PubMed Health⌕ Search

Biomedical subjects

E Svedström

Publications and source records attributed to E Svedström.

13 recordsLinked to original sources
PubMed1992

The size and contractility of the gallbladder in infants.

The size of the gallbladder and the common bile duct as well as the contractility of the gallbladder were measured in infants under the age of 1 year. A total of 43 healthy infants were studied at their routine visit to the well-baby clinic at the ages of 6 weeks, 4 months, 8 months or 12 months. Gallbladder size was measured before and after a test meal. Fasting gallbladder size increased with the age of the infants. However, when the size was corrected for the infant's weight, no age-related variation was found. The contraction index (CI) was determined as a percentage decrement of planimetric gallbladder size from the initial size. The mean CI declined with age from 75% (+/- 27%) (mean (+/- SD)) at the age of 6 weeks to 24% (+/- 28%) at the age of 12 months. Overall CI varied from -44% to 100%. An increase in gallbladder size after the test meal was observed in 4 infants. Gallbladder volumes were also calculated, but two-dimensional measurements were regarded as more accurate in infants. A large variation was found in the size as well as in the contractility of the gallbladder in infants less than 1 year of age.

Common Bile Duct↗
PubMed1992

Information compression in dynamic radiological studies.

The large volumes of digital image data from radiological examinations demand further research and practical solutions in image compression before PACS solutions in large radiological departments are plausible. But another type of compression of image information is also possible, which has, in fact, been somewhat utilized already in analog form, but which has far better possibilities in the digital world. The number of essential images in dynamic X-ray, nuclear medicine, examinations etc. can be greatly reduced. These examinations producing image series are reviewed in terms of compression of information. 3-D displays are very useful in slice imaging, because they provide a means to see easier inside the human body than a number of slice images side by side. We also provide a new method, dynamic pulmonary imaging with digital fluoroscopy, as an example of the digital possibilities to compress a number of images into parametric images, numbers, histograms and curves. These processes also have other positive consequences information is transformed into a more easily perceptible form.

Diagnostic Imaging↗
PubMed1991

Dynamic imaging of pulmonary ventilation. Description of a novel digital fluoroscopic system.

A new fluoroscopic imaging device consisting of an AT-microcomputer and a digital image memory unit has been used in experimental and clinical ventilation studies during a 2-year period. Digital images with 256 shades of gray were collected during one to 3 ventilation cycles at the rate of 6 to 25 images/s and stored on an optical laser disc. Both subtracted time interval difference (TID-) images and images relative, for example, to the mean image of the cycle (REL-images) were produced. The series of images could also be evaluated dynamically using animation sequences or analyzed using region of interest calculations. The method gave dynamic information with adequate spatial resolution and was easy to use in clinical practice. The radiation dose was kept low due to the high kilovoltage and heavy beam filtration technique. In experimental studies the software enabled flexible measurements of physiological pulmonary parameters.

Animals↗
PubMed1989

How accurate is chest radiography in the diagnosis of tracheobronchial foreign bodies in children?

The radiographic and endoscopic findings of 83 consecutive patients with suspected foreign body (FB) inhalation into the tracheobronchial tree were compared and the accuracy of chest radiography was estimated. Typical radiologic signs of FB aspiration, such as localized air trapping, atelectasis and infection occurred on radiographs of patients with and without FB. Twenty-four percent of patients with endoscopically verified FB had no abnormalities on chest radiography. In an analysis of radiographs of 83 consecutive patients, in which the prevalence of FB aspiration was 41%, the diagnostic accuracy was 67%, sensitivity 68% and specificity 67%. Plain film radiology alone is not a sufficiently sensitive nor specific method for the diagnosis of FB aspiration.

Bronchi↗
PubMed1989

Acute bronchial obstruction: an experimental rabbit model study.

An animal model of bronchial obstruction was developed to radiologically follow up the development of postobstructive pulmonary changes. The study material consisted of 21 healthy rabbits (New Zealand White) of which 5 animals served as controls. A piece of Surgicel (Ethicon) shaped as a 3 x 3 x 10 mm cylinder was placed endobronchially through a 3-mm bronchoscope. The animals were followed up radiologically and endoscopically during the first 30 min after which the bronchoscope was extracted. Sixteen animals were followed up for at least 4 h and, in 4 animals, the foreign body (FB) was removed after 24 h. During follow-up, total collapse of the lung was observed after 1-4 h in all but 2 animals with obstruction of the main brochus. After extraction of the FB, atelectasis of the respective lung had resolved within 24 h. The animal model developed in the present study seems to be rather physiological resembling the development of pulmonary atelectasis in pediatric patients.

Airway Obstruction↗
PubMed1989

Disc degeneration and lumbar instability. Magnetic resonance examination of 16 patients.

Flexion and extension radiographs of 75 young males with low back pain disclosed abnormal segmental motion of the lumbar spine in 16 patients with translational movements in 20 intervertebral segments. These 16 patients were further investigated by magnetic resonance imaging to assess disc degeneration in the unstable segments. On T2-weighted images of the 20 segments, the disc was normal in 13 and degenerated in only 7 patients. Thus, the initial factor in lumbar instability in young patients with low back pain is not always degeneration of the disc.

