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Zedde M, Napoli M, Grisendi I, Assenza F, Moratti C, Valzania F, Pascarella R. Perfusion Status in Lacunar Stroke: A Pathophysiological Issue. Diagnostics (Basel) 2023; 13:2003. [PMID: 37370898 DOI: 10.3390/diagnostics13122003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 06/02/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
The pathophysiology of lacunar infarction is an evolving and debated field, where relevant information comes from histopathology, old anatomical studies and animal models. Only in the last years, have neuroimaging techniques allowed a sufficient resolution to directly or indirectly assess the dynamic evolution of small vessel occlusion and to formulate hypotheses about the tissue status and the mechanisms of damage. The core-penumbra concept was extensively explored in large vessel occlusions (LVOs) both from the experimental and clinical point of view. Then, the perfusion thresholds on one side and the neuroimaging techniques studying the perfusion of brain tissue were focused and optimized for LVOs. The presence of a perfusion deficit in the territory of a single small perforating artery was negated for years until the recent proposal of the existence of a perfusion defect in a subgroup of lacunar infarcts by using magnetic resonance imaging (MRI). This last finding opens pathophysiological hypotheses and triggers a neurovascular multidisciplinary reasoning about how to image this perfusion deficit in the acute phase in particular. The aim of this review is to summarize the pathophysiological issues and the application of the core-penumbra hypothesis to lacunar stroke.
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Affiliation(s)
- Marialuisa Zedde
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Manuela Napoli
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Ilaria Grisendi
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Federica Assenza
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Claudio Moratti
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Franco Valzania
- Neurology Unit, Stroke Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
| | - Rosario Pascarella
- Neuroradiology Unit, AUSL-IRCCS di Reggio Emilia, Via Amendola 2, 42122 Reggio Emilia, Italy
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Jiang S, Cui JY, Yan YY, Yang T, Tao WD, Wu B. Association of compromised cerebral perfusion with lenticulostriate artery impairments in the subacute phase of branch atheromatous disease. Ther Adv Neurol Disord 2022; 15:17562864221109746. [PMID: 35813607 PMCID: PMC9260584 DOI: 10.1177/17562864221109746] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 06/09/2022] [Indexed: 02/05/2023] Open
Abstract
Background Purpose: Whether altered cerebral perfusion is associated with the pathogenesis of
single subcortical infarctions (SSIs) in the lenticulostriate artery (LSA)
territory remains unclear. Objective: We aimed to assess whether cerebral perfusion abnormalities are related to
LSA impairments in the subacute phase of SSIs and then to examine their
correlations with etiological subtypes of SSIs. Methods: A total of 110 patients with acute SSIs in the LSA territory were
prospectively recruited between July 2017 and October 2021, and they
underwent magnetic resonance perfusion-weighted imaging (PWI) and
whole-brain vessel-wall imaging (VWI) within 7 days of stroke onset. Based
on VWI, patients were assigned to one of two SSI subtypes: branch
atheromatous disease (BAD, n = 78, 70.9%) or lacunar
infarction related to cerebral small vessel disease (CSVD-related LI,
n = 32, 29.1%). Perfusion maps and LSA morphology were
also quantitatively assessed. Results: Based on PWI, 22 patients (20%) had hypoperfusion and 88 (80%) showed normal
perfusion. Compared with normal individuals, patients with hypoperfusion
showed shorter average LSA length (23.48 ± 4.81 mm versus
25.47 ± 3.74 mm, p = 0.037). Compared with patients with
CSVD-related LI, patients with BAD had significantly lower relative cerebral
blood flow [0.95 (IQR 0.81–1.12) versus 1.04 (IQR
0.92–1.22); p = 0.036] and cerebral blood volume [0.95 (IQR
0.84–1.15) versus 1.14 (IQR 0.97–1.27);
p = 0.020] after adjusting for hypertension, number of LSA
branches, and infarct volume. Conclusion: Compromised cerebral perfusion is associated with impairments in the LSA and
with BAD pathogenesis. Perfusion magnetic resonance imaging can provide
important insights into acute SSI pathophysiology, and it may be useful for
determining the clinical significance of perfusion abnormalities in BAD
occurrence.
