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- Bone, B, et al.
(författare)
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Mechanism of contrast enhancement in breast lesions at MR imaging
- 1998
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 39:5, s. 494-500
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: the aim of the study was to explain why breast lesions are enhanced by contrast medium at MR imaging and to elucidate the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions Material and Methods: Ten invasive breast carcinomas and 10 benign breast lesions were selected for the study. of the 10 carcinomas, 5 showed a strong and early contrast enhancement, and 5 did not. of the 10 benign lesions, 5 showed a strong and early contrast enhancement, and 5 showed no enhancement. the following morphometric variables were evaluated: proliferation cell index of neoplastic parenchymal cells, S-phase fraction, nuclear ploidy analysed by image DNA-cytometry, microvessel density, and the percentage proportion of the interstitial area Results: Contrast enhancement was related to the proliferating activity of the hyperplastic or neoplastic parenchymal cells and was inversely correlated with the interstitial area in carcinomas as well as in benign tumours and non-neo-plastic lesions of the breast Conclusion: Morphometric variables play an important role in the general mechanism of MR contrast enhancement in examinations of the breast and explain the histopathological basis for the overlap in the enhancement patterns of benign and malignant breast lesions
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- Cavallin, L, et al.
(författare)
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Can dynamic susceptibility contrast magnetic resonance imaging replace single-photon emission computed tomography in the diagnosis of patients with Alzheimer's disease? A pilot study
- 2006
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 47:9, s. 977-985
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To compare single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer's disease (AD). Material and Methods: Twenty-four patients, eight with AD, 10 with MCI, and six controls were investigated with SPECT using 99mTc-hexamethylpropyleneamine oxime (HMPAO) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with gadobutrol. Three observers performed a visual interpretation of the SPECT and MR images using a four-point visual scale. Results: SPECT was superior to DSC-MRI in differentiating normal from pathological. All three observers showed statistically significant results in discriminating between the control group, AD, and MCI by SPECT, with a P value of 0.0006, 0.04, and 0.01 for each observer. The statistical results were not significant for MR ( P values 0.8, 0.1, and 0.2, respectively). Conclusion: DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer's disease. Several patient- and method-related improvements should be made before this method can be recommended for clinical practice.
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- Cavallin, L, et al.
(författare)
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Voxel-based correlation between coregistered single-photon emission computed tomography and dynamic susceptibility contrast magnetic resonance imaging in subjects with suspected Alzheimer disease
- 2008
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 49:10, s. 1154-1161
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Tidskriftsartikel (refereegranskat)abstract
- Background: Current diagnosis of Alzheimer disease is made by clinical, neuropsychologic, and neuroimaging assessments. Neuroimaging techniques such as magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) could be valuable in the differential diagnosis of Alzheimer disease, as well as in assessing prognosis. Purpose: To compare SPECT and MRI in a cohort of patients examined for suspected dementia, including patients with no objective cognitive impairment (control group), mild cognitive impairment (MCI), and Alzheimer disease (AD). Material and Methods: 24 patients, eight with AD, 10 with MCI, and six controls, were investigated with SPECT using 99mTc-hexamethylpropyleneamine oxime (HMPAO, Ceretec; GE Healthcare Ltd., Little Chalsont UK) and dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a contrast-enhancing gadobutrol formula (Gadovist; Bayer Schering Pharma, Berlin, Germany). Voxel-based correlation between coregistered SPECT and DSC-MR images was calculated. Region-of-interest (ROI) analyses were then performed in 24 different brain areas using brain registration and analysis of SPECT studies (BRASS; Nuclear Diagnostics AB, Stockholm, Sweden) on both SPECT and DSC-MRI. Results: Voxel-based correlation between coregistered SPECT and DSC-MR showed a high correlation, with a mean correlation coefficient of 0.94. ROI analyses of 24 regions showed significant differences between the control group and AD patients in 10 regions using SPECT and five regions in DSC-MR. Conclusion: SPECT remains superior to DSC-MRI in differentiating normal from pathological perfusion, and DSC-MRI could not replace SPECT in the diagnosis of patients with Alzheimer disease.
