GLINT: GlucoCEST in neoplastic tumors at 3 T—clinical results of GlucoCEST in gliomas

Objective: Clinical relevance of dynamic glucose enhanced (DGE) chemical exchange saturation transfer (CEST) imaging has mostly been demonstrated at ultra-high field (UHF) due to low effect size. Results of a cohort study at clinical field strength are shown herein. // Materials and methods: Motion and field inhomogeneity corrected T1ρ‐based DGE (DGE⍴) images were acquired before, during and after a D-glucose injection with 6.3 s temporal resolution to detect accumulation in the brain. Six glioma patients with clear blood–brain barrier (BBB) leakage, two glioma patients with suspected BBB leakage, and three glioma patients without BBB leakage were scanned at 3 T. // Results: In high-grade gliomas with BBB leakage, D-glucose uptake could be detected in the gadolinium (Gd) enhancing region as well as in the tumor necrosis with a maximum increase of ∆DGE⍴ around 0.25%, whereas unaffected white matter did not show any significant DGE⍴ increase. Glioma patients without Gd enhancement showed no detectable DGE⍴ effect within the tumor. // Conclusion: First application of DGE⍴ in a patient cohort shows an association between BBB leakage and DGE signal irrespective of the tumor grade. This indicates that glucoCEST corresponds more to the disruptions of BBB with Gd uptake than to the molecular tumor profile or tumor grading

Penumbral Rescue by normobaric O = O administration in patients with ischemic stroke and target mismatch proFile (PROOF): Study protocol of a phase IIb trial.

Oxygen is essential for cellular energy metabolism. Neurons are particularly vulnerable to hypoxia. Increasing oxygen supply shortly after stroke onset could preserve the ischemic penumbra until revascularization occurs. PROOF investigates the use of normobaric oxygen (NBO) therapy within 6 h of symptom onset/notice for brain-protective bridging until endovascular revascularization of acute intracranial anterior-circulation occlusion. Randomized (1:1), standard treatment-controlled, open-label, blinded endpoint, multicenter adaptive phase IIb trial. Primary outcome is ischemic core growth (mL) from baseline to 24 h (intention-to-treat analysis). Secondary efficacy outcomes include change in NIHSS from baseline to 24 h, mRS at 90 days, cognitive and emotional function, and quality of life. Safety outcomes include mortality, intracranial hemorrhage, and respiratory failure. Exploratory analyses of imaging and blood biomarkers will be conducted. Using an adaptive design with interim analysis at 80 patients per arm, up to 456 participants (228 per arm) would be needed for 80% power (one-sided alpha 0.05) to detect a mean reduction of ischemic core growth by 6.68 mL, assuming 21.4 mL standard deviation. By enrolling endovascular thrombectomy candidates in an early time window, the trial replicates insights from preclinical studies in which NBO showed beneficial effects, namely early initiation of near 100% inspired oxygen during short temporary ischemia. Primary outcome assessment at 24 h on follow-up imaging reduces variability due to withdrawal of care and early clinical confounders such as delayed extubation and aspiration pneumonia. ClinicalTrials.gov: NCT03500939; EudraCT: 2017-001355-31

Chronic intracranial hypertension due to a tumor of the sinus wall: MRI and angiography

Chronic benign intracranial hypertension may have a variety of causes. Most frequent is this syndrome found in obese young women ('pseudotumor cerebri'), still of unknown etiology. However, venous congestion due to sinus occlusion has to be ruled out. We report a young woman with an intrasinusal meningioma of the transverse sinus and hypoplasia of the transverse sinus contralaterally. Diagnosis was achieved by MRI and angiography. Imaging signs of increased intracranial pressure comprised dilated perioptic sheaths and an empty sella. Abnormalities of the brain parenchyma or the CSF spaces were absent

Automated detection of MCI to Alzheimer's disease conversion before clinical onset by evaluation of atrophy rates

