| 1. |
- Annertz, Mårten, et al.
(författare)
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Serial MRI in the early postoperative period after lumbar discectomy
- 1995
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Ingår i: Neuroradiology. - 1432-1920. ; 37:3, s. 177-182
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to determine MRI findings in patients successfully operated upon for lumbar disc herniation. We investigated 20 patients with a successful outcome after L4-5 or L5-S1 disc operations clinically and with MRI preoperatively, and at 5 days, 6 weeks, and 4 months after surgery. Postoperatively, T1- and T2-weighted images were obtained. At 4 months gadolinium-enhanced images were added. Pronounced intraspinal MRI changes were seen during follow-up. Deformation of the dural sac was seen in 13 patients preoperatively, in 19 at 5 days after operation, in 15 at 6 weeks, and in 12 at 4 months. Nerve root involvement was seen in all cases both preoperatively and at 5 days after operation, in 17 at 6 weeks, and in 15 at 4 months. No correlation between symptoms or the straight leg raising test and the size or nature of the abnormal tissue in the spinal canal postoperatively could be demonstrated. It was concluded that early postoperative MRI after lumbar discectomy must be interpreted carefully, and that oedema and scar formation are probable reasons for difficulties in interpretation.
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| 2. |
- Autti, Taina, et al.
(författare)
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MRI of neuronal ceroid lipofuscinosis : II. Postmortem MRI and histopathological study of the brain in 16 cases of neuronal ceroid lipofuscinosis of juvenile or late infantile type
- 1997
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 39:5, s. 371-7
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Tidskriftsartikel (refereegranskat)abstract
- Postmortem MRI was carried out on the formalin-fixed brains of 14 patients with juvenile (JNCL) and two with late infantile neuronal ceroid lipofuscinosis, one of variant and the other of classical type. Two patients with JNCL had also undergone MRI during life. After MRI, specimens for histopathological analysis were taken from standard areas of the cerebral cortex, deep nuclei and white matter. The signal intensity of the periventricular white matter was usually higher than that of the peripheral white matter, a finding which correlated with the severe periventricular loss of myelin and gliosis observed histologically. The signal intensity was usually lower in the thalamus than in the putamen; in some patients the signal intensity of the thalamus was equal to or even lower than that of the white matter. However, myelin loss, gliosis, the storage process or neuronal loss in the thalamus did not correlate with the MRI findings. Since in one patient with JNCL the ante- and postmortem MRI did not differ basically, it appears probable that the periventricular changes detected in vivo on MRI are due to the severe loss of myelin and gliosis observed in this study. However, changes resulting from the fixation process must be considered, when postmortem and in vivo MRI are correlated.
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| 3. |
- Autti, Taina, et al.
(författare)
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MRI of neuronal ceroid lipofuscinosis : I. Cranial MRI of 30 patients with juvenile neuronal lipofuscinosis
- 1996
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Ingår i: Neuroradiology. - 0028-3940 .- 1432-1920. ; 38:5, s. 476-82
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Tidskriftsartikel (refereegranskat)abstract
- We studied 30 patients with juvenile neuronal ceroid lipofuscinosis (JNCL). The patients (aged 6-25 years) and 43 age-matched healthy volunteers underwent MRI. After visual assessment, the signal intensity was measured on T2-weighted images in numerous locations. The thickness of the cortex and corpus callosum and the dimensions of the brain stem were measured. Mild to moderate cerebral atrophy was found in 14 of 30 patients, most of them over 14 years of age; 5 older patients had mild to moderate cerebellar atrophy. There was reduction in the size of the corpus callosum and brain stem. The thalamus, caudate nucleus and putamen appeared to give low signal in patients from the ages of 7, 11 and 11 years, respectively. In contrast, the signal intensity measured from the thalamus in these patients showed only a slight (insignificant) decrease compared with controls. The most significant alteration, an increase in measured signal intensity, was found in the white matter (P < 0.0001), even in the youngest patients. The MRI findings correlated significantly with decreased intelligence, speech disturbances and motor problems. Although MRI findings in JNCL do not appear very specific and the visual changes develop relatively late, the absence of pathological MRI findings in the very early stage of the disease may play a part in differential diagnosis of the different types of NCL. Furthermore, the MRI findings may be used in assessing severity and prognosis, particularly in young patients.