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- Martola, J, et al.
(författare)
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One-dimensional-ratio measures of atrophy progression in multiple sclerosis as evaluated by longitudinal magnetic resonance imaging
- 2009
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 50:8, s. 924-932
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Tidskriftsartikel (refereegranskat)abstract
- Background: For decades, normalized one-dimensional (1D) measures have been used in the evaluation of brain atrophy. In multiple sclerosis (MS), the use of normalized linear measures over longitudinal follow-up remains insufficiently documented. Purpose: To evaluate the association between different regional atrophy measures and disability in MS patients over four decades in a longitudinal cross-sectional study. Material and Methods: 37 consecutively selected MS patients were included. At baseline, patients had a range of disease duration (1–33 years) and age (24–65 years). Each patient was followed by magnetic resonance imaging (MRI) for a mean of 9.25 years (range 7.3–10 years). Four 1D measures were applied at three time points on axial 5-mm T1-weighted images. Three clinical MS subgroups were represented: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS). Results: There were significant changes in all 1D ratios during follow-up. The Evans ratio (ER) and the bifrontal ratio (BFR) were associated with the development of disability. Changes of ER and BFR reflected more aggressive disease progression, as expressed by MS severity score (MSSS). Conclusion: All four normalized ratios showed uniform atrophy progression, suggesting a consistent rate of atrophy over long-term disease duration independent of MS course. Disability status correlated with 1D measures, suggesting that serial evaluation of Evans and bifrontal ratios might contribute to the radiological evaluation of MS patients.
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| 14. |
- Martola, J, et al.
(författare)
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Rate of ventricular enlargement in multiple sclerosis: a nine-year magnetic resonance imaging follow-up study
- 2008
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 49:5, s. 570-579
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Tidskriftsartikel (refereegranskat)abstract
- Background: In multiple sclerosis (MS), brain atrophy assessed by linear measurements of ventricular widths has been reported to be well correlated with three-dimensional (3D) measurements. Therefore, serial linear measurements with no need for advanced 3D evaluation may be proven to be robust markers of irreversible, destructive changes. Purpose: To evaluate the rate of supratentorial ventricular enlargement representing four decades of disease span. Material and Methods: 37 MS patients with disease duration at baseline ranging from 1 to 33 years were included. The mean time of the individual magnetic resonance imaging (MRI) follow-up was 9.25 years (range 7.3–10 years). Enlargement rate of the third and lateral ventricles was studied over time by applying three linear measurements on axial 5-mm T1-weighted MRI images. Results: Progression of supratentorial ventricular widths during 9 years’ follow-up was found. The mean annual width increase of the third ventricle was 0.20 mm ( P<0.001, 95% confidence interval [CI] 0.15–0.25), for the frontal horn width 0.32 mm ( P<0.001, 95% CI 0.23–0.40), and increase of the intercaudate distance was 0.26 mm ( P<0.001, 95% CI 0.19–0.33). The association between these three measurements and disability status persisted at the time of follow-up. Conclusion: We found uniform ventricular enlargement progression during four decades of disease span, suggesting unchanging total brain atrophy progression over time.
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- Shams, M, et al.
