Illustrer la sémiologie radiologique du syndrome de Budd Chiari en particulier à la lumière du scanner multidétecteur et étudier les différentes possibilités thérapeutiques de la radiologie interventionnelle. A partir de 14 patients (6 hommes et 8 femmes, 54 ans +/-7, nous avons pu explorer par différentes méthodes d’imagerie des syndromes de Budd Chiari d’étiologies variées (diaphragme, obstruction tumorale, syndromes myéloprolifératifs, états d’hypercoagulabilité…). Quatre d’entre eux ont bénéficié de thérapeutiques endovasculaires (1 TIPS par voie transhépatique et 3 par voie transcave). Suspecté sur des arguments cliniques, le diagnostic d’obstruction des veines hépatiques est le plus souvent posé par l’imagerie. Habituellement relégué au second plan derrière l’écho-Doppler et l’IRM, le scanner multidétecteur semble reprendre toute sa place par sa résolution spatiale et ses possibilités de reconstructions vasculaires. L’imagerie permet d’orienter l’étiologie et de choisir l’attitude thérapeutique la plus adaptée. La radiologie interventionnelle (en particulier les shunts porto-systémiques) offre une option efficace en complément du traitement médical. Les techniques récentes de la radiologie optimisent la prise en charge diagnostique et thérapeutique du syndrome de Budd Chiari.

Définir le rôle du scanner multidétecteur dans le bilan étiologique et pré-thérapeutique de l’hypertension artérielle pulmonaire (HTAP). Comparer les anomalies de perfusion scintigraphiques aux anomalies vasculaires distales accessibles en scanner multidétecteur et en IRM de perfusion pulmonaire. Définir le rôle de l’IRM fonctionnelle cardiaque dans la prise en charge thérapeutique en comparaison avec l’échographie cardiaque. Analyse rétrospective et prospective de patients présentant une HTAP ayant bénéficié d’un scanner multidétecteur, d’une scintigraphie ventilation-perfusion, d’une échographie cardiaque et pour certains d’un cathéterisme cardiaque droit et d’une IRM fonctionnelle cardiaque et de perfusion pulmonaire. La technologie multidétecteur améliore l’analyse morphologique de la vascularisation artérielle pulmonaire et systémique pulmonaire par rapport à la technologie monodétecteur. La resolution anatomique du scanner multidétecteur permet d’analyser avec plus de précision que la scintigraphie de perfusion les anomalies de la vascularisation distale pulmonaire (mosaïque vasculaire). L’hypervascularisation sytémique du poumon mise en évidence dans la maladie thromboembolique chronique notamment n’est correctement démontrée que par le scanner. L’IRM fonctionnelle cardiaque aide à l’analyse du retentissement cardiaque de l’HTAP. La résolution anatomique de l’IRM de perfusion est inférieure à celle du scanner multidétecteur. Le scanner multidétecteur est l’examen de première ligne dans la prise en charge diagnostique et thérapeutique des HTAP. L’IRM précise le retentissement cardiaque de l’HTAP.

Imaging is performed: (a) to follow the progression of the causal disease; (b) to evaluate the structural and functional integrity of the surgical reconstruction and (c) to detect postoperative comjunctions.

The ureter is the central structure of the retroperitoneal space and the pelvic cavity. Any expansive or infiltrative pathological process in these regions may have an impact on the ureter. Most extrinsic disorders, whether tumoral or not, compress without direct extension and frequently displace the ureter. However, the mechanism of ureteral involvement by extrinsic malignancies can be different (; ): — Direct tumoral involvement of the ureteral wall (serosal, intramural, mucosal, or a combination of all of them) — Metastatic extension to periureteral lymph nodes or periureteral fatty tissue with frequent desmoplastic reaction, so-called malignant retroperitoneal fibrosis (RPF) — Mucosal or intramural metastases may be isolated or associated with retroperitoneal metastases. Their patterns are described in Chap. 6

The electrochemical polymerization of 10-undecenoic acid via the Kolbe reaction was studied in methanol:pyridine (1:1). Besides the expected dimeric coupling product (α, ω-eicosadiene), soluble oligomeric and insoluble infusible polymeric products were formed in 25% yield, by attack of the free radicals, formed from oxidation of the carboxyl groups, on the vinyl double bonds. Due to the multiple functionality of the reactants, crosslinked polymers were formed.

The electrochemical polymerization of oligomeric polyesters (prepared from adipic acid and ethylene glycol or polyethylene glycols), oligomeric polyamides (prepared from adipic or succinic acid and ethylene diamine or hexamethylene diamine), oligomeric polybutadiene (having carboxyl terminal groups) and pyrrolidone dicarboxylic acids were studied. In the latter the pyrrolidone ring was found to participate in the polymerization. Insoluble and infusible polymers as well as soluble short polymers were formed. The proportion of the latter increased in the case of polyesters by copolymerization with a monoacid.