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| 4. |
- Luoma, Katariina, et al.
(författare)
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Suitability of cerebrospinal fluid for a signal intensity reference on MRI : Evaluation of signal intensity variations in the lumbosacral dural sac
- 1997
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 39:10, s. 728-32
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Tidskriftsartikel (refereegranskat)abstract
- The suitability of the cerebrospinal fluid (CSF) in the lumbosacral dural sac as an internal signal-intensity reference was studied on magnetic resonance imaging (MRI) of the lumbar spine using a surface coil and motion artefact suppression technique. A signal-intensity reference is needed when signal is compared between images, studies or subjects. Homogeneity of the CSF was estimated visually on T2-weighted images of 60 subjects at 1.5 T and of another 60 subjects at 0.1 T. Spines with a severely narrowed dural sac or marked scoliosis were excluded from the study to avoid partial volume effect. CSF was homogeneous in 82% and 73% of the examinations at 1.5 T and 0.1 T, respectively. The type and location of the local inhomogeneities did not relate to local narrowings of the dural sac. The signal intensity of CSF was measured in 108 examinations at 0.1 T after correcting the spatially-dependent signal-intensity non-uniformities with a phantom-based method. The signal-intensity difference between the CSF in the upper and lower lumbar dural sac was less than 10% in 73% of the examinations. The CSF in the lumbosacral dural sac can be a useful signal-intensity reference for estimation of the signal of the adjacent structures in patients without severe narrowing of the dural sac or marked scoliosis. It may contribute to assessing spinal disease processes.
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| 5. |
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| 6. |
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| 7. |
- Salonen, O., et al.
(författare)
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MRI of the brain in neurologically healthy middle-aged and elderly individuals
- 1997
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 39:8, s. 537-45
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Tidskriftsartikel (refereegranskat)abstract
- Our purpose was to document the MRI appearances of the brain in healthy middle-aged to elderly subjects. T2- and proton density-weighted axial slices were obtained in 61 volunteers, 30-86 years of age. After visual inspection, signal intensities of brain structures were measured on T2-weighted images. Age-related changes became increasingly apparent after age 50. The main findings were that signal intensity of the white matter increased concomitantly with widening of the cerebrospinal fluid spaces; that basal ganglia remained stable; that high-signal foci in white matter increased in number and size after the age of 50 years; that periventricular high-signal foci were constant after the age of 65 years. Our visual impression of a decrease in signal intensity of the central grey matter with age seems to be mistaken. Pathological processes should be suspected if periventricular foci are found in middle-aged or young subjects.
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| 8. |
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| 9. |
- Sundgren, P C, et al.
(författare)
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MRI and proton spectroscopy in a child with Rasmussen's encephalitis. Case report
- 1999
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 41:12, s. 935-940
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Tidskriftsartikel (refereegranskat)abstract
- The greater sensitivity of magnetic resonance spectroscopy (MRS) compared with MRI to brain abnormalities in Rasmussen's encephalitis was demonstrated in a 3-year-old boy. The patient, with symptoms, signs and morphological findings consistent with Rasmussen's encephalitis, was followed with MRI and MRS over 30 months. That metabolic changes can be disclosed by MRS before the development of symptoms or signs was demonstrated as pathological spectra were found not only in the diseased left hemisphere but also in the morphologically normal right hemisphere before any neurological disturbance of that side.
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| 10. |
- Sundgren, P, et al.
(författare)
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Paragangliomas of the spinal canal
- 1999
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 41:10, s. 788-794
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Tidskriftsartikel (refereegranskat)abstract
- We report the clinical MRI and histopathological features of five consecutive cases of spinal paraganglioma. Three intradural tumours were found in the typical location (two at the L4, one at the S2 level); one intradural extramedullary tumour arose at an unusual level, from the ventral C2 root, and one extradural tumour growing along the L5 nerve root sheath had an aggressive growth pattern with early, local paraspinal recurrence and, eventually, intradural metastatic spread. This type of growth pattern has not been described previously. Paragangliomas of the spinal canal are more common than previously thought and can be located anywhere along the spine, although the lumbosacral level is the most common. Their appearance on MRI can not distinguish them from other tumours in the spinal canal. Even though paragangliomas in general are benign and slowly growing their growth pattern can vary and be more aggressive, to the point of metastatic spread.
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