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L'IRM permet une exploration en un seul temps du parenchyme pancreatique, des canaux bilio-pancreatiques, des structures vasculaires periglandulaires. Pour ce faire, elle necessite des imageurs tres performants employant les hypergradients, des antennes de surface en reseau. La qualite des images est identique en resolution spatiale a celle du scanner, et bien superieure en ce qui concerne la resolution en densite, particulierement avec l'utilisation de produits de contraste IV non specifiques.

Les maladies inflammatoires chroniques de l’intestin sont frequemment decouvertes au scanner, a l’heure actuelle. Il est important que radiologistes et gastro-enterologues se familiarisent avec les correlations anatomo-radiologiques dans ce domaine. Ils doivent comprendre les differences entre la maladie de Crohn (caracterisee par les signes macroscopiques d’inflammation transmurale et la tres importante proliferation fibro-graisseuse du mesentere) et la colite ulcereuse (epaississement parietal plus modere et extension continue du rectum au colon). L’analyse detaillee de la «stratification» parietale avec rehaussement iode peut apporter des informations utiles pour distinguer les poussees aigues et aider a optimiser les choix therapeutiques. Le diagnostic des complications pancreatiques et hepato-biliaires (cholangite sclerosante primitive, lithiase biliaire, pancreatites medicamenteuses, steatose hepatique focale, lithiase urinaire...) peut etre facilite par le scanner et plus encore par l’IRM.

National audience; But : Évaluer l'efficacité de la radiofréquence comme traitement antalgique à visée palliative dans la prise en charge des tumeurs des parties molles. Matériel et méthode : Etude rétrospective ayant porté sur 12 patients en soins palliatifs présentant des tumeurs des parties molles (5 tumeurs primitives dont 4 sarcomes et 1 PECOME et 7 tumeurs métastatiques) avec des douleurs réfractaires aux traitements usuels. La radiofréquence était effectuée sous guidage tomodensitométrique ou échographique. Résultats : L'efficacité du traitement a été évaluée par cotation de la douleur et sur les modifications apportées au traitement après la radiofréquence. La réponse antalgique était jugée absente, partielle ou totale. Nous avons observé 100% de réponse antalgique à court terme dont 43% de réponse totale, 70% de réponse antalgique à moyen terme et 83% à long terme. En outre, nous avons observé une réduction des doses et effets secondaires des traitements morphiniques et parfois une amélioration de symptômes fonctionnels. Un seul cas de complication post-radiofréquence sous forme d'une collection séro-hématique au sein du foyer de nécrose. Conclusion : Le traitement antalgique à visée palliative des tumeurs des parties molles par radiofréquence représente un complément intéressant aux traitements usuels. Il permet une amélioration de la qualité de vie et n'induit que peu de complications.

To assess the value of single shot fast spin echo MR sequence (SS-FSE) in the evaluation of the normal and pathologic intrahepatic biliary tree.418 consecutive patients (457 examinations) referred for clinical and/or biological suspicion of biliary obstruction underwent MR cholangiopancreatography (MRCP). All patients were imaged with a Signa 1.5 T GE MR unit, with High Gradient Field Strength and Torso Phased Array Coil. Biliary ducts were imaged with SS-FSE sequence, coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Total acquisition time was 1 second. Source images were reviewed by two radiologists blinded to clinical information. In case of disagreement, a third radiologist's opinion was requested. In all cases, MRCP results were compared with direct biliary tract evaluation, other imaging studies and clinical and biological follow-up.In all cases, MRCP produced high quality images. Numerous branch of division were observed although the peripheral intrahepatic ducts were well seen in more than 90% in an area 2 cm below the capsule. The number of division was statistically higher when mechanical obstruction was present. Intrahepatic calculi or peripheral cholangiocarcinoma were well detect by MRCP. For the detection of cholangitis, MRCP sensitivity was 87.5% but the positive predictive value was only 57.7% because of a high number of false positive. The diagnosis of primary sclerosing cholangitis must be made only on strict criteria and slightly dilated peripheral bile ducts unconnected to the central ducts in several hepatic segments were a characteristic MR sign of primary sclerosing cholangitis.MRCP can be proposed as a first intention imaging technique for the evaluation of intrahepatic ducts.

