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| 2. |
- Sundgren, Pia, et al.
(författare)
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Value of conventional, and diffusion- and perfusion weighted MRI in the management of patients with unclear cerebral pathology, admitted to the intensive care unit
- 2002
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 44:8, s. 674-680
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Tidskriftsartikel (refereegranskat)abstract
- The aim of our retrospective study was to determine the extent to which diffusion- and perfusion- weighted MRI combined with conventional MRI could be helpful in the evaluation of intensive care unit (ICU) patients who have unknown or unclear cerebral pathology underlying a serious clinical condition. Twenty-one ICU patients with disparity between the findings on brain CT scan and their clinical status were studied. All patients underwent conventional MR and diffusion-weighted imaging and 14 also had MR perfusion studies. Abnormalities were present on diffusion-weighted imaging of 17 of the 21 patients and on perfusion-weighted studies of 7 of 14 patients. The MRI results changed the preliminary/working diagnosis in six patients. In eight other patients, MRI revealed additional pathology that had not been suspected clinically, and/or characterized more closely findings that had already been detected by CT or suspected clinically. MRI showed abnormalities in four of the five patients who had normal CT. MRI findings suggested a negative clinical outcome in all nine patients who subsequently died. MRI findings also suggested positive long-term outcome in five of nine patients who improved significantly as based on Glasgow and extended Glasgow outcome scales. In the three unconscious patients who had normal diffusion- and perfusion weighted imaging the clinical outcome was good. This study suggests that MRI in seriously ill ICU patients with unclear cerebral pathology can provide information that changes, characterizes, or supports diagnoses and/or prognoses and therefore facilitates further management.
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| 3. |
- Brabec, Jan, et al.
(författare)
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Histogram analysis of tensor-valued diffusion MRI in meningiomas : Relation to consistency, histological grade and type
- 2022
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Ingår i: NeuroImage: Clinical. - : Elsevier BV. - 2213-1582. ; 33
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Preoperative radiological assessment of meningioma characteristics is of value for pre- and post-operative patient management, counselling, and surgical approach.PURPOSE: To investigate whether tensor-valued diffusion MRI can add to the preoperative prediction of meningioma consistency, grade and type.MATERIALS AND METHODS: 30 patients with intracranial meningiomas (22 WHO grade I, 8 WHO grade II) underwent MRI prior to surgery. Diffusion MRI was performed with linear and spherical b-tensors with b-values up to 2000 s/mm2. The data were used to estimate mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK) and its components-the anisotropic and isotropic kurtoses (MKA and MKI). Meningioma consistency was estimated for 16 patients during resection based on ultrasonic aspiration intensity, ease of resection with instrumentation or suction. Grade and type were determined by histopathological analysis. The relation between consistency, grade and type and dMRI parameters was analyzed inside the tumor ("whole-tumor") and within brain tissue in the immediate periphery outside the tumor ("rim") by histogram analysis.RESULTS: Lower 10th percentiles of MK and MKA in the whole-tumor were associated with firm consistency compared with pooled soft and variable consistency (n = 7 vs 9; U test, p = 0.02 for MKA 10 and p = 0.04 for MK10) and lower 10th percentile of MD with variable against soft and firm (n = 5 vs 11; U test, p = 0.02). Higher standard deviation of MKI in the rim was associated with lower grade (n = 22 vs 8; U test, p = 0.04) and in the MKI maps we observed elevated rim-like structure that could be associated with grade. Higher median MKA and lower median MKI distinguished psammomatous type from other pooled meningioma types (n = 5 vs 25; U test; p = 0.03 for MKA 50 and p = 0.03 and p = 0.04 for MKI 50).CONCLUSION: Parameters from tensor-valued dMRI can facilitate prediction of consistency, grade and type.
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| 4. |
- Follin, Cecilia, et al.
(författare)
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Microstructural white matter alterations associated to neurocognitive deficits in childhood leukemia survivors treated with cranial radiotherapy–a diffusional kurtosis study
- 2019
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Ingår i: Acta Oncologica. - 0284-186X. ; 58:7, s. 1021-1028
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cranial radiotherapy (CRT) is a known risk factor for neurocognitive impairment in survivors of childhood acute lymphoblastic leukemia (ALL). Diffusion tensor imaging (DTI) and diffusional kurtosis imaging (DKI) are MRI techniques that quantify microstructural changes in brain white matter (WM) and DKI is regarded as the more sensitive of them. Our aim was to more thoroughly understand the nature of cognitive deficits after cranial radiotherapy (CRT) in adulthood after childhood ALL. Material and methods: Thirty-eight (21 women) ALL survivors, median age 38 (27–46) years, were investigated at median 34 years after diagnosis. All had been treated with a CRT dose of 24 Gy and with 11 years of complete hormone supplementation. DTI and DKI parameters were determined and neurocognitive tests were performed in ALL survivors and 29 matched controls. Results: ALL survivors scored lower than controls in neurocognitive tests of vocabulary, memory, learning capacity, spatial ability, executive functions, and attention (p <.001). The survivors had altered DTI parameters in the fornix, uncinate fasciculus, and ventral cingulum (all p <.05) and altered DKI parameters in the fornix, uncinate fasciculus, and dorsal and ventral cingulum (p <.05). Altered DTI parameters in the fornix were associated with impaired episodic verbal memory (r = −0.40, p <.04). The left and right uncinate fasciculus (r = 0.6, p <.001), (r = −0.5, p <.02) as well as the right ventral cingulum (r = 0.5, p <.007) were associated with impaired episodic visual memory. Altered DKI parameters in the fornix, right uncinate fasciculus (r = 0.3, r = 0.05, p =.02), and ventral cingulum (r = 0.3, p =.02) were associated with impaired results of episodic visual memory. Conclusion: ALL survivors with cognitive deficits demonstrated microstructural damage in several WM tracts that were more extensive with DKI as compared to DTI; this might be a marker of radiation and chemotherapy neurotoxicity underlying cognitive dysfunction.
