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Jin T, Wang J, Chung J, Hitchens TK, Sun D, Mettenburg J, Wang P. Amide proton transfer MRI at 9.4 T for differentiating tissue acidosis in a rodent model of ischemic stroke. Magn Reson Med 2024. [PMID: 38923094 DOI: 10.1002/mrm.30194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 04/08/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024]
Abstract
PURPOSE Differentiating ischemic brain damage is critical for decision making in acute stroke treatment for better outcomes. We examined the sensitivity of amide proton transfer (APT) MRI, a pH-weighted imaging technique, to achieve this differentiation. METHODS In a rat stroke model, the ischemic core, oligemia, and the infarct-growth region (IGR) were identified by tracking the progression of the lesions. APT MRI signals were measured alongside ADC, T1, and T2 maps to evaluate their sensitivity in distinguishing ischemic tissues. Additionally, stroke under hyperglycemic conditions was studied. RESULTS The APT signal in the IGR decreased by about 10% shortly after stroke onset, and further decreased to 35% at 5 h, indicating a progression from mild to severe acidosis as the lesion evolved into infarction. Although ADC, T1, and T2 contrasts can only detect significant differences between the IGR and oligemia for a portion of the stroke duration, APT contrast consistently differentiates between them at all time points. However, the contrast to variation ratio at 1 h is only about 20% of the contrast to variation ratio between the core and normal tissues, indicating limited sensitivity. In the ischemic core, the APT signal decreases to about 45% and 33% of normal tissue level at 1 h for the normoglycemic and hyperglycemic groups, respectively, confirming more severe acidosis under hyperglycemia. CONCLUSION The sensitivity of APT MRI is high in detecting severe acidosis of the ischemic core but is much lower in detecting mild acidosis, which may affect the accuracy of differentiation between the IGR and oligemia.
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Affiliation(s)
- Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jicheng Wang
- Department of Urology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Julius Chung
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - T Kevin Hitchens
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joseph Mettenburg
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ping Wang
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Kuo DP, Chen YC, Cheng SJ, Hsieh KLC, Ou CY, Li YT, Chen CY. Ischemia-reperfusion injury in a salvaged penumbra: Longitudinal high-tesla perfusion magnetic resonance imaging in a rat model. Magn Reson Imaging 2024; 112:47-53. [PMID: 38909765 DOI: 10.1016/j.mri.2024.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/23/2024] [Accepted: 06/20/2024] [Indexed: 06/25/2024]
Abstract
INTRODUCTION Although ischemia-reperfusion (I/R) injury varies between cortical and subcortical regions, its effects on specific regions remain unclear. In this study, we used various magnetic resonance imaging (MRI) techniques to examine the spatiotemporal dynamics of I/R injury within the salvaged ischemic penumbra (IP) and reperfused ischemic core (IC) of a rodent model, with the aim of enhancing therapeutic strategies by elucidating these dynamics. MATERIALS AND METHODS A total of 17 Sprague-Dawley rats were subjected to 1 h of transient middle cerebral artery occlusion with a suture model. MRI, including diffusion tensor imaging (DTI), T2-weighted imaging, perfusion-weighted imaging, and T1 mapping, was conducted at multiple time points for up to 5 days during the I/R phases. The spatiotemporal dynamics of blood-brain barrier (BBB) modifications were characterized through changes in T1 within the IP and IC regions and compared with mean diffusivity (MD), T2, and cerebral blood flow. RESULTS During the I/R phases, the MD of the IC initially decreased, normalized after recanalization, decreased again at 24 h, and peaked on day 5. By contrast, the IP remained relatively stable. Both the IP and IC exhibited hyperperfusion, with the IP reaching its peak at 24 h, followed by resolution, whereas hyperperfusion was maintained in the IC until day 5. Despite hyperperfusion, the IP maintained an intact BBB, whereas the IC experienced persistent BBB leakage. At 24 h, the IC exhibited an increase in the T2 signal, corresponding to regions exhibiting BBB disruption at 5 days. CONCLUSIONS Hyperperfusion and BBB impairment have distinct patterns in the IP and IC. Quantitative T1 mapping may serve as a supplementary tool for the early detection of malignant hyperemia accompanied by BBB leakage, aiding in precise interventions after recanalization. These findings underscore the value of MRI markers in monitoring ischemia-specific regions and customizing therapeutic strategies to improve patient outcomes.
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Affiliation(s)
- Duen-Pang Kuo
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yung-Chieh Chen
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Sho-Jen Cheng
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Kevin Li-Chun Hsieh
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chen-Yin Ou
- Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yi-Tien Li
- Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Research Center for Neuroscience, Taipei Medical University, Taipei, Taiwan; Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
| | - Cheng-Yu Chen
- Department of Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan; Translational Imaging Research Center, Taipei Medical University Hospital, Taipei, Taiwan; Research Center for Artificial Intelligence in Medicine, Taipei Medical University, Taipei, Taiwan; Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Radiology, National Defense Medical Center, Taipei, Taiwan
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Erdoğan MŞ, Arpak ES, Keles CSK, Villagra F, Işık EÖ, Afşar N, Yucesoy CA, Mur LAJ, Akanyeti O, Saybaşılı H. Biochemical, biomechanical and imaging biomarkers of ischemic stroke: Time for integrative thinking. Eur J Neurosci 2024; 59:1789-1818. [PMID: 38221768 DOI: 10.1111/ejn.16245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 12/12/2023] [Accepted: 12/16/2023] [Indexed: 01/16/2024]
Abstract
Stroke is one of the leading causes of adult disability affecting millions of people worldwide. Post-stroke cognitive and motor impairments diminish quality of life and functional independence. There is an increased risk of having a second stroke and developing secondary conditions with long-term social and economic impacts. With increasing number of stroke incidents, shortage of medical professionals and limited budgets, health services are struggling to provide a care that can break the vicious cycle of stroke. Effective post-stroke recovery hinges on holistic, integrative and personalized care starting from improved diagnosis and treatment in clinics to continuous rehabilitation and support in the community. To improve stroke care pathways, there have been growing efforts in discovering biomarkers that can provide valuable insights into the neural, physiological and biomechanical consequences of stroke and how patients respond to new interventions. In this review paper, we aim to summarize recent biomarker discovery research focusing on three modalities (brain imaging, blood sampling and gait assessments), look at some established and forthcoming biomarkers, and discuss their usefulness and complementarity within the context of comprehensive stroke care. We also emphasize the importance of biomarker guided personalized interventions to enhance stroke treatment and post-stroke recovery.
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Affiliation(s)
| | - Esra Sümer Arpak
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey
| | - Cemre Su Kaya Keles
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey
- Institute of Structural Mechanics and Dynamics in Aerospace Engineering, University of Stuttgart, Stuttgart, Germany
| | - Federico Villagra
- Department of Life Sciences, Aberystwyth University, Aberystwyth, Wales, UK
| | - Esin Öztürk Işık
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey
| | - Nazire Afşar
- Neurology, Acıbadem Mehmet Ali Aydınlar University, İstanbul, Turkey
| | - Can A Yucesoy
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey
| | - Luis A J Mur
- Department of Life Sciences, Aberystwyth University, Aberystwyth, Wales, UK
| | - Otar Akanyeti
- Department of Computer Science, Llandinam Building, Aberystwyth University, Aberystwyth, UK
| | - Hale Saybaşılı
- Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey
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Cho J, Zhang J, Spincemaille P, Zhang H, Nguyen TD, Zhang S, Gupta A, Wang Y. Multi-Echo Complex Quantitative Susceptibility Mapping and Quantitative Blood Oxygen Level-Dependent Magnitude (mcQSM + qBOLD or mcQQ) for Oxygen Extraction Fraction (OEF) Mapping. Bioengineering (Basel) 2024; 11:131. [PMID: 38391617 PMCID: PMC10886243 DOI: 10.3390/bioengineering11020131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
Oxygen extraction fraction (OEF), the fraction of oxygen that tissue extracts from blood, is an essential biomarker used to directly assess tissue viability and function in neurologic disorders. In ischemic stroke, for example, increased OEF can indicate the presence of penumbra-tissue with low perfusion yet intact cellular integrity-making it a primary therapeutic target. However, practical OEF mapping methods are not currently available in clinical settings, owing to the impractical data acquisitions in positron emission tomography (PET) and the limitations of existing MRI techniques. Recently, a novel MRI-based OEF mapping technique, termed QQ, was proposed. It shows high potential for clinical use by utilizing a routine sequence and removing the need for impractical multiple gas inhalations. However, QQ relies on the assumptions of Gaussian noise in susceptibility and multi-echo gradient echo (mGRE) magnitude signals for OEF estimation. This assumption is unreliable in low signal-to-noise ratio (SNR) regions like disease-related lesions, risking inaccurate OEF estimation and potentially impacting clinical decisions. Addressing this, our study presents a novel multi-echo complex QQ (mcQQ) that models realistic Gaussian noise in mGRE complex signals. We implemented mcQQ using a deep learning framework (mcQQ-NET) and compared it with the existing QQ-NET in simulations, ischemic stroke patients, and healthy subjects, using identical training and testing datasets and schemes. In simulations, mcQQ-NET provided more accurate OEF than QQ-NET. In the subacute stroke patients, mcQQ-NET showed a lower average OEF ratio in lesions relative to unaffected contralateral normal tissue than QQ-NET. In the healthy subjects, mcQQ-NET provided uniform OEF maps, similar to QQ-NET, but without unrealistically high OEF outliers in areas of low SNR, such as SNR ≤ 15 (dB). Therefore, mcQQ-NET improves OEF accuracy by more accurately reflecting realistic Gaussian noise in complex mGRE signals. Its enhanced sensitivity to OEF abnormalities, based on more realistic biophysics modeling, suggests that mcQQ-NET has potential for investigating tissue variability in neurologic disorders.
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Affiliation(s)
- Junghun Cho
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY 14228, USA
| | - Jinwei Zhang
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | | | - Hang Zhang
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Thanh D Nguyen
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Shun Zhang
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ajay Gupta
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Yi Wang
- Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
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Fainardi E, Busto G, Morotti A. Automated advanced imaging in acute ischemic stroke. Certainties and uncertainties. Eur J Radiol Open 2023; 11:100524. [PMID: 37771657 PMCID: PMC10523426 DOI: 10.1016/j.ejro.2023.100524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
The purpose of this is study was to review pearls and pitfalls of advanced imaging, such as computed tomography perfusion and diffusion-weighed imaging and perfusion-weighted imaging in the selection of acute ischemic stroke (AIS) patients suitable for endovascular treatment (EVT) in the late time window (6-24 h from symptom onset). Advanced imaging can quantify infarct core and ischemic penumbra using specific threshold values and provides optimal selection parameters, collectively called target mismatch. More precisely, target mismatch criteria consist of core volume and/or penumbra volume and mismatch ratio (the ratio between total hypoperfusion and core volumes) with precise cut-off values. The parameters of target mismatch are automatically calculated with dedicated software packages that allow a quick and standardized interpretation of advanced imaging. However, this approach has several limitations leading to a misclassification of core and penumbra volumes. In fact, automatic software platforms are affected by technical artifacts and are not interchangeable due to a remarkable vendor-dependent variability, resulting in different estimate of target mismatch parameters. In addition, advanced imaging is not completely accurate in detecting infarct core, that can be under- or overestimated. Finally, the selection of candidates for EVT remains currently suboptimal due to the high rates of futile reperfusion and overselection caused by the use of very stringent inclusion criteria. For these reasons, some investigators recently proposed to replace advanced with conventional imaging in the selection for EVT, after the demonstration that non-contrast CT ASPECTS and computed tomography angiography collateral evaluation are not inferior to advanced images in predicting outcome in AIS patients treated with EVT. However, other authors confirmed that CTP and PWI/DWI postprocessed images are superior to conventional imaging in establishing the eligibility of patients for EVT. Therefore, the routine application of automatic assessment of advanced imaging remains a matter of debate. Recent findings suggest that the combination of conventional and advanced imaging might improving our selection criteria.
