Acta radiologica: diagnosis最新文献

The adult respiratory distress syndrome was induced in pigs (n = 11) by a continuous infusion of E. coli endotoxin in order to evaluate the use of radiographic videodensitometry and chest radiography for assessment of pulmonary circulation and pulmonary oedema. A further aim was to determine the effect of an ionic contrast medium, Urografin 60%, on extravascular lung water (EVLW). The infusion resulted in a decline in arterial oxygen tension. Mean pulmonary arterial pressure increased, and cardiac output decreased, resulting in a marked rise in pulmonary vascular resistance. EVLW increased moderately. The corresponding variables in control animals (saline infusion; n = 5) changed very little. Good correlations were found (r = 0.87-1.0) between absolute flows as measured by the thermodilution technique and relative flows as determined by videodensitometry in animals with pulmonary damage. In the endotoxin group there was a significant correlation (r = 0.75) between the change in EVLW from baseline to the final measurement (at 6 hours) and the corresponding change in radiographic density. Radiographic signs of pulmonary damage were sparse. Only 3 of 11 animals displayed increased radiographic density of the lung parenchyma indicative of pulmonary oedema. Pleural effusion developed in 4 animals. Injection of Urografin 60%, 1 ml X kg-1, caused a slight but significant decrease in EVLW. We propose that at this concentration and dosage the contrast medium acts mainly as an osmotic diuretic.

A method for the diagnosis of disc herniation and nerve root compression in the lower lumbar and upper sacral spine is presented. Computed tomography of the spine was carried out after injection of a positive contrast medium into the epidural space. Preliminary results indicate a high diagnostic accuracy.

Venous malformations in the face and neck have a characteristic clinical picture. They consist of a cluster of venous cavities with a very slow blood flow and are normally not demonstrated at conventional external carotid angiography. Previous methods of treatment have been of limited value but recently good results have been reported with instillation of fibrosing agents as Ethibloc and ethanol. Five patients with facial venous malformations were referred for therapy. External carotid angiography was performed and was almost normal in all patients. Superselective catheterization demonstrated the malformation clearly in 2 patients only. Direct puncture phlebography confirmed the diagnosis by demonstrating the venous cavities in all the patients. This procedure was concluded by instillation of absolute ethanol into the cavities. There was a marked reduction in size of the malformation but it was not permanently completely occluded. The treatment was repeated in 4 patients with further reduction of the size, but small remnants are still left. Serious complications with extensive soft tissue necrosis occurred in one patient probably as a result of extravasation of ethanol. The necrosis later healed well after surgical treatment. Instillation of ethanol under radiologic control seems to be a promising way of treatment of venous malformations.

In a radiographic examination using a water-soluble contrast medium this may form a layer beneath a body fluid. Between the two liquids a zone consisting of a mixture of the two liquids then forms through diffusion. This diffusion layer produces some characteristic features in the radiographic image, an analysis of which was the purpose of the model experiments performed in this investigation. In this analysis of the layering phenomenon the radiographed objects were cylindrical tubes of methyl methacrylate partly filled with water. In some cases a rod was placed concentrically in the tube. Contrast medium was layered below the water. Radiographs were produced with the tube either vertical or inclined, and with either a horizontal or a vertical projection. In the image the layer of contrast medium was visualized as a light field, and the water layer as an overlying relatively dark field. The diffusion layer was visualized as a transitional zone--the diffusion field. Distinct boundaries and Mach lines observed in the bottom field were produced by the interface between the contrast medium and the solid wall where it was touched by the roentgen rays. These boundaries continued into the diffusion field where they gradually became less visible and eventually disappeared. The upper and lower boundaries of the diffusion field were diffuse and associated with dark and light Mach bands, respectively. The upper boundary appeared to be convex upwards. In the case of the inclined model and a vertical beam the diffusion field was elliptical, with a still more diffuse transition to the fields above and below than in the case of the vertical model and a horizontal beam.(ABSTRACT TRUNCATED AT 250 WORDS)

The proton relaxation times T1 and T2 of plasma and clotted blood stored in test tubes were studied at a magnetic field of 0.225 T as a function of time. A satisfactory description of both relaxation processes could be made by two exponential components for the plasma and three components for the clot. The major relaxation component in plasma was the slower one, the T1 of which shortened from about 1 300 ms to about 400 ms between the second and sixth day of storage. The plasma T2 behaved similarly, but shortened less. The shortening of the relaxation time in plasma surrounding the experimental thrombus was concluded to be due to a number of factors, including the release of hemoglobin into plasma, the conversion of hemoglobin to methemoglobin, a concomitant change in the configuration of hemoglobin molecules, and an increased concentration of iron in plasma. The shortening of the relaxation time may also occur in an in vivo hematoma and change the magnetic resonance appearance of a hematoma with time.

The anatomic variations of the semicircular canals were investigated in a series of 95 plastic temporal bone preparations. The results showed a wider range of variability than has been assumed previously. An intraindividual correlation was found between the sizes of the superior and lateral semicircular canals. Observations indicate why a semicircular canal is not invariably delineated on one tomographic plane despite correct positioning for its optimum reproduction.

Aorto-femoral angiography carried out in 839 patients revealed that 139 males and females had uni- or bilateral occlusion of the common or external iliac arteries. Pelvic or lumbar/intercostal arteries served as collaterals in 786 patients. In the remaining 53 patients the collateral blood supply originated from the thoracic arteries. Among the 53 patients, only 7 were females. A chi 2-test revealed the difference to be significant (p less than 0.0005), indicating a sex-linked difference, a male preponderance, in the development of collateral circulation of thoracic origin.

A fistula between the left pyriform sinus and the left thyroid gland region has been reported to be the route of infection in several cases of acute suppurative thyroiditis. Another four patients with acute suppurative thyroiditis have been encountered in whom a fistula from the hypopharynx was demonstrated radiographically. In three patients the fistulous tract was situated on the right side, and in one of these cases the fistula originated from the epiglottic vallecula rather than the pyriform sinus. These locations have not been reported earlier. Endoscopic examination was valuable for confirming the diagnosis.

Eighty-five patients subjected to routine heart catheterization were examined with duplex scanning of the inferior vena cava. Adequate Doppler recordings and a right ventricular angiography were obtained in 79 of them. Tricuspid insufficiency was found to be present in 34 patients at angiography and in 24 at duplex examination. No false positive Doppler diagnoses of tricuspid insufficiency occurred. The possibility of false positive angiographic diagnoses is discussed. A high correlation was found between percentage reversed flow in the inferior vena cava during ventricular systole and degree of angiographic tricuspid insufficiency. It is concluded that duplex scanning of the inferior vena cava seems to be a good alternative to angiography in the diagnosis and quantification of tricuspid insufficiency.

The non-ionic contrast medium metrizamide (370 mg I/ml) was injected into the cisterna magna of rabbits at 2 dose levels (0.1 ml/kg and 0.5 ml/kg) to investigate whether visually evaluated EEG can detect neurotoxicity at a lower dose level than a method based on observation and ranking of signs of excitation and depression in animal behaviour. Half of the metrizamide injections were made without anaesthesia, whereas the remaining injections were made during a short alphadolon/alphaxolon anaesthesia. EEG and animal behaviour were followed for 24 h after the injection of metrizamide. At the low 'clinical' dose, EEG could not detect statistically significant neurotoxicity, neither in anaesthetized nor in non-anaesthetized rabbits. Observation of animal behaviour, however, could detect statistically significant signs of depression in animals that had been anaesthetized. At the high dose level, both methods could detect significantly more serious symptoms of neurotoxicity than at the low dose level.