| 1. |
- Latini, Francesco, M.D. 1982-
(författare)
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Significance of white matter anatomy in interpreting features and behaviour of low-grade gliomas and implications for surgical treatment
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Diffuse gliomas are extremely heterogeneous tumours characterized by slow growth but extensive infiltration. Their kinetic features reflect the complex interaction over time with the surrounding brain, influencing treatment planning and outcome. Indeed, resection of diffuse gliomas present a surgical challenge due to their invasiveness and the preferential location in eloquent regions. White matter bundles are the main eloquent limit to surgical resection, but this anatomical-functional information cannot be predicted preoperatively on the individual level. The incomplete description of the human brain connectome, the complex application of pathological/lesion model to the brain connectomic organization, and the underestimated role of white matter anatomy in radiological classification systems are among the major limitations for the comprehension of the glioma/white matter interaction. The overall aim of this thesis was to explore a new approach and new techniques to study the glioma/white matter interaction. A combination of white matter dissection and diffusion tensor tractography (DTT) was used to describe the connectomic organization of two major temporo-occipital connections, the inferior and the middle longitudinal fasciculus. This information was applied to patients with diffuse gliomas, demonstrating how white matter analysis was important to decode patient specific cognitive and language impairment. A new classification system for diffuse gliomas, the Brain-Grid, was created, merging local radiological anatomy with a DTT atlas for infiltration analysis. This standardized radiological tool provided information on subcortical extension (tumour invasiveness), speed, and preferential direction of glioma progression. Applied to a larger cohort of patients, differences were detected between diffuse gliomas subtypes. Tumour invasiveness and the preferential location, type, and extent of white matter involvement differed, impacting overall survival. Regional differences in white matter infiltration were detected among five major white matter bundles, and possible favourable morphological and diffusion features were investigated with transmission electron microscopy and DTT. Fibre diameter, myelin thickness, and the organization of the white matter fibres were different in regions with high infiltration frequency, providing a possible link to the preferential location of diffuse gliomas. Finally, the white matter connectivity, tumour-induced neuroplasticity, clinical and demographic information, preoperative assessment (neuropsychological and language evaluation) were compared with intraoperative findings during awake surgery. Neuropsychological impairment was associated with more invasive tumours and a higher risk of the intraoperative finding of eloquent tumour. The pattern of early cortical neuroplasticity seemed exhausted at the time of diagnosis, with age as a factor predicting the neuroplasticity potential. The combined use of these new techniques revealed new insights into the glioma/white matter interaction. The results provided in this thesis, describe a new way to structure the multidisciplinary perioperative management of these patients. This new information may improve the functional outcome at the individual level, resulting in prolonged survival for adults with diffuse gliomas.
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| 2. |
- Engström, Gunnar, et al.
(författare)
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The Swedish CArdioPulmonary BioImage Study : objectives and design
- 2015
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Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 278:6, s. 645-659
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Tidskriftsartikel (refereegranskat)abstract
- Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.
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| 3. |
- Wang, Chunliang, 1980-, et al.
(författare)
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An interactive software module for visualizing coronary arteries in CT angiography
- 2008
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Ingår i: International Journal of Computer Assisted Radiology and Surgery. - Heidelberg/Berlin : Springer. - 1861-6410 .- 1861-6429. ; 3:1-2, s. 11-18
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Tidskriftsartikel (refereegranskat)abstract
- A new software module for coronary artery segmentation and visualization in CT angiography (CTA) datasets is presented, which aims to interactively segment coronary arteries and visualize them in 3D with maximum intensity projection (MIP) and volume rendering (VRT).Materials and Methods: The software was built as a plug-in for the open-source PACS workstation OsiriX. The main segmentation function is based an optimized “virtual contrast injection” algorithm, which uses fuzzy connectedness of the vessel lumen to separate the contrast-filled structures from each other. The software was evaluated in 42 clinical coronary CTA datasets acquired with 64-slice CT using isotropic voxels of 0.3–0.5 mm.Results: The median processing time was 6.4 min, and 100% of main branches (right coronary artery, left circumflex artery and left anterior descending artery) and 86.9% (219/252) of visible minor branches were intact. Visually correct centerlines were obtained automatically in 94.7% (321/339) of the intact branches.Conclusion: The new software is a promising tool for coronary CTA post-processing providing good overviews of the coronary artery with limited user interaction on low-end hardware, and the coronary CTA diagnosis procedure could potentially be more time-efficient than using thin-slab technique.
