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.

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.

Cavernous carotid artery large aneurysm treated with a new flow diverter - Xcalibur aneurysm occlusion device (AOD).

We report a case of an unruptured, symptomatic, large right cavernous internal carotid artery aneurysm successfully treated with a new balloon-expandable flow diverter - Xcalibur Aneurysm Occlusion Device (AOD). Follow up imaging performed at six months demonstrated complete exclusion of the aneurysm and regression in dimensions, resulting in resolution of mass effect and clinical improvement.

XCalibur aneurysm occlusion device for the treatment of direct carotid cavernous fistula: expansion of armamentarium.

We report the first case of a post-traumatic direct carotid cavernous fistula (CCF) treated with the XCalibur aneurysm occlusion device, which is a balloon mounted stent with flow diversion effect. Two devices were deployed across the fistula in an overlapping manner, resulting in complete occlusion of the fistula. Flow diversion with this device can provide a safe and alternative treatment option in direct CCF.

Mitochondrial Membrane Protein Associated Neurodegeneration (MPAN) with a Novel C19orf12 Mutation in the First Decade of Life.

Mitochondrial membrane protein associated neurodegeneration (MPAN) belongs to the Neuronal brain iron accumulation (NBIA) spectrum disorder. It is caused by mutation in the C19orf12 gene. A 13-y-old previously healthy girl born to non-consanguineous marriage couple presented with regression of motor and cognitive milestones and decreased vision in both eyes, since 8 y of age. Examination revealed pyramidal signs, dystonia, dysarthria and pale optic disc. Neuroimaging showed streaking of medial medullary lamina of Globus pallidus. Genetic analysis revealed a novel p. G55 W in exon 3 of C19orf12 gene in homozygous state. Mitochondrial membrane protein associated neurodegeneration should be considered in any child presenting with neuronal brain iron accumulation spectrum disorder with findings of streaking of medial medullary lamina of Globus pallidus and absent retinitis pigmentosa.