women had a mean age of 59 years. Fourteen patients had a paravertebral abscess (n=12) and/or an epidural abscess (n=6). On day 30, 14 of the 16 patients were clinically improved and ten were radiologically improved. The C-reactive protein level was still elevated in five cases. All reevaluated patients were improved after three months (16/16) and six months (15/15). Only two magnetic resonance imaging features improved during the first month: the size of paravertebral abscesses decreased in 11 of 12 patients, and the size of epidural abscesses decreased in four of six patients. CONCLUSION: Paravertebral and epidural abscesses improve promptly under antimicrobial therapy. However, the presence of these lesions have no prognostic significance. Magnetic resonance imaging does not add significantly to the follow-up of patients who respond clinically to antimicrobial therapy. However, in patients with an unsatisfactory clinical response, follow-up magnetic resonance imaging can provide useful therapeutic orientation by showing whether the paravertebral and/or epidural abscesses have decreased in size.

[Evaluation of carboxy-angiography in the study of arteriopathy of the lower limbs]. / Evaluation de la carboxy-angiographie dans l'étude de l'artériopathie des membres inférieurs.

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.

[Value of automated medical indexing of an image database and a digital radiological library]. / Intérêt de l'indexation médicale automatique d'une iconothèque et d'une bibliothèque radiologiques numériques.

We indexed the contents of a radiology server on the web to facilitate access to research documents and to link reference texts to images contained in radiology databases. Indexation also allows case reports to be transformed with no supplementary work into formats compatible with computer-assisted training. Indexation was performed automatically by ADM-Index, the aim being to identify the medical concepts expressed within each medical text. Two types of texts were indexed: medical imaging reference books (Edicerf) and case reports with illustrations and captions (Iconocerf). These documents are now available on a web server with HTML format for Edicerf and on an Oracle database for Iconocerf. When the user consults a chapter of a book or a case report, the indexed terms are displayed in the heading; all reference texts and case reports containing the indexed terms can then be called up instantaneously. The user can express his search in natural language. Indexation follows the same process allowing instantaneous recall of all reference texts and case reports where the same concept appears in the diagnosis or clinical context. By using the context of the case reports as the search index, all case reports involving a common medical concept can be found. The context is interpreted as a question. When the user responds to this question, ADM-Index compares this response with the answer furnished by the reference texts and case reports. Correct or erroneous responses can thus be identified, converting the system into a computer-assisted training tool.

[The virtual university in medicine. Context, concepts, specifications, users' manual]. / Université virtuelle en médecine. Contexte, concept, cahier des charges, mode d'emploi.

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.

[Preliminary evaluation of the performance of 3D morphometer and spiral scanner in carotid stenoses]. / Evaluation préliminaire de la performance du morphomtre 3D et du scanner hélicoïdal dans les sténoses carotidiennes.

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.

[Cervical epidural injection technic under computed tomography guidance in the treatment of cervicobrachial neuralgia]. / Technique des infiltrations épidurales cervicales sous contrôle tomodensitométrique dans le traitement des névralgies cervico-brachiales.

Epidural injections of corticosteroids in the cervical spine can provide effective treatment of cervicobrachial neuralgia. This technique is mainly described by anesthesiologists who perform injections without imaging control. We demonstrate that this infiltration can be easily performed under CT-guidance by radiologists.

[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]. / Comparaison des procédures d'accréditation, de certification ISO 9000 et d'évaluation en qualité totale. Expérience personnelle et application à la gestion de la qualité d'un département de radiologie et imagerie médicale.

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.

[Image data bases and multimedia works on server and CD-ROM in medical imaging. A French experience]. / Iconothèques et ouvrages multimédia sur serveur et CD-ROM en imagerie médicale. Expérience Française.

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.

[Rupture of the diaphragm in closed traumas: apropos of 28 cases]. / Rupture du diaphragme lors des traumatismes fermés: à propos de 28 observations.

Twenty-eight cases of ruptured diaphragm due to blunt trauma are reported, including three with rupture on the right. Most of the patients were young men and rupture was an isolated lesion in only 6 patients, all others having multiple trauma. One patient died during surgery (3.6%) and complications, mostly respiratory, occurred in 17 patients (60.7%). Mid-term functional digestive and respiratory sequellae were evaluated. The gravity of ruptured diaphragm is basically related to the severity of the trauma and associated lesions. The diagnosis remains unrecognized in an important number of cases emphasizing the importance of repeated chest X-rays.

[Image archiving and communication systems: review of ten years' experiences and perspectives]. / Les systèmes de communication et d'archivage d'images: bilan de dix années d'expérimentations et perspectives.

