Ultra-low-field magnetization transfer imaging at 0.055T with low specific absorption rate.

Purpose: To demonstrate magnetization transfer (MT) effects with low specific absorption rate (SAR) on ultra-low-field (ULF) MRI.

Methods: MT imaging was implemented by using sinc-modulated RF pulse train (SPT) modules to provide bilateral off-resonance irradiation. They were incorporated into 3D gradient echo (GRE) and fast spin echo (FSE) protocols on a shielding-free 0.

Deep learning enabled fast 3D brain MRI at 0.055 tesla.

In recent years, there has been an intensive development of portable ultralow-field magnetic resonance imaging (MRI) for low-cost, shielding-free, and point-of-care applications. However, its quality is poor and scan time is long. We propose a fast acquisition and deep learning reconstruction framework to accelerate brain MRI at 0.

Location-Specific Hematoma Volume Cutoff and Clinical Outcomes in Intracerebral Hemorrhage.

Background: Major intracerebral hemorrhage (ICH) trials have largely been unable to demonstrate therapeutic benefit in improving functional outcomes. This may be partly due to the heterogeneity of ICH outcomes based on their location, where a small strategic ICH could be debilitating, thus confounding therapeutic effects. We aimed to determine the ideal hematoma volume cutoff for different ICH locations in predicting ICH outcomes.

Pushing the limits of low-cost ultra-low-field MRI by dual-acquisition deep learning 3D superresolution.

Purpose: Recent development of ultra-low-field (ULF) MRI presents opportunities for low-power, shielding-free, and portable clinical applications at a fraction of the cost. However, its performance remains limited by poor image quality. Here, a computational approach is formulated to advance ULF MR brain imaging through deep learning of large-scale publicly available 3T brain data.

Chemical Exchange Saturation Transfer Magnetic Resonance Imaging for Longitudinal Assessment of Intracerebral Hemorrhage and Deferoxamine Treatment at 3T in a Mouse Model.

Background: Noninvasive imaging of molecular alterations after intracerebral hemorrhage (ICH) could provide valuable information to guide and monitor treatments. Chemical exchange saturation transfer (CEST) magnetic resonance imaging has demonstrated promises in identifying proliferation, necrosis, and changes in cellularity in brain tumors. Here, we applied CEST magnetic resonance imaging to monitor molecular changes in hematoma without and with treatment noninvasively over 2 weeks at 3T using endogenous contrast.

Modulation of the proteoglycan receptor PTPσ promotes white matter integrity and functional recovery after intracerebral hemorrhage stroke in mice.

Background: Intracerebral hemorrhage (ICH) is associated with high morbidity and mortality rates. However, extant investigations have mainly focused on gray matter injury within the primary injury site after ICH rather than on white matter (WM) injury in the brain and spinal cord. This focus partly accounts for the diminished therapeutic discovery.

Development and Validation of Indicators for Population Injury Surveillance in Hong Kong: Development and Usability Study.

Background: Injury is an increasingly pressing global health issue. An effective surveillance system is required to monitor the trends and burden of injuries.

Objective: This study aimed to identify a set of valid and context-specific injury indicators to facilitate the establishment of an injury surveillance program in Hong Kong.

Predictive value of Bispectral Index (BIS) in emergency neurosurgical patients: Loss of BIS reactivity to propofol predicts poor functional outcomes.

Aim: In emergency neurosurgical patients, evaluation with Glasgow Coma Scale (GCS) alone immediately after stopping sedation post-operatively might not differentiate those with good recovery from those with poor outcomes at 3 months. This study aimed to evaluate the prognostic value of measuring the Bispectral Index (BIS) and the correlation to propofol dosage during the use of sedation in the early post-operative period.

Methods: This is a prospective study on consecutive post-operative neurosurgical patients admitted to the neurosurgical ICU on propofol sedation.

A previous hemorrhagic stroke protects against a subsequent stroke via microglia alternative polarization.

Microglia in hemorrhagic stroke contribute to both acute-phase exacerbation and late-phase attenuation of injury. Here, by using the mouse model, we reported that the shift in polarization of microglia from M1 to M2 phenotype could be altered by a past 'mini' stroke, resulting in better neurological function recovery, faster attenuation of lesion volume, and better survival. In mice with a previous stroke, M2 predominance appeared markedly in advance compared to mice without a previous stroke.

Surgical revascularization for moyamoya angiopathy: Clinical and radiological outcomes of direct and indirect bypasses in 86 affected hemispheres.

Moyamoya is a progressive cerebral angiopathy that entails a formidable natural history of repeated ischemic or haemorrhagic insults if not intervened. The potential advantages of direct/combined bypass can be harvested only if they are not outweighed by perioperative morbidity. Direct bypasses for the paediatric group have been less utilized because of small vessel calibres and an inherently more robust angioplasticity.

Postcooling But Not Precooling Benefits Motor Recovery by Suppressing Cell Death After Surgical Spinal Cord Injury in Rats.

