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Carisch L, Lindt B, Richter H, Del Chicca F. Regional ADC values of the morphologically normal canine brain. Front Vet Sci 2023; 10:1219943. [PMID: 38026624 PMCID: PMC10663295 DOI: 10.3389/fvets.2023.1219943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Diffusion-weighted magnetic resonance imaging is increasingly available for investigation of canine brain diseases. Apparent diffusion coefficient (ADC) of normal canine brains is reported only in small numbers of subjects. The aim of the study was to investigate the ADC of different anatomical regions in the morphologically normal brain in a large population of canine patients in clinical setting. Additionally, possible influence on the ADC value of patient-related factors like sex, age and body weight, difference between the left and right side of the cerebral hemispheres, and between gray and white matter were investigated. Methods Brain magnetic resonance studies including diffusion-weighted images of dogs presented at the Vetsuisse Faculty-University Zurich between 2015 and 2020 were reviewed retrospectively. Only morphologically normal brain magnetic resonance studies of dogs presented with neurological signs or non-neurological signs were included. Apparent diffusion coefficient values of 12 regions of interest (ROIs) in each hemisphere and an additional region in the cerebellar vermis were examined in each dog. Results A total of 321 dogs (including 247 dogs with neurological signs and 62 dogs with non-neurological signs) of various breeds, sex and age were included. Apparent diffusion coefficient significantly varied among most anatomical brain regions. A significantly higher ADC was measured in the gray [median 0.79 (range 0.69-0.90) × 10-3 mm2/s] compared to the white matter [median 0.70 (range 0.63-0.85) × 10-3 mm2/s]. No significant differences were found between the left and right cerebral hemispheres in most of the regions, neither between sexes, different reproductive status, and not consistently between body weight groups. Age was correlated first with a decrease from dogs <1 year of age to middle-age (⩾3 to <8 years) dogs and later with an increase of ADC values in dogs ⩾8 years. Discussion Apparent diffusion coefficient values of 25 ROIs were described in 321 morphologically normal canine brains in clinical setting. Apparent diffusion coefficient differences depending on the brain anatomical region are present. Apparent diffusion coefficient differences among age classes are present, likely consistent with brain maturation and aging. The described data can be a reference for future studies in clinical settings on the canine brain.
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Affiliation(s)
- Lea Carisch
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Canazza A, Minati L, Boffano C, Parati E, Binks S. Experimental models of brain ischemia: a review of techniques, magnetic resonance imaging, and investigational cell-based therapies. Front Neurol 2014; 5:19. [PMID: 24600434 PMCID: PMC3928567 DOI: 10.3389/fneur.2014.00019] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 02/06/2014] [Indexed: 01/17/2023] Open
Abstract
Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment, and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.
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Affiliation(s)
- Alessandra Canazza
- Cerebrovascular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta" , Milan , Italy
| | - Ludovico Minati
- Scientific Department, Fondazione IRCCS Istituto Neurologico "Carlo Besta" , Milan , Italy ; Brighton and Sussex Medical School , Brighton , UK
| | - Carlo Boffano
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta" , Milan , Italy
| | - Eugenio Parati
- Cerebrovascular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta" , Milan , Italy
| | - Sophie Binks
- Brighton and Sussex Medical School , Brighton , UK ; Brighton and Sussex University Hospitals NHS Trust , Brighton , UK
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Bouts MJRJ, Tiebosch IACW, van der Toorn A, Hendrikse J, Dijkhuizen RM. Lesion development and reperfusion benefit in relation to vascular occlusion patterns after embolic stroke in rats. J Cereb Blood Flow Metab 2014; 34:332-8. [PMID: 24301289 PMCID: PMC3915211 DOI: 10.1038/jcbfm.2013.202] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/08/2013] [Accepted: 10/25/2013] [Indexed: 11/09/2022]
Abstract
Vascular occlusion sites largely determine the pattern of cerebral tissue damage and likelihood of subsequent reperfusion after acute ischemic stroke. We aimed to elucidate relationships between flow obstruction in segments of the internal carotid artery (ICA) and middle cerebral artery (MCA), and (1) profiles of acute ischemic lesions and (2) probability of subsequent beneficial reperfusion. Embolic stroke was induced by unilateral intracarotid blood clot injection in normotensive (n=53) or spontaneously hypertensive (n=20) rats, followed within 2 hours by magnetic resonance (MR) angiography (MRA), diffusion- (DWI) and perfusion-weighted magnetic resonance imaging (MRI) (PWI). In a subset of animals (n=9), MRI was repeated after 24 and 168 hours to determine the predictive value of the occlusion pattern on benefit of reperfusion. The extent of cerebral perfusion and diffusion abnormality was related to the pattern of flow obstruction in ICA and MCA segments. Hypertensive animals displayed significantly larger cortical perfusion lesions. Acute perfusion-diffusion lesion mismatches were detected in all animals that subsequently benefitted from reperfusion. Yet, the presence of an angiography-diffusion mismatch was more specific in predicting reperfusion benefit. Combination of DWI, PWI, and MRA exclusively informs on the impact of arterial occlusion profiles after acute ischemic stroke, which may improve prognostication and subsequent treatment decisions.