Adult↗
PubMed1989

Tracheobronchial foreign bodies. A persistent problem in pediatric patients.

Extraction of a foreign body from the tracheobronchial tree was accomplished for 83 children. The mean age was 1 year 9 months for the 27 girls and 3 years 1 month for the 56 boys; 46 children (55%) were younger than 2 years of age. Sixteen (19%) of the foreign bodies were radiopaque, and 35 (42%) were either verified or suspected radiologically before endoscopy. Forty-one foreign bodies (49%) were situated in the right bronchial tree. Extraction was successful in 81 children (98%) and was performed on 50 children (60%) during the first 24 hours. Twenty-five (30%) of the foreign bodies were peanuts. Three children experienced a residual foreign body, without serious complications. We believe that an open tube bronchoscopy should be performed whenever abnormal stridor or cough is observed in a healthy child and when appropriate antibiotic therapy is unsuccessful.

Bronchi↗
PubMed1979

Adherence of multiple sclerosis lymphocytes to measles infected cells.

Adherence of lymphocytes from multiple sclerosis (MS) patients and control subjects to cells persistently infected by measles and control cells was studied. No statistically significant difference between MS patients and controls could be found in this test. Lymphocytes adhered more readily to cells infected by measles than to control cells. The cell to cell contacts are made by the tips of the microvillii of the Lu cells.

Antigens, Viral↗
PubMedDate not supplied

Radiology in the Nordic Countries.

NEMT, Nordic Evaluation of Medical Technology, conducted a study in 1988-89 on the use and diffusion of diagnostic radiology technologies in Denmark, Finland, Iceland, Norway and Sweden, i.e. the Nordic Countries. The study analysed the responses to a questionnaire sent to all Nordic radiology departments. Our findings show a variation from about 500 to nearly 900 radiology examinations per 1000 inhabitants among the Nordic Countries. Some of the differences are explained by unique structural factors of the health care system in each country, even if they all provide comparable public health services. Other differences are explained by variations in medical practice, accessibility to new imaging modalities, and replacement policies. This paper summarizes the results of the study.

Diffusion of Innovation↗
PubMedDate not supplied

Radiologic diagnosis of renal colic: the role of plain films, excretory urography and sonography.

The accuracy of plain films, excretory urography and ultrasound for the clinical work-up of renal colic for detecting urinary calculi was evaluated prospectively in 49 patients. Excretory urography was the most sensitive and specific test. Plain films and sonography each had a sensitivity of approximately 60%, but combined yielded a sensitivity of 80%; specificity did not improve. A diagnostic algorithm where sonography was performed first followed by an excretory urography in case of a negative sonography was highly sensitive (93%) and rather specific (79%). This algorithm appears also to have a good cost-benefit rate.

Acute Disease↗
PubMedDate not supplied

Dynamic pulmonary imaging: performance properties of a digital fluoroscopy system.

The physical characteristics of dynamic pulmonary imaging with digital fluoroscopy, which differ from those in DSA equipment, have been determined. The spectral distributions and mean energies were calculated and corresponding exposures with varying high voltage and copper filtration (60-100 kVp, 0-2.83 mm Cu) were measured. The utilization of 90-100 kVp with a filter consisting of 1.39 mm Cu and 3 mm Al minimized disturbing skeletal artifacts and reduced the radiation exposure by a factor of approximately 5 in comparison with imaging at 60 kVp without copper filtration. Simultaneously, the measured signal decreased by about 25%. The mean energy of this spectrum exceeded that of 140 kVp chest imaging. The dynamic pulmonary imaging method produces logarithmically transformed x-ray transmittance values linearly related (r = -0.999) to water thickness between 7-10.5 cm, which is equivalent to the normal range of the chest in pediatric patients. A good linear correlation (r = 0.933,N = 92) was obtained when the change in transmitted radiation was compared with tidal volume measured in a rabbit model using a pneumotachometer. The results indicate that the method is applicable for quantitative measurements of pulmonary ventilation. Changes in tidal ventilation can be measured with this noninvasive x-ray imaging technique.

Animals↗
PubMedDate not supplied

Ultrasonic guidance of lumbar sympathetic and celiac plexus block: a new technique.

BACKGROUND AND OBJECTIVES: Lumbar sympathetic and celiac plexus block are widely used to treat chronic pain of diverse etiologies. To avoid complications and confirm the correct position of the needle, fluoroscopy and computed tomography have been used to follow the procedure visually. Our objective was to examine whether ultrasonography could be used instead of these techniques. METHODS: Forty-eight neurolytic sympathectomies were performed using ultrasonographic guidance. The results were evaluated clinically and by color-doppler technique as applicable. RESULTS: This new technique was shown to provide excellent results in ensuring the safe passage of the needle and documenting the correct spread of neurolytic agent (phenol-glycerol). The correct position of the needle was achieved on the first attempt in all cases. CONCLUSIONS: The benefits of this technique are that it is inexpensive, there is no radiation, and the anatomy involved can be thoroughly examined before and after the procedure. Phenolglycerol may be the best choice as the neurolytic agent because it provides excellent contrast.

Autonomic Nerve Block↗