Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Randomized Controlled Trial
Utilization of Emergent Neuroimaging for Thrombolysis-Eligible Stroke Patients.
Advances in diagnostic imaging of stroke include multimodal techniques such as noninvasive angiography and perfusion imaging. We aimed to characterize trends in neuroimaging utilization among acute stroke patients. Utilization of multimodal imaging for acute stroke in the community has remained largely uncharacterized despite its increased adoption at academic medical centers. ⋯ Among acute stroke patients, noncontrast CT was the most common initial imaging strategy in clinical practice in the 2005-2012 time period, though use of concomitant CTA grew to one-quarter of cases, suggestive of an upward trend.
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Neurosurgery makes use of preoperative imaging to visualize pathology, inform surgical planning, and evaluate the safety of selected approaches. The utility of preoperative imaging for neuronavigation, however, is diminished by the well-characterized phenomenon of brain shift, in which the brain deforms intraoperatively as a result of craniotomy, swelling, gravity, tumor resection, cerebrospinal fluid (CSF) drainage, and many other factors. As such, there is a need for updated intraoperative information that accurately reflects intraoperative conditions. ⋯ We begin by evaluating these ultrasound technologies and their relative advantages and disadvantages. We then review three specific applications of these ultrasound technologies to brain tumor resection: (1) intraoperative navigation, (2) assessment of extent of resection, and (3) brain shift monitoring and compensation. We conclude by identifying opportunities for future directions in the development of ultrasound technologies.
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Randomized Controlled Trial Multicenter Study
The Relationship Between Brain MR Spectroscopy and Disability in Multiple Sclerosis: 20-Year Data from the U.S. Glatiramer Acetate Extension Study.
Conventional MRI techniques do not necessarily provide information about multiple sclerosis (MS) disease pathology or progression. Nonconventional MRI techniques, including proton magnetic resonance spectroscopy ((1) H-MRS), are increasingly used to improve the qualitative and quantitative specificity of MR images. This study explores potential correlations between MRI measures of disease and disability progression as measured by the Expanded Disability Status Scale (EDSS), Functional Systems (FS), and ambulation index scores in a unique cohort of MS patients treated with glatiramer acetate that has been closely monitored for over 20 years. ⋯ Among patients with MS receiving long-term glatiramer acetate therapy, consistent effects on disability levels indicated by EDSS and pyramidal FS score thresholds were found for tNAA/tCr concentration ratio and T1 lesion volume.
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Brain mapping studies have demonstrated that functional poststroke brain reorganization is associated with recovery of motor function. Nonetheless, the specific mechanisms associated with functional reorganization leading to motor recovery are still partly unknown. In this study, we performed a cross-sectional evaluation of poststroke subjects with the following goals: (1) To assess intra- and interhemispheric functional brain activation patterns associated with motor function in poststroke patients with variable degrees of recovery; (2) to investigate the involvement of other nonmotor functional networks in relationship with recovery. ⋯ Functional recovery after stroke is associated with preserved functional connectivity of motor to nonmotor networks.
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We detected a novel imaging sign, which consists of a specific imaging pattern of diffuse susceptibility effect, delineating the cortical-subcortical junction on high-resolution susceptibility-weighted images (SWIs). We describe magnetic resonance imaging findings in 10 patients with "susceptibility etching" and possible association with their abnormal coagulation profile. ⋯ In this preliminary case series, we describe patients with "susceptibility etching" on SWI who were also found to have profound coagulation impairment. While other comorbities may also contribute to this novel sign, we suggest that a possible etiology may be secondary to microvascular in situ formation of fine thrombi and/or emboli lodged into an area of vascular caliber reduction and maybe related to thrombotic microangiopathy.