scholarly journals The ischemic penumbra: From concept to reality

2020 ◽  
pp. 174749302097522
Author(s):  
Charlotte M Ermine ◽  
Andrew Bivard ◽  
Mark W Parsons ◽  
Jean-Claude Baron
Keyword(s):  
Clinical Practice ◽  
Animal Studies ◽  
Treatment Time ◽  
Time Window ◽  
Imaging Techniques ◽  
Reperfusion Therapy ◽  
Ischemic Penumbra ◽  
Positron Emission ◽  
Imaging Research ◽  
Ischaemic Penumbra

The discovery that brain tissue could potentially be salvaged from ischaemia due to stroke, has led to major advances in the development of therapies for ischemic stroke. In this review, we detail the advances in the understanding of this area termed the ischaemic penumbra, from its discovery to the evolution of imaging techniques, and finally some of the treatments developed. Evolving from animal studies from the 70s and 80s and translated to clinical practice, the field of ischemic reperfusion therapy has largely been guided by an array of imaging techniques developed to positively identify the ischemic penumbra, including positron emission tomography, computed tomography and magnetic resonance imaging. More recently, numerous penumbral identification imaging studies have allowed for a better understanding of the progression of the ischaemic core at the expense of the penumbra, and identification of patients than can benefit from reperfusion therapies in the acute phase. Importantly, 40 years of critical imaging research on the ischaemic penumbra have allowed for considerable extension of the treatment time window and better patient selection for reperfusion therapy. The translation of the penumbra concept into routine clinical practice has shown that “tissue is at least as important as time.”

scholarly journals Ischemic Penumbra: A Personal View

2021 ◽  
pp. 1-10
Author(s):  
Stephen M. Davis ◽  
Geoffrey A. Donnan
Keyword(s):  
Time Window ◽  
Imaging Techniques ◽  
Intravenous Thrombolysis ◽  
Ischemic Penumbra ◽  
Mobile Platforms ◽  
Personal View ◽  
Penumbral Imaging ◽  
Positron Emission ◽  
Slow Growing ◽  
Over 40 Years

The concept of the ischemic penumbra was defined over 40 years ago by Lindsay Symon and his group and is now an established principle of all acute ischemic stroke therapies. These reperfusion treatments rescue threatened, critically hypoperfused brain tissue and have been proven to improve clinical outcomes. We have been fortunate to have observed and played a small part in the penumbral story from its beginnings in the 1970s to its pivotal position today. Over this period, we have witnessed penumbral imaging evolve from positron emission tomography through to magnetic resonance imaging and now predominantly computed tomography perfusion, with the advent of automated imaging facilitating case selection for reperfusion therapies. We and others have conducted clinical trials using penumbral imaging to extend the time window for intravenous thrombolysis and select patients for thrombectomy. Together with the concept of fast- and slow-growing ischemic infarct patterns, this embeds the penumbral principle in everyday clinical management. The opportunity now exists to make penumbral imaging even more portable, affordable, and more widely available using mobile platforms, novel imaging techniques, digital linkage, and artificial intelligence.

scholarly journals Neurological update: neuroimaging in dementia

2020 ◽  
Vol 267 (11) ◽  
pp. 3429-3435
Author(s):  
Timothy Rittman
Keyword(s):  
Artificial Intelligence ◽  
Positron Emission Tomography ◽  
Clinical Practice ◽  
Imaging Techniques ◽  
Emission Tomography ◽  
Structural Imaging ◽  
Regulatory Issues ◽  
Positron Emission ◽  
Remarkable Progress

Abstract Neuroimaging for dementia has made remarkable progress in recent years, shedding light on diagnostic subtypes of dementia, predicting prognosis and monitoring pathology. This review covers some updates in the understanding of dementia using structural imaging, positron emission tomography (PET), structural and functional connectivity, and using big data and artificial intelligence. Progress with neuroimaging methods allows neuropathology to be examined in vivo, providing a suite of biomarkers for understanding neurodegeneration and for application in clinical trials. In addition, we highlight quantitative susceptibility imaging as an exciting new technique that may prove to be a sensitive biomarker for a range of neurodegenerative diseases. There are challenges in translating novel imaging techniques to clinical practice, particularly in developing standard methodologies and overcoming regulatory issues. It is likely that clinicians will need to lead the way if these obstacles are to be overcome. Continued efforts applying neuroimaging to understand mechanisms of neurodegeneration and translating them to clinical practice will complete a revolution in neuroimaging.

