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Objectifs Dresser le bilan des avancees technologiques et evaluer leur impact sur l’imagerie medicale. Materiels et Methodes Les principaux facteurs de progres sont passes en revue : nombre de coupes par rotation, collimation, temps de rotation, economie d’irradiation, algorithmes de correction des artefacts, reconstructions ciblees et orientees, detections automatiques de lesions, analyse de vaisseaux. Partant de la generation 2004, les principaux parametres emanant de donnees constructeurs et utilisables dans les prochaines annees sont analyses, selon les informations recues. Resultats Le gain en resolution spatiale de voxels isotropiques est programme a 0,2 x 0,2 x 0,2 mm. Mais il ne peut etre exploite que par la maitrise des mouvements physiologiques, donc des temps de balayage, circulaire ou spirale. Les effets de la transformation de la geometrie conique des faisceaux restent a evaluer de meme que ceux des sur-echantillonnages dans l’axe Z, indispensable pour installer l’imagerie de perfusion dans certains organes. Il reste egalement a demontrer que les tres grandes rapidites d’acquisition seront benefiques aux applications cliniques. Conclusion De fascinants progres s’annoncent dans une imagerie medicale morpho-fonctionnelle de haute precision.

Pulmonary involvement was investigated by High Resolution Computed Tomographic scan (H.R.C.T.), bronchoalveolar lavage (B.A.L.) and pulmonary fonction tests (P.F.T.) initially and in the follow up of 42 patients with progressive systemic sclerosis: B.A.L. was more sensitive than H.R.C.T. or P.F.T. to assess lung involvement in P.S.S., although not correlated with disease severity. H.R.C.T. is the method of choice for evaluation of parenchymal destruction.

This paper gives a monograph of freezing and quick-freezing equipment. Following a brief summary of the theory of freezing time, the author reviews the principal industrial processes and equipment in use today, classifying them according to their technological characteristics.

A campaign of audio-magnetotelluric soundings in the crater of Momotombo has shown that the structure of this volcano is suitable to a surveillance by this method; it has an only central activity, and the resistivity versus the depth decreases suddenly at least 100 times at about 270 m.

Osteodysplasty (Melnick and Needles syndrome) without facial dysmorphy in a 26 1/2 years old woman, mother of a normal 5 months female infant. First male newborn was stillborn at 37 weeks of amenorrhea with Potter syndrome and severe malformations (microcephaly, cleft lip and palate, posterior scalp lesions, bilateral palmar transverse crease) just like 13 trisomy. Spine and limb X-ray anomalies pointed out a week before foetus expulsion are not proved subsequently because examinations deficiency.

The authors describe 6 cases of unilateral obstruction to pulmonary venous return: two cases of Halasz syndrome and postoperative obstruction of the reimplanted collector vein, one patient with Halasz syndrome and spontaneous obstruction of the vein in the form of a scimitar, one case of neoplastic invasion of the atrium-vein junction, one with unilateral absence of the right intra- and extraparenchymatous regions of the pulmonary veins, and lastly, a case of juxta-auricular interruption in the right pulmonary veins. The anatomy and physiopathology of the collateral venous pathways are briefly described, together with the relations between systemic arterial hypervascularization and pulmonary venous obstruction. The authors then review the radiological, clinical, and angiohemodynamic features of the unilateral venous obstruction syndrome, and conclude that precise diagnosis of venous occlusion, its location, and its tolerance are essential for deciding the therapeutic measures required.

The so-called left "tracheal" bronchus is usually found to be a transposition of the segmental apicoposterior bronchus of the upper left lobe onto the terminal portion of the main trunk. This systematisation abnormality is less common on the left than on the right. In our experience, based on 1,500 bronchographs carried out on adults and children, we have discovered seven left "tracheal" bronchi four of them associated with an obstructive emphysema in the same area. Although this malformation is rarely encountered in the etiologies of interlobular or poly-segmental emphysemas in children, it does however appear that an upper left emphysema has two etiologies which are peculiar to it: segmental bronchial atresia and left "tracheal" bronchi. Why the left "tracheal" bronchi is more often pathogenetic in comparison with the right is open to speculation. As in many other examples of tracheo-bronchial compression for vascular reasons, the close contact between the hyperarterial ectopic bronchi and the left pulmonary artery seems, logically, to be the culprit.

Transposition of the contralateral submaxillary gland to the submental region is proposed as a method for preventing asialia following salivary gland irradiation during radiotherapy for oropharyngeal cancer. Good results were obtained in the majority of cases treated, salivary secretion being conserved, as confirmed by scintigraphy, but the method should be reserved for patients with oropharyngeal cancer without lymph node metastases on the contralateral side.

