AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Sep 2018
Vessel Wall Enhancement in Unruptured Intracranial Aneurysms: An Indicator for Higher Risk of Rupture? High-Resolution MR Imaging and Correlated Histologic Findings.
Recent studies have suggested that wall enhancement of unruptured intracranial aneurysms in high-resolution MR imaging might serve as an imaging biomarker for higher risk of rupture. Histologic studies have revealed a possible association among inflammatory processes, degeneration, and destabilization of the aneurysm wall preceding rupture. Understanding the histologic condition underlying aneurysm wall enhancement could be an important step toward assessing the value of this method for risk stratification. We present our observations of aneurysm wall enhancement in MR vessel wall imaging and underlying histologic changes. ⋯ Wall enhancement in MR vessel wall imaging is associated with inflammatory cell invasion, neovascularization, and the presence of vasa vasorum. Enhancement does not occur when histologic signs of inflammation are absent. Our results support the hypothesis that MR vessel wall imaging could provide valuable information for risk stratification.
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AJNR Am J Neuroradiol · Sep 2018
Brachial Plexus Ultrasound and MRI in Children with Brachial Plexus Birth Injury.
Brachial plexus birth injury is caused by traction on the neck during delivery and results in flaccid palsy of an upper extremity commonly involving C5-C6 nerve roots. MR imaging and MR myelography help to assess the anatomic location, extent, and severity of brachial plexus injuries which influence the long-term prognosis along with the surgical decision making. Recently, sonography has been increasingly used as the imaging modality of choice for brachial plexus injuries. The aim of this study was to assess the degree of correlation among brachial plexus sonography, MR imaging, and surgical findings in children with brachial plexus birth injury. ⋯ High-resolution sonography can identify and locate the postganglionic injury associated with the upper and middle trunks. The ability of sonography to evaluate pre- and the postganglionic injury associated with the lower trunk was quite limited. Sonography can be used as a complement to MR imaging; thus, the duration of the MR imaging examination and the need for sedation can be reduced by sonography.
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AJNR Am J Neuroradiol · Sep 2018
Time Course of Cerebral Perfusion Changes in Children with Migraine with Aura Mimicking Stroke.
Hemiplegic migraine is a common cause of acute brain attack in pediatrics. MR imaging sequences useful in differentiating hemiplegic migraine from other entities include arterial spin-labeling, SWI, MRA, and DWI. There has been limited exploration on the simultaneous use of these sequences in pediatrics. ⋯ All 12 patients had normal DWI and abnormal arterial spin-labeling findings. Furthermore, we observed a more rapid transition from hypoperfusion to rebound hyperperfusion in 3 patients compared with prior reports. These findings support the use of multimodal MR imaging to distinguish migraine with aura from stroke and the simultaneous use of these MR imaging sequences to improve understanding of perfusion changes during migraine with aura.
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AJNR Am J Neuroradiol · Aug 2018
Comparative StudyComparative Study of MRI Biomarkers in the Substantia Nigra to Discriminate Idiopathic Parkinson Disease.
Several new MR imaging techniques have shown promising results in patients with Parkinson disease; however, the comparative diagnostic values of these measures at the individual level remain unclear. Our aim was to compare the diagnostic value of MR imaging biomarkers of substantia nigra damage for distinguishing patients with Parkinson disease from healthy volunteers. ⋯ The combination of neuromelanin signal and volume changes with fractional anisotropy measurements in the substantia nigra showed excellent diagnostic accuracy. Moreover, the high diagnostic accuracy of visual assessment of substantia nigra changes using dorsolateral hyperintensity analysis or neuromelanin-sensitive signal changes indicates that these techniques are promising for clinical practice.
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AJNR Am J Neuroradiol · Aug 2018
ReviewResting-State Functional MRI: Everything That Nonexperts Have Always Wanted to Know.
Resting-state fMRI was first described by Biswal et al in 1995 and has since then been widely used in both healthy subjects and patients with various neurologic, neurosurgical, and psychiatric disorders. As opposed to paradigm- or task-based functional MR imaging, resting-state fMRI does not require subjects to perform any specific task. ⋯ In this review article, we will briefly describe a few of these and highlight the advantages and limitations of each. This description is to facilitate the adoption and use of resting-state fMRI in the clinical setting, helping neuroradiologists become familiar with these techniques and applying them for the care of patients with neurologic and psychiatric diseases.