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Affiliation(s)
- Enrico Fainardi
- Neuroradiology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
- Neuroradiology Unit, Department of Radiology, Careggi University Hospital, Florence, Italy
| | - Giorgio Busto
- Neuroradiology Unit, Department of Radiology, Careggi University Hospital, Florence, Italy
| | - Andrea Morotti
- Department of Neurological and Vision Sciences, Neurology Unit, ASST Spedali Civili, Brescia, Italy
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Wang J, Li Y, Qi L, Mamtilahun M, Liu C, Liu Z, Shi R, Wu S, Yang GY. Advanced rehabilitation in ischaemic stroke research. Stroke Vasc Neurol 2023:svn-2022-002285. [PMID: 37788912 DOI: 10.1136/svn-2022-002285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 03/20/2023] [Indexed: 10/05/2023] Open
Abstract
At present, due to the rapid progress of treatment technology in the acute phase of ischaemic stroke, the mortality of patients has been greatly reduced but the number of disabled survivors is increasing, and most of them are elderly patients. Physicians and rehabilitation therapists pay attention to develop all kinds of therapist techniques including physical therapy techniques, robot-assisted technology and artificial intelligence technology, and study the molecular, cellular or synergistic mechanisms of rehabilitation therapies to promote the effect of rehabilitation therapy. Here, we discussed different animal and in vitro models of ischaemic stroke for rehabilitation studies; the compound concept and technology of neurological rehabilitation; all kinds of biological mechanisms of physical therapy; the significance, assessment and efficacy of neurological rehabilitation; the application of brain-computer interface, rehabilitation robotic and non-invasive brain stimulation technology in stroke rehabilitation.
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Affiliation(s)
- Jixian Wang
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medical, Shanghai, China
| | - Yongfang Li
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medical, Shanghai, China
| | - Lin Qi
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Muyassar Mamtilahun
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Chang Liu
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Ze Liu
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Rubing Shi
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Shengju Wu
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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Guo Y, Kacker K, Chamanzar A, Grover P. EEG Source Imaging of Infarct Core and Penumbra for Ischemic Stroke Patients. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-5. [PMID: 38083009 DOI: 10.1109/embc40787.2023.10340954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
A quantitative method of analyzing EEG signals after stroke onset can help monitor disease progression and tailor treatments. In this work, we present an EEG-based imaging algorithm to estimate the location and size of the stroke infarct core and penumbra tissues. Building on recent advancements in localizing neural silences, we develop an algorithm that utilizes known spectral properties of the infarct core and penumbra to separately localize them. Our algorithm uses these properties to estimate source contributions to the scalp EEG recordings in different frequency bands. Subsequently, it utilizes optimization techniques to search for the affected brain sources iteratively. We test our algorithm on simulated datasets using a realistic MRI head model, achieving center-of-mass error of 12.80mm and 17.24mm, and size estimation error of 21.78% and 36.62% for infarct core and penumbra respectively.
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Discrimination between progressive penumbra and benign oligemia of the diffusion-perfusion mismatch region by amide proton transfer-weighted imaging. Magn Reson Imaging 2023; 99:123-129. [PMID: 36822450 DOI: 10.1016/j.mri.2023.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 02/15/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023]
Abstract
PURPOSE Amide proton transfer-weighted (APTw) imaging was an effective tool to reveal the tissue acidosis of acute ischemic stroke. This study aimed to evaluate the ability of APTw MRI to distinguish progressive penumbra and benign oligemia in the diffusion-perfusion mismatch region. MATERIALS AND METHODS 38 acute cerebral infarction patients who underwent a comprehensive MRI examination, including diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), APT imaging, and a follow-up scan in one week were recruited. There were 12 DWI/PWI match cases. The DWI/PWI mismatch patients were divided into 10 progressive cases and 16 stable cases according to the lesion size on the follow-up DWI image compared to the admission scan. Three ROIs: infarction lesion, peripheral, and contralateral normal regions were measured on each subject's MTRasym map. The Friedman test was used to compare the changes of MTRasym among three different regions within each group. The Kruskal-Wallis ANOVA test was used to compare them among the same region of different groups. The correlation between the MTRasym of the peripheral region and the lesion enlargement was analyzed by the Spearman test. RESULTS The MTRasym at the infarction lesion of all three groups showed significant decrease to the contralateral normal tissue. In the progressive mismatch group, the MTRasym at the peripheral region within the DWI/PWI mismatch showed a significant difference with the contralateral normal region and no difference with the infarct core. Whereas both the MTRasym at the peripheral region of the stable mismatch and match groups had no significant difference with the contralateral side, but the differences were significant from those of the central core. When comparing the peripheral region of three groups, the MTRasym of the progressive mismatch group showed a significant decrease to that of the stable mismatch and match groups. The MTRasym of the peripheral region showed a negative correlation with lesion enlargement. CONCLUSION APTw imaging is promising to stratify the heterogeneous PWI/DWI mismatch region and benefit the clinical treatment.
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Oxygen Challenge Imaging Reveals Differences in Metabolic Activity Between Kurtosis Lesion and Diffusion/Kurtosis Lesion Mismatch in a Rodent Model of Acute Stroke. J Comput Assist Tomogr 2022; 46:792-799. [PMID: 36103679 DOI: 10.1097/rct.0000000000001333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Accurate identification of potentially salvageable tissues is critical for improving acute stroke treatment. A previous study showed that the kurtosis lesion exhibited insignificant response after prompt reperfusion treatment, while the diffusion/kurtosis lesion mismatch could recover after reperfusion. We hypothesized that these 2 regions are in different metabolic states. MATERIALS AND METHODS Transient oxygen challenge (OC) is a procedure that uses oxygen as a metabolic bio-tracer and has been performed to explore metabolic activity in tissues. We combined OC with multiparameter magnetic resonance imaging (including diffusion kurtosis imaging and T2* mapping sequences) to study metabolic activity in the ischemic brain of Sprague Dawley rats. RESULTS Oxygen challenge image analysis revealed changes in T2* values, most significantly in the mean diffusivity (MD)/mean kurtosis (MK) lesion mismatch (22.3 ± 1.6%) and least significantly in the MK lesions (6.6 ± 0.6%). The MD images acquired within 138 ± 9 minutes after ischemia showed a larger ischemic lesion (45.5 ± 3.0% of the total area) than the MK images (33.2 ± 4.2% of the total area). The change rate of the MK value (53.0 ± 4.4%) was higher than that of the MD value (37.5 ± 3.2%). CONCLUSIONS The present study shows that MK lesion and MD/MK lesion mismatch exhibited different metabolic activity states. The MK lesion presented metabolic-related values close to the ischemic core, while at least part of the MD/MK mismatch area was comparable with ischemic penumbra metabolic activity. These findings are important to support image-guided individualized stroke therapies.
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Tedyanto EH, Tini K, Pramana NAK. Magnetic Resonance Imaging in Acute Ischemic Stroke. Cureus 2022; 14:e27224. [PMID: 36035056 PMCID: PMC9399663 DOI: 10.7759/cureus.27224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/25/2022] [Indexed: 11/23/2022] Open
Abstract
Ischemic stroke is one of the leading causes of mortality and disability. The only effective non-surgical treatment for acute ischemic stroke within three to four and a half hours of the onset of symptoms is thrombolytic therapy. Time is of the essence when diagnosing and treating an acute ischemic stroke. After evaluating the advantages and disadvantages of thrombolysis, selecting the ideal patient for the indication is essential. Magnetic Resonance Imaging (MRI) is more sensitive and specific than Computed Tomography (CT) scans when identifying acute ischemic stroke. In approximately 80% of cases, infarcts are detectable within the first 24 hours. MRI can detect an ischemic stroke within a few hours of its onset. Multimodal imaging provides information for the diagnosis of ischemic stroke, patient selection for thrombolytic therapy, and prognosis estimation.
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Lee SJ, Hong JM, Kim JS, Lee JS. Endovascular Treatment for Posterior Circulation Stroke: Ways to Maximize Therapeutic Efficacy. J Stroke 2022; 24:207-223. [PMID: 35677976 PMCID: PMC9194547 DOI: 10.5853/jos.2022.00941] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/20/2022] [Indexed: 11/11/2022] Open
Abstract
The efficacy of endovascular treatment (EVT) in patients with posterior circulation stroke has not been proven. Two recent randomized controlled trials failed to show improved functional outcomes after EVT for posterior circulation stroke (PC-EVT). However, promising results for two additional randomized controlled trials have also been presented at a recent conference. Studies have shown that patients undergoing PC-EVT had a higher rate of futile recanalization than those undergoing EVT for anterior circulation stroke. These findings call for further identification of prognostic factors beyond recanalization. The significance of baseline clinical severity, infarct volume, collaterals, time metrics, core-penumbra mismatch, and methods to accurately measure these parameters are discussed. Furthermore, their interplay on EVT outcomes and the potential to individualize patient selection for PC-EVT are reviewed. We also discuss technical considerations for improving the treatment efficacy of PC-EVT.
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Affiliation(s)
- Seong-Joon Lee
- Department of Neurology, Ajou University School of Medicine, Suwon, Korea
| | - Ji Man Hong
- Department of Neurology, Ajou University School of Medicine, Suwon, Korea
| | - Jong S. Kim
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jin Soo Lee
- Department of Neurology, Ajou University School of Medicine, Suwon, Korea
- Correspondence: Jin Soo Lee Department of Neurology, Ajou University School of Medicine, 164 World cup-ro, Yeongtong-gu, Suwon 16499, Korea Tel: +82-31-219-5175 Fax: +82-31-219-5178 E-mail:
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12
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Sun PZ. Consistent depiction of the acidic ischemic lesion with APT MRI-Dual RF power evaluation of pH-sensitive image in acute stroke. Magn Reson Med 2022; 87:850-858. [PMID: 34590730 PMCID: PMC8627494 DOI: 10.1002/mrm.29029] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/31/2021] [Accepted: 09/09/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE Amide proton transfer-weighted (APTw) MRI provides a non-invasive pH-sensitive image, complementing perfusion and diffusion imaging for refined stratification of ischemic tissue. Although the commonly used magnetization transfer (MT) asymmetry (MTRasym ) calculation reasonably corrects the direct RF saturation effect, it is susceptible to the concomitant semisolid macromolecular MT contribution. Therefore, this study aimed to compare the performance of MTRasym and magnetization transfer and relaxation-normalized APT (MRAPT) analyses under 2 representative experimental conditions. METHODS Multiparametric MRI scans were performed in a rodent model of acute stroke, including relaxation, diffusion, and Z spectral images under 2 representative RF levels of 0.75 and 1.5 µT. Both MTRasym and MRAPT values in the ischemic diffusion lesion and the contralateral normal areas were compared using correlation and Bland-Altman tests. In addition, the acidic lesion volumes were compared. RESULTS MRAPT measurements from the diffusion lesion under the 2 conditions were highly correlated (R2 = 0.97) versus MTRasym measures (R2 = 0.58). The pH lesion sizes determined from MRAPT analysis were in good agreement (178 ± 43 mm3 vs. 186 ± 55 mm3 for B1 of 0.75 and 1.5 µT, respectively). CONCLUSIONS The study demonstrated that MRAPT analysis could be generalized to moderately different RF amplitudes, providing a more consistent depiction of acidic lesions than the MTRasym analysis.
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Affiliation(s)
- Phillip Zhe Sun
- Athinoula A Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA,Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta GA,Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta GA,Corresponding Author: Phillip Zhe Sun, Ph.D., Department of Radiology and Imaging Sciences, Emory University School of Medicine, 954 Gatewood Road NE, Atlanta, GA 30329, Phone: (404) 727-7786; (404) 712-1667,
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Zhao Y, Zhang X, Chen X, Wei Y. Neuronal injuries in cerebral infarction and ischemic stroke: From mechanisms to treatment (Review). Int J Mol Med 2021; 49:15. [PMID: 34878154 PMCID: PMC8711586 DOI: 10.3892/ijmm.2021.5070] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/13/2021] [Indexed: 11/10/2022] Open
Abstract
Stroke is the leading cause of disabilities and cognitive deficits, accounting for 5.2% of all mortalities worldwide. Transient or permanent occlusion of cerebral vessels leads to ischemic strokes, which constitutes the majority of strokes. Ischemic strokes induce brain infarcts, along with cerebral tissue death and focal neuronal damage. The infarct size and neurological severity after ischemic stroke episodes depends on the time period since occurrence, the severity of ischemia, systemic blood pressure, vein systems and location of infarcts, amongst others. Ischemic stroke is a complex disease, and neuronal injuries after ischemic strokes have been the focus of current studies. The present review will provide a basic pathological background of ischemic stroke and cerebral infarcts. Moreover, the major mechanisms underlying ischemic stroke and neuronal injuries are summarized. This review will also briefly summarize some representative clinical trials and up-to-date treatments that have been applied to stroke and brain infarcts.