(författare)
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MRI Markers of Small Vessel Disease and the APOE Allele in Cognitive Impairment
- 2022
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Ingår i: Frontiers in aging neuroscience. - : Frontiers Media SA. - 1663-4365. ; 14, s. 897674-
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Tidskriftsartikel (refereegranskat)abstract
- The apolipoprotein E (APOE) ε4 allele is the main genetic risk factor for dementia and Alzheimer's disease (AD), but the underlying mechanism for the increased risk is not well understood. Cerebral small vessel disease (SVD) is prevalent among patients with cognitive impairment and is thought to play an important role in the pathophysiology of dementia. We aimed to investigate the association between the APOE ε genotype and magnetic resonance imaging (MRI) markers of SVD in a memory clinic population.Material and MethodsThis is a cross-sectional study with a total of 520 patients undergoing dementia investigation, including an MRI brain scan and APOE genotyping in all patients enrolled, and cerebrospinal fluid (CSF) analysis for routine AD biomarkers in 399 patients. MR images were assessed for markers of SVD: cerebral microbleeds (CMBs), cortical superficial siderosis, intracerebral hemorrhage, white matter hyperintensities, lacunar infarcts, and enlarged perivascular spaces.ResultsApolipoprotein E carriers with AD had a higher number of CMBs when looking at all brain regions and lobar brain regions (p < 0.001). A lower number of CMBs were seen in APOE ε2 (p < 0.05), ε3 and ε3/3 carriers (p < 0.001) when looking at all brain regions. A higher number of CMBs in deep and infratentorial regions were seen in APOE ε2 and ε3 (p < 0.05). In APOE ε4/4 carriers, CMBs, cortical superficial siderosis, white matter hyperintensities, and enlarged perivascular spaces were associated with lower levels of CSF amyloid β (Aβ) 42 in the whole cohort, and in individuals with AD and mild cognitive impairment (p < 0.05).ConclusionApolipoprotein E ε4 is associated with MRI markers of SVD related to amyloid pathology, specifically CMBs and Aβ42 plaque formation in the brain, as reflected by decreased CSF Aβ42 levels, whereas APOE ε3 and ε2 are associated with the markers of hypertensive arteriopathy, as reflected by the association with CMBs in deep and infratentorial brain regions.
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| 29. |
- Wiberg, MK, et al.
(författare)
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Comparison of the contrast enhancement pattern in two different T1-weighted 3-D sequences in MR imaging of the breast
- 1998
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 39:6, s. 680-685
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Can a complementary 3-D T1-weighted sequence (MPRAGE) facilitate the evaluation of contrast enhancement in patients with widespread and early contrast enhancement in our standard 3-D T1-weighted FLASH sequence? Material and Methods: Twenty patients with 21 breast lesions were examined with both FLASH and MPRAGE sequences. the MR examinations were reviewed independently by three radiologists. Results: In both the FLASH and MPRAGE sequences, 11 lesions were true-positive. In the FLASH sequence alone, 3 lesions were true-negative and 13 false-positive in comparison to the MPRAGE sequence alone in which 10 lesions were true-negative and 6 false-positive. Seven lesions that were false-positive in the FLASH sequence were true-negative in the MPRAGE sequence: this shows that MPRAGE has the potential to downgrade the false-positive findings found in the FLASH sequence. Conclusion: Due to its higher sensitivity, FLASH is the sequence of first choice at routine examination. However, when atypical increased enhancement was found, the addition of the MPRAGE sequence improved the specificity of the MR investigation.
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| 30. |
- Wiberg, MK, et al.
(författare)
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The potential influence of fine-needle aspiration on MR imaging of the breast
- 2000
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 41:3, s. 222-226
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this study was to determine whether fine-needle aspiration biopsy (FNAB) of breast lesions causes structural changes or changes in contrast enhancement, that could impair the evaluation of these lesions at MR investigation of the breast. Material and Methods: Fifteen patients with 17 lesions were examined with MR imaging of the breast both before and after the FNAB with a mean interval of 7.1 days. At both examinations, signal intensities were measured pre- and post-contrast enhancement in the lesions as well as in surrounding breast parenchyma and muscle. Imaging with contrast enhancement was performed semi-dynamically with two images obtained in rapid sequence (acquisition time 6.23 min) immediately after bolus injection of gadopentetate dimeglumine, 0.1 mmol/kg b.w., and the contrast enhancement in both images was calculated. Results: The diagnostic value of MR images was unimpaired by FNAB, and no statistical difference between contrast enhancement in corresponding images obtained before and after FNAB was found, either within the lesions or in the breast parenchyma or muscle. Conclusion: FNAB of the breast can be performed without impairing the diagnostic outcome of MR investigation.
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