Journal of neuroimaging : official journal of the American Society of Neuroimaging
-
In vivo detection of β-amyloid (Aβ) plaques in Alzheimer's disease (AD) is now possible with 11 C-PiB positron emission tomography (PET). Conventionally, a cortical:cerebellar PiB uptake ratio threshold of 1.4-1.5 has been used to categorize at-risk subjects as "amyloid-positive" and "amyloid-negative." It has been suggested that this threshold is too conservative and may miss early amyloid pathology. We investigated the relationship between conventional and lower baseline 11 C-PiB PET thresholds for raised amyloid load and the subsequent clinical and radiological progression of mild cognitive impairment (MCI) cases longitudinally. ⋯ Use of a PiB SUVR threshold of >1.5 for raised amyloid missed 14.3% of MCI cases who likely had Thal stage 1 or 2 pathology and showed a progressive amyloid increase over 2 years. Lowering the threshold for abnormality to 1.3 abolished all false negatives but resulted in 75% of HCs being falsely diagnosed as raised amyloid subjects.
-
Hemodynamic and metabolic impairment in intracranial atherosclerotic stenosis (ICAS) may promote stroke vulnerability particularly in borderzone areas. Perfusion and oxygen mapping magnetic resonance imaging (MRI) may provide useful information in this setting. ⋯ Symptomatic ICAS had no global impact on perfusion and oxygen mapping MRI at resting state. A significant increase in nCBV was found within anterior borderzone areas.
-
There is evidence suggesting that Los Angeles Motor Scale (LAMS) ≥ 4 predicts large vessel occlusion (LVO). We aim to determine whether atrial fibrillation (AF) can improve the ability of LAMS in predicting LVO. ⋯ In patients with LAMS = 3, using the LAMS-AF score may improve the ability of LAMS in predicting LVO. Larger studies are needed to confirm our findings.
-
Aneurysm hemodynamics play an important role in aneurysm growth and subsequent rupture. Within the available hemodynamic characteristics, particle residence time (PRT) is relatively unexplored. However, some studies have shown that PRT is related to thrombus formation and inflammation. The goal of this study is to evaluate the association between PRT and aneurysm rupture and morphology. ⋯ Our study shows an influence of aneurysm morphology on PRT. Nevertheless, it suggests that PRT cannot be used to differentiate unruptured and ruptured aneurysms.
-
We aim to correlate the patterns of brain diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) map in post cardiac arrest (PCA) patients with clinical outcomes. ⋯ Simple visual categorization system using DWI/ADC map may be helpful and practical in estimating the clinical outcome of PCA patients.