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| 4. |
- Jutberger, Hans, et al.
(författare)
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Smoking Predicts Incident Fractures in Elderly Men : Mr OS Sweden
- 2010
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Ingår i: Journal of Bone and Mineral Research. - : Wiley. - 0884-0431 .- 1523-4681. ; 25:5, s. 1010-1016
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate the association between smoking and BMD, radiographically verified prevalent vertebral fractures and incident fractures in elderly men. At baseline 3003 men, aged 69 - 80 years old from the Swedish Mr Os study, completed a standard questionnaire concerning smoking habits and had BMD of the hip and spine measured using DXA; 1412 men had an X-ray of the thoracic-/lumbar spine. Radiological registers were used to confirm reported new fractures after the baseline visit. At baseline 8.4 % were current smokers. Current smokers had 6.2 % lower BMD at the total hip and 5.4 % at the lumbar spine (p<0.001). Current smoking remained independently, inversely associated with BMD at the hip and lumbar spine after adjusting for age, height, weight, calcium intake, physical activity and centres as co-variates. Prevalent vertebral fractures among current smokers were increased in unadjusted analyses (OR 1.90; 95% CI: 1.26-2.87) and after adjustment for lumbar BMD (OR 1.67; 1.09-2.55). Smokers had a high risk for two or more prevalent vertebral fractures (OR 3.18; 1.88-5.36). During the average follow-up of 3.3 years, 209 men sustained an X-ray verified fracture. Incident fracture risk among smokers was calculated with Cox proportional hazard models. Current smokers had increased risk of all new fractures (HR 1.76; 1.19-2.61), non-vertebral osteoporotic fractures defined as humerus, radius, pelvis and hip fractures (HR 2.14; 1.18-3.88), clinical and X-ray verified vertebral fractures (HR 2.53; 1.37-4.65) as well as of hip fracture (HR 3.16; 1.44-6.95). After adjustment for BMD, including other co-variates, no significant association between smoking and incident fractures was found. Current tobacco smoking in elderly men is associated with low BMD, prevalent vertebral fractures and incident fractures, especially vertebral and hip fractures.
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| 5. |
- Kaltsouni, Elisavet, et al.
(författare)
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Selective progesterone receptor modulation and brain activity at rest in patients with premenstrual dysphoric disorder
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Ovarian hormones have been indicated to impact brain connectivity and mood. However, there is no consistent evidence on hormone-dependent functional connectivity and mental health. Alterations in resting state networks have been suggested as markers of affective disorders, but only preliminary evidence is provided on premenstrual dysphoric disorder, in which symptoms occur upon fluctuations of ovarian hormones. Recently, three-month low-dose selective progesterone receptor modulator (SPRM) administration has been associated with symptom relief and altered task-based brain reactivity during a reactive aggression condition. The present study sought to investigate the effect of this treatment on resting state functional connectivity (rs-FC) in patients with PMDD. Seed-based analyses were conducted, including including seeds from the classic resting state networks along with the functional cluster affected by SPRM treatment. Within previously identified networks related with emotional processing, rs-FC was compared between individuals with PMDD during the symptomatic luteal phase before randomization to treatment or placebo and during the end of the last treatment cycle. Seed-based rs-FC analyses yielded significant treatment by time effects on rs-FC between the left posterior superior temporal gyrus and the right insula cortex, between the posterior cerebellum and the left temporal pole, and between the right lateral visual network and left superior frontal gyrus. Visuo-frontal luteal phase connectivity decreased for the SPRM group and was positively correlated with changes in mood symptom severity in the placebo group. Cerebellar and temporal connectivity increased for the SPRM treatment group, while temporo-insular connectivity decreased and was positively correlated with cortisol levels. These findings indicate that SPRM treatment influenced rs-FC, which could be a relevant mechanism behind symptom alleviation.
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| 6. |
- Velickaite, Vilma, et al.