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Affiliation(s)
- Mark J R J Bouts
- 1] Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands [2] Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts, USA
| | - Ivo A C W Tiebosch
- Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Annette van der Toorn
- Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rick M Dijkhuizen
- Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center Utrecht, Utrecht, The Netherlands
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Jung S, Gilgen M, Slotboom J, El-Koussy M, Zubler C, Kiefer C, Luedi R, Mono ML, Heldner MR, Weck A, Mordasini P, Schroth G, Mattle HP, Arnold M, Gralla J, Fischer U. Factors that determine penumbral tissue loss in acute ischaemic stroke. Brain 2013; 136:3554-60. [PMID: 24065722 DOI: 10.1093/brain/awt246] [Citation(s) in RCA: 145] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Simon Jung
- 1 Department of Neurology, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland
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Boyer AC, Gonçalves LF, Lee W, Shetty A, Holman A, Yeo L, Romero R. Magnetic resonance diffusion-weighted imaging: reproducibility of regional apparent diffusion coefficients for the normal fetal brain. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2013; 41:190-7. [PMID: 22744761 PMCID: PMC3562408 DOI: 10.1002/uog.11219] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/2012] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To evaluate the reproducibility of regional apparent diffusion coefficient (ADC) measurements of the normal fetal brain in the second and third trimesters of pregnancy. METHODS Fifty normal singleton fetuses from healthy pregnant women between 19 and 37 weeks' gestation were studied without sedation. Single-shot diffusion-weighted images of the fetal brain were obtained using a 1.5-Tesla magnetic resonance scanner and a six-channel body array coil. ADC maps were created using 0 and 1000 b-values along three orthogonal directions. Two examiners independently measured ADC values in the cerebellar hemispheres (CH), pons, thalamus, basal ganglia (BG), centrum semiovale (CSO), and frontal (FWM), parietal (PWM), temporal (TWM) and occipital (OWM) white matter. Correlation between ADC values and menstrual age was assessed by linear regression analysis. The bias and agreement of ADC measurements were determined using Bland-Altman plots. RESULTS ADC values either remained constant (BG, FWM, PWM, TWM, OWM, CSO) or decreased (CH, pons, thalamus) with advancing menstrual age. Mean intraobserver bias for ADC measurements was not significantly different from zero. Small interobserver differences in mean ADC measurements (i.e. a small mean bias) were detected for CH (1.26 ± 0.20 vs 1.20 ± 0.18 μm(2) /ms, P = 0.006), PWM (1.37 ± 0.29 vs 1.33 ± 0.26 μm(2) /ms, P = 0.02) and CSO (1.36 ± 0.29 vs 1.33 ± 0.28 μm(2) /ms, P < 0.0001). Measurement agreement was acceptable. CONCLUSIONS ADC measurements in normal unsedated fetuses in the second and third trimesters are reproducible except for small differences for PWM, CH and CSO between examiners.