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Affiliation(s)
- Shuai Jiang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Jing-Yu Cui
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Yu-Ying Yan
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Tang Yang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Wen-Dan Tao
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Bo Wu
- Department of Neurology, West China Hospital, Sichuan University, No. 37, Guo Xue Xiang, Chengdu 610041, Sichuan, China
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Ben Alaya I, Limam H, Kraiem T. Applications of artificial intelligence for DWI and PWI data processing in acute ischemic stroke: Current practices and future directions. Clin Imaging 2021; 81:79-86. [PMID: 34649081 DOI: 10.1016/j.clinimag.2021.09.015] [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] [Received: 05/10/2021] [Revised: 09/05/2021] [Accepted: 09/22/2021] [Indexed: 11/03/2022]
Abstract
Multimodal Magnetic Resonance Imaging (MRI) techniques of Perfusion-Weighted Imaging (PWI) and Diffusion-Weighted Imaging (DWI) data are integral parts of the diagnostic workup in the acute stroke setting. The visual interpretation of PWI/DWI data is the most likely procedure to triage Acute Ischemic Stroke (AIS) patients who will access reperfusion therapy, especially in those exceeding 6 h of stroke onset. In fact, this process defines two classes of tissue: the ischemic core, which is presumed to be irreversibly damaged, visualized on DWI data and the penumbra which is the reversibly injured brain tissue around the ischemic tissue, visualized on PWI data. AIS patients with a large ischemic penumbra and limited infarction core have a high probability of benefiting from endovascular treatment. However, it is a tedious and time-consuming procedure. Consequently, it is subject to high inter- and intra-observer variability. Thus, the assessment of the potential risks and benefits of endovascular treatment is uncertain. Fast, accurate and automatic post-processing of PWI and DWI data is important for clinical diagnosis and is necessary to help the decision making for therapy. Therefore, an automated procedure that identifies stroke slices, stroke hemisphere, segments stroke regions in DWI, and measures hypoperfused tissue in PWI enhances considerably the reproducibility and the accuracy of stroke assessment. In this work, we draw an overview of several applications of Artificial Intelligence (AI) for the automation processing and their potential contributions in clinical practices. We compare the current approaches among each other's with respect to some key requirements.
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Affiliation(s)
- Ines Ben Alaya
- Tunis El Manar University, Higher Institute of Medical Technology of Tunis, Laboratory of Biophysics and Medical Technology, 1006 Tunis, Tunisia.
| | - Hela Limam
- Université de Tunis El Manar, Institut Supérieur d'Informatique, Institut Supérieur de Gestion de Tunis, Laboratoire BestMod, 1002 Tunis, Tunisie.
| | - Tarek Kraiem
- Tunis El Manar University, Higher Institute of Medical Technology of Tunis, Laboratory of Biophysics and Medical Technology, 1006 Tunis, Tunisia.
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Darwish EAF, Abdelhameed-El-Nouby M, Geneidy E. Mapping the ischemic penumbra and predicting stroke progression in acute ischemic stroke: the overlooked role of susceptibility weighted imaging. Insights Imaging 2020; 11:6. [PMID: 31930428 PMCID: PMC6955386 DOI: 10.1186/s13244-019-0810-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 10/25/2019] [Indexed: 12/15/2022] Open
Abstract
Objectives Asymmetrically prominent veins (APVs) detected on susceptibility weighted imaging (SWI) in acute stroke patients are assumed to signify compromised cerebral perfusion. We aimed to explore the role of APVs in identifying the ischemic penumbra and predicting stroke progression in acute stroke patients Methods Twenty patients with a middle cerebral artery ischemic infarction presenting within 24 h of symptoms onset underwent SWI following our standard MR stroke protocol imaging sequences which included diffusion-weighted imaging (DWI). Follow-up (FUP) FLAIR images were obtained at least 5 days after the initial MRI study. The Alberta Stroke Program Early CT Score (ASPECTS) was used to determine the initial infarct size, extent of APVs and final infarct size on initial DWI, SWI, and FUP images respectively. For each patient, SWI was compared with DWI images to determine match/mismatch of their respective ASPECTS values and calculate mismatch scores, whereas acute DWI findings were compared with follow-up images to identify infarct growth (IG) and calculate infarction growth scores (IGS). Results IG occurred in 6/10 patients with a positive DWI-SWI mismatch and in none of the patients without a positive DWI-SWI mismatch. A positive DWI/SWI mismatch was significantly associated with IG (χ2 = 8.57, p = 0.0138, Cramer’s V = 0.65). A significant inverse correlation was found between SWI ASPECTS and IGS (rs = − 0.702, p = 0.001). DWI-SWI mismatch scores were strongly correlated with IGS. (rs = 0.788, p = 0.000) Conclusion A positive DWI-SWI mismatch is an indicator of the ischemic penumbra and a predictor of infarct expansion if left untreated.
