| 1. |
- Agerskov, Simon, et al.
(författare)
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Absence of Disproportionately Enlarged Subarachnoid Space Hydrocephalus, a Sharp Callosal Angle, or Other Morphologic MRI Markers Should Not Be Used to Exclude Patients with Idiopathic Normal Pressure Hydrocephalus from Shunt Surgery
- 2019
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Ingår i: American Journal of Neuroradiology. - 0195-6108. ; 40:1, s. 74-79
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Several studies have evaluated the use of MR imaging markers for the prediction of outcome after shunt surgery in idiopathic normal pressure hydrocephalus with conflicting results. Our aim was to investigate the predictive value of a number of earlier proposed morphologic MR imaging markers in a large group of patients with idiopathic normal pressure hydrocephalus. MATERIALS AND METHODS: One hundred sixty-eight patients (mean age, 70 +/- 9.3 years) with idiopathic normal pressure hydrocephalus, subjected to standardized quantification of clinical symptoms before and after shunt surgery, were included in the study. Outcome was calculated using a composite score. Preoperative T1, FLAIR, and flow-sensitive images were analyzed regarding the presence of 13 different morphologic MR imaging markers. RESULTS: The median Evans index was 0.41 (interquartile range, 0.37-0.44). All patients had an aqueductal flow void sign present and white matter hyperintensities. The median callosal angle was 68.8 degrees (interquartile range, 57.7 degrees-80.8 degrees). Dilated Sylvian fissures were found in 69%; focally dilated sulci, in 25%; and widening of the interhemispheric fissure, in 55%. Obliteration of the sulci at the convexity was found in 36%, and 36% of patients were characterized as having disproportionately enlarged subarachnoid space hydrocephalus. Sixty-eight percent of patients improved after surgery. None of the investigated MR imaging markers were significant predictors of improvement after shunt surgery. CONCLUSIONS: Disproportionately enlarged subarachnoid space hydrocephalus, a small callosal angle, and the other MR imaging markers evaluated in this study should not be used to exclude patients from shunt surgery. These markers, though they may be indicative of idiopathic normal pressure hydrocephalus, do not seem to be a part of the mechanisms connected to the reversibility of the syndrome.
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| 2. |
- Ambarki, Khalid, et al.
(författare)
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Accuracy of Parenchymal Cerebral Blood Flow Measurements Using Pseudocontinuous Arterial Spin-labeling in Healthy Volunteers
- 2015
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 36:10, s. 1816-1821
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The arterial spin-labeling method for CBF assessment is widely available, but its accuracy is not fully established. We investigated the accuracy of a whole-brain arterial spin-labeling technique for assessing the mean parenchymal CBF and the effect of aging in healthy volunteers. Phase-contrast MR imaging was used as the reference method. MATERIALS AND METHODS: Ninety-two healthy volunteers were included: 49 young (age range, 20-30 years) and 43 elderly (age range, 65-80 years). Arterial spin-labeling parenchymal CBF values were averaged over the whole brain to quantify the mean pCBF(ASL) value. Total. CBF was assessed with phase-contrast MR imaging as the sum of flows in the internal carotid and vertebral arteries, and subsequent division by brain volume returned the pCBF(PCMRI) value. Accuracy was considered as good as that of the reference method if the systematic difference was less than 5 mL/min/100 g of brain tissue and if the 95% confidence intervals were equal to or better than +/- 10 mL/min/100 g. RESULTS: pCBF(ASL) correlated to pCBF(PCMRI) (r = 0.73; P < .001). Significant differences were observed between the pCBF(ASL) and pCBF(PCMRI) values in the young (P = .001) and the elderly (P < .001) volunteers. The systematic differences (mean 2 standard deviations) were -4 +/- 14 mL/min/100 g in the young subjects and 6 +/- 12 mL/min/100 g in the elderly subjects. Young subjects showed higher values than the elderly subjects for pCBF(PCMRI) (young, 57 +/- 8 mL/min/100 g; elderly, 54 +/- 7 mL/min/100 g; P = .05) and pCBF(ASL) (young, 61 +/- 10 mL/min/100 g; elderly, 48 +/- 10 mL/min/100 g; P < .001). CONCLUSIONS: The limits of agreement were too wide for the arterial spin-labeling method to be considered satisfactorily accurate, whereas the systematic overestimation in the young subjects and underestimation in the elderly subjects were close to acceptable. The age-related decrease in parenchymal CBF was augmented in arterial spin-labeling compared with phase-contrast MR imaging.