Diagnosis and Management of Cardiomyopathies – A Focus on Genetics, Cardiac Magnetic Resonance and Clinical Features

2011 ◽  
Vol 7 (3) ◽  
pp. 225
Author(s):  
Gianfranco Sinagra ◽  
Michele Moretti ◽  
Giancarlo Vitrella ◽  
Marco Merlo ◽  
Rossana Bussani ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Routine Clinical Practice ◽  
Clinical Approach ◽  
Diagnosis And Management ◽  
Made In

In recent years, outstanding progress has been made in the diagnosis and treatment of cardiomyopathies. Genetics is emerging as a primary point in the diagnosis and management of these diseases. However, molecular genetic analyses are not yet included in routine clinical practice, mainly because of their elevated costs and execution time. A patient-based and patient-oriented clinical approach, coupled with new imaging techniques such as cardiac magnetic resonance, can be of great help in selecting patients for molecular genetic analysis and is crucial for a better characterisation of these diseases. This article will specifically address clinical, magnetic resonance and genetic aspects of the diagnosis and management of cardiomyopathies.

A Novel Secure and Robust encryption scheme for medical images

2020 ◽  
Vol 16 ◽  
Author(s):  
Siyamol Chirakkarottu ◽  
Sheena Mathew
Keyword(s):  
Medical Images ◽  
Technological Development ◽  
Imaging Techniques ◽  
Chaotic Map ◽  
Two Phase ◽  
Positron Emission ◽  
Medical Diagnostic ◽  
Wireless Medium ◽  
Health Care Applications ◽  
Magnetic Resonance Imaging Mri

Background: Medical imaging encloses different imaging techniques and processes to image the human body for medical diagnostic and treatment purposes. Hence it plays an important role to improve public health. The technological development in biomedical imaging specifically in X-ray, Computed Tomography (CT), nuclear ultrasound including Positron Emission Tomography (PET), optical and Magnetic Resonance Imaging (MRI) can provide valuable information unique to a person. Objective: In health care applications, the images are needed to be exchanged mostly over wireless medium. The diagnostic images with confidential information of a patient need to be protected from unauthorized access during transmission. In this paper, a novel encryption method is proposed to improve the security and integrity of medical images. Methods: Chaotic map along with DNA cryptography is used for encryption. The proposed method describes a two phase encryption of medical images. Results: Performance of the proposed method is also tested by various analysis metrics. Robustness of the method against different noises and attacks is analyzed. Conclusion: The results show that the method is efficient and well suitable to medical images.

scholarly journals Late Thrombectomy in Clinical Practice

2021 ◽  
Author(s):  
Moriz Herzberg ◽  
Korbinian Scherling ◽  
Robert Stahl ◽  
Steffen Tiedt ◽  
Frank A. Wollenweber ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Clinical Outcome ◽  
Perfusion Imaging ◽  
Time Window ◽  
Ct Perfusion ◽  
Large Trial ◽  
Real World Data ◽  
Baseline Trial ◽  
Good Outcome ◽  
Number Of Patients

Abstract Background and Purpose To provide real-world data on outcome and procedural factors of late thrombectomy patients. Methods We retrospectively analyzed patients from the multicenter German Stroke Registry. The primary endpoint was clinical outcome on the modified Rankin scale (mRS) at 3 months. Trial-eligible patients and the subgroups were compared to the ineligible group. Secondary analyses included multivariate logistic regression to identify predictors of good outcome (mRS ≤ 2). Results Of 1917 patients who underwent thrombectomy, 208 (11%) were treated within a time window ≥ 6–24 h and met the baseline trial criteria. Of these, 27 patients (13%) were eligible for DAWN and 39 (19%) for DEFUSE3 and 156 patients were not eligible for DAWN or DEFUSE3 (75%), mainly because there was no perfusion imaging (62%; n = 129). Good outcome was not significantly higher in trial-ineligible (27%) than in trial-eligible (20%) patients (p = 0.343). Patients with large trial-ineligible CT perfusion imaging (CTP) lesions had significantly more hemorrhagic complications (33%) as well as unfavorable outcomes. Conclusion In clinical practice, the high number of patients with a good clinical outcome after endovascular therapy ≥ 6–24 h as in DAWN/DEFUSE3 could not be achieved. Similar outcomes are seen in patients selected for EVT ≥ 6 h based on factors other than CTP. Patients triaged without CTP showed trends for shorter arrival to reperfusion times and higher rates of independence.

