Deuterium Metabolic Imaging of Alzheimer Disease at 3-T Magnetic Field Strength: A Pilot Case-Control Study

Background: Impaired glucose metabolism is characteristic of several dementia types, preceding cognitive symptoms and structural brain changes. Reduced glucose uptake detection in specific brain regions using 18F-fluorodeoxyglucose-PET (18F-FDG-PET) is a valuable diagnostic marker in Alzheimer’s disease (AD). However, 18F-FDG-PET use in clinical practice may be limited by equipment availability and high cost. Purpose: To test the feasibility of using MRI-based deuterium metabolic imaging (DMI) at a clinical magnetic-field strength (3 T) to detect and localize changes in glucose and its metabolites in patients with a clinical diagnosis of AD. Materials and Methods: Participants were recruited for this prospective case‒control pilot study between March 2021 and February 2023. DMI was performed at 3 T using a custom birdcage head coil following oral administration of deuterium-labeled glucose (0.75 g/kg). Unlocalized whole-brain magnetic resonance spectroscopy (MRS) and 3D magnetic resonance spectroscopic images (MRSI, cubic 3.2 cm voxel) were acquired. Ratios of 2H-glucose, 2H-glutamate/glutamine (2H-Glx) and 2H-lactate spectroscopic peak signals to 2H-water peak signal were calculated for the whole-brain MRS, and for individual MRSI voxels. Results: A total of 19 participants, including 10 participants with AD (mean age, 68 years ±5 [SD]; 8 males) and 9 cognitively healthy control participants (mean age, 70 years ± 6 [SD]; 6 males) were evaluated. Whole-brain spectra demonstrated a reduced ratio of the peak 2H-Glx to 2H-glucose signals in participants with AD compared with control participants (0.41±0.09 vs. 0.58±0.20, P=.04), suggesting an impairment of oxidative glucose metabolism in AD. However, there was no evidence of localization of these changes to the expected regions of metabolic impairment on MRSI presumably due to insufficient spatial resolution. Conclusion: DMI at 3 T demonstrated impairment of oxidative glucose metabolism in patients with Alzheimer’s disease but no evidence of regional signal differences.Evelyn Trus

Comparison of Drip‐and‐Ship Versus Mothership Delivery Models of Mechanical Thrombectomy Delivery

Background It remains uncertain whether the drip‐and‐ship (DS) strategy (transport to the nearest primary stroke centers) or the mothership (MS) model (direct transportation to the comprehensive stroke center) is the organizational stroke model associated with the best functional outcome in acute stroke patients with large vessel occlusion. In this study, we compared the periprocedural complications and outcomes at 90 days of acute stroke patients with large vessel occlusion of the anterior circulation directly admitted to our comprehensive stroke center compared to those referred from primary stroke centers treated with mechanical thrombectomy. Methods This is a single‐center prospective observational study where patients with DS and MS were compared regarding the disability at 90 days, as assessed by applying the modified Rankin scale, the rate of successful reperfusion, and the rate of immediate complications postprocedure. Results Of 579 patients, 216 (37.30%) were MS, and 363 (62.7%) were DS. There was no difference regarding the modified Rankin scale at 3 months between the MS (36.4%) and DS (39.3%) groups of patients treated with mechanical thrombectomy (P=0.362). There was no significant difference regarding the National Institutes of Health Stroke Scale at 24 hours, mortality at 90 days, and rate of successful recanalization postprocedure between the 2 groups. DS was associated with an increased risk of hemorrhagic transformation and symptomatic intracranial hemorrhage (odds ratio, 5.414 [95% CI, 1.572–18.644]; P=0.007). Conclusion Our single‐center study showed no difference in terms of functional independence between the DS and MS organizational paradigm. DS was associated with an increased risk of hemorrhagic transformation and symptomatic intracranial hemorrhage