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Affiliation(s)
- Yunfei Zhao
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Xiaojing Zhang
- Shanghai Licheng Bio‑Technique Co. Ltd., Shanghai 201900, P.R. China
| | - Xinye Chen
- Shanghai Licheng Bio‑Technique Co. Ltd., Shanghai 201900, P.R. China
| | - Yun Wei
- Shanghai Licheng Bio‑Technique Co. Ltd., Shanghai 201900, P.R. China
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14
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Khodanovich MY, Gubskiy IL, Kudabaeva MS, Namestnikova DD, Kisel AA, Anan’ina TV, Tumentceva YA, Mustafina LR, Yarnykh VL. Long-term monitoring of chronic demyelination and remyelination in a rat ischemic stroke model using macromolecular proton fraction mapping. J Cereb Blood Flow Metab 2021; 41:2856-2869. [PMID: 34107787 PMCID: PMC8756474 DOI: 10.1177/0271678x211020860] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 04/24/2021] [Accepted: 04/26/2021] [Indexed: 12/23/2022]
Abstract
Remyelination is a key process enabling post-stroke brain tissue recovery and plasticity. This study aimed to explore the feasibility of demyelination and remyelination monitoring in experimental stroke from the acute to chronic stage using an emerging myelin imaging biomarker, macromolecular proton fraction (MPF). After stroke induction by transient middle cerebral artery occlusion, rats underwent repeated MRI examinations during 85 days after surgery with histological endpoints for the animal subgroups on the 7th, 21st, 56th, and 85th days. MPF maps revealed two sub-regions within the infarct characterized by distinct temporal profiles exhibiting either a persistent decrease by 30%-40% or a transient decrease followed by return to nearly normal values after one month of observation. Myelin histology confirmed that these sub-regions had nearly similar extent of demyelination in the sub-acute phase and then demonstrated either chronic demyelination or remyelination. The remyelination zones also exhibited active axonal regrowth, reconstitution of compact fiber bundles, and proliferation of neuronal and oligodendroglial precursors. The demyelination zones showed more extensive astrogliosis from the 21st day endpoint. Both sub-regions had substantially depleted neuronal population over all endpoints. These results histologically validate MPF mapping as a novel approach for quantitative assessment of myelin damage and repair in ischemic stroke.
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Affiliation(s)
| | - Ilya L Gubskiy
- Research Institute of Cerebrovascular Pathology and Stroke, Pirogov Russian Medical University, Moscow, Russian Federation
| | - Marina S Kudabaeva
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation
| | - Darya D Namestnikova
- Research Institute of Cerebrovascular Pathology and Stroke, Pirogov Russian Medical University, Moscow, Russian Federation
| | - Alena A Kisel
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation
- Department of Radiology, University of Washington, Seattle, USA
| | - Tatyana V Anan’ina
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation
| | - Yana A Tumentceva
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation
| | - Lilia R Mustafina
- Department of histology, embriology, and cytology, Siberian State Medical University, Tomsk, Russian Federation
| | - Vasily L Yarnykh
- Laboratory of Neurobiology, Tomsk State University, Tomsk, Russian Federation
- Department of Radiology, University of Washington, Seattle, USA
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15
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Lu J, Mei Q, Hou X, Manaenko A, Zhou L, Liebeskind DS, Zhang JH, Li Y, Hu Q. Imaging Acute Stroke: From One-Size-Fit-All to Biomarkers. Front Neurol 2021; 12:697779. [PMID: 34630278 PMCID: PMC8497192 DOI: 10.3389/fneur.2021.697779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/30/2021] [Indexed: 12/27/2022] Open
Abstract
In acute stroke management, time window has been rigidly used as a guide for decades and the reperfusion treatment is only available in the first few limited hours. Recently, imaging-based selection of patients has successfully expanded the treatment window out to 16 and even 24 h in the DEFUSE 3 and DAWN trials, respectively. Recent guidelines recommend the use of imaging techniques to guide therapeutic decision-making and expanded eligibility in acute ischemic stroke. A tissue window is proposed to replace the time window and serve as the surrogate marker for potentially salvageable tissue. This article reviews the evolution of time window, addresses the advantage of a tissue window in precision medicine for ischemic stroke, and discusses both the established and emerging techniques of neuroimaging and their roles in defining a tissue window. We also emphasize the metabolic imaging and molecular imaging of brain pathophysiology, and highlight its potential in patient selection and treatment response prediction in ischemic stroke.
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Affiliation(s)
- Jianfei Lu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiyong Mei
- Department of Neurosurgery, Changzheng Hospital, Navy Medical University, Shanghai, China
| | - Xianhua Hou
- Department of Neurology, Southwest Hospital, Army Medical University, Chongqing, China
| | - Anatol Manaenko
- National Health Commission Key Laboratory of Diagnosis and Treatment on Brain Functional Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lili Zhou
- Department of Neurology, Chinese People's Liberation Army General Hospital, Beijing, China
| | - David S Liebeskind
- Neurovascular Imaging Research Core and University of California Los Angeles Stroke Center, University of California, Los Angeles, Los Angeles, CA, United States
| | - John H Zhang
- Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda, CA, United States
| | - Yao Li
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Hu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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16
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Cheung J, Doerr M, Hu R, Sun PZ. Refined Ischemic Penumbra Imaging with Tissue pH and Diffusion Kurtosis Magnetic Resonance Imaging. Transl Stroke Res 2021; 12:742-753. [PMID: 33159656 PMCID: PMC8102648 DOI: 10.1007/s12975-020-00868-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 10/14/2020] [Accepted: 10/18/2020] [Indexed: 12/19/2022]
Abstract
Imaging has played a vital role in our mechanistic understanding of acute ischemia and the management of acute stroke patients. The most recent DAWN and DEFUSE-3 trials showed that endovascular therapy could be extended to a selected group of late-presenting stroke patients with the aid of imaging. Although perfusion and diffusion MRI have been commonly used in stroke imaging, the approximation of their mismatch as the penumbra is oversimplified, particularly in the era of endovascular therapy. Briefly, the hypoperfusion lesion includes the benign oligemia that does not proceed to infarction. Also, with prompt and effective reperfusion therapy, a portion of the diffusion lesion is potentially reversible. Therefore, advanced imaging that provides improved ischemic tissue characterization may enable new experimental stroke therapeutics and eventually further individualize stroke treatment upon translation to the clinical setting. Specifically, pH imaging captures tissue of altered metabolic state that demarcates the hypoperfused lesion into ischemic penumbra and benign oligemia, which remains promising to define the ischemic penumbra's outer boundary. On the other hand, diffusion kurtosis imaging (DKI) differentiates the most severely damaged and irreversibly injured diffusion lesion from the portion of diffusion lesion that is potentially reversible, refining the inner boundary of the penumbra. Altogether, the development of advanced imaging has the potential to not only transform the experimental stroke research but also aid clinical translation and patient management.
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Affiliation(s)
- Jesse Cheung
- Emory College of Arts and Sciences, Emory University, Atlanta, GA, 30329, USA
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
| | - Madeline Doerr
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA
- Dartmouth College, Hanover, NH, 03755, USA
| | - Ranliang Hu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1364 Clifton RD NE, Atlanta, GA, 30322, USA
| | - Phillip Zhe Sun
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, 30329, USA.
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, 1364 Clifton RD NE, Atlanta, GA, 30322, USA.
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17
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Hampton DG, Goldman-Yassen AE, Sun PZ, Hu R. Metabolic Magnetic Resonance Imaging in Neuroimaging: Magnetic Resonance Spectroscopy, Sodium Magnetic Resonance Imaging and Chemical Exchange Saturation Transfer. Semin Ultrasound CT MR 2021; 42:452-462. [PMID: 34537114 DOI: 10.1053/j.sult.2021.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Magnetic resonance (MR) is a powerful and versatile technique that offers much more beyond conventional anatomic imaging and has the potential of probing in vivo metabolism. Although MR spectroscopy (MRS) predates clinical MR imaging (MRI), its clinical application has been limited by technical and practical challenges. Other MR techniques actively being developed for in vivo metabolic imaging include sodium concentration imaging and chemical exchange saturation transfer. This article will review some of the practical aspects of MRS in neuroimaging, introduce sodium MRI and chemical exchange saturation transfer MRI, and highlight some of their emerging clinical applications.
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Affiliation(s)
- Daniel G Hampton
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA.
| | - Adam E Goldman-Yassen
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
| | - Phillip Zhe Sun
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA; Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA
| | - Ranliang Hu
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA
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18
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Magoufis G, Safouris A, Raphaeli G, Kargiotis O, Psychogios K, Krogias C, Palaiodimou L, Spiliopoulos S, Polizogopoulou E, Mantatzis M, Finitsis S, Karapanayiotides T, Ellul J, Bakola E, Brountzos E, Mitsias P, Giannopoulos S, Tsivgoulis G. Acute reperfusion therapies for acute ischemic stroke patients with unknown time of symptom onset or in extended time windows: an individualized approach. Ther Adv Neurol Disord 2021; 14:17562864211021182. [PMID: 34122624 PMCID: PMC8175833 DOI: 10.1177/17562864211021182] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/10/2021] [Indexed: 02/05/2023] Open
Abstract
Recent randomized controlled clinical trials (RCTs) have revolutionized acute ischemic stroke care by extending the use of intravenous thrombolysis and endovascular reperfusion therapies in time windows that have been originally considered futile or even unsafe. Both systemic and endovascular reperfusion therapies have been shown to improve outcome in patients with wake-up strokes or symptom onset beyond 4.5 h for intravenous thrombolysis and beyond 6 h for endovascular treatment; however, they require advanced neuroimaging to select stroke patients safely. Experts have proposed simpler imaging algorithms but high-quality data on safety and efficacy are currently missing. RCTs used diverse imaging and clinical inclusion criteria for patient selection during the dawn of this novel stroke treatment paradigm. After taking into consideration the dismal prognosis of nonrecanalized ischemic stroke patients and the substantial clinical benefit of reperfusion therapies in selected late presenters, we propose rescue reperfusion therapies for acute ischemic stroke patients not fulfilling all clinical and imaging inclusion criteria as an option in a subgroup of patients with clinical and radiological profiles suggesting low risk for complications, notably hemorrhagic transformation as well as local or remote parenchymal hemorrhage. Incorporating new data to treatment algorithms may seem perplexing to stroke physicians, since treatment and imaging capabilities of each stroke center may dictate diverse treatment pathways. This narrative review will summarize current data that will assist clinicians in the selection of those late presenters that will most likely benefit from acute reperfusion therapies. Different treatment algorithms are provided according to available neuroimaging and endovascular treatment capabilities.
