Neuroradiology
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The origin of the vertebral artery (VA) varies, though most VAs enter the transverse foramen (TF) of the sixth cervical vertebra. On computed tomography (CT) angiographic images, we evaluated the prevalence of variations of both VA origin and its level of entry into the TF. ⋯ The total prevalence of variation in the origin of the LVA was 6.0 % and of the RVA, 3.8 %. The total prevalence of variation in entry level into the TF was 7.0 % for the LVA and 6.2 % for the RVA. Recognition and reporting of these variations is important in interpreting CT angiography to prevent complications during surgery of the aortic arch or lower neck.
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Comparative Study
Intracranial artery velocity measurement using 4D PC MRI at 3 T: comparison with transcranial ultrasound techniques and 2D PC MRI.
4D phase contrast MR imaging (4D PC MRI) has been introduced for spatiotemporal evaluation of intracranial hemodynamics in various cerebrovascular diseases. However, it still lacks validation with standards of reference. Our goal was to compare blood flow quantification derived from 4D PC MRI with transcranial ultrasound and 2D PC MRI. ⋯ 4D PC MRI appears as valid alternative for intracranial velocity measurement consistent with previous reference standards, foremost with TCD. Spatiotemporal averaging effects might contribute to vessel size-dependent mild underestimation of velocities in smaller (MCA), and overestimation in larger-sized (BA and ICA) arteries, respectively. Complete spatiotemporal flow analysis may be advantageous in anatomically complex regions (e.g. carotid siphon) relative to restrictions of ultrasound techniques.
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Comparative Study
Functional lesions in dysphagia due to acute stroke: discordance between abnormal findings of bedside swallowing assessment and aspiration on videofluorography.
Bedside swallowing assessments are often used to assess dysphagia. However, in some patients, aspiration pneumonia occurs without any problems on bedside swallowing assessments and some patients do not suffer aspiration pneumonia despite abnormal results of bedside swallowing assessments in acute stroke. To detect the differences of lesions related to bedside swallowing assessment abnormality and aspiration, we investigated swallowing-related functional lesions in terms of cerebral blood flow in patients with dysphagia after stroke. ⋯ Based on the analysis of cerebral blood flow, functional lesions differed across abnormal repetitive saliva swallowing test and abnormal modified water swallowing test findings and aspiration on videofluorography, and each test may assess different functions among the many processes involved in swallowing.
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Comparative Study
Axial 3D gradient-echo imaging for improved multiple sclerosis lesion detection in the cervical spinal cord at 3T.
In multiple sclerosis (MS), spinal cord imaging can help in diagnosis and follow-up evaluation. However, spinal cord magnetic resonance imaging (MRI) is technically challenging, and image quality, particularly in the axial plane, is typically poor compared to brain MRI. Because gradient-recalled echo (GRE) images might offer improved contrast resolution within the spinal cord at high magnetic field strength, both without and with a magnetization transfer prepulse, we compared them to T2-weighted fast-spin-echo (T2-FSE) images for the detection of MS lesions in the cervical cord at 3T. ⋯ Axial 3D GRE sequences are useful for MS lesion detection when compared to 2D T2-FSE sequences in the cervical spinal cord at 3T and should be considered when examining intramedullary spinal cord lesions.
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Vertebral artery hypoplasia (VAH), which has been found in about 10 % of normal individuals, does not produce symptoms but may be associated with an increased risk of cerebral posterior circulation ischemic (PCI) stroke. The aims of this study were to determine the prevalence of VAH in Chinese patients with cerebral infarction and investigate whether VAH is an independent risk factor for PCI stroke. ⋯ Our results show that VAH is not rare in Chinese patients with stroke and that its presence increases the risk of PCI stroke.