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Affiliation(s)
- Eman A F Darwish
- Department of Radiology, Faculty of Medicine, Ain Shams University, Abbassiya, Cairo, 11566, Egypt.
| | | | - Eman Geneidy
- Department of Radiology, Faculty of Medicine, Ain Shams University, Abbassiya, Cairo, 11566, Egypt
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Tan MYQ, Singhal S, Ma H, Chandra RV, Cheong J, Clissold BB, Ly J, Srikanth V, Phan TG. Examining Subcortical Infarcts in the Era of Acute Multimodality CT Imaging. Front Neurol 2016; 7:220. [PMID: 27994572 PMCID: PMC5136539 DOI: 10.3389/fneur.2016.00220] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/22/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Lacunar infarct has been characterized as small subcortical infarct. It is postulated to occur from "in situ microatheroma or lipohyalinosis" in small vessel or lacunar mechanism. Based on this idea, such infarcts by lacunar mechanism should not be associated with large area of perfusion deficits that extend beyond the subcortical region to the cortical region. By contrast, selected small subcortical infarcts, as defined by MR imaging in the subacute and chronic stage, may initially have large perfusion deficit or related large vessel occlusions. These infarcts with "lacunar" phenotype may also be caused by disease in the parent vessel and may have very different stroke mechanism from small vessel disease. Our aim is to describe differences in imaging characteristics between patients with small subcortical infarction with "lacunar phenotype" from those with lacunar mechanism. MATERIALS AND METHODS Patients undergoing acute CT perfusion/angiography (CTP/CTA) within 6 h of symptom onset and follow-up magnetic resonance imaging (MRI) for ischemic stroke were included (2009-2013). Lacunar infarct was defined as a single subcortical infarct ≤20 mm on follow-up MRI. Presence of perfusion deficits, vessel occlusion, and infarct dimensions was compared between lacunar infarcts and other topographical infarct types. RESULTS Overall, 182 patients (mean age 66.4 ± 15.3 years, 66% males) were included. Lacunar infarct occurred in 31 (17%) patients. Of these, 12 (39%) patients had a perfusion deficit compared with those with any cortical infarction (120/142, 67%), and the smallest lacunar infarct with a perfusion deficit had a diameter of <5 mm. The majority of patients with lacunar infarction (8/12, 66.7%) had a relevant vessel occlusion. A quarter of lacunar infarcts had a large artery stroke mechanism evident on acute CTP/CTA. Lacunar mechanism was present in 3/8 patients with corona radiata, 5/10 lentiform nucleus, 5/6 posterior limb of internal capsule (PLIC), 3/5 thalamic infarcts, 1/2 miscellaneous locations. There was a trend to significant with regards to finding lacunar mechanism among patients with thalamic and PLIC infarcts versus lentiform nucleus and corona radiata infarcts (p = 0.13). CONCLUSION Diverse stroke mechanisms were present among subcortical infarcts in different locations. When available acute CTP/CTA should be combined with subacute imaging of subcortical infarct to separate "lacunar phenotype" from those with lacunar mechanism.