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Affiliation(s)
- Georgios Magoufis
- Interventional Neuroradiology Unit, Metropolitan Hospital, Piraeus, Greece
| | - Apostolos Safouris
- Stroke Unit, Metropolitan Hospital, Piraeus, Greece
- Interventional Neuroradiology Unit, Rabin Medical Center, Beilinson Hospital, Petach-Tikva, Israel
- Second Department of Neurology, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Guy Raphaeli
- Interventional Neuroradiology Unit, Rabin Medical Center, Beilinson Hospital, Petach-Tikva, Israel
| | | | - Klearchos Psychogios
- Stroke Unit, Metropolitan Hospital, Piraeus, Greece
- Second Department of Neurology, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Christos Krogias
- Department of Neurology, St. Josef-Hospital, Ruhr University Bochum, Bochum, Germany
| | - Lina Palaiodimou
- Second Department of Neurology, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Stavros Spiliopoulos
- Second Department of Radiology, Interventional Radiology Unit, “ATTIKON” University General Hospital, Athens, Greece
| | - Eftihia Polizogopoulou
- Emergency Medicine Clinic, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Michael Mantatzis
- Department of Radiology, University Hospital of Alexandroupolis, Democritus University of Thrace, School of Medicine, Alexandroupolis, Greece
| | - Stephanos Finitsis
- Department of Interventional Radiology, AHEPA University General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Theodore Karapanayiotides
- Second Department of Neurology, Aristotle University of Thessaloniki, School of Medicine, Faculty of Health Sciences, AHEPA University Hospital, Thessaloniki, Greece
| | - John Ellul
- Department of Neurology, University Hospital of Patras, School of Medicine, University of Patras, Patras, Greece
| | - Eleni Bakola
- Second Department of Neurology, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Elias Brountzos
- Second Department of Radiology, Interventional Radiology Unit, “ATTIKON” University General Hospital, Athens, Greece
| | - Panayiotis Mitsias
- Department of Neurology Medical School, University of Crete, Heraklion, Crete, Greece
| | - Sotirios Giannopoulos
- Second Department of Neurology, National & Kapodistrian University of Athens, School of Medicine, “Attikon” University Hospital, Athens, Greece
| | - Georgios Tsivgoulis
- Second Department of Neurology, National & Kapodistrian, University of Athens, School of Medicine, “Attikon” University Hospital, Iras 39, Gerakas Attikis, Athens, 15344, Greece
- Department of Neurology, The University of Tennessee Health Science Center, Memphis, TN, USA
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19
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Aoki J, Sakamoto Y, Suzuki K, Nishi Y, Kutsuna A, Takei Y, Sawada K, Kanamaru T, Abe A, Katano T, Takeshi Y, Nakagami T, Numao S, Kimura R, Suda S, Nishiyama Y, Kimura K. Fluid-Attenuated Inversion Recovery May Serve As a Tissue Clock in Patients Treated With Endovascular Thrombectomy. Stroke 2021; 52:2232-2240. [PMID: 33957776 DOI: 10.1161/strokeaha.120.033374] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Junya Aoki
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Yuki Sakamoto
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Kentaro Suzuki
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Yuji Nishi
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Akihito Kutsuna
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Yukako Takei
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Kazutaka Sawada
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Takuya Kanamaru
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Arata Abe
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Takehiro Katano
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Yuho Takeshi
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Toru Nakagami
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Shinichiro Numao
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Ryutaro Kimura
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Satoshi Suda
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Yasuhiro Nishiyama
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
| | - Kazumi Kimura
- Department of Neurology, Nippon Medical School Graduate School of Medicine, Japan
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20
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Wu HM, Lee IH, Luo CB, Chung CP, Lin YY. Clinical-CT mismatch defined NIHSS ≥ 8 and CT-ASPECTS ≥ 9 as a reliable marker of candidacy for intravenous thrombolytic therapy in acute ischemic stroke. PLoS One 2021; 16:e0251077. [PMID: 33930103 PMCID: PMC8087040 DOI: 10.1371/journal.pone.0251077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/20/2021] [Indexed: 11/24/2022] Open
Abstract
Background Clinical-diffusion mismatch between stroke severity and diffusion-weighted imaging lesion volume seems to identify stroke patients with penumbra. However, urgent magnetic resonance imaging is sometimes inaccessible or contraindicated. Thus, we hypothesized that using brain computed tomography (CT) to determine a baseline “clinical-CT mismatch” may also predict the responses to thrombolytic therapy. Methods Brain CT lesions were measured using the Alberta Stroke Program Early CT Score (ASPECTS). A total of 104 patients were included: 79 patients with a baseline National Institutes of Health Stroke Scale (NIHSS) score ≥ 8 and a CT-ASPECTS ≥ 9 who were defined as clinical-CT mismatch-positive (P group) and 25 patients with an NIHSS score ≥ 8 and a CT-ASPECTS < 9 who were defined as clinical-CT mismatch-negative (the N group). We compared their clinical outcomes, including early neurological improvement (ENI), early neurological deterioration (END), delta NIHSS score (admission NIHSS—baseline NIHSS score), symptomatic intracranial hemorrhage (sICH), mortality, and favorable outcome at 3 months. Results Patients in the P group had a greater proportion of favorable outcome at 3 months (p = 0.032) and more frequent ENI (p = 0.038) and a greater delta NIHSS score (p = 0.001), as well as a lower proportion of END (p = 0.004) than those in the N group patients. There were no significant differences in the incidence rates of sICH and mortality between the two groups. Conclusions Clinical-CT mismatch may be able to predict which patients would benefit from intravenous thrombolysis.
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Affiliation(s)
- Hung-Ming Wu
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Department of Neurology, Taipei Hospital, Ministry of Health and Welfare, New Taipei City, Taiwan, Republic of China
| | - I-Hui Lee
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
| | - Chao-Bao Luo
- School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- * E-mail: (CBL); (YYL)
| | - Chih-Ping Chung
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Yung-Yang Lin
- Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Department of Critical Care Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- Institute of Physiology, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
- * E-mail: (CBL); (YYL)
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21
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Lampinen B, Lätt J, Wasselius J, van Westen D, Nilsson M. Time dependence in diffusion MRI predicts tissue outcome in ischemic stroke patients. Magn Reson Med 2021; 86:754-764. [PMID: 33755261 PMCID: PMC8445077 DOI: 10.1002/mrm.28743] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/18/2022]
Abstract
Purpose: Reperfusion therapy enables effective treatment of ischemic stroke presenting within 4–6 hours. However, tissue progression from ischemia to infarction is variable, and some patients benefit from treatment up until 24 hours. Improved imaging techniques are needed to identify these patients. Here, it was hypothesized that time dependence in diffusion MRI may predict tissue outcome in ischemic stroke. Methods: Diffusion MRI data were acquired with multiple diffusion times in five non-reperfused patients at 2, 9, and 100 days after stroke onset. Maps of “rate of kurtosis change” (k), mean kurtosis, ADC, and fractional anisotropy were derived. The ADC maps defined lesions, normal-appearing tissue, and the lesion tissue that would either be infarcted or remain viable by day 100. Diffusion parameters were compared (1) between lesions and normal-appearing tissue, and (2) between lesion tissue that would be infarcted or remain viable. Results: Positive values of k were observed within stroke lesions on day 2 (P = .001) and on day 9 (P = .023), indicating diffusional exchange. On day 100, high ADC values indicated infarction of 50 ± 20% of the lesion volumes. Tissue infarction was predicted by high k values both on day 2 (P = .026) and on day 9 (P = .046), by low mean kurtosis values on day 2 (P = .043), and by low fractional anisotropy values on day 9 (P = .029), but not by low ADC values. Conclusions: Diffusion time dependence predicted tissue outcome in ischemic stroke more accurately than the ADC, and may be useful for predicting reperfusion benefit.
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Affiliation(s)
- Björn Lampinen
- Clinical Sciences Lund, Medical Radiation Physics, Lund University, Lund, Sweden
| | - Jimmy Lätt
- Center for Medical Imaging and Physiology, Skåne University Hospital Lund, Lund, Sweden
| | - Johan Wasselius
- Clinical Sciences Lund, Radiology, Lund University, Lund, Sweden
| | | | - Markus Nilsson
- Clinical Sciences Lund, Radiology, Lund University, Lund, Sweden
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22
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Pan Y, Shi G. Silver Jubilee of Stroke Thrombolysis With Alteplase: Evolution of the Therapeutic Window. Front Neurol 2021; 12:593887. [PMID: 33732203 PMCID: PMC7956989 DOI: 10.3389/fneur.2021.593887] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 02/01/2021] [Indexed: 01/01/2023] Open
Abstract
In 1995, the results of a landmark clinical trial by National Institute of Neurological Disorders and Stroke (NINDS) made a paradigm shift in managing acute cerebral ischemic stroke (AIS) patients at critical care centers. The study demonstrated the efficacy of tissue-type plasminogen activator (tPA), alteplase in improving neurological and functional outcome in AIS patients when administered within 3 h of stroke onset. After about 12 years of efforts and the results of the ECASS-III trial, it was possible to expand the therapeutic window to 4.5 h, which still represents a major logistic issue, depriving many AIS patients from the benefits of tPA therapy. Constant efforts in this regards are directed toward either speeding up the patient recruitment for tPA therapy or expanding the current tPA window. Efficient protocols to reduce the door-to-needle time and advanced technologies like telestroke services and mobile stroke units are being deployed for early management of AIS patients. Studies have demonstrated benefit of thrombolysis guided by perfusion imaging in AIS patients at up to 9 h of stroke onset, signifying “tissue window.” Several promising pharmacological and non-pharmacological approaches are being explored to mitigate the adverse effects of delayed tPA therapy, thus hoping to further expand the current tPA therapeutic window without compromising safety. With accumulation of scientific data, stroke organizations across the world are amending/updating the clinical recommendations of tPA, the only US-FDA approved drug for managing AIS patients. Alteplase has been a part of our neurocritical care and we intend to celebrate its silver jubilee by dedicating this review article discussing its journey so far and possible future evolution.
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Affiliation(s)
- Yuanmei Pan
- Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guowen Shi
- Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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23
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Affiliation(s)
- Binbin Sui
- Radiology Department, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Radiology Department, Beijing Neurosurgical Institute, Beijing, China.,Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, China
| | - Peiyi Gao
- Radiology Department, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,Radiology Department, Beijing Neurosurgical Institute, Beijing, China.,Beijing Key Laboratory of Magnetic Resonance Imaging and Brain Informatics, Beijing, China
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24
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Li Y, Wang T, Zhang T, Lin Z, Li Y, Guo R, Zhao Y, Meng Z, Liu J, Yu X, Liang ZP, Nachev P. Fast high-resolution metabolic imaging of acute stroke with 3D magnetic resonance spectroscopy. Brain 2020; 143:3225-3233. [PMID: 33141145 PMCID: PMC7719019 DOI: 10.1093/brain/awaa264] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/05/2020] [Accepted: 06/29/2020] [Indexed: 01/24/2023] Open
Abstract
Impaired oxygen and cellular metabolism is a hallmark of ischaemic injury in acute stroke. Magnetic resonance spectroscopic imaging (MRSI) has long been recognized as a potentially powerful tool for non-invasive metabolic imaging. Nonetheless, long acquisition time, poor spatial resolution, and narrow coverage have limited its clinical application. Here we investigated the feasibility and potential clinical utility of rapid, high spatial resolution, near whole-brain 3D metabolic imaging based on a novel MRSI technology. In an 8-min scan, we simultaneously obtained 3D maps of N-acetylaspartate and lactate at a nominal spatial resolution of 2.0 × 3.0 × 3.0 mm3 with near whole-brain coverage from a cohort of 18 patients with acute ischaemic stroke. Serial structural and perfusion MRI was used to define detailed spatial maps of tissue-level outcomes against which high-resolution metabolic changes were evaluated. Within hypoperfused tissue, the lactate signal was higher in areas that ultimately infarcted compared with those that recovered (P < 0.0001). Both lactate (P < 0.0001) and N-acetylaspartate (P < 0.001) differed between infarcted and other regions. Within the areas of diffusion-weighted abnormality, lactate was lower where recovery was observed compared with elsewhere (P < 0.001). This feasibility study supports further investigation of fast high-resolution MRSI in acute stroke.
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Affiliation(s)
- Yao Li
- Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Tianyao Wang
- Radiology Department, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Tianxiao Zhang
- Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Zengping Lin
- Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yudu Li
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Rong Guo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yibo Zhao
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Ziyu Meng
- Institute for Medical Imaging Technology, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Jun Liu
- Radiology Department, Shanghai Fifth People’s Hospital, Fudan University, Shanghai, China
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Zhi-Pei Liang
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Parashkev Nachev
- High-Dimensional Neurology Group, Institute of Neurology, University College London, London, UK
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25
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Abstract
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."