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Affiliation(s)
- A C Boyer
- Department of Diagnostic Radiology, Oakland University William Beaumont School of Medicine, Rochester, MI 48073, USA.
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Floery D, Vosko MR, Fellner FA, Fellner C, Ginthoer C, Gruber F, Ransmayr G, Doerfler A, Uder M, Bradley WG. Acute-onset migrainous aura mimicking acute stroke: MR perfusion imaging features. AJNR Am J Neuroradiol 2012; 33:1546-52. [PMID: 22517281 DOI: 10.3174/ajnr.a3020] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE In a very limited number of cases, acute migrainous aura may mimic acute brain infarction. The aim of this study was to recognize patterns of MR perfusion abnormalities in this presentation. MATERIALS AND METHODS One thousand eight hundred fifty MR imaging studies performed for the suspicion of acute brain infarction were analyzed retrospectively to detect patients with acute migrainous aura not from stroke. All patients were examined clinically by 2 neurologists and underwent a standard stroke MR imaging protocol, including PWI. Two radiologists reviewed the perfusion maps visually and quantitatively for the presence, distribution, and grade of perfusion abnormalities. RESULTS Among 1850 MR imaging studies, 20 (1.08%) patients were found to have acute migrainous aura. Hypoperfusion was found in 14/20 patients (70%) with delayed rMTT and TTP, decreased rCBF, and minimal decrease in rCBV. In contrast to the typical pattern in stroke, perfusion abnormalities were not limited to a single vascular territory but extended to >1. Bilateral hypoperfusion was seen in 3/14 cases. In 11/14 cases, hypoperfusion with a posterior predominance was found. TTP and rMTT were the best maps to depict perfusion changes at visual assessment, but also rCBF maps demonstrated significant hypoperfusion in quantitative analysis. In all patients, clinical and imaging follow-up findings were negative for stroke. CONCLUSIONS Acute migrainous aura is rare but important in the differential diagnosis among patients with the suspicion of acute brain infarction. Atypical stroke perfusion abnormalities can be seen in these patients.
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Affiliation(s)
- D Floery
- Institute of Radiology, AKH Linz, Linz, Austria
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Hong CT, Sun Y, Lu CJ, Shin HC, Chen RC. Prediction of infarct growth and neurologic deterioration in patients with positive perfusion-diffusion mismatch. Clin Neurol Neurosurg 2011; 114:376-80. [PMID: 22137784 DOI: 10.1016/j.clineuro.2011.11.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 10/01/2011] [Accepted: 11/10/2011] [Indexed: 12/01/2022]
Abstract
BACKGROUND To assess the value of baseline clinical severity and perfusion-diffusion mismatch as predictors for further infarct growth and clinical outcome. METHODS Patients with acute ischemic stroke and initial perfusion-diffusion mismatch within 72 h were enrolled. Baseline perfusion defects on time-to-peak (TTP) and cerebral blood volume (CBV) maps were measured. Infarct volume and stroke severity were assessed by diffusion-weighted image (DWI) and NIHSS, and were repeatedly assessed 7 days later. The predictive value of baseline NIHSS and perfusion defects on further infarct growth and neurologic deterioration was determined. RESULTS Fifty-two patients (mean age 68.3±12.8 years, 42% women) were enrolled. CBV defects were significantly associated with infarct growth (CBV, p=0.02). Initial stroke severity, but not TTP and CBV mismatch (p=0.65 and 0.76, respectively), significantly inversely correlated with neurologic deterioration (p=0.001). CONCLUSIONS In patients with mismatch, those with severe symptoms initially are more likely to have infarct growth, while those with minor symptoms tend to suffer from larger extent of neurologic deterioration within 1 week. CBV is associated with further infarct growth but not clinical deterioration.
