| 1. |
- Hägerström, Douglas, et al.
(författare)
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A new automated method for analysis of rCBF-SPECT images based on the active-shape algorithm: Normal values
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - 1475-0961 .- 1475-097X. ; 32, s. 114-119
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Tidskriftsartikel (refereegranskat)abstract
- Most nuclear medicine clinicians use only visual assessment when interpreting regional cerebral blood flow (rCBF) from single-photon emission computed tomography (SPECT) images in clinical practice. The aims of this study were to develop a new, easy to use, automated method for quantification of rCBF-SPECT and to create normal values by using the method on a normal population. We developed a 3-dimensional method based on a brain-shaped model and the active-shape algorithm. The method defines the surface shape of the brain and then projects the maximum counts 0-1·5cm deep for designated surface points. These surface projection values are divided into cortical regions representing the different lobes and presented relative to the whole cortex, cerebellum or cerebellar maximum.99mTc-hexa methyl propylene amine oxime (HMPAO) SPECT was performed on 30 healthy volunteers with a mean age of 74years (range 64-98). The ability of the active-shape algorithm to define the shape of the brain was satisfactory when visually scrutinized. The results of the quantification show rCBF values in the frontal, temporal and parietal lobes of 87-88% using cerebellum as the reference. There were no significant differences in normal rCBF values between male and female subjects and only a weak relation between rCBF and age. In conclusion, our new automated method was able to quantify rCBF-SPECT images and create normal values in ranges as expected. Further studies are needed to assess the clinical value of this method and the normal values. © 2011 The Authors. Clinical Physiology and Functional Imaging © 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine.
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| 2. |
- Reinstrup, Peter, et al.
(författare)
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Regional cerebral metabolic rate (positron emission tomography) during inhalation of nitrous oxide 50% in humans
- 2008
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Ingår i: British Journal of Anaesthesia. - : Elsevier BV. - 1471-6771 .- 0007-0912. ; 100:1, s. 66-71
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent studies in man have shown that cerebral blood flow increases during inhalation of nitrous oxide (N2O), a finding which is believed to be a result of an increased cerebral metabolic rate (CMR). However, this has not previously been evaluated in man. METHODS: Regional CMR(glu) (rCMR(glu)) was measured three dimensionally with positron emission tomography (PET) after injection of 2-(18F)fluoro-2-deoxy-D-glucose in 10 spontaneously breathing men (mean age 31 yr) inhaling either N2O 50% in O2 30% or O2 30% in N2. RESULTS: Global CMR(glu) in young men was 27 (3) micromol 100 g(-1) min(-1) [mean (SD)]. Inhalation of N2O 50% did not change global CMR(glu) [30 (5) micromol 100 g(-1) min(-1)] significantly, but it changed the distribution of the metabolism in the brain (P<0.0001 analysis of variance). Compared with inhalation of O2 30% in N2, N2O 50% inhalation increased the metabolism in the basal ganglia [14 (17)%, P<0.05] and thalamus [22 (23) %, P<0.05]. There was a prolonged metabolic effect of N2O inhalation seen on a succeeding PET scan with oxygen-enriched air (P<0.0001) performed 1 h after the N2O administration. CONCLUSIONS: Inhalation of N2O 50% did not change global CMR(glu), but the metabolism increased in central brain structures, an effect that was still present 1 h after discontinuation of N2O.
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| 3. |
- Stomrud, Erik, et al.
(författare)
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CSF biomarkers correlate with cerebral blood flow on SPECT in healthy elderly.
- 2012
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Ingår i: Dementia and geriatric cognitive disorders. - : S. Karger AG. - 1421-9824 .- 1420-8008. ; 33:2-3, s. 156-63
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Tidskriftsartikel (refereegranskat)abstract
- The preclinical patterns of biological markers for Alzheimer's disease (AD) in vivo need further exploration. The aim of this study was therefore to investigate CSF biomarkers, regional cerebral blood flow (rCBF) and cognitive performance in cognitively healthy older individuals.
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| 4. |
- Thorngren-Jerneck, Kristina, et al.
(författare)
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Cerebral glucose metabolism measured by positron emission tomography in term newborn infants with hypoxic ischemic encephalopathy
- 2001
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Ingår i: Pediatric Research. - 1530-0447. ; 49:4, s. 495-501
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Tidskriftsartikel (refereegranskat)abstract
- Total and regional cerebral glucose metabolism (CMRgl) was measured by positron emission tomography with 2-(F-18) fluoro-2-deoxy-D-glucose ((18)FDG) in 20 term infants with hypoxic ischemic encephalopathy (HIE) after perinatal asphyxia. All infants had signs of perinatal distress, and 15 were severely acidotic at birth. Six infants developed mild HIE, twelve moderate HIE, and two severe HIE during their first days of life. The positron emission tomographic scans were performed at 4-24 d of age (median, 11 d). One hour before scanning, 2-3.7 MBq/kg (54-100 µCi/kg) (18)FDG was injected i.v. No sedation was used. Quantification of CMRgl was based on a new method employing the glucose metabolism of the erythrocytes, requiring only one blood sample. In all infants, the most metabolically active brain areas were the deep subcortical parts, thalamus, basal ganglia, and sensorimotor cortex. Frontal, temporal, and parietal cortex were less metabolically active in all infants. Total CMRgl was inversely correlated with the severity of HIE (p < 0.01). Six infants with mild HIE had a mean (range) CMRgL of 55.5 (37.7-100.8) mol.min(-1).100 g(-1), 11 with moderate HIE had 26.6 (13.0-65.1) µmol.min(-1).100 g(-1), and two with severe HIE had 10.4 and 15.0 µmol.min(-1).100 g(-1), respectively. Five of six infants who developed cerebral palsy had a mean (range) CMRgl of 18.1 (10.2-31.4) µmol.min(-1).100 g(-1) compared with 41.5 (13.0-100.8) µmol.min(-1).100 g(-1) in the infants with no neurologic sequela at 2 y. We conclude that CMRgl measured during the subacute period after perinatal asphyxia in term infants is highly correlated with the severity of HIE and short-term outcome.