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| 3. |
- Barnaure, I., et al.
(författare)
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Clinicoradiologic Correlations of Cerebral Microbleeds in Advanced Age
- 2017
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 38, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The presence of cerebral microbleeds has been associated with dementia and cognitive decline, although studies report conflicting results. Our aim was to determine the potential role of the presence and location of cerebral microbleeds in early stages of cognitive decline.MATERIALS AND METHODS: Baseline 3T MR imaging examinations including SWI sequences of 328 cognitively intact community-dwelling controls and 72 subjects with mild cognitive impairment were analyzed with respect to the presence and distribution of cerebral microbleeds. A neuropsychological follow-up of controls was performed at 18 months post inclusion and identified cases with subtle cognitive deficits were referred to as controls with a deteriorating condition. Group differences in radiologic parameters were studied by using nonparametric tests, 1-way analysis of variance, and Spearman correlation coefficients.RESULTS: Cerebral microbleed prevalence was similar in subjects with mild cognitive impairment and controls with stable and cognitively deteriorating conditions (25%-31.9%). In all diagnostic groups, lobar cerebral microbleeds were more common. They occurred in 20.1% of all cases compared with 6.5% of cases with deep cerebral microbleeds. None of the investigated variables (age, sex, microbleed number, location and depth, baseline Mini-Mental State Examination score, and the Fazekas score) were significantly associated with cognitive deterioration with the exception of education of >12 years showing a slight but significant protective effect (OR, 0.44; 95% CI, 0.22-0.92; P = .028). The Mini-Mental State Examination and the Buschke total score were correlated with neither the total number nor lobar-versus-deep location of cerebral microbleeds.CONCLUSIONS: Cerebral microbleed presence, location, and severity are not related to the early stages of cognitive decline in advanced age.
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| 4. |
- Blystad, Ida, et al.
(författare)
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Quantitative MRI for Analysis of Active Multiple Sclerosis Lesions without Gadolinium-Based Contrast Agent
- 2016
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Ingår i: American Journal of Neuroradiology. - : American Society of Neuroradiology (ASNR). - 0195-6108 .- 1936-959X. ; 37:1, s. 94-100
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Contrast-enhancing MS lesions are important markers of active inflammation in the diagnostic work-up of MS and in disease monitoring with MR imaging. Because intravenous contrast agents involve an expense and a potential risk of adverse events, it would be desirable to identify active lesions without using a contrast agent. The purpose of this study was to evaluate whether pre-contrast injection tissue-relaxation rates and proton density of MS lesions, by using a new quantitative MR imaging sequence, can identify active lesions.MATERIALS AND METHODS: Forty-four patients with a clinical suspicion of MS were studied. MR imaging with a standard clinical MS protocol and a quantitative MR imaging sequence was performed at inclusion (baseline) and after 1 year. ROIs were placed in MS lesions, classified as nonenhancing or enhancing. Longitudinal and transverse relaxation rates, as well as proton density were obtained from the quantitative MR imaging sequence. Statistical analyses of ROI values were performed by using a mixed linear model, logistic regression, and receiver operating characteristic analysis.RESULTS: Enhancing lesions had a significantly (P < .001) higher mean longitudinal relaxation rate (1.22 ± 0.36 versus 0.89 ± 0.24), a higher mean transverse relaxation rate (9.8 ± 2.6 versus 7.4 ± 1.9), and a lower mean proton density (77 ± 11.2 versus 90 ± 8.4) than nonenhancing lesions. An area under the receiver operating characteristic curve value of 0.832 was obtained.CONCLUSIONS: Contrast-enhancing MS lesions often have proton density and relaxation times that differ from those in nonenhancing lesions, with lower proton density and shorter relaxation times in enhancing lesions compared with nonenhancing lesions.
