Recent advances have enabled delivery of high-intensity focused ultrasound through the intact human cranium with magnetic resonance imaging (MRI) guidance. This preliminary study investigates the use ...of transcranial MRI-guided focused ultrasound thalamotomy for the treatment of essential tremor.
From February 2011 through December 2011, in an open-label, uncontrolled study, we used transcranial MRI-guided focused ultrasound to target the unilateral ventral intermediate nucleus of the thalamus in 15 patients with severe, medication-refractory essential tremor. We recorded all safety data and measured the effectiveness of tremor suppression using the Clinical Rating Scale for Tremor to calculate the total score (ranging from 0 to 160), hand subscore (primary outcome, ranging from 0 to 32), and disability subscore (ranging from 0 to 32), with higher scores indicating worse tremor. We assessed the patients' perceptions of treatment efficacy with the Quality of Life in Essential Tremor Questionnaire (ranging from 0 to 100%, with higher scores indicating greater perceived disability).
Thermal ablation of the thalamic target occurred in all patients. Adverse effects of the procedure included transient sensory, cerebellar, motor, and speech abnormalities, with persistent paresthesias in four patients. Scores for hand tremor improved from 20.4 at baseline to 5.2 at 12 months (P=0.001). Total tremor scores improved from 54.9 to 24.3 (P=0.001). Disability scores improved from 18.2 to 2.8 (P=0.001). Quality-of-life scores improved from 37% to 11% (P=0.001).
In this pilot study, essential tremor improved in 15 patients treated with MRI-guided focused ultrasound thalamotomy. Large, randomized, controlled trials will be required to assess the procedure's efficacy and safety. (Funded by the Focused Ultrasound Surgery Foundation; ClinicalTrials.gov number, NCT01304758.).
Whether brain imaging can identify patients who are most likely to benefit from therapies for acute ischemic stroke and whether endovascular thrombectomy improves clinical outcomes in such patients ...remains unclear.
In this study, we randomly assigned patients within 8 hours after the onset of large-vessel, anterior-circulation strokes to undergo mechanical embolectomy (Merci Retriever or Penumbra System) or receive standard care. All patients underwent pretreatment computed tomography or magnetic resonance imaging of the brain. Randomization was stratified according to whether the patient had a favorable penumbral pattern (substantial salvageable tissue and small infarct core) or a nonpenumbral pattern (large core or small or absent penumbra). We assessed outcomes using the 90-day modified Rankin scale, ranging from 0 (no symptoms) to 6 (dead).
Among 118 eligible patients, the mean age was 65.5 years, the mean time to enrollment was 5.5 hours, and 58% had a favorable penumbral pattern. Revascularization in the embolectomy group was achieved in 67% of the patients. Ninety-day mortality was 21%, and the rate of symptomatic intracranial hemorrhage was 4%; neither rate differed across groups. Among all patients, mean scores on the modified Rankin scale did not differ between embolectomy and standard care (3.9 vs. 3.9, P=0.99). Embolectomy was not superior to standard care in patients with either a favorable penumbral pattern (mean score, 3.9 vs. 3.4; P=0.23) or a nonpenumbral pattern (mean score, 4.0 vs. 4.4; P=0.32). In the primary analysis of scores on the 90-day modified Rankin scale, there was no interaction between the pretreatment imaging pattern and treatment assignment (P=0.14).
A favorable penumbral pattern on neuroimaging did not identify patients who would differentially benefit from endovascular therapy for acute ischemic stroke, nor was embolectomy shown to be superior to standard care. (Funded by the National Institute of Neurological Disorders and Stroke; MR RESCUE ClinicalTrials.gov number, NCT00389467.).
As the global COVID-19 pandemic evolves, our knowledge of the respiratory and non-respiratory symptoms continues to grow. One such symptom, anosmia, may be a neurologic marker of coronavirus ...infection and the initial presentation of infected patients. Because this symptom is not routinely investigated by imaging, there is conflicting literature on neuroimaging abnormalities related to COVID-19-related anosmia. We present a novel case of COVID-19 anosmia with definitive olfactory bulb atrophy compared with pre-COVID imaging. The patient had prior MR imaging related to a history of prolactinoma that provided baseline volumes of her olfactory bulbs. After a positive diagnosis of COVID-19 and approximately 2 months duration of anosmia, an MRI was performed that showed clear interval olfactory bulb atrophy. This diagnostic finding is of prognostic importance and indicates that the olfactory entry point to the brain should be further investigated to improve our understanding of COVID infectious pathophysiology.
