| 1. |
- Norgren, Lars, et al.
(författare)
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Immune response to collagen impregnated Dacron double velour grafts for aortic and aorto-femoral reconstructions
- 1990
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Ingår i: European Journal of Vascular Surgery. - 0950-821X. ; 4:4, s. 379-384
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Tidskriftsartikel (refereegranskat)abstract
- This study presents 20 patients, randomised to receive either a collagen-treated or an ordinary Dacron graft for aortic reconstructions, and the results of a skin-prick test, blood parameters and ELISA for anti-collagen antibodies as well as NMR pictures during a 6 week follow-up period. Forty per cent (4/11) of those receiving a collagen impregnated graft had a significantly increased titre of antibodies and NMR revealed in two out of 11 patients either a slightly increased amount of fluid or fibrosis around the graft, both collagen impregnated. No differences were found between the graft groups concerning body temperature and leucocyte or platelet counts. The skin-prick test for collagen was negative in all cases.
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| 2. |
- Maeder, Philippe P, et al.
(författare)
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Colloid cysts of the third ventricle: correlation of MR and CT findings with histology and chemical analysis
- 1990
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Ingår i: AJNR. - 1936-959X. ; 155:1, s. 135-141
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Tidskriftsartikel (refereegranskat)abstract
- Eight patients with colloid cysts of the third ventricle were examined with CT and MR. In six, surgical resection was performed and the material was subjected to histologic evaluation; the concentrations of trace elements were determined by particle-induced X-ray emission. Stereotaxic aspiration was performed in two. The investigation showed that colloid cysts are often iso- or hypodense relative to brain on CT (5/8), but sometimes have a center of increased density. Increased density did not correlate with increased concentration of calcium or other metals but did not correlate with high cholesterol content. Colloid cysts appear more heterogeneous on MR (6/8) than on CT (3/8), despite a homogeneous appearance at histology. High signal on short TR/TE sequences is correlated with a high cholesterol content. A marked shortening of the T2 relaxation time is often noticed in the central part of the cyst. Analysis of trace elements showed that this phenomenon is not related to the presence of metals with paramagnetic effects. Our analysis of the contents of colloid cysts does not support the theory that differing metallic concentrations are responsible for differences in MR signal intensity or CT density. We did find that increased CT density and high MR signal correlated with high cholesterol content.
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| 3. |
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| 4. |
- Sandberg Wollheim, Magnhild, et al.
(författare)
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A long-term prospective study of optic neuritis: evaluation of risk factors
- 1990
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 27:4, s. 386-393
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Tidskriftsartikel (refereegranskat)abstract
- Eighty-six patients with monosymptomatic optic neuritis of unknown cause were followed prospectively for a median period of 12.9 years. At onset, cerebrospinal fluid (CSF) pleocytosis was present in 46 patients (53%) but oligoclonal immunoglobulin in only 40 (47%) of the patients. The human leukocyte antigen (HLA)-DR2 was present in 45 (52%). Clinically definite multiple sclerosis (MS) was established in 33 patients. Actuarial analysis showed that the cumulative probability of developing MS within 15 years was 45%. Three risk factors were identified: low age and abnormal CSF at onset, and early recurrence of optic neuritis. Female gender, onset in the winter season, and the presence of HLA-DR2 antigen increased the risk for MS, but not significantly. Magnetic resonance imaging detected bilateral discrete white matter lesions, similar to those in MS, in 11 of 25 patients, 7 to 18 years after the isolated attack of optic neuritis. Nine were among the 13 with abnormal CSF and only 2 belonged to the group of 12 with normal CSF (p = 0.01). Normal CSF at the onset of optic neuritis conferred better prognosis but did not preclude the development of MS.
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| 5. |
- Brådvik, Björn, et al.
(författare)
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Do single right hemisphere infarcts or transient ischaemic attacks result in aprosody?