Purpose or Learning Objective: Alzheimer's disease (AD) is the most common type of an irreversible neurodegenerative disorder, affecting millions of people. Especially early stratification of patients with mild cognitive impairment (MCI) into patients who will convert to AD remains a challenging task. We aimed to predict automatically whether MCI patients will develop the disease (MCIc) by following subjects over time and quantifying spatial atrophy rates (AR) in magnetic resonance imaging (MRI). Methods or Background: 3D T1w MRIs at 3T from 276 MCI patients participating in the first period of Alzheimer’s Disease National Initiative (ADNI-1) with at least two MRIs more than 60 days apart without evident artifacts were segmented by a deep-learning-based 3D-UNet into 30 anatomical regions. Z-scores of TIV-adjusted volumes were calculated compared to a normal reference population, and AR of these z-scores were calculated longitudinally per subject (AR=0 normal aging). Rolling AR were calculated as the mean AR over a half-year time window (mRAR). A 80:20 train-test-partition was used to train a logistic regression to discriminate MCIc vs MCInc. Results or Findings: We found accelerated regional mRAR in MCIc. The temporal cortex and hippocampal regions showed the most striking mRAR. On the test set, of 34 MCIc, the classifier predicted 27 as true positive with a median of 1.7 Y (Q1/3=2.0/0.6Y) before conversion (sensitivity=0.79), with 5/22 false positives MCInc (stable specificity=0.77, AUC ROC=0.81). Conclusion: Our method provides reliable results due to a stable specificity that can be obtained well before previous clinical diagnoses for conversions to disease. Therefore, it is suitable for use in subsequent studies. Limitations: Validation in an independent sample is missing

In-vivo Vergleich der T1-Werte des Thalamus bei 3T und 9.4 Tesla

Einleitung: In den letzten Jahren gab es vielfältige Versuche, die histologische Anatomie des Thalamus mittels MR Bildgebung abzubilden. Wegen des niedrigen Kontrasts der Thalamusstrukturen sind entsprechende Messungen bisher nur durch entweder lange Meßzeit, hohe Feldstärke, Kontrastoptimierung mittels Inversionspulsen oder einer Kombination dieser Verfahren möglich. Ziel dieser Arbeit war es die T1 Zeiten im Thalamus zu bestimmen, um in Zukunft optimierte Inversionzeiten für Zielstrukturen berechnen zu können. Methode: Mit einer MP2RAGE Sequenz wurden insgesamt 11 gesunde Probanden (5 Frauen, 6 Männer, mittleres Alter 35 ± 11, Min-Max 20–56 J.) sowohl bei 3 Tesla als auch bei 9,4 Tesla gemessen und aus den zwei erhaltenen Datensätzen die T1 Zeit voxelweise berechnet. Nach einer Normalisierung mittels DART EL in SPM12 wurden die großen thalamischen Kerngebiete (Anterior, Medial, Lateral, Posterior) und die zwei klar abgrenzbaren anatomischen Referenzstrukturen mtt und Hb von Hand auf dem gemittelten 9,4 T Datensatz segmentiert (siehe Bild 1 rechts). Anschließend erfolgte eine Analyse der T1-Zeiten. Ergebnisse: Das Verhältnis der T1- Zeiten von 3 T zu 9,4 T zeigte eine annährend logarithmische Verteilungskurve mit mu = 1,51 und sigma = 0,024. Dadurch, dass mehrere Kerne in einem Kerngebiet enthalten sind, fand sich in allen Kerngebieten eine nicht symmetrische Verteilung der T1 Zeiten. Die T1 Zeiten bei 3T variierten in einem Bereich von 800 bis 1450 ms und bei 9,4 T in einem Bereich von 1220 bis 2210 ms (siehe Bild 1 links). Zusammenfassung: Für einen optimalen Kontrast des Thalamus sollten Inversionszeiten so gewählt werden, dass die maximale Grauwertspreizung in einem T1-Bereich von 800–1450 ms bei 3T bzw. 1220–2210 ms bei 9.4 T erfolgt