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Affiliation(s)
- Charlotte M Ermine
- Florey Institute of Neuroscience and Mental Health, Melbourne, Australia
| | - Andrew Bivard
- Department of Medicine, Melbourne Brain Centre at The Royal Melbourne Hospital, Parkville, Australia.,Department of Neurology, Melbourne Brain Centre at The Royal Melbourne Hospital, Parkville, Australia
| | - Mark W Parsons
- Department of Medicine, Melbourne Brain Centre at The Royal Melbourne Hospital, Parkville, Australia.,Department of Neurology, Melbourne Brain Centre at The Royal Melbourne Hospital, Parkville, Australia
| | - Jean-Claude Baron
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université de Paris, Paris, France.,GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, Paris, France
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26
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Jiang Z, Alamuri TT, Muir ER, Choi DW, Duong TQ. Longitudinal multiparametric MRI study of hydrogen-enriched water with minocycline combination therapy in experimental ischemic stroke in rats. Brain Res 2020; 1748:147122. [DOI: 10.1016/j.brainres.2020.147122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022]
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27
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Ma R, Xie Q, Li Y, Chen Z, Ren M, Chen H, Li H, Li J, Wang J. Animal models of cerebral ischemia: A review. Biomed Pharmacother 2020; 131:110686. [PMID: 32937247 DOI: 10.1016/j.biopha.2020.110686] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/09/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
Stroke seriously threatens human health because of its characteristics of high morbidity, disability, recurrence, and mortality, thus representing a heavy financial and mental burden to affected families and society. Many preclinical effective drugs end in clinical-translation failure. Animal models are an important approach for studying diseases and drug effects, and play a central role in biomedical research. Some details about animal models of cerebral ischemia have not been published, such as left-/right-sided lesions or permanent cerebral ischemia/cerebral ischemia-reperfusion. In this review, ischemia in the left- and right-hemisphere in patients with clinical stroke and preclinical studies were compared for the first time, as were the mechanisms of permanent cerebral ischemia and cerebral ischemia-reperfusion in different phases of the disease. The results showed that stroke in the left hemisphere was more common in clinical patients, and that most patients with stroke failed to achieve successful recanalization. Significant differences were detected between permanent cerebral ischemia and cerebral ischemia-reperfusion models in the early, subacute, and recovery phases. Therefore, it is recommended that, with the exception of the determined experimental purpose or drug mechanism, left-sided permanent cerebral ischemia animal models should be prioritized, as they would be more in line with the clinical scenario and would promote clinical translation. In addition, other details regarding the preoperative management, surgical procedures, and postoperative care of these animals are provided, to help establish a precise, effective, and reproducible model of cerebral ischemia model and establish a reference for researchers in this field.
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Affiliation(s)
- Rong Ma
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Qian Xie
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Yong Li
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Zhuoping Chen
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Mihong Ren
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Hai Chen
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Hongyan Li
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Jinxiu Li
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Jian Wang
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China.
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28
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Kuo DP, Kuo PC, Chen YC, Kao YCJ, Lee CY, Chung HW, Chen CY. Machine learning-based segmentation of ischemic penumbra by using diffusion tensor metrics in a rat model. J Biomed Sci 2020; 27:80. [PMID: 32664906 PMCID: PMC7362663 DOI: 10.1186/s12929-020-00672-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/09/2020] [Indexed: 01/01/2023] Open
Abstract
Background Recent trials have shown promise in intra-arterial thrombectomy after the first 6–24 h of stroke onset. Quick and precise identification of the salvageable tissue is essential for successful stroke management. In this study, we examined the feasibility of machine learning (ML) approaches for differentiating the ischemic penumbra (IP) from the infarct core (IC) by using diffusion tensor imaging (DTI)-derived metrics. Methods Fourteen male rats subjected to permanent middle cerebral artery occlusion (pMCAO) were included in this study. Using a 7 T magnetic resonance imaging, DTI metrics such as fractional anisotropy, pure anisotropy, diffusion magnitude, mean diffusivity (MD), axial diffusivity, and radial diffusivity were derived. The MD and relative cerebral blood flow maps were coregistered to define the IP and IC at 0.5 h after pMCAO. A 2-level classifier was proposed based on DTI-derived metrics to classify stroke hemispheres into the IP, IC, and normal tissue (NT). The classification performance was evaluated using leave-one-out cross validation. Results The IC and non-IC can be accurately segmented by the proposed 2-level classifier with an area under the receiver operating characteristic curve (AUC) between 0.99 and 1.00, and with accuracies between 96.3 and 96.7%. For the training dataset, the non-IC can be further classified into the IP and NT with an AUC between 0.96 and 0.98, and with accuracies between 95.0 and 95.9%. For the testing dataset, the classification accuracy for IC and non-IC was 96.0 ± 2.3% whereas for IP and NT, it was 80.1 ± 8.0%. Overall, we achieved the accuracy of 88.1 ± 6.7% for classifying three tissue subtypes (IP, IC, and NT) in the stroke hemisphere and the estimated lesion volumes were not significantly different from those of the ground truth (p = .56, .94, and .78, respectively). Conclusions Our method achieved comparable results to the conventional approach using perfusion–diffusion mismatch. We suggest that a single DTI sequence along with ML algorithms is capable of dichotomizing ischemic tissue into the IC and IP.
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Affiliation(s)
- Duen-Pang Kuo
- Department of Medical Imaging, Taipei Medical University Hospital, No.250, Wu-Hsing St, Taipei, 11031, Taiwan.,Department of Radiology, Taoyuan Armed Forces General Hospital, Taoyuan, Taiwan
| | - Po-Chih Kuo
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yung-Chieh Chen
- Department of Medical Imaging, Taipei Medical University Hospital, No.250, Wu-Hsing St, Taipei, 11031, Taiwan
| | - Yu-Chieh Jill Kao
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, No.155, Sec.2, Linong St, Taipei, 11221, Taiwan
| | - Ching-Yen Lee
- TMU Center for Big Data and Artificial Intelligence in Medical Imaging, Taipei Medical University Hospital, Taipei, Taiwan.,TMU Research Center for Artificial Intelligence in Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Hsiao-Wen Chung
- Graduate Institute of Biomedical Electrics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Cheng-Yu Chen
- Department of Medical Imaging, Taipei Medical University Hospital, No.250, Wu-Hsing St, Taipei, 11031, Taiwan. .,Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, No.155, Sec.2, Linong St, Taipei, 11221, Taiwan. .,Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, No.250, Wu-Hsing St, Taipei, 11031, Taiwan. .,Radiogenomic Research Center, Taipei Medical University Hospital, No.250, Wu-Hsing St, Taipei, 11031, Taiwan. .,Center for Artificial Intelligence in Medicine, Taipei Medical University, No.250, Wu-Hsing St, Taipei, 11031, Taiwan. .,Department of Radiology, National Defense Medical Center, No.250, Wu-Hsing St, Taipei, 11031, Taiwan.
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29
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Nagaraja N, Forder JR, Warach S, Merino JG. Reversible diffusion-weighted imaging lesions in acute ischemic stroke: A systematic review. Neurology 2020; 94:571-587. [PMID: 32132175 DOI: 10.1212/wnl.0000000000009173] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 01/27/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVES To systematically review the literature for reversible diffusion-weighted imaging (DWIR) lesions and to describe its prevalence, predictors, and clinical significance. METHODS Studies were included if the first DWI MRI was performed within 24 hours of stroke onset and follow-up DWI or fluid-attenuated inversion recovery (FLAIR)/T2 was performed within 7 or 90 days, respectively, to measure DWIR. We abstracted clinical, imaging, and outcomes data. RESULTS Twenty-three studies met the study criteria. The prevalence of DWIR was 26.5% in DWI-based studies and 6% in FLAIR/T2-based studies. DWIR was associated with recanalization or reperfusion of the ischemic tissue with or without the use of tissue plasminogen activator (t-PA) or endovascular therapy, earlier treatment with t-PA, shorter time to endovascular therapy after MRI, and absent or less severe perfusion deficit within the DWI lesion. DWIR was associated with early neurologic improvement in 5 of 6 studies (defined as improvement in the NIH Stroke Scale (NIHSS) score by 4 or 8 points from baseline or NIHSS score 0 to 2 at 24 hours after treatment or at discharge or median NIHSS score at 7 days) and long-term outcome in 6 of 7 studies (defined as NIHSS score ≤1, improvement in the NIHSS score ≥8 points, or modified Rankin Scale score up to ≤2 at 30 or 90 days) likely due to reperfusion. CONCLUSIONS DWIR is seen in up to a quarter of patients with acute ischemic stroke, and it is associated with good clinical outcome following reperfusion. Our findings highlight the pitfalls of DWI to define ischemic core in the early hours of stroke.
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Affiliation(s)
- Nandakumar Nagaraja
- From the Department of Neurology (N.N.), University of Florida College of Medicine, Gainesville; Department of Radiology and Biomedical Engineering (J.R.F.), University of Florida, Gainesville; Dell Medical School (S.W.), University of Texas at Austin; and Department of Neurology (J.G.M.), Georgetown University School of Medicine, Washington, DC.
| | - John R Forder
- From the Department of Neurology (N.N.), University of Florida College of Medicine, Gainesville; Department of Radiology and Biomedical Engineering (J.R.F.), University of Florida, Gainesville; Dell Medical School (S.W.), University of Texas at Austin; and Department of Neurology (J.G.M.), Georgetown University School of Medicine, Washington, DC
| | - Steven Warach
- From the Department of Neurology (N.N.), University of Florida College of Medicine, Gainesville; Department of Radiology and Biomedical Engineering (J.R.F.), University of Florida, Gainesville; Dell Medical School (S.W.), University of Texas at Austin; and Department of Neurology (J.G.M.), Georgetown University School of Medicine, Washington, DC
| | - Jośe G Merino
- From the Department of Neurology (N.N.), University of Florida College of Medicine, Gainesville; Department of Radiology and Biomedical Engineering (J.R.F.), University of Florida, Gainesville; Dell Medical School (S.W.), University of Texas at Austin; and Department of Neurology (J.G.M.), Georgetown University School of Medicine, Washington, DC
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30
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Li X, Wu L, Xie H, Bao Y, He D, Luo X. Endovascular treatment for ischemic stroke beyond the time window: A meta-analysis. Acta Neurol Scand 2020; 141:3-13. [PMID: 31494924 DOI: 10.1111/ane.13161] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/11/2019] [Accepted: 09/02/2019] [Indexed: 12/16/2022]
Abstract
Currently, endovascular treatment has been proven to be effective when conducted within 6 hours of symptom onset. However, when patients have symptoms for more than 6 hours, have a daytime-unwitnessed stroke (DUS) or wake up with a stroke (wake-up stroke, WUS), the safety and efficacy of endovascular treatment need to be further elucidated. Therefore, we performed a systematic review and meta-analysis to compare the clinical outcomes of endovascular treatment in patients with ischemic stroke beyond the time window with that ≤6 hours. PubMed, EMBASE, and Ovid MEDLINE were searched from inception to November 2018. The following outcomes were evaluated by a random-effects model: efficacy outcomes, that is, functional independence and successful recanalization, and safety outcomes, that is, symptomatic intracranial hemorrhage and mortality. Subgroup analyses were also performed to examine whether patient or study characteristics were associated with the outcomes. Nine observational studies, including 5192 patients (1414 patients with extended time windows [ETWs]; 3778 patients ≤6 hours), were eligible for analysis. The overall analysis demonstrated that the functional independence was worse in patients with ETWs vs those ≤6 hours (OR, 0.78; 95% CI, 0.68-0.90, P = .0006). However, subgroup analysis showed that there was no significant difference in functional independence between the two groups when patients were selected for a perfusion mismatch by imaging (OR, 1.00; 95% CI, 0.70-1.43, P = 1.000). Therefore, compared with a window ≤6 hours, endovascular treatment with ETWs for ischemic stroke may not result in poor outcomes when patients are typically selected by perfusion techniques.