To assess the value of pericolonic findings at CT in the evaluation of the sigmoid colon.A total of 210 CT examinations were retrospectively reviewed by 3 blinded radiologists. Data was analyzed to determine the interobserver correlation and the value of pericolonic and colonic wall findings in diagnosis of sigmoid colon pathology.The interobserver correlation for pericolonic findings was equal to or superior to that for colonic wall findings. The presence of abnormal pericolonic fat was the most sensitive (88%) and specific (93%) sign to differentiate a diseased sigmoid colon from a normal one or from sigmoid diverticulosis. Wall-thickening was less sensitive (82%) and specific (76%). Findings suggesting malignancy over diverticulitis included acute zone of transition, focal fatty infiltration, and lymph nodes. Symmetrical and circumferential wall thickening, target-like enhancement, and local fatty proliferation were findings suggesting colitis over diverticulitis. Wall thickening more than 15 mm, involvement of 15 cm or less, asymmetrical involvement, acute zone of transition, and homogeneous or heterogeneous enhancement were findings suggesting malignancy over colitis.To render a diagnosis, the evaluation of the fat infiltration must prevail on the parietal thickening appreciation.

To assess the value of single shot fast spin echo MR sequence (SS-FSE) in the morphological analysis of the biliary tree and pancreatic ducts and to compare its accuracy with other imaging methods.95 consecutive patients referred for clinical and/or biological suspicion of biliary obstruction were explored with MR cholangiopancreatography (MRCP). All patients were explored with a Signa 1.5 T GE MR unit, with High Gradient Field Strength and Torso Phased Array Coil. Biliary ducts were explored with SS-FSE sequence, coronal and oblique coronal 20 mm thick slices on a 256 x 256 matrix. Total acquisition time was 1 second. Native pictures were reviewed by two radiologists blinded to clinical information. In case of disagreement, a third radiologist's judgement was requested. In 88 cases, MRCP results were compared with direct biligraphy methods.In all cases, MRCP produced high quality images without MIP or other post-processing methods. For detection of biliary tree distensions, the concordance value of MRCP was over 91% (Kappa 0.82). For detection of biliary tree and/or pancreatic duct obstruction, MR sensitivity was 100% and specificity 91%. The overall diagnostic concordance value of MRCP wasor = 93%. Difficulties in MRCP were caused by functional diseases or benign stenosis. MRCP accurately diagnosed all lithiasic obstructions starting from a stone size of 3 mm.MRCP produces fastly high-quality images. As it is totally safe, it can be proposed as a first intention method in biliopancreatic duct explorations.

To compare helical CT with MR angiography in pre-operative assessment of abdominal aortic aneurysm (AAA).Twenty patients with AAA underwent helical-CT, MR-angiography and digital angiography. All exams were interpreted independently by two groups of observers. Kappa and rho were calculated to assess correlations. Sensitivity and specificity were calculated to compare each method with the "gold standard" digital angiography.Inter-observer correlation was excellent. There was a very good agreement between both methods in the assessment of the maximal diameter and the proximal neck of the aneurysm. There was no significant difference in the assessment of stenoses of the visceral and iliac arteries, the number of renal arteries, and iliac extension.Helical CT and MR angiography are equivalent in pre-operative assessment of AAA.

