Diffusion and perfusion imaging biomarkers of H3 K27M mutation status in diffuse midline gliomas.

PURPOSE: H3K27M-mutant diffuse midline gliomas (M-DMGs) exhibit a clinically aggressive course. We studied diffusion-weighted imaging (DWI) and perfusion (PWI) MRI features of DMG with the hypothesis that DWI-PWI metrics can serve as biomarkers for the prediction of the H3K27M mutation status in DMGs. METHODS: A retrospective review of the institutional database (imaging and histopathology) of patients with DMG (July 2016 to July 2020) was performed. Tumoral apparent diffusion coefficient (ADC) and peritumoral ADC (PT ADC) values and their normalized values (nADC and nPT ADC) were computed. Perfusion data were analyzed with manual arterial input function (AIF) and leakage correction (LC) Boxerman-Weiskoff models. Normalized maximum relative CBV (rCBV) was evaluated. Intergroup analysis of the imaging variables was done between M-DMGs and wild-type (WT-DMGs) groups. RESULTS: Ninety-four cases (M-DMGs-n = 48 (51%) and WT-DMGs-n = 46(49%)) were included. Significantly lower PT ADC (mutant-1.1 ± 0.33, WT-1.23 ± 0.34; P = 0.033) and nPT ADC (mutant-1.64 ± 0.48, WT-1.83 ± 0.54; P = 0.040) were noted in the M-DMGs. The rCBV (mutant-25.17 ± 27.76, WT-13.73 ± 14.83; P = 0.018) and nrCBV (mutant-3.44 ± 2.16, WT-2.39 ± 1.25; P = 0.049) were significantly higher in the M-DMGs group. Among thalamic DMGs, the min ADC, PT ADC, and nADC and nPT ADC were lower in M-DMGs while nrCBV (corrected and uncorrected) was significantly higher. Receiver operator characteristic curve analysis demonstrated that PT ADC (cut-off-1.245), nPT ADC (cut-off-1.853), and nrCBV (cut-off-1.83) were significant independent predictors of H3K27M mutational status in DMGs. CONCLUSION: DWI and PWI features hold value in preoperative prediction of H3K27M-mutation status in DMGs.

Lubo Airway Collar as a Rescue in Magnetic Resonance Imaging.

Adverse respiratory events in the out-of-operation theatre premises can be challenging to anesthesiologists. Manual jaw thrust application by anesthesiologists can be a temporary solution during an adverse airway event in remote locations. This report highlights the utility of a novel collar in alleviating upper airway obstruction in a patient in the MRI suite under IV sedation. The Lubo collar provides an automated jaw thrust and can also be applied electively for patients undergoing MRI under sedation and who are at risk of upper airway obstruction.

Role of Nimodipine and Milrinone in Delayed Cerebral Ischemia.

OBJECTIVE: The role of nimodipine and milrinone in the management of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH) was studied using clinical and TCD (transcranial Doppler) parameters. METHODS: In this prospective observational study, patients with DCI after aneurysmal SAH presenting between November 2020 and June 2021 who were treated by either intra-arterial nimodipine (IAN) or intravenous milrinone (IVM) were included after excluding patients in whom both IAN and IVM had been given or mechanical angioplasty was performed. Twelve-hourly TCD was performed during the course of the therapy. Clinical improvement and the development of new brain infarcts were also assessed. A P value <0.05 was considered statistically significant. RESULTS: Thirty-four patients fulfilled the inclusion criteria (IVM, 13/34 [38%]; IAN, 21/34 [62%]); patients in the IVM group (vs. IAN group) had poorer median Glasgow Coma Scale score (12 vs. 13), poorer motor response (

Prediction of H3K27M mutation status of diffuse midline gliomas using MRI features.

BACKGROUND AND PURPOSE: Presurgical prediction of H3K27M mutation in diffuse midline gliomas (DMGs) on MRI is desirable. The purpose of this study is to elaborate conventional MRI (cMRI) features of H3K27M-mutant DMGs and identify features that could discriminate them from wild-type (WT) DMGs. METHODS: CMRI features of 123 patients with DMG were evaluated conforming to the institutional research protocols. Multimodality MRI was performed on 1.5 or 3.0 Tesla MR Scanners with imaging protocol, including T1-weighted (w), T2w, fluid-attenuated inversion recovery, diffusion-weighted, susceptibility-weighted, and postcontrast T1w sequences. Pertinent cMRI features were annotated along the lines of Visually AcceSAble Rembrandt Images features, and Intra Tumoral Susceptibility Signal score (ITSS) was evaluated. R software was used for statistical analysis. RESULTS: Sixty-one DMGs were H3K27M-mutant (mutant DMGs). The patients in the H3K27M-mutant DMG group were younger compared to the WT-DMG group (mean age 24.13 ± 13.13 years vs. 35.79±18.74 years) (p = 0.016). The two groups differed on five cMRI features--(1) enhancement quality (p = 0.032), (2) thickness of enhancing margin (p = 0.05), (3) proportion of edema (p = 0.002), (4) definition of noncontrast-enhancing tumor (NCET) margin (p = 0.001), and (5) cortical invasion (p = 0.037). The mutant DMGs showed greater enhancement and greater thickness of enhancing margin, while the WT DMGs exhibited significantly larger edema proportion with poorly defined NCET margins and cortical invasion. ITSS was not significantly different among the groups. CONCLUSION: CMRI features like enhancement quality, the thickness of the enhancing margin, proportion of edema, definition of NCET margin, and cortical invasion can discriminate between the H3K27M-mutant and WT DMGs.