Renal metastases are tumours which are not rare and which may reveal a primary neoplasm previously undiagnosed. The primary tumours identified in the nine cases reported were six squamous cell carcinomas of the bronchus, one carcinoma of the breast, one carcinoma of the thyroid and one meningioblastoma. Signs at intravenous pyelography are variable, with a marked predominance of appearances of infiltration of the excretory passages by the renal mass, with or without direct involvement of the excretory passages. Angiographic signs appear to be related to the nature of the primary tumour with frank hypovascularisation in the metastases of bronchial tumours and hypervascularisation in those of carcinoma of the thyroid and meningioblastoma. Radiological diagnosis is difficult given the absence of specificity of the urological and anglographic signs. Even histologically the diagnosis may be difficult, particularly in the case of primary bronchial tumours-this being the commonest possibility.

Development of resistance to 9-hydroxyellipticine in Chinese hamster lung cells is associated with a loss of oncogenic potential. In order to determine whether these phenotypical traits are the consequences of the same biochemical modification, or whether they can be dissociated, we have studied their expression in intraspecies hybrids between sensitive and resistant cells. Thirteen hybrid clones were thus examined. At early passages after fusion, they displayed drug sensitivities intermediate to those of parental cells, but relatively close to that of the sensitive parent. Upon injection into nude mice, these clones exhibited variable oncogenic potentials. These variations were independent of the drug sensitivity. After further growth in the presence of 9-hydroxyellipticine, the hybrid cells recovered the drug resistance of the resistant parent. Yet, most of them remained clearly tumorigenic. Finally, the tumors produced by injection of the initial hybrids to nude mice were explanted in culture and then tested again for their drug sensitivity and tumorigenicity. These cells displayed both the tumorigenicity of the sensitive parent and the resistance of the resistant parent. Karyological analyses at the different steps of this work did not reveal any significant change which could be related to modifications of the expression of the characters studied. Our results show that the loss of tumorigenicity and the resistance to 9-hydroxyellipticine can be expressed independently and cannot be accounted for by a unique biochemical alteration.

Extramedullary hematopoiesis is usually secondary to a severe and prolonged reduction in medullary functions, but can be the rare consequence of an extrusion of tissue formed of weakened or fractured bone. The hematopoietic nature of this pseudotumor can be confirmed histologically or, as in this case of Paget's disease, by Indium scintigraphy which can define the specific locations of the hematopoietic marrow.

Described for the first time by Bradshaw in 1846, actinomycosis is a rare, slowly progressing disease associated with the development of anaerobic bacteria of the Actinomyces genus. It predominates in males and is actively encouraged by poor buccal and dental hygiene and by overall decline of defence mechanisms. Thoracic lesions constitute 15 to 20% of the cases and seem to be relatively increasing. Apart from fistulization to the skin, physical examination usually does not show much; only the presence of yellow grains suggests the diagnosis. Radiography is often misleading, suggesting tuberculosis or cancer. Ultrasonography and, chiefly, computerized tomography are the best methods to evaluate the extension of the disease to the pleura, the chest wall and the mediastinum. The final diagnosis is more often supplied by pathological examination than by bacteriology, which is frequently negative. Treatment is facilitated by the fact that Actinomyces is sensitive to antibiotics, notably to penicillin which still is the first choice drug. A well-conducted treatment will give satisfactory results, but sequelae of retractile fibrosis may be disabling.

The authors report in detail the observation of a patient who presented with urticaria and anaphylactic shock during hysterosalpingography. A review of the literature analyzing different accidents and incidents related to this examination, showed the rarity of such reactions. The authors insist, once more, on the necessity of always having the adequate material and drugs for early intensive treatment. These should be at hand whenever investigation with iodine contrast products are used, whatever the route of administration.

Fibrous polyps of the ureter are rarely encountered: only twenty cases have been reported in the literature. They are nothing but pseudo-tumours, for they probably arise through a simple outpouching of the submucosa. The case reported was of a 60-year-old woman presenting with pain of the right iliac fossa associated with gross haematuria. The radiographic appearances were of a 14-cm long polyp, presenting as an intraluminal defect of the right ureter, with smooth edges and separated from the ureteral wall by a thin radio-opaque strip. It was attached by a very small area of insertion. Despite its size, the polyp caused relatively little obstruction. At surgery, the benign nature of this polyp was confirmed, as well as its invariably recurrence-free postoperative course.