(författare)
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Cognitive function in very old men does not correlate to biomarkers of Alzheimer's disease
- 2017
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Ingår i: Bmc Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Alzheimer's disease (AD) brain displays atrophy with amyloid-beta (A beta) and tau deposition, whereas decreased A beta 42 and increased tau are measured in cerebrospinal fluid (CSF). The aim of this study was to relate cognitive performance to the degree of brain atrophy, CSF biomarker levels and neuropathology in a cohort of aged men. Methods: Fifty-eight 86-92-year-old men from the Uppsala Longitudinal Study of Adult Men (ULSAM) cohort underwent cognitive testing, brain computed tomography and lumbar puncture. Atrophy was graded with established scales. Concentrations of CSF A beta 42, t-tau and p-tau were measured by ELISA. Thirteen brains were examined post mortem. Results: Forty-six of the individuals were considered non-demented, whereas twelve were diagnosed with dementia, either at baseline (n = 4) or during follow-up (n = 8). When comparing subjects with and without dementia, there were no differences in the degree of atrophy, although the mini mental state examination (MMSE) scoring correlated weakly with the degree of medial temporal atrophy (MTA) (p = 0.04). Moreover, the CSF biomarker levels did not differ significantly between healthy (n = 27) and demented (n = 8) subjects (median values 715 vs 472 pg/ml for A beta 42, 414 vs 427 pg/ml for t-tau and 63 vs 60 pg/ml for p-tau). Similarly, there were no differences in the biomarker levels between individuals with mild (n = 24) and severe (n = 11) MTA (median values 643 vs 715 pg/ml for A beta 42, 441 vs 401 pg/ml for t-tau and 64 vs 53 pg/ml for p-tau). Finally, the neuropathological changes did not correlate with any of the other measures. Conclusion: In this cohort of aged men only a weak correlation could be seen between cognitive performance and MTA, whereas the various neuroradiological, biochemical and neuropathological measures did not correlate with each other. Thus, AD biomarkers seem to be less informative in subjects of an advanced age.
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| 7. |
- Sarve, Hamid, et al.
(författare)
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Extracting 3D information on bone remodeling in the proximity of titanium implants in SRμCT image volumes.
- 2011
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Ingår i: Computer methods and programs in biomedicine. - : Elsevier BV. - 1872-7565 .- 0169-2607. ; 102:1, s. 25-34
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Tidskriftsartikel (refereegranskat)abstract
- Bone-implant integration is measured in several ways. Traditionally and routinely, 2D histological sections of samples, containing bone and the biomaterial, are stained and analyzed using a light microscope. Such histological section provides detailed cellular information about the bone regeneration in the proximity of the implant. However, this information reflects the integration in only a very small fraction, a 10 μm thick slice, of the sample. In this study, we show that feature values quantified on 2D sections are highly dependent on the orientation and the placement of the section, suggesting that a 3D analysis of the whole sample is of importance for a more complete judgment of the bone structure in the proximity of the implant. We propose features describing the 3D data by extending the features traditionally used for 2D-analysis. We present a method for extracting these features from 3D image data and we measure them on five 3D SRμCT image volumes. We also simulate cuts through the image volume positioned at all possible section positions. These simulations show that the measurement variations due to the orientation of the section around the center line of the implant are about 30%.
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| 8. |
- Corell, Alba, et al.
(författare)
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The clinical significance of the T2-FLAIR mismatch sign in grade II and III gliomas: a population-based study.
