Arterial spin labeling MR imaging had an excellent diagnostic accuracy for differentiation between high-grade and low-grade glioma. Given its low cost, non-invasiveness, and efficacy, ASL MR imaging should be considered for implementation in the routine workup of patients with glioma.

As is well known from literature, the grinding process, which is an unavoidable step in sample preparation, may strongly modify the physical properties of chrysotile through amorphisation. The aim of this work is to establish the proper milling time to apply to the samples before an accurate X-ray powder diffraction quantitative analysis. We have used the RIR (reference intensity ratio) analytical method, based on the measurement of the ratio I/Is between the intensity of the strongest line of an analyte and the intensity of the analytical peak of a standard material, when they are thoroughly mixed 50:50 by weight. We have studied how the RIR value changes as a function of the milling time of the sample and how the accuracy of this quantitative method is affected.

Background Fast multi‐contrast echo planar MRI (EPIMix) has comparable diagnostic performance to standard MRI for detecting brain pathology but its performance in detecting acute cerebral infarctions has not been determined. Purpose To assess the diagnostic performance of EPIMix for the detection of acute cerebral infarctions. Study Type Retrospective observational cohort. Population One hundred and seventy‐two consecutive patients with a clinical suspicion of non‐hyperacute ischemic stroke (January 2018 to December 2019). Field Strength and Sequence 1.5 T or 3 T. EPIMix ((echo‐planar based: diffusion weighted (DWI), T2*‐weighted, T2‐weighted, T2‐ and T1‐fluid attenuated inversion recovery (FLAIR) images) vs. standard MRI: echo‐planar DWI, echo‐planar T2*‐weighted or susceptibility weighted, turbo spin‐echo T2‐weighted, T2‐ and T1‐FLAIR turbo spin‐echo sequences. Assessment Three neuroradiologists rated EPIMix and standard MRI on two separate occasions. Incongruent assessments were resolved in consensus with the fourth reader. The ratings included the diagnostic category (acute infarct, normal, and other pathology). Congruent diagnoses together with consensus diagnoses served as the reference standard. Statistical Tests The diagnostic performance of EPIMix and standard MRI against the reference standard was calculated by the area under the receiver operating characteristic curve (AUC) and compared by DeLong's test. Sensitivity and specificity were determined. Inter‐rater agreements were evaluated by Fleiss's kappa. Results Of 172 patients (61 ± 16 years, 103 men), acute infarcts were present in 80/172 (47%), normal findings in 60/172 (35%), and other pathology in 32/172 (19%). Across readers, the AUCs were .94–.95 for EPIMix and .95–.99 for standard MRI, with overlapping 95% CI (P = .02–.18). Inter‐rater agreement for EPIMix was 0.90 and for standard MRI was 0.93. The sensitivity for EPIMix and standard MRI was 88–91% and 91–98%, respectively, while the specificity was 98–100% and 98–99%, both with overlapping 95% CI. Conclusion Multi‐contrast echo planar MRI showed a high but marginally lower diagnostic performance compared to standard MRI for the detection and characterization of acute brain infarct. Level of Evidence 3 Technical Efficacy Stage 2

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.