Endoscopic sphincterotomy (ES) is a minimally invasive technique which is the standard of reference in many clinical situations (e.g distal choledocolithiasis, recurrent lithiasis or bile duct stenosis). Complication are rare but are often misdiagnosed although radiological aspects are demonstrative. The purpose of this study is to illustrate the patterns of the complications. Ten patients have been treated for the last four years in our institution for ES complications. There were eight cases of pancreatitis, three of which had associated perforation, one arterioportal fistula, and one isolated perforation. Diagnosis was reached with CT in all but one case. Two patients have been successfully treated with percutaneous treatment (one embolization with Gianturco coils, and one drainage). Two patients died, one of necrotizing pancreatitis and the second of decubitus complication. The other patient were followed with CT. We give exemples of different observations and discuss their follow up. The severity and extent of post ES pancreatitis were readily assessed by CT and response to therapy monitored by serial examinations. Severity of disease, evaluated according to the length of hospitalization, correlated well with the presence and degree of pancreatic necrosis. CT also highlights perforations including minimal effusions. In our study differential diagnosis between post ES pancreatitis and perforation is not significant regarding the initial conservative therapy in both situations. CT scan helps us to opt for a surgical decision or for a percutaneous drainage. It also permits to follow the evolution of the lesions. In our cases involving perforations, we noted a spontaneous complete resolution of gas effusion on control and we also observed that pancreatitis evolution was similar to standard pancreatitis evolution. In a life threatening post ES hemobilia, not responding to standard medical treatment, angiography is the diagnostic exam of choice before embolization which is regarded as the best initial treatment of vascular lesions. We conclude that CT is the exam of choice in the initial diagnosis and follow up post ES complications.

To describe the US, CT and MRI pattern of the severe rectus sheath hematoma (RSH) complicating anticoagulant therapy.CT scans were performed in thirteen patients (12 women, 1 man) aged from 53 to 90 (mean age, 74) with severe RSH. Five patients also underwent ultrasound examination and three MR examination. Nine patients (69%) were receiving subcutaneous injection of heparin, three (23%) oral anticoagulant therapy and one continuous IV infusion of heparin. Clinical diagnosis was reached in 6 cases. Excessive activity of anticoagulant therapy was noted in 4 cases. The location of the RSH, their densities and their signal were analysed.All the RSH were mostly developed in the lower third of the abdominal wall, had a large spreading into the Retzius space and compressed the bladder and/or the bowels. RSH were all hyperdense and in 8 cases (61%) a fluid-fluid level due to the hematocrit effect was noted. In one case, a retroperitoneal hematoma was discovered. The extension of the RSH was well delineated with MRI. The RSH showed itself with heterogeneous signal intensities with areas of high-signal-intensity on T1-weighted images. Fluid-fluid levels and a concentric ring sign were also noted.Older women with subcutaneous injection of heparin are especially prone to RSH even though there is no overall excessive activity of anticoagulant therapy. Clinical and biological diagnosis may be difficult. CT scan is the exam of choice to reach a precise and acute diagnosis of RSH.

Three hundred and sixty seven patients were studied for cerebrovascular disease with intra-arterial digital subtraction. Examination were performed using a right transbrachial approach with a 4F catheter. Selective catheterization of the carotid arteries was possible in 98% for the left and 99% for the right. Image quality was consistently good or excellent. There was 2 neurologic complications and 1 local complication (hematoma) requiring surgery few weeks later. Selective carotid and vertebral catheterizations by the brachial route is safe, simple, accurate and rapid (15 mn) and can be employed in outpatients.

Objectifs Montrer l’interet du positionnement percutane scanoguide de grains d’or pour le balisage de tumeurs avant radiotherapie stereotaxique par Cyberknife ® . Ce reperage permet de detecter, suivre et corriger en temps reel les deplacements de la tumeur et les mouvements du patient intra et inter-seances, avec une exactitude submillimetrique, indispensable pour le traitement des tumeurs des organes mobiles : poumon, foie, reins. Materiels et methodes Nancy est l’un des trois premiers centres francais a disposer du Cyberknife ® , nouveau systeme de radiotherapie stereotaxique. Il s’agit d’un accelerateur lineaire faible energie fixe sur un robot industriel a 6 degres de liberte. Le reperage en temps reel de la tumeur est effectue par 2 faisceaux de RX disposes orthogona-lement, qui detectent la presence des grains d’or, prealablement deposes sous scanner en peripherie de la tumeur. Resultats Vingt et un patients ont beneficie de la pose scanoguidee de grains d’or (15 tumeurs pulmonaires, 6 hepatiques). Trois migrations secondaires des grains d’or ont ete observees. Conclusion Le positionnement scanoguide des grains d’or est la premiere etape du traitement par Cyberknife ® , indispensable car elle permet un tracking des tumeurs mobiles (poumon, foie). Les grains d’or peuvent migrer secondairement. Cette migration doit etre prevenue par un positionnement optimise.