The electrochemical polymerization of adipic acid via the Kolbe synthesis was investigated in methanol, methanol-pyridine and methanol-acetonitrile mixtures. The complex variety of products formed from C 4 and higher hydrocarbons, methyl esters, methyl ethers, lactones, oligomers and polymers in the various solvents were analyzed and compared. Generally the major products were the hydrocarbons and the polymers; the yield of the former decreased with increasing pyridine concentration and that of the latter increased.

The electrolysis of sebacic acid was investigated in methanol, methanol:pyridine (1:1) and methanol:acetonitrile (1:1). The various products were analyzed. In methanol, the major product was the oligomeric carboxylic acid fraction (55%) and the yield of oligomeric hydrocarbons and polymer was lower. With the other two solvents, the polymer was the major product. Four types of hydrocarbons were formed: n-alkane, 1-alkene, x-alkene (the position of the double bond is not known) and cycloalkane. The polymers obtained in all the solvents had the character of cross-linked and branched polyethylene, having ester and methoxy groups. These polymers did not suffer degradation during basic hydrolysis. In comparison with adipic acid, sebacic acid had more tendency to yield polymer and carboxylic acids than hydrocarbons.

The mechanism of the electrochemical polymerization of dicarboxylic acids in various solvents, which also leads to the formation of various side products, is discussed. The formation of hydrocarbons was rationalized through the formation of α,ω-biradicals which suffer coupling or disproportionation reactions. Carboxylic acids are shown to originate from reactions of • (CH 2 ) k COOH radicals which couple radicals which couple or disproportionate among themselves or other radicals to give saturated and unsaturated acids. Cations formed from anodic oxidation of the radicals are the precursors of lactones and some olefins. The conformations of the dicarboxylate anions at the anode surface are discussed with a view of rationalizing the formation of the various products. Polymer formation was explained as occurring through α,ω-biradicals having a definite conformation. Pyridine affected to a large extent these conformations, and higher concentrations of pyridine led to an increase in the conformations which lead to polymer formation.

The electrochemical polymerizations of suberic and azelaic acids were investigated in methanol: pyridine (1:1) and the results compared with those previously obtained for adipic and sebacic acids, to find out the effect of chain length between the carboxyl groups on formation of polymer and oligomeric side products. On passing from adipic to sebacic acid, the ratio of hydrocarbons formed to polymer decreased, polymer yield increased a little, and the extent of decarboxylation increased indicating a greater hydrocarbon structure to the polymers. This is reflected in the properties of the polymers; that obtained from adipic acid was degraded considerably on alkaline hydrolysis unlike those obtained from azelaic and sebacic acids which remained insoluble and high melting.

The electrochemical polymerization of adipic acid via the Kolbe synthesis was investigated in various solvent systems. High melting insoluble polymers were obtained; they contained, besides the hydrocarbon chains obtained from the free radical Kolbe mechanism ester groups obtained through the cationic mechanism Polymer yield, as well as ester group content, increased on passing from methanol to methanol-pyridine (1:4). The structure of the polymers is discussed.

The electrochemical polymerization of adipic acid in methanol and in methanol-pyridine (1:1) via the Kolbe reaction was investigated as regards the oligomeric and side products. GC-MS, i.r. and NMR were used to identify the many products. Gaseous and volatile compounds were identified as C4 and C8 hydrocarbons besides λ- and δ-valerolactones. The less volatile compounds were separated on silica gel columns to fractions, viz. that eluted by heptane which contained hydrocarbons, that eluted by benzene which contained ether and ester groups and that eluted by methanol which contained higher oligomeric products containing oxygen. Four types of hydrocarbons were formed, viz. n-alkanes, n-alkenes, x-alkenes (the place of the double bond is not known) and cycloalkanes. Saturated and unsaturated oligomeric mono- and di-carboxylic acids were also formed.

The reaction of alkali metals with nitrobenzene and p-nitro-toluene in THF at various molar ratios was found to lead to the formation of radical ions, dianions, and alkali metal adducts of reduction derivatives of the nitro compounds such as azo- and azoxybenzene. The anionic polymerization of styrene, methyl methacrylate, methacrylonitrile, and acrylo-nitrile by these anions was investigated. All the initiators did not polymerize styrene while the least reactive radical-anion was found to polymerize acrylonitrile completely, methacrylonitrile to a small extent, but not methyl methacrylate. The order of reactivity of those adducts toward organic halides was similar to that found in polymerization. Metalla-tion of polynitrostyrene by lithium biphenyl solution led only to partial conversion of the nitro groups to radical-anions which were not reactive.