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Affiliation(s)
- Xuefei Li
- Department of Neurology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Lingshan Wu
- Department of Neurology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Hongxian Xie
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Sun Yat‐sen University Guangzhou China
| | - Yuxian Bao
- The First Affiliated Hospital Sun Yat‐sen University Guangzhou China
| | - Dan He
- Department of Neurology National Key Clinical Department and Key Discipline of Neurology The First Affiliated Hospital Sun Yat‐sen University Guangzhou China
| | - Xiang Luo
- Department of Neurology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
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31
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Kwon JI, Woo CW, Kim KW, Choi Y, Kim ST, Kim YJ, Kang J, Lee DW, Tak E, Kim JK, Jung SC, Kim TH, Woo DC. Does the Apparent Diffusion Coefficient Value Predict Permanent Cerebral Ischemia/Reperfusion Injury in Rats? Acad Radiol 2019; 26:e348-e354. [PMID: 30661976 DOI: 10.1016/j.acra.2018.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/17/2018] [Accepted: 12/17/2018] [Indexed: 10/27/2022]
Abstract
RATIONALE AND OBJECTIVES Variation in tissue damage after cerebral ischemia/reperfusion (I/R) can cause uncertainty in stroke-related studies, which can be reduced if the damage can be predicted early after ischemia by measuring the apparent diffusion coefficient (ADC). We investigated whether ADC measurement in the acute phase can predict permanent cerebral I/R injury. MATERIALS AND METHODS The middle cerebral artery occlusion model was established using the intraluminal suture method to induce 60 minutes of ischemia followed by reperfusion in rats. T2-weighted images and diffusion-weighted images were obtained at 30 minutes and 24 hours after ischemia. Neuronal cell survival was assessed by neuronal nuclei (NeuN) immunofluorescence staining. The correlation between relative ADC (rADC) values at 30 minutes and I/R injury at 24 hours after ischemia was analyzed. Magnetic resonance imaging results were confirmed by histologic analysis. RESULTS The correlation between rADC values at 30 minutes and 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Histologic analysis revealed that the correlation between rADC values at 30 minutes and the number of NeuN-positive cells at 24 hours was strong in the ischemic core and peri-infarct region but moderate in the anterior choroidal and hypothalamic region. Furthermore, there was a strong positive correlation between the sum of rADC values of three regions at 30 minutes and the infarct volume at 24 hours. CONCLUSION ADC measurement in the acute phase can predict permanent cerebral I/R injury and provide important information for the evaluation of ischemic stroke.
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32
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Choi WJ, Li Y, Wang RK. Monitoring Acute Stroke Progression: Multi-Parametric OCT Imaging of Cortical Perfusion, Flow, and Tissue Scattering in a Mouse Model of Permanent Focal Ischemia. IEEE TRANSACTIONS ON MEDICAL IMAGING 2019; 38:1427-1437. [PMID: 30714910 PMCID: PMC6660833 DOI: 10.1109/tmi.2019.2895779] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Cerebral ischemic stroke causes injury to brain tissue characterized by a complex cascade of neuronal and vascular events. Imaging during the early stages of its development allows prediction of tissue infarction and penumbra so that optimal intervention can be determined in order to salvage brain function impairment. Therefore, there is a critical need for novel imaging techniques that can characterize brain injury in the earliest phases of the ischemic stroke. This paper examined optical coherence tomography (OCT) for imaging acute injury in experimental ischemic stroke in vivo. Based on endogenous optical scattering signals provided by OCT imaging, we have developed a single, integrated imaging platform enabling the measurement of changes in blood perfusion, blood flow, erythrocyte velocity, and light attenuation within a cortical tissue, during focal cerebral ischemia in a mouse model. During the acute phase (from 5 min to the first few hours following the blood occlusion), the multi-parametric OCT imaging revealed multiple hemodynamic and tissue scattering responses in vivo, including cerebral blood flow deficits, capillary non-perfusion, displacement of penetrating vessels, and increased light attenuation in the cortical tissue at risk that are spatially correlated with the infarct core, as determined by postmortem staining with triphenyltetrazolium chloride. The use of multi-parametric OCT imaging may aid in the comprehensive evaluation of ischemic lesions during the early stages of stroke, thereby providing essential knowledge for guiding treatment decisions.
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Affiliation(s)
- Woo June Choi
- School of Electrical and Electronics Engineering, College of ICT Engineering, Chung-Ang University, Seoul, 06974, Korea
| | - Yuandong Li
- Department of Bioengineering, University of Washington, Seattle WA 98195, USA
| | - Ruikang K. Wang
- Corresponding author, phone: 206-616-5025; fax: 206-616-5025;
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33
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Heiss WD, Zaro-Weber O. Extension of therapeutic window in ischemic stroke by selective mismatch imaging. Int J Stroke 2019; 14:351-358. [DOI: 10.1177/1747493019840936] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The concept of the ischemic penumbra was formulated on the basis of animal experiments showing functional impairment and electrophysiologic disturbances with decreasing flow to the brain below defined values (the threshold for function) and irreversible tissue damage with blood supply further decreased (the threshold for infarction). The perfusion range between these thresholds was termed the “penumbra,” and restitution of flow above the functional threshold was able to reverse the deficits without permanent damage. In further experiments, the dependency of the development of irreversible lesions on the interaction of the severity and the duration of critically reduced blood flow was established, proving that the lower the flow, the shorter the time for efficient reperfusion. As a consequence, infarction develops from the core of ischemia to the areas of less severe hypoperfusion. The translation of this experimental concept as the basis for the efficient treatment of stroke requires methods by which regional flow and energy metabolism can be repeatedly investigated to demonstrate penumbra tissue, which can benefit from therapeutic interventions. Positron emission tomography allows the quantification of regional cerebral blood flow, the regional oxygen extraction fraction, and the regional metabolic rate for oxygen. With these variables, clear definitions of irreversible tissue damage and of critically hypoperfused but potentially salvageable tissue (i.e. the penumbra) in stroke patients can be achieved. However, positron emission tomography is a research tool, and its complex logistics limit clinical routine applications. Perfusion-weighted or diffusion-weighted magnetic resonance imaging is a widely applicable clinical tool, and the “mismatch” between perfusion-weighted and diffusion-weighted abnormalities serves as an indicator of the penumbra. Also computed tomography angiography and computed tomography perfusion imaging can be used to detect areas suspicious of penumbra. The findings with both methods should be validated by positron emission tomography measurements. Several studies included the selection of patients for intravenous thrombolysis on the basis of a perfusion-weighted imaging–diffusion-weighted imaging mismatch or computed tomography perfusion studies. A meta-analysis of several mismatch-based thrombolysis studies of delayed treatment from the DIAS, DIAS-2, DEDAS, EPITHET, and DEFUSE trials revealed increased recanalization. However, this analysis did not confirm an improvement in clinical outcome with delayed thrombolysis. Randomized controlled trials that did enroll patients based on the presence of a target mismatch on multimodal imaging demonstrated a higher benefit of revascularization treatment by comparison with those who did not and demonstrated for the first time that revascularization treatment for occlusion of an internal carotid artery (ICA) or a proximal middle cerebral artery (MCA) was still beneficial from 6 to 24 h after onset among patients in whom the clinical examination and the multimodal brain imaging indicate a persistent penumbra. On this background, the yield of imaging for the selection of patients for a revascularization therapy will be discussed.
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Affiliation(s)
- Wolf-Dieter Heiss
- Max Planck Institute for Metabolism Research, Cologne, Germany
- Max Planck Institute for Neurological Research, Cologne, Germany
| | - Olivier Zaro-Weber
- Max Planck Institute for Metabolism Research, Cologne, Germany
- Max Planck Institute for Neurological Research, Cologne, Germany
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34
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Stone AJ, Harston GWJ, Carone D, Okell TW, Kennedy J, Blockley NP. Prospects for investigating brain oxygenation in acute stroke: Experience with a non-contrast quantitative BOLD based approach. Hum Brain Mapp 2019; 40:2853-2866. [PMID: 30860660 PMCID: PMC6563088 DOI: 10.1002/hbm.24564] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 12/13/2022] Open
Abstract
Metabolic markers of baseline brain oxygenation and tissue perfusion have an important role to play in the early identification of ischaemic tissue in acute stroke. Although well established MRI techniques exist for mapping brain perfusion, quantitative imaging of brain oxygenation is poorly served. Streamlined-qBOLD (sqBOLD) is a recently developed technique for mapping oxygenation that is well suited to the challenge of investigating acute stroke. In this study a noninvasive serial imaging protocol was implemented, incorporating sqBOLD and arterial spin labelling to map blood oxygenation and perfusion, respectively. The utility of these parameters was investigated using imaging based definitions of tissue outcome (ischaemic core, infarct growth and contralateral tissue). Voxel wise analysis revealed significant differences between all tissue outcomes using pairwise comparisons for the transverse reversible relaxation rate (R 2 '), deoxygenated blood volume (DBV) and deoxyghaemoglobin concentration ([dHb]; p < 0.01 in all cases). At the patient level (n = 9), a significant difference was observed for [dHb] between ischaemic core and contralateral tissue. Furthermore, serial analysis at the patient level (n = 6) revealed significant changes in R 2 ' between the presentation and 1 week scans for both ischaemic core (p < 0.01) and infarct growth (p < 0.05). In conclusion, this study presents evidence supporting the potential of sqBOLD for imaging oxygenation in stroke.
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Affiliation(s)
- Alan J Stone
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - George W J Harston
- Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Davide Carone
- Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Thomas W Okell
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - James Kennedy
- Acute Vascular Imaging Centre, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas P Blockley
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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35
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Bill O, Inácio NM, Lambrou D, Wintermark M, Ntaios G, Dunet V, Michel P. Focal Hypoperfusion in Acute Ischemic Stroke Perfusion CT: Clinical and Radiologic Predictors and Accuracy for Infarct Prediction. AJNR Am J Neuroradiol 2019; 40:483-489. [PMID: 30792249 DOI: 10.3174/ajnr.a5984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/30/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Perfusion CT may improve the diagnostic performance of noncontrast CT in acute ischemic stroke. We assessed predictors of focal hypoperfusion in acute ischemic stroke and perfusion CT performance in predicting infarction on follow-up imaging. MATERIALS AND METHODS Patients from the Acute STroke Registry and Analysis of Lausanne data base with acute ischemic stroke and perfusion CT were included. Clinical and radiologic data were collected. We identified predictors of focal hypoperfusion using multivariate analyses. RESULTS From the 2216 patients with perfusion CT, 38.2% had an acute ischemic lesion on NCCT and 73.3% had focal hypoperfusion on perfusion CT. After we analyzed 104 covariates, high-admission NIHSS, visual field defect, aphasia, hemineglect, sensory deficits, and impaired consciousness were positively associated with focal hypoperfusion. Negative associations were pure posterior circulation, lacunar strokes, and anticoagulation. After integrating radiologic variables into the multivariate analyses, we found that visual field defect, sensory deficits, hemineglect, early ischemic changes on NCCT, anterior circulation, cardioembolic etiology, and arterial occlusion were positively associated with focal hypoperfusion, whereas increasing onset-to-CT delay, chronic vascular lesions, and lacunar etiology showed negative association. Sensitivity, specificity, and positive and negative predictive values of focal hypoperfusion on perfusion CT for infarct detection on follow-up MR imaging were 66.5%, 79.4%, 96.2%, and 22.8%, respectively, with an overall accuracy of 76.8%. CONCLUSIONS Compared with NCCT, perfusion CT doubles the sensitivity in detecting acute ischemic stroke. Focal hypoperfusion is independently predicted by stroke severity, cortical clinical deficits, nonlacunar supratentorial strokes, and shorter onset-to-imaging delays. A high proportion of patients with focal hypoperfusion developed infarction on subsequent imaging, as did some patients without focal hypoperfusion, indicating the complementarity of perfusion CT and MR imaging in acute ischemic stroke.
