Project description:The current research tested the hypothesis that inversion time (TI) shorter than 2,400 ms under 3T for FLAIR can improve the diagnostic accuracy of the T2-FLAIR mismatch sign for identifying IDHmt, non-CODEL astrocytomas. We prepared three different cohorts; 94 MRI from 76 IDHmt, non-CODEL Lower-grade gliomas (LrGGs), 33 MRI from 31 LrGG under the restriction of FLAIR being acquired with TI < 2,400 ms for 3T or 2,016 ms for 1.5T, and 112 MRI from 112 patients from the TCIA/TCGA dataset for LrGG. The presence or absence of the "T2-FLAIR mismatch sign" was evaluated, and we compared diagnostic accuracies according to TI used for FLAIR acquisition. The T2-FLAIR mismatch sign was more frequently positive when TI was shorter than 2,400 ms under 3T for FLAIR acquisition (p = 0.0009, Fisher's exact test). The T2-FLAIR mismatch sign was positive only for IDHmt, non-CODEL astrocytomas even if we confined the cohort with FLAIR acquired with shorter TI (p = 0.0001, Fisher's exact test). TCIA/TCGA dataset validated that the sensitivity, specificity, PPV, and NPV of the T2-FLAIR mismatch sign to identify IDHmt, non-CODEL astrocytomas improved from 31, 90, 79, and 51% to 67, 94, 92, and 74%, respectively and the area under the curve of ROC improved from 0.63 to 0.87 when FLAIR was acquired with shorter TI. We revealed that TI for FLAIR impacts the T2-FLAIR mismatch sign's diagnostic accuracy and that FLAIR scanned with TI < 2,400 ms in 3T is necessary for LrGG imaging.

| S-EPMC7841010 | biostudies-literature

Population-Based Prevalence of Infarctions on 3D Fluid-Attenuated Inversion Recovery (FLAIR) Imaging.

Project description:ObjectivesTo report population-based, age-specific prevalence of infarctions as identified via 3D fluid-attenuated inversion recovery (FLAIR) imaging.Materials and methodsParticipants without dementia in the Mayo Clinic Study of Aging (MCSA), a population-based study in Olmsted County, MN, age 50-89 who underwent 3D FLAIR imaging between 2017 and 2020 were included. Infarctions per participant were determined via visual interpretation. Inter- and intra-reader reliability were calculated. Infarction prevalence on 3D FLAIR was derived by standardization to the Olmsted County population and was compared to that previously reported on 2D FLAIR imaging.ResultsAmong 580 participants (mean age 71 years, 46% female) the prevalence (95% confidence interval) of any infarction was 5.0% (0.0%-9.9%) at age 50-59 years and 38.8% (28.6%-49.0%) at 80-89 years. In addition to increasing with age, the prevalence varied by sex and type of infarction. Prevalence estimates of cortical infarcts were 0.9% (0.0%-2.7%) at age 50-59 years and 20.2% (10.7%-29.7%) at 80-89 years and lacunar infarcts 4.1% (0.0%-8.8%) at age 50-59 years and 31.2% (21.5%-41.0%) at 80-89 years. Prevalence estimates of any infarction by sex were: men, 8.7% (0.0%-18.7%) at 50-59 years and 54.9% (41.0%-68.8%) at 80-89 years and women, 2.4% (0.0%-7.3%) at age 50-59 years and 27.3% (12.9%-41.7%) at 80-89 years. Intra- and inter- reader reliability were very good (kappa = 0.85 and 0.82, respectively). After adjusting for age, sex and education, individuals imaged with 3D FLAIR were 1.5 times (95% CI 1.2-1.8, p<0.001) more likely to be identified as positive for infarction compared to those imaged with 2D FLAIR.ConclusionsInfarction prevalence increases with age and is greater in men than women. Infarction prevalence on 3D FLAIR imaging, which has become more widely implemented as an alternative to 2D FLAIR over the past several years, will be a useful reference in future work.

| S-EPMC9329259 | biostudies-literature

Quantitative measurements of relative fluid-attenuated inversion recovery (FLAIR) signal intensities in acute stroke for the prediction of time from symptom onset.

Project description:In acute stroke magnetic resonance imaging, a 'mismatch' between visibility of an ischemic lesion on diffusion-weighted imaging (DWI) and missing corresponding parenchymal hyperintensities on fluid-attenuated inversion recovery (FLAIR) data sets was shown to identify patients with time from symptom onset ≤4.5 hours with high specificity. However, moderate sensitivity and suboptimal interpreter agreement are limitations of a visual rating of FLAIR lesion visibility. We tested refined image analysis methods in patients included in the previously published PREFLAIR study using refined visual analysis and quantitative measurements of relative FLAIR signal intensity (rSI) from a three-dimensional, segmented stroke lesion volume. A total of 399 patients were included. The rSI of FLAIR lesions showed a moderate correlation with time from symptom onset (r=0.382, P<0.001). A FLAIR rSI threshold of <1.0721 predicted symptom onset ≤4.5 hours with slightly increased specificity (0.85 versus 0.78) but also slightly decreased sensitivity (0.47 versus 0.58) as compared with visual analysis. Refined visual analysis differentiating between 'subtle' and 'obvious' FLAIR hyperintensities and classification and regression tree algorithms combining information from visual and quantitative analysis also did not improve diagnostic accuracy. Our results raise doubts whether the prediction of stroke onset time by visual image judgment can be improved by quantitative rSI measurements.

| S-EPMC3965287 | biostudies-literature

Reply to: The pitfalls of interpreting hyperintense FLAIR signal as lymph outside the human brain.