Double diffusion encoding MRI for the clinic Yang, Grant; Tian, Qiyuan; Leuze, Christoph ...
Magnetic resonance in medicine,
August 2018, Letnik:
80, Številka:
2
Journal Article
Many clinical applications based on deep learning and pertaining to radiology have been proposed and studied in radiology for classification, risk assessment, segmentation tasks, diagnosis, ...prognosis, and even prediction of therapy responses. There are many other innovative applications of AI in various technical aspects of medical imaging, particularly applied to the acquisition of images, ranging from removing image artifacts, normalizing/harmonizing images, improving image quality, lowering radiation and contrast dose, and shortening the duration of imaging studies. This article will address this topic and will seek to present an overview of deep learning applied to neuroimaging techniques.
This article reviews the physical principles of MRI-guided focused ultra-sound and discusses current and potential applications of this exciting technology.
MRI-guided focused ultrasound is a new ...minimally invasive method of targeted tissue thermal ablation that may be of use to treat central neuropathic pain, essential tremor, Parkinson tremor, and brain tumors. The system has also been used to temporarily disrupt the blood-brain barrier to allow targeted drug delivery to brain tumors.
Summary Multimodal CT features prominently in the rapidly evolving field of acute stroke triage, with perfusion CT applications at the forefront of many clinical research efforts. Perfusion CT offers ...a time sensitive and widely practicable assessment of cerebral hemodynamics and parenchymal viability that is key in acute stroke management. The following article reviews perfusion CT foundations and technical considerations while highlighting recent modality advances and frontline clinical applications. Ischemic penumbra and other prognostic imaging biomarkers are discussed in the context of results of recent clinical trials (MR-RESCUE, IMS III, Tenecteplase, etc.), with an emphasis on evidence based image guided stroke triage.
What’s new in imaging of acute stroke? Shams, Mana; Shams, Sara; Wintermark, Max
Intensive care medicine,
07/2020, Letnik:
46, Številka:
7
Journal Article
Imaging of Intracranial Hemorrhage Heit, Jeremy J; Iv, Michael; Wintermark, Max
Journal of stroke,
01/2017, Letnik:
19, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Intracranial hemorrhage is common and is caused by diverse pathology, including trauma, hypertension, cerebral amyloid angiopathy, hemorrhagic conversion of ischemic infarction, cerebral aneurysms, ...cerebral arteriovenous malformations, dural arteriovenous fistula, vasculitis, and venous sinus thrombosis, among other causes. Neuroimaging is essential for the treating physician to identify the cause of hemorrhage and to understand the location and severity of hemorrhage, the risk of impending cerebral injury, and to guide often emergent patient treatment. We review CT and MRI evaluation of intracranial hemorrhage with the goal of providing a broad overview of the diverse causes and varied appearances of intracranial hemorrhage.
Muscle fat infiltration (MFI) of the deep cervical spine extensors has been observed in cervical spine conditions using time-consuming and rater-dependent manual techniques. Deep learning ...convolutional neural network (CNN) models have demonstrated state-of-the-art performance in segmentation tasks. Here, we train and test a CNN for muscle segmentation and automatic MFI calculation using high-resolution fat-water images from 39 participants (26 female, average = 31.7 ± 9.3 years) 3 months post whiplash injury. First, we demonstrate high test reliability and accuracy of the CNN compared to manual segmentation. Then we explore the relationships between CNN muscle volume, CNN MFI, and clinical measures of pain and neck-related disability. Across all participants, we demonstrate that CNN muscle volume was negatively correlated to pain (R = -0.415, p = 0.006) and disability (R = -0.286, p = 0.045), while CNN MFI tended to be positively correlated to disability (R = 0.214, p = 0.105). Additionally, CNN MFI was higher in participants with persisting pain and disability (p = 0.049). Overall, CNN's may improve the efficiency and objectivity of muscle measures allowing for the quantitative monitoring of muscle properties in disorders of and beyond the cervical spine.
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