- 1990
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Ingår i: Acta Neurologica Scandinavica. - 1600-0404. ; 81:1, s. 61-70
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Tidskriftsartikel (refereegranskat)abstract
- The ability to perceive and express prosodic qualities of speech was tested in 21 patients with a single focal ischaemic disturbance of the right hemisphere, 14 patients having an infarct and 7 transient ischaemic attacks, and in 21 age-matched normal controls. All patients were predominantly right-handed. None showed signs of aphasia. Pure tone audiometry showed acceptable hearing for speech. The cerebral lesions were assessed by clinical neurologic examination, and by CT, EEG and measurement of regional cerebral blood flow (rCBF) using intravenous 133-xenon. The prosodia test included items testing: the ability to perceive accentual and emotional qualities of speech, and the ability to express and vary such qualities. The test did not discriminate between the patients and the controls, although some patients had large right-sided lesions. This negative finding indicates that aprosody in patients with brain lesions appears more difficult to detect than has previously been assumed. Highly sensitive tests are most likely required.
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| 6. |
- Annertz, Mårten, et al.
(författare)
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Isthmic lumbar spondylolisthesis with sciatica. MR imaging vs myelography
- 1990
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Ingår i: Acta Radiologica. - 1600-0455. ; 31:5, s. 449-453
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Tidskriftsartikel (refereegranskat)abstract
- Seventeen patients with sciatica and isthmic lumbar spondylolisthesis were studied with magnetic resonance (MR) imaging. In 13, myelography was also performed: 5 had dural sac deformation and root sleeve shortening, 2 had deformation with unilateral root sleeve shortening, one had bilateral root sleeve shortening only, and one had sac deformation only. In 4, myelography was normal. On sagittal MR examinations the neural foramen had an altered shape bilaterally with the long axis horizontal in all cases. In addition to altered shape the following was found in the 33 foramina evaluated. I: normal nerve (n = 8); II: compressed nerve (n = 16); III: disappearance of fat, nerve not possible to identify (n = 9). In patients with unilateral sciatica, the degree of foraminal stenosis correlated well with the side of symptoms. Coronal views showed the course of the nerve and pedicular kinking. Eight patients underwent decompressive surgery which revealed nerve compression by hypertrophic fibrous tissue and pedicular kinking, which correlated well with the findings on MR. Since the site of nerve compression often was peripheral to the root sleeves, myelography did not give complete information.
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| 7. |
- Björkengren, Ann G, et al.
(författare)
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MR imaging of the knee in acute rheumatoid arthritis: synovial uptake of gadolinium-DOTA
- 1990
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Ingår i: American Journal of Roentgenology: diagnostic imaging and related sciences. - 1546-3141. ; 155:2, s. 329-332
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Tidskriftsartikel (refereegranskat)abstract
- In patients with rheumatoid arthritis, the presence of acute synovial inflammation is an indication of the activity of the disease. It is an important finding because it often influences therapeutic decisions. However, acute synovitis may be difficult to detect by clinical examination, especially if a joint effusion also is present. As gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) can be expected to accumulate in areas of acute inflammation, we studied the value of Gd-DOTA-enhanced MR to determine the presence of acute synovitis. Nine patients with current knee symptoms underwent MR examination of the knee. Short and long TR/TE MR images were obtained with a 0.3-T magnet before and immediately after IV administration of Gd-DOTA. A 15-min delayed short TR/TE image also was obtained. Of eight patients with moderate to severe clinical evidence of acute synovitis, six had marked increase and two had moderate increase in signal intensity from synovial tissue on the short TR/TE image obtained immediately after administration of contrast material. In the ninth patient, who had minimal synovitis clinically, the signal from the synovium did not change after administration of contrast material. No difference was seen between the enhancement pattern on the immediate and the 15-min delayed images. These results suggest that Gd-DOTA is taken up by inflamed synovium and that Gd-DOTA-enhanced MR scans may be useful in detecting acute synovitis in patients with rheumatoid arthritis.
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| 8. |
- Holtås, Stig, et al.
(författare)
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Signal alterations, artifacts and image distortion induced by a superparamagnetic contrast medium. A phantom study in a 0.3 tesla MR system
- 1990
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Ingår i: Acta Radiologica. - 1600-0455. ; 31:2, s. 213-216
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Tidskriftsartikel (refereegranskat)abstract
- In a phantom study using a 0.3 tesla MR system the signal alterations, artifacts and image distortion induced by a bowel contrast medium containing superparamagnetic magnetite particles were evaluated. A concentration of 20 mg iron/l was most useful because it caused a significant signal reduction without disturbing artifacts and image distortion. The signal reduction was most pronounced on long TR/TE spin echo sequences. The appearance and distribution of artifacts are related to the direction of the static magnetic field and frequency encoding gradient. The size of artifacts is related to the concentration of the contrast medium and the band width used.
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