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Affiliation(s)
- Chien-Tai Hong
- Department of Neurology, En Chu Kong Hospital, Taipei, Taiwan
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Letourneur A, Roussel S, Toutain J, Bernaudin M, Touzani O. Impact of genetic and renovascular chronic arterial hypertension on the acute spatiotemporal evolution of the ischemic penumbra: a sequential study with MRI in the rat. J Cereb Blood Flow Metab 2011; 31:504-13. [PMID: 20648035 PMCID: PMC3049506 DOI: 10.1038/jcbfm.2010.118] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although chronic arterial hypertension (CAH) increases the risk of stroke and the severity of the resultant lesion, it is rarely integrated in preclinical studies. Here, we analyzed the impact of CAH on the acute spatiotemporal evolution of the ischemic penumbra as defined by the perfusion-weighted imaging/diffusion-weighted imaging mismatch. Sequential 7T-MRI examinations were performed from 30 minutes up to 4 hours after permanent cerebral ischemia in genetically hypertensive rats (spontaneously hypertensive rats, SHR), renovascular-hypertensive rats (RH-WKY), and their normotensive controls (Wistar-Kyoto rats, WKY). The apparent diffusion coefficient (ADC)-defined lesion was larger in hypertensive rats than in normotensive animals as early as 30 minutes after the ischemia. The ischemic penumbra was smaller in both genetically and renovascular-hypertensive rats (at 30 minutes; SHR=66±25 mm(3), RH-WKY=55±17 mm(3) versus WKY=117±14 mm(3); P<0.008) and there was no significant difference between the perfusion deficit and ADC lesion (mismatch definition of penumbra) as early as 90 minutes after the occlusion. Genetic hypertension and induced renovascular hypertension resulted in larger lesion and smaller penumbra that vanished rapidly. These data support the need to integrate CAH in preclinical studies relative to the treatment of stroke, as failure to do so may lead to preclinical results nonpredictive of clinical trials, which include hypertensive patients.
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Affiliation(s)
- Annelise Letourneur
- UMR CI-NAPS 6232, CNRS, CEA, Université de Caen Basse-Normandie, Centre CYCERON, Caen, France
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Zhao Y, Rempe DA. Targeting astrocytes for stroke therapy. Neurotherapeutics 2010; 7:439-51. [PMID: 20880507 PMCID: PMC5084305 DOI: 10.1016/j.nurt.2010.07.004] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 07/01/2010] [Accepted: 07/26/2010] [Indexed: 12/12/2022] Open
Abstract
Stroke remains a major health problem and is a leading cause of death and disability. Past research and neurotherapeutic clinical trials have targeted the molecular mechanisms of neuronal cell death during stroke, but this approach has uniformly failed to reduce stroke-induced damage or to improve functional recovery. Beyond the intrinsic molecular mechanisms inducing neuronal death during ischemia, survival and function of astrocytes is absolutely required for neuronal survival and for functional recovery after stroke. Many functions of astrocytes likely improve neuronal viability during stroke. For example, uptake of glutamate and release of neurotrophins enhances neuronal viability during ischemia. Under certain conditions, however, astrocyte function may compromise neuronal viability. For example, astrocytes may produce inflammatory cytokines or toxic mediators, or may release glutamate. The only clinical neurotherapeutic trial for stroke that specifically targeted astrocyte function focused on reducing release of S-100β from astrocytes, which becomes a neurotoxin when present at high levels. Recent work also suggests that astrocytes, beyond their influence on cell survival, also contribute to angiogenesis, neuronal plasticity, and functional recovery in the several days to weeks after stroke. If these delayed functions of astrocytes could be targeted for enhancing stroke recovery, it could contribute importantly to improving stroke recovery. This review focuses on both the positive and the negative influences of astrocytes during stroke, especially as they may be targeted for translation to human trials.
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Affiliation(s)
- Yanxin Zhao
- grid.16416.340000000419369174Department of Neurology in the Center for Neural Development and Disease, University of Rochester School of Medicine and Dentistry, 14642 Rochester, New York
| | - David A. Rempe
- grid.16416.340000000419369174Department of Neurology in the Center for Neural Development and Disease, University of Rochester School of Medicine and Dentistry, 14642 Rochester, New York
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Jayaraman MV. Neurovascular imaging. Top Magn Reson Imaging 2008; 19:223. [PMID: 19512853 DOI: 10.1097/rmr.0b013e3181aaf2d5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
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