Objectifs pedagogiques Recenser et expliciter les methodes d’imagerie a disposition pour explorer un abord d’hemodialyse. Connaitre la semeiologie et les images pieges. Savoir exiger les elements cliniques pertinents. Proposer une strategie therapeutique adaptee. Messages a retenir L’angioscanner est une alternative a l’echo-Doppler dans l’imagerie des fistules. Les donnees cliniques et hemodynamiques sont indispensables a l’interpretation eclairee des lesions. Le «cutting balloon » s’annonce comme une evolution notable dans le traitement des stenoses veineuses des montages de dialyse.

Objectifs Comparer les survies globales en fonction de l’etiologie alcoolique ou virale de la cirrhose. Materiels et methodes Etude retrospective bi-centrique de 233 patients cirrhotiques traites par chimioembolisation lipiodolee de 1992 a 2004. Survie evaluee en fonction de l’etiologie de la cirrhose, du score de Child-Pugh, du stade d’Okuda, du score de CLIP, de l’extension tumorale. Analyses uni-et multi-variees des facteurs predictifs de survie. Resultats : Mediane de survie des CHC sur cirrhose virale : 29 mois. Resultats Mediane de survie des CHC sur cirrhose virale : 29 mois. Mediane de survie des CHC sur cirrhose alcoolique : 16 mois (p Conclusion La survie, apres CEL, des CHC sur cirrhoses alcooliques est plus mauvaise que la survie des CHC sur cirrhoses virales. Cela pourrait expliquer, en partie, la disparite des resultats de la CEL en fonction des etudes.

Objectifs Illustrer grâce a l’imagerie en coupe les pathologies hepatiques impliquant primitivement le reseau vasculaire arteriel et/ou veineux. Materiels et methodes Observations selectionnees retrospectivement entre 2002 et 2004. Resultats Nous aborderons sur un mode didactique le syndrome de Rendu-Osler-Weber, le syndrome de Budd-Chiari et les pathologies apparentees, la maladie veino-occlusive hepatique, le foie cardiaque, la thrombose portale en detaillant la semeiologie lesionnelle parallelement aux donnees physiopathologiques, les points cruciaux du diagnostic, les signes associes notamment sur le parenchyme hepatique ainsi que l’interet respectif des differentes methodes d’imagerie et les protocoles adaptes. Les implications therapeutiques seront egalement abordees. Conclusion L’exploration du « foie vasculaire » repose sur l’imagerie en coupe et requiert une bonne connaissance de la physiopathologie des lesions.

Objectifs Les variations anatomiques courantes de l’etage sous mesocolique : defauts d’accolement du fascia de Toldt, variations de taille et de longueur des structures digestives, en particulier dolichosigmoide, malrotation de l’anse intestinale primitive, sont a l’origine de tableaux cliniques tres atypiques et/ou trompeurs par les modifications positionnelles des organes digestifs qu’elles determinent. Materiels et methodes L’experience acquise sur deux decennies de pratique intensive de l’exploration scanographique des urgences abdominales a permis de rassembler de nombreux cas dans lesquels la symptomatologie clinique etait modifiee par les anomalies positionnelles des segments digestifs en cause. Resultats Les pieges frequents sont illustres en particulier avec un carrefour ileo-caecal en position ectopique par defaut d’accolement du fascia de Toldt ou anomalie de rotation de l’anse intestinale primitive : les appendicites mesocœliaque et sous hepatiques, la hernie du hiatus de Winslow, l’ischemie caecale mesocœliaque ou le volvulus du caecum. Avec un dolichosigmoide, peuvent etre observes des tableaux radio-cliniques particuliers : la sigmoidite de la fosse iliaque droite, la pneumatose kystique colique de l’adulte, le volvulus du sigmoide et le nœud ileo-sigmoidien. Conclusion Les reformations multiplanaires permises par les acquisitions volumiques actuelles sont un appoint precieux pour le diagnostic et la comprehension des anomalies anatomiques de l’etage sous mesocolique et de leurs consequences cliniques.