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Affiliation(s)
- O Bill
- From the Neurology Service (O.B., D.L., P.M.), Department of Clinical Neurosciences .,Stroke Unit (O.B.), Groupement Hospitalier de l'Ouest Lausannois, Nyon, Switzerland
| | - N M Inácio
- Neurology Department (N.M.I.), Hospital Beatriz Ângelo, Loures, Portugal
| | - D Lambrou
- From the Neurology Service (O.B., D.L., P.M.), Department of Clinical Neurosciences
| | - M Wintermark
- Department of Radiology (M.W.), Neuroradiology Division, Stanford University and Medical Center, Stanford, California
| | - G Ntaios
- Department of Medicine (G.N.), University of Thessaly, Larissa, Greece
| | - V Dunet
- Department of Diagnostic and Interventional Radiology (V.D.), Lausanne University Hospital, Lausanne, Switzerland
| | - P Michel
- From the Neurology Service (O.B., D.L., P.M.), Department of Clinical Neurosciences
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Yao Q, Zhang L, Zhou J, Li M, Jing W, Li X, Han J, He L, Zhang Y. Imaging Diagnosis of Transient Ischemic Attack in Clinic and Traditional Chinese Medicine. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5094842. [PMID: 30906774 PMCID: PMC6398052 DOI: 10.1155/2019/5094842] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/04/2019] [Accepted: 02/02/2019] [Indexed: 11/18/2022]
Abstract
Neuroimaging plays a pivotal role in Transient Ischemic Attack (TIA). Generally, clinicians focus on the specific changes in morphology and function, but the diagnosis of TIA often depends on imaging evidence. Whereas Traditional Chinese Medicine (TCM) is concerned with the performance of clinical symptoms, they began to use imaging methods to diagnose TIA. CT and MRI are the recommended modality to diagnose TIA and image ischemic lesions. In addition, Transcranial Doppler sonography (TCD) and Digital Subtraction Angiography (DSA) are two acceptable alternatives for diagnosing TIA patients. This article elaborates the update of imaging modalities in clinic and the development of imaging modalities in TCM. Besides, multiple joint imaging technologies also will be evaluated whether enhanced diagnostic yields availably.
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Affiliation(s)
- Qigu Yao
- Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Lincheng Zhang
- Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Jing Zhou
- College of Life Sciences of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Min Li
- College of Life Sciences of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Weifeng Jing
- College of Pharmaceutical Science of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Xiaohong Li
- College of Pharmaceutical Science of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Jin Han
- Basic Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Lan He
- Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Yuyan Zhang
- College of Life Sciences of Zhejiang Chinese Medical University, Hangzhou 310053, China
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Evolution of acute lacunar lesions in terms of size and shape: a PICASSO sub-study. J Neurol 2019; 266:766-772. [PMID: 30673852 DOI: 10.1007/s00415-019-09201-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 11/27/2022]
Abstract
The imaging definition of lacunar infarcts is variable, particularly regarding their size and the presence of cavitation. We investigated the changes of diameter and evolution pattern of acute lacunar infarcts, and the factors associated with the evolution pattern. Patients with acute single subcortical hemispheric or brainstem ischemic lesions of penetrating arterial territories were included. Maximal diameters on initial diffusion-weighted image (DWI) and follow-up fluid-attenuated inversion recovery image (FLAIR), which performed > 12 months after initial DWI, were semi-automatically measured. Clinical characteristics were compared according to evolution patterns on follow-up FLAIR, classified as cavitated, focal lesion without cavitation, and disappeared. Five hundred nine patients were included. Mean time to follow-up was 31.3 ± 13.7 months. Mean diameter of acute lacunar lesions decreased from 12.9 ± 4.4 to 8.5 ± 4.8 mm during follow-up. Lesions of 58.2% patients remained as cavitated, 18.3% as focal lesion without cavitation, and 23.6% disappeared. Initial NIHSS score (p = 0.005), diameter of initial lesion (p < 0.001), number of slices showing acute lesion on DWI (p < 0.001), progression of white matter lesion (p < 0.001), number of acute lesions involving gray matter (p = 0.008) and lesion location (p < 0.001) were different among three groups. After adjustment for covariates, diameter of the acute lesion, initial number of old lacunes, and anterior lesion location were associated with the appearance of cavitation. Initial lesion diameter and posterior lesion location were associated with the disappearance. We observed reduction of the acute lacunar lesion diameter in 86%. There were predictive factors of disappearance and cavitation of acute lacunar infarction.
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Li YM, Zhou HM, Xu XY, Shi HS. Research Progress in MRI of the Visual Pathway in Diabetic Retinopathy. Curr Med Sci 2018; 38:968-975. [DOI: 10.1007/s11596-018-1971-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 10/10/2018] [Indexed: 12/17/2022]
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39
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Bazzigaluppi P, Adams C, Koletar MM, Dorr A, Pikula A, Carlen PL, Stefanovic B. Oophorectomy Reduces Estradiol Levels and Long-Term Spontaneous Neurovascular Recovery in a Female Rat Model of Focal Ischemic Stroke. Front Mol Neurosci 2018; 11:338. [PMID: 30271324 PMCID: PMC6146137 DOI: 10.3389/fnmol.2018.00338] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 08/28/2018] [Indexed: 12/31/2022] Open
Abstract
Although epidemiological evidence suggests significant sex and gender-based differences in stroke risk and recovery, females have been widely under-represented in preclinical stroke research. The neurovascular sequelae of brain ischemia in females, in particular, are largely uncertain. We set out to address this gap by a multimodal in vivo study of neurovascular recovery from endothelin-1 model of cortical focal-stroke in sham vs. ovariectomized female rats. Three weeks post ischemic insult, sham operated females recapitulated the phenotype previously reported in male rats in this model, of normalized resting perfusion but sustained peri-lesional cerebrovascular hyperreactivity. In contrast, ovariectomized (Ovx) females showed reduced peri-lesional resting blood flow, and elevated cerebrovascular responsivity to hypercapnia in the peri-lesional and contra-lateral cortices. Electrophysiological recordings showed an attenuation of theta to low-gamma phase-amplitude coupling in the peri-lesional tissue of Ovx animals, despite relative preservation of neuronal power. Further, this chronic stage neuronal network dysfunction was inversely correlated with serum estradiol concentration. Our pioneering data demonstrate dramatic differences in spontaneous recovery in the neurovascular unit between Ovx and Sham females in the chronic stage of stroke, underscoring the importance of considering hormonal-dependent aspects of the ischemic sequelae in the development of novel therapeutic approaches and patient recruitment in clinical trials.
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Affiliation(s)
- Paolo Bazzigaluppi
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Conner Adams
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Margaret M Koletar
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Adrienne Dorr
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Aleksandra Pikula
- Adult Vascular Neurology, Toronto Western Hospital, Toronto, ON, Canada
| | - Peter L Carlen
- Fundamental Neurobiology, Krembil Research Institute, Toronto, ON, Canada
| | - Bojana Stefanovic
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
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Leigh R, Knutsson L, Zhou J, van Zijl PC. Imaging the physiological evolution of the ischemic penumbra in acute ischemic stroke. J Cereb Blood Flow Metab 2018; 38:1500-1516. [PMID: 28345479 PMCID: PMC6125975 DOI: 10.1177/0271678x17700913] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We review the hemodynamic, metabolic and cellular parameters affected during early ischemia and their changes as a function of approximate cerebral blood flow ( CBF) thresholds. These parameters underlie the current practical definition of an ischemic penumbra, namely metabolically affected but still viable brain tissue. Such tissue is at risk of infarction under continuing conditions of reduced CBF, but can be rescued through timely intervention. This definition will be useful in clinical diagnosis only if imaging techniques exist that can rapidly, and with sufficient accuracy, visualize the existence of a mismatch between such a metabolically affected area and regions that have suffered cell depolarization. Unfortunately, clinical data show that defining the outer boundary of the penumbra based solely on perfusion-related thresholds may not be sufficiently accurate. Also, thresholds for CBF and cerebral blood volume ( CBV) differ for white and gray matter and evolve with time for both inner and outer penumbral boundaries. As such, practical penumbral imaging would involve parameters in which the physiology is immediately displayed in a manner independent of baseline CBF or CBF threshold, namely pH, oxygen extraction fraction ( OEF), diffusion constant and mean transit time ( MTT). Suitable imaging technologies will need to meet this requirement in a 10-20 min exam.
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Affiliation(s)
- Richard Leigh
- 1 National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, USA
| | - Linda Knutsson
- 2 Department of Medical Radiation Physics, Lund University, Lund, Sweden.,3 Department of Radiology, Johns Hopkins University, Baltimore, MD, USA
| | - Jinyuan Zhou
- 3 Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.,4 F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Peter Cm van Zijl
- 3 Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.,4 F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
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42
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Gomez CR. Time Is Brain: The Stroke Theory of Relativity. J Stroke Cerebrovasc Dis 2018; 27:2214-2227. [DOI: 10.1016/j.jstrokecerebrovasdis.2018.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/04/2018] [Indexed: 01/24/2023] Open
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43
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Bahr Hosseini M, Woolf G, Sharma LK, Hinman JD, Rao NM, Yoo B, Jahan R, Starkman S, Nour M, Raychev R, Liebeskind DS, Saver JL. The Frequency of Substantial Salvageable Penumbra in Thrombectomy-ineligible Patients with Acute Stroke. J Neuroimaging 2018; 28:676-682. [PMID: 30010229 DOI: 10.1111/jon.12544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/21/2018] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Endovascular therapy (ET) has become the standard of care for selected patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, many LVO or medium vessel occlusion (MVO) patients are ineligible for ET, including some who harbor salvageable tissues. To develop complementary therapies for these patients, it is important to delineate their prevalence, clinical features, and outcomes. METHODS In a prospectively maintained database, we reviewed consecutive AIS patients between December 2015 and September 2016. Based on the first multimodal computed tomography or magnetic resonance imaging, patients were categorized as having substantial penumbra if perfusion lesion volume (Tmax >6 seconds) exceeded ischemic core volume (relative cerebral blood flow <30% on CT perfusion or apparent diffusion coefficient <620 on diffusion weighted image) by ≥20%. RESULTS Among 174 consecutive AIS patients presenting within 24 hours of last known well time, 29 (17%) had LVO or MVO and substantial penumbra, but were deemed ET ineligible. Among these patients, mean age was 81 (±13), 45% were female, and median National Institute of Health Stroke Scale score was 11 (interquartile range [IQR]: 5-19). The most common reasons for not pursuing ET were: distal occlusion (28%), mild neurologic deficit (16%), and temporally advanced core injury (16%). Ischemic core volume was 20 mL (±31), penumbral volume was 54 mL (±63), and mismatch ratio median was 5.6 (IQR: 2-infinite). Severe disability or death at discharge (modified Rankin scale: 4-6) occurred in 72% of the patients. CONCLUSION Even in the modern stent retriever era, 1 in 6 AIS patients presents with substantial penumbra judged not appropriate for ET. This population may benefit from the development of alternative therapies, including collateral enhancement, neuroprotection, and thrombectomy devices deployable in distal arteries.
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Affiliation(s)
- Mersedeh Bahr Hosseini
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Graham Woolf
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Latisha K Sharma
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Jason D Hinman
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Neal M Rao
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Bryan Yoo
- Division of Neuroradiology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Reza Jahan
- Division of Neuroradiology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Sidney Starkman
- Departments of Emergency Medicine and Neurology, and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - May Nour
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Radoslav Raychev
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - David S Liebeskind
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
| | - Jeffrey L Saver
- Department of Neurology and Comprehensive Stroke Center, David Geffen School of Medicine at the University of California-Los Angeles (UCLA), Los Angeles, CA
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44
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Wang S, Du H, Lin B, Liao C, Zhu X, Wang X, Chen H, Zhuo S, Jiang L, Li L, Tu H, Chen J. Spatial and temporal identification of cerebral infarctions based on multiphoton microscopic imaging. BIOMEDICAL OPTICS EXPRESS 2018; 9:2312-2325. [PMID: 29760990 PMCID: PMC5946791 DOI: 10.1364/boe.9.002312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/08/2018] [Accepted: 04/18/2018] [Indexed: 05/06/2023]
Abstract
Ischemic stroke is a leading cause of death and permanent disability worldwide. Middle cerebral artery occlusion (MCAO) of variable duration times could be anticipated to result in varying degrees of injury that evolve spatially over time. Therefore, investigations following strokes require information concerning the spatiotemporal dimensions of the ischemic core as well as of perilesional areas. In the present study, multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) was applied to image such pathophysiological events. The ischemic time-points for evaluation were set at 6, 24, 48, and 72 hours after MCAO. Our results demonstrated that MPM has the ability to not only identify the normal and ischemic brain regions, but also reveal morphological changes of the cortex and striatum at various times following permanent MCAO. These findings corresponded well with the hematoxylin and eosin (H&E) stained tissue images. With the technologic progression of miniaturized imaging devices, MPM can be developed into an effective diagnostic and monitoring tool for ischemic stroke.