Project description: Not available

| S-EPMC10432520 | biostudies-literature

Human skull base chordoma LC-MSMS

Project description:The prognostic factors of skull base chordoma associated with outcomes of patients after surgical resection remain poorly defined. This project aimed to identify a novel prognostic factor for patients with skull base chordoma. Using a proteomics approach, we screened tumor biomarkersthat upregulated in the rapid-recurrence group of chordoma, narrowed down by bioinformatics analysis, and finally potential biomarker was chosen for validation by immunohistochemistry using tissue microarray.

2021-11-03 | PXD025894 | Pride

Skull base repair following endonasal pituitary and skull base tumour resection: a systematic review.

Project description:PurposePostoperative cerebrospinal fluid rhinorrhoea (CSFR) remains a frequent complication of endonasal approaches to pituitary and skull base tumours. Watertight skull base reconstruction is important in preventing CSFR. We sought to systematically review the current literature of available skull base repair techniques.MethodsPubmed and Embase databases were searched for studies (2000-2020) that (a) reported on the endonasal resection of pituitary and skull base tumours, (b) focussed on skull base repair techniques and/or postoperative CSFR risk factors, and (c) included CSFR data. Roles, advantages and disadvantages of each repair method were detailed. Random-effects meta-analyses were performed where possible.Results193 studies were included. Repair methods were categorised based on function and anatomical level. There was absolute heterogeneity in repair methods used, with no independent studies sharing the same repair protocol. Techniques most commonly used for low CSFR risk cases were fat grafts, fascia lata grafts and synthetic grafts. For cases with higher CSFR risk, multilayer regimes were utilized with vascularized flaps, gasket sealing and lumbar drains. Lumbar drain use for high CSFR risk cases was supported by a randomised study (Oxford CEBM: Grade B recommendation), but otherwise there was limited high-level evidence. Pooled CSFR incidence by approach was 3.7% (CI 3-4.5%) for transsphenoidal, 9% (CI 7.2-11.3%) for expanded endonasal, and 5.3% (CI 3.4-7%) for studies describing both. Further meaningful meta-analyses of repair methods were not performed due to significant repair protocol heterogeneity.ConclusionsModern reconstructive protocols are heterogeneous and there is limited evidence to suggest the optimal repair technique after pituitary and skull base tumour resection. Further studies are needed to guide practice.

| S-EPMC8416859 | biostudies-literature

Infarct morphology assessment in patients with carotid artery/middle cerebral artery occlusion using fast fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH).

Project description:We aim to evaluate the value of fast fluid-attenuated inversion recovery (FLAIR) vascular hyperintensity (FVH) in assessing infarct morphology in patients with symptomatic internal carotid artery (ICA) or middle cerebral artery (MCA) occlusions. Magnetic resonance (MR) diffusion-weighted imaging (DWI) FLAIR sequences, and carotid/cerebral magnetic resonance angiography of 102 patients with symptomatic ICA or MCA occlusions were evaluated. The location and score of FVH were determined using Olindo's method; patients were classified as having Low or High FVHs based on FVH score, and either Distal or Proximal FVH based on FVH location. The differences between infarct morphologies were analyzed. FVH were detectable in 62 patients with High FVH and in 40 patients with Low FVHs based on the Olindo's scale. There were no statistically significant differences in age, gender, hypertension, diabetes, hyperlipidemia, smoking history, and vascular occlusive site between High and Low FVHs patients, except for infarct morphology (P<0.01). Patients with Distal FVH presented with significant (P<0.01) perforating artery and border zone infarcts, whereas those with Proximal FVH had significant (P<0.01) large territorial infarcts. The scores and locations of FVH could be a predictive imaging marker for infarct morphology in patients with symptomatic ICA or MCA occlusion.

| S-EPMC5708638 | biostudies-literature

Cerebrospinal Fluid Dynamics Analysis Using Time-Spatial Labeling Inversion Pulse (Time-SLIP) Magnetic Resonance Imaging in Mice.

Project description:Background/Objectives: Abnormalities in cerebrospinal fluid (CSF) dynamics cause diverse conditions, such as hydrocephalus, but the underlying mechanism is still unknown. Methods to study CSF dynamics in small animals have not been established due to the lack of an evaluation system. Therefore, the purpose of this research study is to establish the time-spatial labeling inversion pulse (Time-SLIP) MRI technique for the evaluation of CSF dynamics in mice. Methods: We performed the Time-SLIP technique on 10 wild-type mice and 20 Tiptoe-walking Yoshimura (TWY) mice, a mouse model of ossification of the posterior longitudinal ligament (OPLL). We defined the stir distance as the distance of CSF stirring and calculated the mean ± standard deviation. The intraclass correlation coefficient of intraobserver reliability was also calculated. Furthermore, in TWY mice, the correlation coefficient between stir distance and canal stenosis ratio (CSR) was calculated. Results: The stir distance was significantly lower in TWY mice at 12 weeks and 17 weeks of age (1.20 ± 0.16, 1.21 ± 0.06, and 1.21 ± 0.15 mm at 12 weeks and 1.32 ± 0.21, 1.28 ± 0.23, and 1.38 ± 0.31 mm at 17 weeks for examiners A, B, and C). The intrarater reliability of the three examiners was excellent (>0.90) and there was a strongly negative correlation between stir distance and CSR in TWY mice (>-0.80). Conclusions: In this study, we established the Time-SLIP technique in experimental mice. This technique allows for a better understanding of CSF dynamics in small laboratory animals.

| S-EPMC11312514 | biostudies-literature

Reply: Beyond Viral Suppression.

Project description: Not available

| S-EPMC8530261 | biostudies-literature