scholarly journals Recent Progress in the Molecular Imaging of Nonalcoholic Fatty Liver Disease

2021 ◽  
Vol 22 (14) ◽  
pp. 7348
Author(s):  
Olivia Wegrzyniak ◽  
Maria Rosestedt ◽  
Olof Eriksson
Keyword(s):  
Liver Disease ◽  
Molecular Imaging ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Imaging Techniques ◽  
Current Status ◽  
Nonalcoholic Fatty Liver ◽  
Positron Emission ◽  
Activated Fibroblasts

Pathological fibrosis of the liver is a landmark feature in chronic liver diseases, including nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Diagnosis and assessment of progress or treatment efficacy today requires biopsy of the liver, which is a challenge in, e.g., longitudinal interventional studies. Molecular imaging techniques such as positron emission tomography (PET) have the potential to enable minimally invasive assessment of liver fibrosis. This review will summarize and discuss the current status of the development of innovative imaging markers for processes relevant for fibrogenesis in liver, e.g., certain immune cells, activated fibroblasts, and collagen depositions.

scholarly journals In Vivo Imaging of Biodegradable Implants and Related Tissue Biomarkers

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2348
Author(s):  
Leon Riehakainen ◽  
Chiara Cavallini ◽  
Paolo Armanetti ◽  
Daniele Panetta ◽  
Davide Caramella ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Imaging Techniques ◽  
Special Focus ◽  
Tissue Remodelling ◽  
Biodegradable Implant ◽  
Advantages And Disadvantages ◽  
Non Invasive ◽  
Positron Emission ◽  
Longitudinal Imaging

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.

scholarly journals The Clinical Value of PET with Amino Acid Tracers for Gliomas WHO Grade II

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Anja Smits ◽  
Brigitta G. Baumert
Keyword(s):  
Amino Acid ◽  
Hot Spot ◽  
Imaging Techniques ◽  
Biological Behavior ◽  
Optimal Timing ◽  
Low Grade ◽  
Clinical Value ◽  
Who Grade ◽  
Positron Emission ◽  
Therapeutic Procedures

The clinical management of adults with low-grade gliomas (LGGs) remains a challenge. There is no curative treatment, and management of individual patients is a matter of deciding optimal timing as well as right treatment modality. In addition to conventional imaging techniques, positron emission tomography (PET) with amino acid tracers can facilitate diagnostic and therapeutic procedures. In this paper, the clinical applications of PET with amino acid tracers 11C-methyl-L-methionine (MET) and 18F-fluoro-ethyl-L-tyrosine (FET) for patients with LGG are summarized. We also discuss the value of PET for the long-term followup of this patient group. Monitoring metabolic activity by PET in individual patients during course of disease will provide insight in the biological behavior and evolution of these tumors. As such, spatial changes in tumor activity over time, including shifts of hot-spot regions within the tumor, may reflect intratumoral heterogeneity and correlate to clinical parameters.

Review of clinical trials of neuroprotection in acute spinal cord injury

1999 ◽  
Vol 6 (1) ◽  
pp. E10 ◽  
Author(s):  
Charles H. Tator ◽  
Michael G. Fehlings
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Clinical Trials ◽  
Treatment Time ◽  
Time Window ◽  
Current Knowledge ◽  
Acute Spinal Cord Injury ◽  
Randomized Controlled Studies ◽  
Cord Injury ◽  
Therapeutic Time Window

In this paper the authors review the clinical trials of neuroprotection that have been performed for the treatment of acute spinal cord injury (SCI). The biological rationale for the selection of each treatment modality is discussed with reference to current knowledge of the principles in the management of acute SCI as well as the primary and secondary injury mechanisms identified by experimental and clinical studies of the pathophysiology of acute SCI. The trials are evaluated with regard to the availability and use of accurate clinical outcome measures, and the methodologies of the trials are critically evaluated with an emphasis on prospective randomized controlled studies. A detailed description and critical analysis are provided of the results of the 10 clinical trials conducted to date in which a randomized prospective controlled design has been used. The issue of the therapeutic time window in acute SCI is discussed. To date, methylprednisolone is the only effective neuroprotective agent that has been established for use in human SCI, and the only therapeutic time window established in human SCI is a maximum trauma-to-treatment time of 8 hours.

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