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Affiliation(s)
- Shu Wang
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
- These authors contributed equally to this work
| | - Huiping Du
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
- These authors contributed equally to this work
| | - Bingbing Lin
- Fujian University of Traditional Chinese Medicine, Fuzhou 350122, China
- These authors contributed equally to this work
| | - Chenxi Liao
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Xiaoqin Zhu
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Xingfu Wang
- Department of Pathology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350001, China
| | - Hong Chen
- Department of Pathology, The First Affiliated Hospital, Fujian Medical University, Fuzhou 350001, China
| | - Shuangmu Zhuo
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Liwei Jiang
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Lianhuang Li
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
| | - Haohua Tu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jianxin Chen
- Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou 350007, China
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Luo S, Yang L, Luo Y. Susceptibility-weighted imaging predicts infarct size and early-stage clinical prognosis in acute ischemic stroke. Neurol Sci 2018; 39:1049-1055. [PMID: 29557515 DOI: 10.1007/s10072-018-3324-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 03/13/2018] [Indexed: 11/30/2022]
Abstract
Susceptibility-weighted imaging (SWI) is a non-invasive technique that can reveal venous structures and iron in the brain. This retrospective study evaluated SWI, relative to other imaging techniques, for determining cerebral infarct size and early-stage clinical prognosis in patients with acute ischemic stroke. Within 3 days after onset, 22 patients with acute ischemic stroke underwent SWI, diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI), fluid-attenuated inversion recovery (FLAIR), and magnetic resonance angiography (MRA). At least 7 days after onset, the patients also underwent cranial FLAIR or computed tomography (CT). The severity of neurological damage was adjudged with NIHSS (National Institutes of Health Stroke Scale) scores. The imaged cranial lesions were evaluated according to ASPECTS (Alberta Stroke Program Early CT Score). The SWI-ASPECTS significantly correlated with mean transit time (MTT)-ASPECTS (Spearman's test, r = 0.662, P = 0.001) in evaluating ischemic penumbra and significantly correlated with the FLAIR and CT-ASPECTS (Spearman's test, r = 0.765, P < 0.001) in predicting infarct size. SWI is feasible for the early evaluation of cerebral infarct size and clinical prognosis of patients with acute cerebral infarction. SWI is a useful predictor of early infarct growth and early-stage outcome.
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Affiliation(s)
- Song Luo
- Department of Neurology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, 233004, China.
| | - Lijuan Yang
- Department of Pediatrics, The First Affiliated Hospital of Bengbu Medical College, Bengbu, 233004, China
| | - Yanfei Luo
- Department of Urology, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, 233000, China
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46
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Smith AG, Rowland Hill C. Imaging assessment of acute ischaemic stroke: a review of radiological methods. Br J Radiol 2017; 91:20170573. [PMID: 29144166 DOI: 10.1259/bjr.20170573] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Acute ischaemic stroke is the second largest cause of death worldwide and a cause of major physical and psychological morbidity. Current evidence based treatment includes intravenous thrombolysis (IVT) and mechanical thrombectomy (MT), both requiring careful patient selection and to be administered as quickly as possible within a limited time window from symptom onset. Imaging plays a crucial role identifying patients who may benefit from MT or IVT whilst excluding those that may be harmed. For IVT, imaging must as a minimum exclude haemorrhage, stroke mimics and provide an estimate of non-viable brain. For MT, imaging must in addition detect and characterize intra-arterial thrombus and assess the intra and extracranial arterial architecture. More advanced imaging techniques may be used to assess more accurately the volume of non-viable and potentially salvageable brain tissue. It is highly likely that further research will identify patients who would benefit from treatment beyond currently accepted time windows for IVT (4.5 h) and MT (6 h) and patients with an unknown time of symptom onset. Current evidence indicates that best outcomes are achieved when treatment is instituted as soon as possible after symptom onset. A rapid, efficient imaging pathway including interpretation is fundamental to achieving the best outcomes. This review summarizes current techniques for imaging assessment of acute stroke, highlighting strengths and limitations of each. The optimum pathway is a balance between diagnostic information, local resources, specialization and the time taken to acquire, process and interpret the data. As new evidence emerges, it is likely that the minimum required imaging data will change.
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Thirugnanachandran T, Ma H, Singhal S, Slater LA, Davis SM, Donnan GA, Phan T. Refining the ischemic penumbra with topography. Int J Stroke 2017; 13:277-284. [DOI: 10.1177/1747493017743056] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
It has been 40 years since the ischemic penumbra was first conceptualized through work on animal models. The topography of penumbra has been portrayed as an infarcted core surrounded by penumbral tissue and an extreme rim of oligemic tissue. This picture has been used in many review articles and textbooks before the advent of modern imaging. In this paper, we review our understanding of the topography of the ischemic penumbra from the initial experimental animal models to current developments with neuroimaging which have helped to further define the temporal and spatial evolution of the penumbra and refine our knowledge. The concept of the penumbra has been successfully applied in clinical trials of endovascular therapies with a time window as long as 24 h from onset. Further, there are reports of “good” outcome even in patients with a large ischemic core. This latter observation of good outcome despite having a large core requires an understanding of the topography of the penumbra and the function of the infarcted regions. It is proposed that future research in this area takes departure from a time-dependent approach to a more individualized tissue and location-based approach.
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Affiliation(s)
- Tharani Thirugnanachandran
- Stroke & Ageing Research (STARC), Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
| | - Henry Ma
- Stroke & Ageing Research (STARC), Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
| | - Shaloo Singhal
- Stroke & Ageing Research (STARC), Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
| | - Lee-Anne Slater
- Diagnostic Imaging, Monash Health, The Royal Melbourne Hospital and the University of Melbourne, Parkville, VIC, Australia
| | - Stephen M Davis
- Melbourne Brain Centre, The Royal Melbourne Hospital and the University of Melbourne, Parkville, VIC, Australia
| | - Geoffrey A Donnan
- Florey Neuroscience Institute, The Royal Melbourne Hospital and the University of Melbourne, Parkville, VIC, Australia
| | - Thanh Phan
- Stroke & Ageing Research (STARC), Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
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The role of neuroimaging in elucidating the pathophysiology of cerebral ischemia. Neuropharmacology 2017; 134:249-258. [PMID: 28947375 DOI: 10.1016/j.neuropharm.2017.09.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 11/20/2022]
Abstract
Neuroimaging provides detailed information regarding the hemodynamic, metabolic and cellular parameters of cerebral ischemia (CI). Although providing just a snapshot in time, it assists in delineating the boundaries and extent of this continually evolving process, from the irreversibly damaged infarct core to the penumbral tissue, where salvage via reperfusion has been the focus of acute stroke therapies. Beyond the extent of the ischemic lesion, neuroimaging elucidates the topography and underlying mechanism of CI. Finally, based on the pathophysiological information, neuroimaging assists in the selection of optimal therapeutic strategies, from hyperacute to chronic phases of CI. Here we review different neuroimaging techniques by which the pathophysiology of cerebral ischemia can be delineated. This article is part of the Special Issue entitled 'Cerebral Ischemia'.
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Heo HY, Zhang Y, Burton TM, Jiang S, Zhao Y, van Zijl PCM, Leigh R, Zhou J. Improving the detection sensitivity of pH-weighted amide proton transfer MRI in acute stroke patients using extrapolated semisolid magnetization transfer reference signals. Magn Reson Med 2017. [PMID: 28639301 DOI: 10.1002/mrm.26799] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE To quantify amide protein transfer (APT) effects in acidic ischemic lesions and assess the spatial-temporal relationship among diffusion, perfusion, and pH deficits in acute stroke patients. METHODS Thirty acute stroke patients were scanned at 3 T. Quantitative APT (APT# ) effects in acidic ischemic lesions were measured using an extrapolated semisolid magnetization transfer reference signal technique and compared with commonly used MTRasym (3.5ppm) or APT-weighted parameters. RESULTS The APT# images showed clear pH deficits in the ischemic lesion, whereas the MTRasym (3.5ppm) signals were slightly hypointense. The APT# contrast between acidic ischemic lesions and normal tissue in acute stroke patients was more than three times larger than MTRasym (3.5ppm) contrast (-1.45 ± 0.40% for APT# versus -0.39 ± 0.52% for MTRasym (3.5ppm), P < 4.6 × 10-4 ). Hypoperfused and acidic areas without an apparent diffusion coefficient abnormality were observed and assigned to an ischemic acidosis penumbra. Hypoperfused areas at normal pH were also observed and assigned to benign oligemia. Hyperintense APT signals were observed in a hemorrhage area in one case. CONCLUSIONS The quantitative APT study using the extrapolated semisolid magnetization transfer reference signal approach enhances APT MRI sensitivity to pH compared with conventional APT-weighted MRI, allowing more reliable delineation of an ischemic acidosis in the penumbra. Magn Reson Med 78:871-880, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Hye-Young Heo
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Yi Zhang
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Tina M Burton
- Neuro Vascular Brain Imaging Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Shanshan Jiang
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - Peter C M van Zijl
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Richard Leigh
- Neuro Vascular Brain Imaging Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Jinyuan Zhou
- Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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Yi KS, Choi CH, Lee SR, Lee HJ, Lee Y, Jeong KJ, Hwang J, Chang KT, Cha SH. Sustained diffusion reversal with in-bore reperfusion in monkey stroke models: Confirmed by prospective magnetic resonance imaging. J Cereb Blood Flow Metab 2017; 37:2002-2012. [PMID: 27401804 PMCID: PMC5464696 DOI: 10.1177/0271678x16659302] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although early diffusion lesion reversal after recanalization treatment of acute ischaemic stroke has been observed in clinical settings, the reversibility of lesions observed by diffusion-weighted imaging remains controversial. Here, we present consistent observations of sustained diffusion lesion reversal after transient middle cerebral artery occlusion in a monkey stroke model. Seven rhesus macaques were subjected to endovascular transient middle cerebral artery occlusion with in-bore reperfusion confirmed by repeated prospective diffusion-weighted imaging. Early diffusion lesion reversal was defined as lesion reversal at 3 h after reperfusion. Sustained diffusion lesion reversal was defined as the difference between the ADC-derived pre-reperfusion maximal ischemic lesion volume (ADCD-P Match) and the lesion on 4-week follow-up FLAIR magnetic resonance imaging. Diffusion lesions were spatiotemporally assessed using a 3-D voxel-based quantitative technique. The ADCD-P Match was 9.7 ± 6.0% (mean ± SD) and the final infarct was 1.2-6.0% of the volume of the ipsilateral hemisphere. Early diffusion lesion reversal and sustained diffusion lesion reversal were observed in all seven animals, and the calculated percentages compared with their ADCD-P Match ranged from 8.3 to 51.9% (mean ± SD, 26.9 ± 15.3%) and 41.7-77.8% (mean ± SD, 65.4 ± 12.2%), respectively. Substantial sustained diffusion lesion reversal and early reversal were observed in all animals in this monkey model of transient focal cerebral ischaemia.
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Affiliation(s)
- Kyung Sik Yi
- 1 Department of Radiology, Chungbuk National University Hospital, Chungbuk, Republic of Korea
| | - Chi-Hoon Choi
- 1 Department of Radiology, Chungbuk National University Hospital, Chungbuk, Republic of Korea
| | - Sang-Rae Lee
- 2 National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Republic of Korea
| | - Hong Jun Lee
- 3 Medical Research Institute, Chung-Ang University, Seoul, Korea
| | - Youngjeon Lee
- 2 National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Republic of Korea
| | - Kang-Jin Jeong
- 2 National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Republic of Korea
| | - Jinwoo Hwang
- 4 Clinical Science, Philips Healthcare, Seoul, Republic of Korea
| | - Kyu-Tae Chang
- 2 National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Chungbuk, Republic of Korea
| | - Sang-Hoon Cha
- 1 Department of Radiology, Chungbuk National University Hospital, Chungbuk, Republic of Korea.,5 College of Medicine, Chungbuk National University, Chungbuk, Republic of Korea
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