The paper starts by presenting the major PACS (Picture Archiving and Communication Systems) related concepts and highlights the medical motivations which resulted in PACS developments. The authors review some PACS experiments carried out during the last decade and draw the conclusions of these experiments; the experience of the University Hospital of Rennes is also briefly presented. Finally a discussion is engaged about the future of PACS and their position within the Hospital Information System. According to the authors, this process should not be confined within the small community of PACS specialists but should concern all actors of the hospital, namely medical staff involved in the production or utilisation of medical images, technical staff in charge of equipment and the Hospital Information System, and hospital administrators. Three major lines are proposed: the first one deals with the functional capacities of PACS and their adaptation to actual user needs; the second concerns the methodology required to set up such systems to ensure adequate integration within the HIS and the third concerns economic issues.

Prediction of rotator cuff repair results by magnetic resonance imaging.

Thirty chronic rotator cuff tears were repaired consecutively and evaluated prospectively using a precise anatomic description of the tear that included the rotator interval, the Constant functional score, and an assessment of the tendon state and the atrophy of the supraspinatus muscle by preoperative and postoperative magnetic resonance imaging. Early correlations (mean followup, 21.1 months) attempted to define predictive factors of the final outcome of the repair, physical factors indicative of final tendon state, and postoperative evolution of supraspinatus atrophy. Magnetic resonance imaging oblique sagittal views showed that supraspinatus atrophy correlated with the sagittal and coronal extent of the tear and represented a strong predictive factor of postoperative retearing. At followup, 15 (50%) cuffs were continuous and thick, seven (23%) were continuous but thin, and six (20%) were retorn. Two (7%) cuffs had been repaired only partly. In the group with a persistent tear, flexion strength and differential Constant score were correlated with the final tendon state with no excellent or good results, and with less than 4 kg of strength. Supraspinatus atrophy improved in 18 of the 22 postoperative continuous cuffs, but never decreased in persistent tears, although there was pain relief and functional gain.

[Multimodal approach to carotid bifurcation in atherosclerosis]. / Approche multimodalité des bifurcations carotidiennes dans la pathologie athéromateuse.

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.

[Glossary of terms used by radiologists in image processing]. / Lexique des termes utilisés dans le traitement des images à l'usage des médecins radiologues.

We give the definition of 166 words used in image processing. Adaptivity, aliazing, analog-digital converter, analysis, approximation, arc, artifact, artificial intelligence, attribute, autocorrelation, bandwidth, boundary, brightness, calibration, class, classification, classify, centre, cluster, coding, color, compression, contrast, connectivity, convolution, correlation, data base, decision, decomposition, deconvolution, deduction, descriptor, detection, digitization, dilation, discontinuity, discretization, discrimination, disparity, display, distance, distorsion, distribution dynamic, edge, energy, enhancement, entropy, erosion, estimation, event, extrapolation, feature, file, filter, filter floaters, fitting, Fourier transform, frequency, fusion, fuzzy, Gaussian, gradient, graph, gray level, group, growing, histogram, Hough transform, Houndsfield, image, impulse response, inertia, intensity, interpolation, interpretation, invariance, isotropy, iterative, JPEG, knowledge base, label, laplacian, learning, least squares, likelihood, matching, Markov field, mask, matching, mathematical morphology, merge (to), MIP, median, minimization, model, moiré, moment, MPEG, neural network, neuron, node, noise, norm, normal, operator, optical system, optimization, orthogonal, parametric, pattern recognition, periodicity, photometry, pixel, polygon, polynomial, prediction, pulsation, pyramidal, quantization, raster, reconstruction, recursive, region, rendering, representation space, resolution, restoration, robustness, ROC, thinning, transform, sampling, saturation, scene analysis, segmentation, separable function, sequential, smoothing, spline, split (to), shape, threshold, tree, signal, speckle, spectrum, spline, stationarity, statistical, stochastic, structuring element, support, syntaxic, synthesis, texture, truncation, variance, vision, voxel, windowing.

[Analysis of texture in medical imaging. Review of the literature]. / Analyse de texture en imagerie médicale. Revue de la littérature.

This paper presents a review of the applications of texture analysis in medical imaging. Many authors take a great interest in this topic (75 papers have been published since 1984) and try to elaborate automatic methods for tissue characterization. The results are not really convincing and applications are often reduced to feasibility studies. This failure is due to the empirical approach to the problem: the first studies were performed on ultrasound images, in which visual texture is very present, but no data standardization is available with this imaging modality. A more rational approach should provide better results. For each organ or tissue, it is necessary to find the appropriate source and texture analysis method. This difficult task requires reflection concerning the interactions between tissues and imaging sources, to define judicious structuring elements. These structuring elements should facilitate the choice of the best texture analysis method, for the particular application. Considerable methodological progress has yet to be made, after which texture analysis should be a useful and efficient tool for clinical use.