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| 5. |
- Cocozza, S., et al.
(författare)
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Redefining the Pulvinar Sign in Fabry Disease
- 2017
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 38:12, s. 2264-2269
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE:The pulvinar sign refers to exclusive T1WI hyperintensity of the lateral pulvinar. Long considered a common sign of Fabry disease, the pulvinar sign has been reported in many pathologic conditions. The exact incidence of the pulvinar sign has never been tested in representative cohorts of patients with Fabry disease. The aim of this study was to assess the prevalence of the pulvinar sign in Fabry disease by analyzing T1WI in a large Fabry disease cohort, determining whether relaxometry changes could be detected in this region independent of the pulvinar sign positivity.MATERIALS AND METHODS:We retrospectively analyzed brain MR imaging of 133 patients with Fabry disease recruited through specialized care clinics. A subgroup of 26 patients underwent a scan including 2 FLASH sequences for relaxometry that were compared with MRI scans of 34 healthy controls.RESULTS:The pulvinar sign was detected in 4 of 133 patients with Fabry disease (3.0%). These 4 subjects were all adult men (4 of 53, 7.5% of the entire male population) with renal failure and under enzyme replacement therapy. When we tested for discrepancies between Fabry disease and healthy controls in quantitative susceptibility mapping and relaxometry maps, no significant difference emerged for any of the tested variables.CONCLUSIONS:The pulvinar sign has a significantly lower incidence in Fabry disease than previously described. This finding, coupled with a lack of significant differences in quantitative MR imaging, allows hypothesizing that selective involvement of the pulvinar is a rare neuroradiologic sign of Fabry disease.
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| 6. |
- Delgado, A. F., et al.
(författare)
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Arterial Spin-Labeling in Children with Brain Tumor : A Meta-Analysis
- 2018
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Ingår i: American Journal of Neuroradiology. - : AMER SOC NEURORADIOLOGY. - 0195-6108 .- 1936-959X. ; 39:8, s. 1536-1542
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:The value of arterial spin-labeling in a pediatric population has not been assessed in a meta-analysis. PURPOSE:Our aim was to assess the diagnostic accuracy of arterial spin-labeling-derived cerebral blood flow to discriminate low- and high-grade tumors. DATA SOURCES:MEDLINE, EMBASE, the Web of Science Core Collection, and the Cochrane Library were used. STUDY SELECTION:Pediatric patients with arterial spin-labeling MR imaging with verified neuropathologic diagnoses were included. DATA ANALYSIS:Relative CBF and absolute CBF and tumor grade were extracted, including sequence-specific information. Mean differences in CBF between low- and high-grade tumors were calculated. Study quality was assessed. DATA SYNTHESIS:Data were aggregated using the bivariate summary receiver operating characteristic curve model. Heterogeneity was explored with meta-regression and subgroup analyses. The study protocol was published at PROSPERO (CRD42017075055). Eight studies encompassing 286 pediatric patients were included. The mean differences in absolute CBF were 29.62 mL/min/100 g (95% CI, 10.43-48.82 mL/min/100 g), I-2 = 74, P = .002, and 1.34 mL/min/100 g (95% CI, 0.95-1.74 mL/min/100 g), P < .001, I-2 = 38 for relative CBF. Pooled sensitivity for relative CBF ranged from 0.75 to 0.90, and specificity, from 0.77 to 0.92 with an area under curve = 0.92. Meta-regression showed no moderating effect of sequence parameters TE, TR, acquisition time, or ROI method. LIMITATIONS:Included tumor types, analysis method, and original data varied among included studies. CONCLUSIONS:Arterial spin-labeling-derived CBF measures showed high diagnostic accuracy for discriminating low- and high-grade tumors in pediatric patients with brain tumors. The relative CBF showed less variation among studies than the absolute CBF.
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| 7. |
- Delgado, Anna F., et al.