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| 6. |
- Grönholm, Erik, et al.
(författare)
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Predominance of caudate nucleus lesions in acute ischemic stroke patients with impairments in language and speech
- 2016
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 23:1, s. 148-153
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose. Whereas traditional views of language processing in the brain have assumed that the language function is concentrated to a limited number of cortical areas (Broca’s and Wernicke’s areas), current knowledge points at a much more complex system of language and speech processing involving many brain areas, both cortical and subcortical. The purpose of the current study was to make an unbiased assessment of which cerebral areas are affected in first-ever acute ischemic stroke patients identified as having language and speech impairments according to the National Institute of Health Stroke Scale (NIHSS). Methods. Data from thirty-four patients with language and speech impairments, with a score of 1-3 on item 9 on the NIHSS, following ischemic stroke was collected from the Lund Stroke Register. MRI images acquired up to 20 days after stroke onset were used to create an overlap lesion image using MRIcron software. Results. The classical language areas, Wernicke’s and Broca’s area, were affected in less than one fourth of the patients. The most frequently affected region was a subcortical region - the left caudate nucleus and the adjacent corona radiata. Conclusions. These findings contribute to the growing body of evidence that the basal ganglia have a crucial role in the control over language and speech processing.
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| 7. |
- Gujar, Sachin, et al.
(författare)
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Magnetic Resonance Spectroscopy.
- 2005
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Ingår i: Journal of Neuro-Ophthalmology. - 1070-8022. ; 25:3, s. 217-226
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Askaner, Krister, et al.
(författare)
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Differentiation of Brain Metastases due to Primary Malignancy and Glioblastomas using Dynamic Susceptibility Contrast-Enhanced MR at 3T
- 2017
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Konferensbidrag (refereegranskat)abstract
- Purpose:To find out differences in cerebral blood volume (CBV) maps derived from dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSCE-MRI) in glioblastomas and cerebral metastases. The main purpose was to compare CBV maps between metastases with different primary malignancies. Furthermore the metastasis group was compared with the glioblastoma group.Method:Conventional imaging and DSCE-MRI using 3T MRI system was performed in 114 patients, 38 glioblastomas and 76 metastases, 32 lung, 12 breast, 12 melanoma, 10 gastrointestinal (GI), and 10 other. CBV values were measured in the solid tumor area, peritumoral edema, area adjacent to peritumoral edema, and in normal apparent white matter in contralateral semioval center. The four subgroups of metastases were compared with one-way ANOVA to determine differences in CBV of significance. CBV values in glioblastomas and metastases were then statistically compared using paired t-test. Receiver -operating characteristic analysis was used to determine optimal cut-off values when parameters showed statistical differences.Results:There were no significantly differences in CBV between the four subgroups of metastases. CBV in the peritumoral edema significantly differentiated metastases from glioblastomas, p=0.0001. CBV cutoff value of 2.3 yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 87, 87, 71, and 91% respectively. Conclusions:Differentiation of glioblastomas and metastases is possible using DSCE-MRI. No statistically significant differences regarding CBV between metastases from lung, breast, melanoma, and GI were detected.
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| 9. |
- Bengtsson, Johan, et al.
(författare)
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Correlation between ADC, ADC ratio, and Gleason Grade group in prostate cancer patients undergoing radical prostatectomy : Retrospective multicenter study with different MRI scanners
- 2023
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Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: MRI is an important tool in the prostate cancer work-up, with special emphasis on the ADC sequence. This study aimed to investigate the correlation between ADC and ADC ratio compared to tumor aggressiveness determined by a histopathological examination after radical prostatectomy.Methods: Ninety-eight patients with prostate cancer underwent MRI at five different hospitals prior to radical prostatectomy. Images were retrospectively analyzed individually by two radiologists. The ADC of the index lesion and reference tissues (contralateral normal prostatic, normal peripheral zone, and urine) was recorded. Absolute ADC and different ADC ratios were compared to tumor aggressivity according to the ISUP Gleason Grade Groups extracted from the pathology report using Spearman’s rank correlation coefficient (ρ). ROC curves were used to evaluate the ability to discriminate between ISUP 1-2 and ISUP 3-5 and intra class correlation and Bland-Altman plots for interrater reliability.Results: All patients had prostate cancer classified as ISUP grade ≥ 2. No correlation was found between ADC and ISUP grade. We found no benefit of using the ADC ratio over absolute ADC. The AUC for all metrics was close to 0.5, and no threshold could be extracted for prediction of tumor aggressivity. The interrater reliability was substantial to almost perfect for all variables analyzed.Conclusions: ADC and ADC ratio did not correlate with tumor aggressiveness defined by ISUP grade in this multicenter MRI study. The result of this study is opposite to previous research in the field.
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| 10. |
- Hedner, Charlotta, et al.
(författare)
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Associations between Presence of Relevant Information in Referrals to Radiology and Prevalence Rates in Patients with Suspected Pulmonary Embolism.
- 2013
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Ingår i: Academic Radiology. - : Elsevier BV. - 1878-4046 .- 1076-6332. ; 20:9, s. 1115-1121
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to assess if the presence of information including the pretest probability (Wells score), other known risk factors, and symptoms given on referrals for computed tomography (CT) pulmonary angiography correlated with prevalence rates for pulmonary embolism (PE). Also, to evaluate for differences between a university and a regional hospital setting regarding patient characteristics, amount of relevant information provided on referrals, and prevalence rates for pulmonary embolism.
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