Background: Surgical spinal cord injury (SSCI) is often inevitable in patients with intramedullary lesions. Although regional hypothermia (RH) has been demonstrated neuroprotective, the value of priming RH in SSCI has never been studied. Herein, the authors investigated the impact of pre- and post-RH on neurologic recovery in a clinically relevant model.

A low-cost and shielding-free ultra-low-field brain MRI scanner.

Magnetic resonance imaging is a key diagnostic tool in modern healthcare, yet it can be cost-prohibitive given the high installation, maintenance and operation costs of the machinery. There are approximately seven scanners per million inhabitants and over 90% are concentrated in high-income countries. We describe an ultra-low-field brain MRI scanner that operates using a standard AC power outlet and is low cost to build.

3D dissimilar-siamese-u-net for hyperdense Middle cerebral artery sign segmentation.

The hyperdense middle cerebral artery sign (HMCAS) representing a thromboembolus has been declared as a vital CT finding for intravascular thrombus in the diagnosis of acute ischemia stroke. Early recognition of HMCAS can assist in patient triage and subsequent thrombolysis or thrombectomy treatment. A total of 624 annotated head non-contrast-enhanced CT (NCCT) image scans were retrospectively collected from multiple public hospitals in Hong Kong.

Quantification of injury burden using multiple data sources: a longitudinal study.

Quantification of injury burden is vital for injury prevention, as it provides a guide for setting policies and priorities. This study generated a set of Hong Kong specific disability weights (DWs) derived from patient experiences and hospital records. Patients were recruited from the Accident and Emergency Department (AED) of three major trauma centers in Hong Kong between September 2014 and December 2015 and subsequently interviewed with a focus on health-related quality of life at most three times over a 12-month period.

Protracted Morphological Changes in the Corticospinal Tract Within the Cervical Spinal Cord After Intracerebral Hemorrhage in the Right Striatum of Mice.

Intracerebral hemorrhage (ICH) is associated with high morbidity and mortality rates. Currently, there is no promising treatment that improves prognosis significantly. While a thorough investigation of the pathological process within the primary site of injury in the brain has been conducted by the research field, the focus was mainly on gray matter injury, which partly accounted for the failure of discovery of clinically efficacious treatments.

More Than a Metabolic Enzyme: MTHFD2 as a Novel Target for Anticancer Therapy?

The bifunctional methylenetetrahydrofolate dehydrogenase/cyclohydrolase (MTHFD2) is a mitochondrial one-carbon folate metabolic enzyme whose role in cancer was not known until recently. MTHFD2 is highly expressed in embryos and a wide range of tumors but has low or absent expression in most adult differentiated tissues. Elevated MTHFD2 expression is associated with poor prognosis in both hematological and solid malignancy.

From bedside to webside: A neurological clinical teaching experience.

With this issue we begin print publishing the responses received in our call for Medical Education Adaptations: Lessons learned from educators' experiences rapidly transforming practice on account of COVID‐19 related disruption.

Automated Hierarchy Evaluation System of Large Vessel Occlusion in Acute Ischemia Stroke.

Background: The detection of large vessel occlusion (LVO) plays a critical role in the diagnosis and treatment of acute ischemic stroke (AIS). Identifying LVO in the pre-hospital setting or early stage of hospitalization would increase the patients' chance of receiving appropriate reperfusion therapy and thereby improve neurological recovery.

Methods: To enable rapid identification of LVO, we established an automated evaluation system based on all recorded AIS patients in Hong Kong Hospital Authority's hospitals in 2016.

Successful Emergency Rescue Open Embolectomy for Failed Endovascular Thrombectomy in Acute Ischemic Stroke: 2-Dimensional Operative Video.

This operative video demonstrates an open surgical thrombectomy for a 61-yr-old woman with failed endovascular embolectomy in acute ischemic stroke. Good functional outcome can be achieved when this operation is timely performed within the therapeutic window. This patient has atrial fibrillation.

Burden of large vessel occlusion stroke and the service gap of thrombectomy: A population-based study using a territory-wide public hospital system registry.

Background: Ischemic stroke due to large vessel occlusion can be effectively treated with thrombectomy but access to this treatment is limited in many parts of the world. Local incidence of large vessel occlusion is critical in determining the development of thrombectomy service, but reliable data from Asian countries are lacking.

Aims: We performed a population-based study to estimate the burden of large vessel occlusion and the service gap for thrombectomy in Hong Kong.

Improving Survival with Tranexamic Acid in Cerebral Contusions or Traumatic Subarachnoid Hemorrhage: Univariate and Multivariate Analysis of Independent Factors Associated with Lower Mortality.

Background: Fall with head injury is a pervasive challenge, especially in the aging population. Contributing factors for mortality include the development of cerebral contusions and delayed traumatic intracerebral hematoma. Currently, there is no established specific treatment for these conditions.