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Affiliation(s)
- Mindy Y Q Tan
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University , Melbourne, VIC , Australia
| | - Shaloo Singhal
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
| | - Henry Ma
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
| | | | - Jamie Cheong
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University , Melbourne, VIC , Australia
| | - Benjamin B Clissold
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
| | - John Ly
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
| | - Velandai Srikanth
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
| | - Thanh G Phan
- Stroke and Aging Research Group, Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Melbourne, VIC, Australia; Stroke Unit, Monash Medical Centre, Monash Health, Melbourne, VIC, Australia
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Förster A, Mürle B, Böhme J, Al-Zghloul M, Kerl HU, Wenz H, Groden C. Perfusion-weighted imaging and dynamic 4D angiograms for the estimation of collateral blood flow in lacunar infarction. J Cereb Blood Flow Metab 2016; 36:1744-1754. [PMID: 26661161 PMCID: PMC5076780 DOI: 10.1177/0271678x15606458] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/22/2015] [Indexed: 01/08/2023]
Abstract
Although lacunar infarction accounts for approximately 25% of ischemic strokes, collateral blood flow through anastomoses is not well evaluated in lacunar infarction. In 111 lacunar infarction patients, we analyzed diffusion-weighted images, perfusion-weighted images, and blood flow on dynamic four-dimensional angiograms generated by use of Signal Processing In NMR-Software. Blood flow was classified as absent (type 1), from periphery to center (type 2), from center to periphery (type 3), and combination of type 2 and 3 (type 4). On diffusion-weighted images, lacunar infarction was found in the basal ganglia (11.7%), internal capsule (24.3%), corona radiata (30.6%), thalamus (24.3%), and brainstem (9.0%). In 58 (52.2%) patients, perfusion-weighted image showed a circumscribed hypoperfusion, in one (0.9%) a circumscribed hyperperfusion, whereas the remainder was normal. In 36 (62.1%) patients, a larger perfusion deficit (>7 mm) was observed. In these, blood flow was classified type 1 in four (11.1%), 2 in 17 (47.2%), 3 in 9 (25.0%), and 4 in six (16.7%) patients. Patients with lacunar infarction in the posterior circulation more often demonstrated blood flow type 2 and less often type 3 (p = 0.01). Detailed examination and graduation of blood flow in lacunar infarction by use of dynamic four-dimensional angiograms is feasible and may serve for a better characterization of this stroke subtype.
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Affiliation(s)
- Alex Förster
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Bettina Mürle
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Johannes Böhme
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Mansour Al-Zghloul
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Hans U Kerl
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Holger Wenz
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
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Kim JP, Kim SJ, Lee JJ, Cha JH, Bang OY, Chung CS, Lee KH, Kim GM. Diffusion-Perfusion Mismatch in Single Subcortical Infarction: A Predictor of Early Neurological Deterioration and Poor Functional Outcome. Eur Neurol 2015; 73:353-9. [DOI: 10.1159/000430461] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 04/12/2015] [Indexed: 11/19/2022]
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Förster A, Kerl HU, Wenz H, Brockmann MA, Nölte I, Groden C. Diffusion- and perfusion-weighted imaging in acute lacunar infarction: is there a mismatch? PLoS One 2013; 8:e77428. [PMID: 24130885 PMCID: PMC3795042 DOI: 10.1371/journal.pone.0077428] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/10/2013] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Characterization of lacunar infarction (LI) by use of multimodal MRI including diffusion- and perfusion-weighted imaging (DWI, PWI) is difficult because of the small lesion size. Only a few studies evaluated PWI in LI and the results are inconsistent. METHODS In 16 LI patients who underwent initial MRI within 6 hours after symptom onset and follow-up MRI within 1 week demographics, clinical presentation, and MRI findings were analyzed with special emphasis on DWI and PWI findings. Time to peak maps were classified as showing a normal perfusion pattern or areas of hypoperfusion which were further categorized in mismatch (PWI>DWI), inverse mismatch (PWI<DWI), and match (PWI=DWI). Quantitative perfusion maps were generated and analyzed by use of Signal Processing in NMR-Software (SPIN). RESULTS Of the 16 patients (mean age 65.5±12.9 years), 14 (87.5%) were male. Clinical symptoms comprised dysarthria (50%), hemiparesis (81.3%), and hemihypaesthesia (18.8%). Intravenous thrombolysis was performed in 7 (43.8%) patients. Clinical improvement was observed in 12 patients (75 %), while 2 (12.5%) patients showed a deterioration and another 2 (12.5%) a stable course. Acute ischemic lesions (mean volume of 0.46±0.29 cm³) were located in the thalamus (n=8, 50%), internal capsule (n=4, 25%), corona Radiata (n=3, 18.8%) and the mesencephalon (n=1, 6.3%). Circumscribed hypoperfusion (mean volume 0.61±0.48 cm³) was evident in 10 (62.5%) patients. Of these, 3 patients demonstrated a match, 4 an inverse mismatch, and 3 a mismatch between DWI and PWI lesion. Mean CBF and CBV ratios were 0.65±0.28 and 0.84±0.41 respectively. Growth of DWI lesions was observed in 7 (43.8%) and reversal of DWI lesions in 3 (18.8%) patients. CONCLUSIONS MRI allows identification of different DWI and PWI patterns in LI, including growth and reversal of ischemic lesions. Consequently, it may serve for a better characterization of this stroke subtype and support treatment decisions in daily clinical practice.