Numerous causes exist for disturbances in pulmonary ventilation in the newborn and infant. Amongst the exobronchic causes, those of cardiovascular origin are not rare. The difficulty in radiological diagnosis varies in relation with the anatomo-radiological appearance of the lesions and their aetiology. Ventilation disturbances are not always obvious. Simple techniques (high penetration films, oblique views, films in inspiration and expiration) make possible the topographical localisation of the lesions and the detection of any obstructive factor. These films should also be adequate as far as the aetiological diagnosis is concerned: severe left-right shunt, pulmonary valve agenesis, fibro-elastosis, retrotracheal left pulmonary artery. Obviously, angiocardiography is often necessary to confirm and accurately determine the nature of the "cardiovascular" lesion responsible. Such disturbances of pulmonary ventilation may either reveal or complicate a cardiac or vascular disorder in the newborn or infant. They often present marked therapeutic problems.

Lymphocytes from freshly diagnosed untreated GD patients can be induced to produce in-vitro IgG, and more precisely TSI in the presence of PWM, a T cell dependent polyclonal activator of B cells. TSI were measured from days 8 to 41 of culture, using a functional cAMP production assay, after the deposition of culture supernatants on HTEC. Spontaneous or PWM induced IgG synthesis was optimal on day 28 of culture for GD MNC, with amounts of IgG in PWM stimulated GD culture supernatants twice those found in unstimulated GD MNC. Moreover only PWM stimulated GD MNC produce IgG which induce cAMP production by cultured HTEC, with a significant correlation between in-vitro IgG and cAMP levels.

A series of fractionated partial irradiations which consisted of either 3 gray x 6 times or 3 gray x 4 times, combined with pharmacological immunosuppression (Cyclosporin A: Cs-A) ensure a SLA semidifferent bone marrow graft in the pig. Bone marrow and peripheral blood lymphocytes chimerism was readily detectable. No graft versus host disease (GVHD) symptoms were noticed as long as Cs-A was given at a sufficient dose. However when Cs-A treatment was stopped GVHD or rejection of the graft developed rapidly.

Study on the LSIV has several points of value: It enters into the normal mediastinal outline, forming the aortic "nipple". It may be the site of dilatation, either congenitally or secondary to haemodynamics changes. This venous dilatation should not be confused with a mediastinal tumour. It forms, in the majority of cases, an anastomosis between the superior vena cava and the azgos vein and therefore plays a part in the collateral circulation of caval obstruction syndromes. Its transverse course explains its involvement in the anterior and posterior mediastinal syndromes. Opacification of the LSIV should be part of the study of mediastinal tumours. By virtue of its relations with the left upper lobe, its study should be part of the pre-therapeutic assessment of such lesions.

A systematic evaluation of the anatomic relationships of the segmental bronchi, arteries, and veins of 107 right and 113 left lower lobes was made from CT scans of patients with normal chest radiographs. The classic taxonomies of Boyden and Jackson and Huber were used for nomenclature. Identification of individual structures was based primarily on careful analysis of contiguous CT slices. The frequency of identification of each of the major segmental bronchi and their corresponding arteries was established, and variations in the number and position of arteries were recorded at four transverse levels on the right side and three levels on the left side. The segmental venous tributaries of the inferior pulmonary vein were also identified. Although there is considerable constancy in the anatomy of the lower lobe segments, variation from the dominant pattern occurred in as many as 20% of cases. Sometimes major segmental bronchi were not identified and presumably varied in their origin. The segmental arteries may be single, duplicate, or even triplicate. Within the segments, the arteries generally lie toward the lung periphery relative to their corresponding bronchi, thus being anterior, lateral, or posterior. The segmental veins generally lie central to their bronchi, thus being posterior, medial, or anterior. Knowledge of prevailing patterns and variant appearances of the lower-lobe vascular structures can be helpful in interpreting CT scans. Such knowledge is a prerequisite for the identification of pulmonary nodules in the vicinity of vascular structures and the recognition of intersegmental lymph nodes and aberrant vessels.

We report the case of a 73 year old man presenting with severe hypoxaemia due to an anatomical right to left shunt from a persistent left superior vena cava (VCSG) anastomosing with the left auricle. This was fortuitously discovered while placing a left sub clavicular catheter; the diagnosis of the VCSG draining into the left auricle was confirmed by superior phlebography and CT scanning. The discovery of this shunt after a pulmonary embolus suggested to us that the rise in venous pressure secondary to the embolus led to both clinical symptoms and hypoxaemia from the shunt, which had until then been clinically silent. No surgical treatment was performed.