(författare)
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Discrimination between Glioma Grades II and III Using Dynamic Susceptibility Perfusion MRI : A Meta-Analysis
- 2017
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 38:7, s. 1348-1355
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: DSC perfusion has been evaluated in the discrimination between low-grade and high-grade glioma but the diagnostic potential to discriminate beween glioma grades II and III remains unclear.PURPOSE: Our aim was to evaluate the diagnostic accuracy of relative maximal CBV from DSC perfusion MR imaging to discriminate glioma grades II and III.DATA SOURCES: A systematic literature search was performed in PubMed/MEDLINE, Embase, Web of Science, and ClinicalTrials.gov.STUDY SELECTION: Eligible studies reported on patients evaluated with relative maximal CBV derived from DSC with a confirmed neuropathologic diagnosis of glioma World Health Organization grades II and III. Studies reporting on mean or individual patient data were considered for inclusion.DATA ANALYSIS: Data were analyzed by using inverse variance with the random-effects model and receiver operating characteristic curves describing optimal cutoffs and areas under the curve. Bivariate diagnostic random-effects meta-analysis was used to calculate diagnostic accuracy.DATA SYNTHESIS: Twenty-eight studies evaluating 727 individuals were included in the meta-analysis. Individual data were available from 10 studies comprising 190 individuals. The mean difference of relative maximal CBV between glioma grades II and III (n = 727) was 1.76 (95% CI, 1.27-2.24; P < .001). Individual patient data (n = 190) had an area under the curve of 0.77 for discriminating glioma grades II and III at an optimal cutoff of 2.02. When we analyzed astrocytomas separately, the area under the curve increased to 0.86 but decreased to 0.61 when we analyzed oligodendrogliomas.LIMITATIONS: A substantial heterogeneity was found among included studies.CONCLUSIONS: Glioma grade III had higher relative maximal CBV compared with glioma grade II. A high diagnostic accuracy was found for all patients and astrocytomas; however, the diagnostic accuracy was substantially reduced when discriminating oligodendroglioma grades II and III.
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| 8. |
- Forslin, Y., et al.
(författare)
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Gadolinium Retention in the Brain: An MRI Relaxometry Study of Linear and Macrocyclic Gadolinium-Based Contrast Agents in Multiple Sclerosis
- 2019
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Ingår i: American Journal of Neuroradiology. - : AMER SOC NEURORADIOLOGY. - 0195-6108 .- 1936-959X. ; 40:8, s. 1265-1273
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Brain gadolinium retention is consistently reported for linear gadolinium-based contrast agents, while the results for macrocyclics are contradictory and potential clinical manifestations remain controversial. Furthermore, most previous studies are based on conventional T1-weighted MR imaging. We therefore aimed to quantitatively investigate longitudinal and transversal relaxation in the brain in relation to previous gadolinium-based contrast agent administration and explore associations with disability in multiple sclerosis. MATERIALS AND METHODS: Eighty-five patients with MS and 21 healthy controls underwent longitudinal and transverse relaxation rate (R-1 and R-2) relaxometry. Patients were divided into linear, mixed, and macrocyclic groups based on previous gadolinium-based contrast agent administration. Neuropsychological testing was performed in 53 patients. The dentate nucleus, globus pallidus, caudate nucleus, and thalamus were manually segmented. Repeatability measures were also performed. RESULTS: The relaxometry was robust (2.0% scan-rescan difference) and detected higher R-1 (dentate nucleus, globus pallidus, caudate nucleus, thalamus) and R-2 (globus pallidus, caudate nucleus) in patients receiving linear gadolinium-based contrast agents compared with controls. The number of linear gadolinium-based contrast agent administrations was associated with higher R-1 and R-2 in all regions (except R-2 in the thalamus). No similar differences and associations were found for the macrocyclic group. Higher relaxation was associated with lower information-processing speed (dentate nucleus, thalamus) and verbal fluency (caudate nucleus, thalamus). No associations were found with physical disability or fatigue. CONCLUSIONS: Previous linear, but not macrocyclic, gadolinium-based contrast agent administration is associated with higher relaxation rates in a dose-dependent manner. Higher relaxation in some regions is associated with cognitive impairment but not physical disability or fatigue in MS. The findings should be interpreted with care but encourage studies into gadolinium retention and cognition.