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| 5. |
- Agardh, Carl-David, et al.
(författare)
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Persistent vegetative state with high cerebral blood flow following profound hypoglycemia
- 1983
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Ingår i: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 14:4, s. 482-486
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Tidskriftsartikel (refereegranskat)abstract
- A persistent vegetative state (severe dementia) developed in a 30-year-old man following hypoglycemic coma. Despite the poor clinical outcome, sensory evoked response recovered between 6 and 34 months after the insult. The cerebral blood flow level at rest after 34 months was slightly above the normal range. This finding contrasts with the low cerebral blood flow regularly reported in patients who are comatose or stuporous following severe brain hypoxia-ischemia.
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| 6. |
- Bah Rösman, Jessica, 1975, et al.
(författare)
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Serotonin transporter gene polymorphisms: Effect on serotonin transporter availability in the brain of suicide attempters
- 2008
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Ingår i: Psychiatry Research: Neuroimaging. - : Elsevier BV. - 0925-4927 .- 0165-1781. ; 162:3, s. 221-229
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Tidskriftsartikel (refereegranskat)abstract
- The efficacy of serotonin reuptake inhibitors in depression and anxiety disorders suggests the gene coding for the serotonin transporter (5-HTT), SLC6A4, as a candidate of importance for these conditions. Positive findings regarding associations between polymorphisms in SLC6A4 have been reported, indicating that these polymorphisms may influence anxiety-related personality traits, as well as the risk of developing depression and suicidality. Serotonin 5-HTT availability was assessed with single photon emission computed tomography (SPECT), using I-123-beta-CIT as ligand, in a population of unmedicated male suicide attempters (n=9) and in matched controls (n=9). Two polymorphisms in SLC6A4 were assessed, including the 5-HTTLPR located in the promoter region and a variable number of tandem repeats (VNTR) polymorphism in intron 2 (STin2). In suicide attempters, but not in controls, low 5-HTT availability was associated with the S allele of 5-HTTLPR and with the 12 repeat allele of STin2. Data suggest that polymorphisms in SLC6A4 may influence the expression of the brain serotonin transporter in suicide attempters.
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| 7. |
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| 8. |
- Bellner, Johan, et al.
(författare)
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Transkraniell dopplermätning avspeglar intrakraniellt tryck
- 2005
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Ingår i: Läkartidningen. - 0023-7205. ; 102:11, s. 840-844
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Tidskriftsartikel (refereegranskat)abstract
- Vid intrakraniell patologi, speciellt om patienten är medvetslös, är kunskap om det intrakraniella trycket av särskilt värde i neurointensivvård. Intraventrikulär kateter för mätning av intrakraniellt tryck har varit etablerad standard i årtionden. Exakta mätningar är möjliga endast genom invasiva tryckmätare. För att undersöka sambandet mellan intrakraniellt tryck och pulsatilt index, erhållet med transkraniell doppler, har vi genomfört en prospektiv studie. Registreringar av intrakraniellt tryck gjordes parallellt med alla dopplerundersökningar. En stark, signifikant korrelation sågs mellan intrakraniellt tryck och pulsatilt index med en korrelationskoefficient på 0,938. För detektion av ett intrakraniellt tryck >20 mm Hg i en population med intrakraniellt tryck mellan 10 och 40 mm Hg hade metoden – för alla mätningar – en sensitivitet på 0,83 och en specificitet på 0,99. Hos patienter med misstänkt förhöjt intrakraniellt tryck eller hos patienter där förhöjt intrakraniellt tryck måste uteslutas kan mätningar av pulsatilt index vara av stort värde.
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| 9. |
- Brådvik, Björn, et al.
(författare)
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Disturbances of speech prosody following right hemisphere infarcts
- 1991
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Ingår i: Acta Neurologica Scandinavica. - 1600-0404. ; 84:2, s. 114-126
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Tidskriftsartikel (refereegranskat)abstract
- The ability to perceive and express emotional, as well as number of linguistic prosodic qualities of speech was tested in 20 Swedish-speaking patients with right-sided cortical, as well as purely subcortical brain infarcts, and in 18 normal controls. The infarcts were assessed by clinical neurological examination, and by CT, EEG, and measurements of regional cerebral blood flow (rCBF). In the patients the identification of emotional messages was disturbed, as well as the identification and production of several linguistic prosodic qualities. The study supports the claim that prosodic impairment could be linguistic in nature, and not secondary to affective disorder. The total degree of anatomical and functional disturbance of the right hemisphere played a role for both the ability to identify emotional messages and for identification of two of the linguistic prosodic qualities tested. However, it was not possible to find support for the hypothesis that the organization of prosody in the right hemisphere mirrors that of propositional speech on the left side.
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| 10. |
- 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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