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Affiliation(s)
- Alex Förster
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
- * E-mail:
| | - Hans Ulrich Kerl
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Holger Wenz
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Marc A. Brockmann
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
- Department of Diagnostic and Interventional Neuroradiology, University Hospital of the RWTH Aachen, Aachen, Germany
| | - Ingo Nölte
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Heidelberg, Germany
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Chen F, Ni YC. Magnetic resonance diffusion-perfusion mismatch in acute ischemic stroke: An update. World J Radiol 2012; 4:63-74. [PMID: 22468186 PMCID: PMC3314930 DOI: 10.4329/wjr.v4.i3.63] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 02/22/2012] [Accepted: 03/01/2012] [Indexed: 02/06/2023] Open
Abstract
The concept of magnetic resonance perfusion-diffusion mismatch (PDM) provides a practical and approximate measure of the tissue at risk and has been increasingly applied for the evaluation of hyperacute and acute stroke in animals and patients. Recent studies demonstrated that PDM does not optimally define the ischemic penumbra; because early abnormality on diffusion-weighted imaging overestimates the infarct core by including part of the penumbra, and the abnormality on perfusion weighted imaging overestimates the penumbra by including regions of benign oligemia. To overcome these limitations, many efforts have been made to optimize conventional PDM. Various alternatives beyond the PDM concept are under investigation in order to better define the penumbra. The PDM theory has been applied in ischemic stroke for at least three purposes: to be used as a practical selection tool for stroke treatment; to test the hypothesis that patients with PDM pattern will benefit from treatment, while those without mismatch pattern will not; to be a surrogate measure for stroke outcome. The main patterns of PDM and its relation with clinical outcomes were also briefly reviewed. The conclusion was that patients with PDM documented more reperfusion, reduced infarct growth and better clinical outcomes compared to patients without PDM, but it was not yet clear that thrombolytic therapy is beneficial when patients were selected on PDM. Studies based on a larger cohort are currently under investigation to further validate the PDM hypothesis.
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Galinovic I, Ostwaldt AC, Soemmer C, Bros H, Hotter B, Brunecker P, Schmidt WU, Jungehülsing J, Fiebach JB. Search for a map and threshold in perfusion MRI to accurately predict tissue fate: a protocol for assessing lesion growth in patients with persistent vessel occlusion. Cerebrovasc Dis 2011; 32:186-93. [PMID: 21849778 DOI: 10.1159/000328663] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 04/06/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The MRI-based mismatch concept has been used to estimate the risk of infarction in ischemic stroke. Based on multiple studies on magnetic resonance perfusion imaging, it seems unlikely that any perfusion parameter threshold will provide a reliable prediction of radiological or clinical outcome for all patients. The goal of our study was to find a minimally biased yet maximally useful perfusion postprocessing protocol which would offer the treating physician a useful estimate of tissue fate. METHODS One hundred and forty-five acute ischemic stroke patients, admitted within 24 h after stroke to the Charité-University Medicine Hospital in Berlin between March 2008 and November 2009, were included in this study. Using three different software packages (Perfscape/Neuroscape, PMA and Stroketool), maps of mean transit time, cerebral blood flow (CBF) and T(max) were created. Three different thresholds were applied on each parameter map and subsequent volumes of hypoperfused tissue were calculated. RESULTS Overall, the maps and thresholds giving the least amount of overestimation of the final infarct volume were T(max) 8 s in Perfscape/Neuroscape, CBF 20 ml/100 g/min in PMA and CBF 15% (of the highest value on the scale for a given patient) in Stroketool. In patients with persistent vessel occlusion, a CBF map with a restrictive threshold showed volumes of tissue at definite risk of infarction in up to 100% of patients. The additional use of a CBF map with a high threshold enabled identification of patients without penumbras. CONCLUSIONS No combination of software, map and threshold was able to give a reliable estimate of tissue fate for either all patients or any subgroup of patients. However, in patients with vessel occlusion, combination of a CBF map with a low and a high threshold can enable calculation of the minimum volume of brain tissue that will inevitably be lost if the occlusion persists.
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Affiliation(s)
- Ivana Galinovic
- Center for Stroke Research Berlin (CSB), Charité-University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany.
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