- 2020
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Ingår i: BMC cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- The T2-FLAIR mismatch sign is an imaging finding highly suggestive of isocitrate dehydrogenase mutated (IDH-mut) 1p19q non-codeleted (non-codel) gliomas (astrocytomas). In previous studies, it has shown excellent specificity but limited sensitivity for IDH-mut astrocytomas. Whether the mismatch sign is a marker of a clinically relevant subtype of IDH-mut astrocytomas is unknown.We included histopathologically verified supratentorial lower-grade gliomas (LGG) WHO grade II-III retrospectively during the period 2010-2016. In the period 2017-2018, patients with suspected LGG radiologically were prospectively included, and in this cohort other diagnoses than glioma could occur. Clinical, radiological and molecular data were collected. For clinical evaluation we included all patients with IDH-mut astrocytomas. In the 2010-2016 cohort DNA methylation analysis with Infinium MethylationEPIC BeadChip (Illumina) was performed for patients withan IDH-mut astrocytomawith available tissue. We aimed to examine the association of the T2-FLAIRmismatch sign with clinical factors and outcomes. Additionally, we evaluated the diagnostic reliability of the mismatch sign and its relation to methylation profiles.Out of 215 patients with LGG, 135 had known IDH-mutation and 1p19q codeletion status. Fifty patients hadan IDH-mut astrocytoma and 12 of these (24.0%) showed a mismatch sign. The sensitivity and specificity of the mismatch sign for IDH-mut detection were 26.4 and 97.6%, respectively. There were no differences between patients withan IDH-mut astrocytoma with or without mismatch sign when grouped according to T2-FLAIR mismatch sign with respect to baseline characteristics, clinical outcomes and methylation profiles. The overall interrater agreement between neuroradiologist and clinical neurosurgeons for the T2-FLAIR mismatch sign was significant when all 215 MRI examination assessed (κ=0.77, p<0.001, N=215).The T2-FLAIR mismatch sign in patients withan IDH-mut astrocytoma is not associated with clinical presentation or outcome. It seems unlikely that the IDH-mut astrocytomas with mismatch sign represent a specific subentity. Finally, we have validated that the T2-FLAIR mismatch sign is a reliable and specific marker of IDH-mut astrocytomas.
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| 9. |
- Wisniewski, Karol, et al.
(författare)
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H3 K27M-Altered Diffuse Midline Gliomas : A Review
- 2023
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Ingår i: Indian Journal of Neurosurgery. - : Georg Thieme Verlag KG. - 2277-954X .- 2277-9167. ; 12:02, s. 104-115
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Forskningsöversikt (refereegranskat)abstract
- Diffuse midline glioma H3 K27M-altered is a recently renamed high-grade glioma in the 2021 World Health Organization (WHO) Classification of Central Nervous System Tumors, previously being labelled diffuse midline glioma H3 K27M-mutant in the 2016 update and diffuse intrinsic pontine glioma prior to 2016. After identification of multiple alterations causing H3 K27 hypomethylation, the definition of this tumor subtype was changed. To further characterize this new entity in both the pediatric and adult population, we conducted a review of the current literature, investigating genetic, epidemiological, clinical, radiological, histopathological, treatment and prognostic characteristics, particularly highlighting the differences between adults and children. This tumor is more common in children, and has a poorer prognosis. Additionally, childhood H3 K27-altered gliomas are more common in the brainstem, but more common in the thalamus in adults. Sadly, limited treatment options exist for these tumors, with radiotherapy the only treatment shown to improve overall survival.
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| 10. |
- Grote, Ludger, 1964, et al.
(författare)
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National Knowledge-Driven Management of Obstructive Sleep Apnea-The Swedish Approach
- 2023
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Ingår i: Diagnostics. - : MDPI AG. - 2075-4418. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: This paper describes the development of "Swedish Guidelines for OSA treatment" and the underlying managed care process. The Apnea Hypopnea Index (AHI) is traditionally used as a single parameter for obstructive sleep apnea (OSA) severity classification, although poorly associated with symptomatology and outcome. We instead implement a novel matrix for shared treatment decisions based on available evidence. Methods: A national expert group including medical and dental specialists, nurses, and patient representatives developed the knowledge-driven management model. A Delphi round was performed amongst experts from all Swedish regions (N = 24). Evidence reflecting treatment effects was extracted from systematic reviews, meta-analyses, and randomized clinical trials. Results: The treatment decision in the process includes a matrix with five categories from a "very weak"" to "very strong" indication to treat, and it includes factors with potential influence on outcome, including (A) OSA-related symptoms, (B) cardiometabolic comorbidities, (C) frequency of respiratory events, and (D) age. OSA-related symptoms indicate a strong incitement to treat, whereas the absence of symptoms, age above 65 years, and no or well-controlled comorbidities indicate a weak treatment indication, irrespective of AHI. Conclusions: The novel treatment matrix is based on the effects of treatments rather than the actual frequency of respiratory events during sleep. A nationwide implementation of this matrix is ongoing, and the outcome is monitored in a prospective evaluation by means of the Swedish Sleep Apnea Registry (SESAR).
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