Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Extracranial carotid artery stenosis (ECAS) due to the presence of atherosclerotic plaque is a well-known risk factor for stroke. Several structural imaging studies have investigated the effect of ECAS on the brain, focusing on structural damage (in particular cerebral small vessel disease) and on the rearrangement of the cerebral circulation. For example, it is known from the literature an association between carotid stenosis and cerebral small vessel disease, and it is also noted that a series of compensatory mechanisms are activated by the cerebrovascular system in order to overcome the cerebral hypoperfusion that is induced by the ECAS. ⋯ Although these studies have been performed on small cohorts of patients without standardized protocols, it is plausible that in the future, such studies will help find early stage markers of cognitive impairment. This could permit an extension of indications for revascularization for the treatment of cognitive impairment in selected patients. The aim of this narrative review is to discuss the current knowledge on the effects of ECAS on brain and cognition by analyzing the main evidence from animal and clinical studies, with a special focus on rs-fc MR studies.
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Comparative Study Observational Study
Transcranial Sonography versus CT for Postoperative Monitoring After Decompressive Craniectomy.
Computed tomography (CT) is the actual gold standard diagnostic tool for monitoring patients after decompressive craniectomy. It is validated and provides a wide number of information. However, it takes time, expensive, and requires patient transportation. Transcranial sonography (TCS) could represent an alternative diagnostic tool in these patients. The aim of this study is to compare TCS versus CT scan after decompressive craniectomy in terms of diagnosing complications and costs evaluation. ⋯ TCS could be a reliable alternative diagnostic tool for major complications in patients undergoing decompressive craniectomy. It could limit the number of CT scans per patient overcoming several limitations, such as costs, radiation exposure, and need to move the patient.
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Despite increasing demand for fluoroscopy-guided lumbar puncture (FG-LP), there is limited quantitative and epidemiological data on patients undergoing this procedure. Additionally, data are scarce on the correlation of iliac crest landmarks to the actual anatomical lumbar level (intercristal line). The aim of this study is to determine if (1) body mass index (BMI) correlates with skin to spinal canal distance (SCD) and (2) the iliac crest landmark correlates with the presumed anatomical landmark on cross-sectional imaging. ⋯ There was direct, positive linear correlation between BMI and SCD at clinically relevant lumbar disc levels. Furthermore, there is considerable anatomical variance in the intervertebral space that aligns with the superior aspect of the iliac crest.
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Transient global amnesia (TGA) is a rare clinical entity with a sudden onset of anterograde amnesia that recovers within 24 hours. The underlying pathophysiology is uncertain. Imaging studies are controversial, but diffusion-weighted images often show small diffusion-restricted lesions in the hippocampus, which may suggest ischemic damage. Thus, we conducted the first clinical study using neurite orientation dispersion and density imaging (NODDI) and arterial spin labeling (ASL) to examine whether the microstructure and perfusion status of the hippocampus are influenced by the presence of diffusion-restricted lesions. ⋯ The first NODDI and ASL study in patients after TGA demonstrated no obvious microstructural or perfusion abnormalities in the hippocampus with typical DWI-positive lesions, which may indicate that TGA does not cause destructive damage or involve baseline microstructure or perfusion abnormalities in the hippocampus in relation to diffusion-restricted lesions.
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Glioblastomas (GBMs) that involve the subventricular zone (SVZ) have a poor prognosis, possibly due to recruitment of neural stem cells. The purpose of this study was to evaluate whether SVZ involvement by lower grade gliomas (LGG), WHO grade II and III, similarly predicts poorer outcomes. We further assessed whether tumor genetics and cellularity are associated with SVZ involvement and outcomes. ⋯ Unlike in GBM, overall SVZ involvement was not found to strongly predict poor prognosis in LGGs. However, occipital SVZ involvement, though uncommon, was prognostic and found to be associated with CDKN2A/B mutations and tumor hypercellularity. Further investigation into these molecular mechanisms underlying occipital SVZ involvement in larger cohorts is warranted.