This study concerns 12 patients who were in hospital for the work-up and treatment of an invasive lympho-epithelial thymoma. The extent of the disease was studied by systemic computed tomographic (CT) scanning of the thorax and abdomen. Three patients out of nine examined presented initially with asymptomatic renal metastasis. Three patients were treated straight away by poly-chemotherapy; the nine others benefitted either from radiotherapy alone (four cases) or from radiotherapy associated with surgery (4 cases) or an isolated surgical exploration (1 case). CT examination was carried out in 11 patients 3 months after the beginning of treatment and 7 times clinically latent metastasis were rediscovered (renal, adrenal, hepatic, thyroid, cerebral and osseous). These 11 patients benefitted secondarily from polychemotherapy. The results confirm the gravity of the condition: only three patients are living and in complete remission with a follow up of 24 to 48 months. The frequency of latent metastasis, detected by CT scanning, during the course of a malignant thymoma justifies the systematic performance of this examination in the work up of the disease extent and therapeutic surveillance in these patients, and leads one to reconsider the place of chemotherapy in the therapeutic strategy of these tumours.

Four cases of non-surgical extraction of iatrogenic vascular foreign bodies are reported, in two of which a basket sound was used, and two others a metallic collar. The percutaneous route was used without denuding the veins. A review of the literature showed 83 cases of non-surgical extraction of vascular foreign bodies, and the methods and materials used are discussed.

Four patients with single or multiple pulmonary arteriovenous aneurysms, including three with Rendu-Osler's disease, were treated by occlusion with metallic spirals of the supplying pedicles during angiography. Results are compared with those of 16 cases treated by the same method and reported in the literature. The technique and its therapeutic indications are discussed based on these 20 cases and a review of documented data concerning 502 other cases with these aneurysms.

One case of Lnger's type mesomelic dwarfism is reported in a 7-day old newborn. Height retardation was severe and concerned essentially the middle segment of limbs. Cubituses and fibulae were hypoplastic. The inferior mandible was intact. No biological change was found. The genetic transmission could be either recessive autosomal (parents double-first cousins), or dominant autosomal with pleiotropic expression (the mother, and an aunt on the father's side presenting with dyschondrosteosis).

Vaso-occlusion of the pulmonary artery is an angiographic technique which involves the voluntary and precise obstruction, temporary or permanent, performed at the end of diagnostic studies or therapeutic studies on one or several branches of the pulmonary artery. The diagnostic indications are touched on briefly at the end of this review because they are older and better known than the therapeutic indications. The latter has developed in less than 10 years and concerns first and foremost two pathologies: hemoptysis and arterio-venous aneurysms of the lung. The erosive pseudo-aneurysm of the pulmonary artery complicating parenchymatous necrosis above all of infections or tumours should be sought in certain situations and treated by vascular occlusion. The pulmonary arteriovenous aneurysms may equally be treated by selective obstruction of their afferent pedicles by metal spirals or detachable balls. This technique, in sacrificing the minimum of pulmonary parenchyma, should be considered according to each case as a possible supplement or replacement for surgery.

The characteristics of gastric secretion following acute gamma exposure (1500 rd) were studied in pigs with a small Pavlov stomach. Spontaneous secretion was practically inhibited when the animals were taken out of the irradiation cell. It slowly recovered in the following hours and its pH, first neutral, turned acid again. However, till the third day, it did not recover normal characteristics. The excretion of sodium ions was much increased. Under histaminic stimulation, the responses of irradiated pigs and controls were much similar. The secretory capacities of the gastric mucosa were retained but without spontaneous manifestations. As a conclusion, the early troubles following overexposure must be the consequences of regulation disorders rather than of the direct action of radiation on the stomach.

In the 4 studied patients presenting with an Halasz's syndrome, the disease was complicated since the neonatal period by pulmonary arterial hypertension and heart failure. Three out of the 4 infants rapidly died, one after pneumonectomy. The fourth is surviving and benefitted solely from medical cardiotonic treatment. The pathogenesis of early pulmonary arterial hypertension in Halasz's syndrome is complex. The possibly associated cardiac malformations, the persistance of fetal obstructive hypertension due to the increase of the flow in the left pulmonary artery, the left to right shunt induced by the abnormal venous return and predominantly by the systemic blood supply to the right lung, are responsible, at various degrees, for pulmonary hypertension. Among surgical procedures to be proposed, the simple ligation of abnormal arteries which take their origin from the aorta seems to be preferable to pneumonectomy.

A radiological opacity of the posterior and inferior mediastinum should evoke a lesion of vascular origin. The venous nature of the mass can be easily confirmed by morphological changes apparent during the respiratory cycle and changes in position. Investigations to establish etiology of this venous ectasia arising from the azygos vein require more extensive radiological examinations, and computed tomography may be of value. Portal hypertension is one cause of increased venous blood flow in the azygos systems, and should be systematically considered.