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| 9. |
- Granberg, T, et al.
(författare)
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Clinical Feasibility of Synthetic MRI in Multiple Sclerosis : A Diagnostic and Volumetric Validation Study.
- 2016
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 37:6, s. 1023-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Quantitative MR imaging techniques are gaining interest as methods of reducing acquisition times while additionally providing robust measurements. This study aimed to implement a synthetic MR imaging method on a new scanner type and to compare its diagnostic accuracy and volumetry with conventional MR imaging in patients with MS and controls.MATERIALS AND METHODS: Twenty patients with MS and 20 healthy controls were enrolled after ethics approval and written informed consent. Synthetic MR imaging was implemented on a Siemens 3T scanner. Comparable conventional and synthetic proton-density-, T1-, and T2-weighted, and FLAIR images were acquired. Diagnostic accuracy, lesion detection, and artifacts were assessed by blinded neuroradiologic evaluation, and contrast-to-noise ratios, by manual tracing. Volumetry was performed with synthetic MR imaging, FreeSurfer, FMRIB Software Library, and Statistical Parametric Mapping. Repeatability was quantified by using the coefficient of variance.RESULTS: Synthetic proton-density-, T1-, and T2-weighted images were of sufficient or good quality and were acquired in 7% less time than with conventional MR imaging. Synthetic FLAIR images were degraded by artifacts. Lesion counts and volumes were higher in synthetic MR imaging due to differences in the contrast of dirty-appearing WM but did not affect the radiologic diagnostic classification or lesion topography (P = .50-.77). Synthetic MR imaging provided segmentations with the shortest processing time (16 seconds) and the lowest repeatability error for brain volume (0.14%), intracranial volume (0.12%), brain parenchymal fraction (0.14%), and GM fraction (0.56%).CONCLUSIONS: Synthetic MR imaging can be an alternative to conventional MR imaging for generating diagnostic proton-density-, T1-, and T2-weighted images in patients with MS and controls while additionally delivering fast and robust volumetric measurements suitable for MS studies.
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| 10. |
- Haller, Sven, et al.
(författare)
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APOE*E4 Is Associated with Gray Matter Loss in the Posterior Cingulate Cortex in Healthy Elderly Controls Subsequently Developing Subtle Cognitive Decline
- 2017
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Ingår i: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 38:7, s. 1335-1342
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The presence of apolipoprotein E4 (APOE*E4) is the strongest currently known genetic risk factor for Alzheimer disease and is associated with brain gray matter loss, notably in areas involved in Alzheimer disease pathology. Our objective was to assess the effect of APOE*E4 on brain structures in healthy elderly controls who subsequently developed subtle cognitive decline.MATERIALS AND METHODS: This prospective study included 382 community-dwelling elderly controls. At baseline, participants underwent MR imaging at 3T, extensive neuropsychological testing, and genotyping. After neuropsychological follow-up at 18 months, participants were classified into cognitively stable controls and cognitively deteriorating controls. Data analysis included whole-brain voxel-based morphometry and ROI analysis of GM.RESULTS: APOE*E4-related GM loss at baseline was found only in the cognitively deteriorating controls in the posterior cingulate cortex. There was no APOE*E4-related effect in the hippocampus, mesial temporal lobe, or brain areas not involved in Alzheimer disease pathology. Controls in the cognitively deteriorating group had slightly lower GM concentration in the hippocampus at baseline. Higher GM densities in the hippocampus, middle temporal lobe, and amygdala were associated with a decreased risk for cognitively deteriorating group status at follow-up.CONCLUSIONS: APOE*E4-related GM loss in the posterior cingulate cortex (an area involved in Alzheimer disease pathology) was found only in those elderly controls who subsequently developed subtle cognitive decline but not in cognitively stable controls. This finding might explain the partially conflicting results of previous studies that typically did not include detailed neuropsychological assessment and follow-up. Most important, APOE*E4 status had no impact on GM density in areas affected early by neurofibrillary tangle formation such as the hippocampus and mesial temporal lobe.
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