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Lee JK, Liu D, Raven EP, Jiang D, Liu P, Qin Q, Kulikowicz E, Santos PT, Adams S, Zhang J, Koehler RC, Martin LJ, Tekes A. Mean Diffusivity in Striatum Correlates With Acute Neuronal Death but Not Lesser Neuronal Injury in a Pilot Study of Neonatal Piglets With Encephalopathy. J Magn Reson Imaging 2020; 52:1216-1226. [PMID: 32396711 DOI: 10.1002/jmri.27181] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/14/2020] [Accepted: 04/16/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Diffusion MRI is routinely used to evaluate brain injury in neonatal encephalopathy. Although abnormal mean diffusivity (MD) is often attributed to cytotoxic edema, the specific contribution from neuronal pathology is unclear. PURPOSE To determine whether MD from high-resolution diffusion tensor imaging (DTI) can detect variable degrees of neuronal degeneration and pathology in piglets with brain injury induced by excitotoxicity or global hypoxia-ischemia (HI) with or without overt infarction. STUDY TYPE Prospective. ANIMAL MODEL Excitotoxic brain injury was induced in six neonatal piglets by intrastriatal stereotaxic injection of the glutamate receptor agonist quinolinic acid (QA). Three piglets underwent global HI or a sham procedure. Piglets recovered for 20-96 hours before undergoing MRI (n = 9). FIELD STRENGTH/SEQUENCE 3.0T MRI with DTI, T1 - and T2 -weighted imaging. ASSESSMENT MD, fractional anisotropy (FA), and qualitative T2 injury were assessed in the putamen and caudate. The cell bodies of normal neurons, degenerating neurons (excitotoxic necrosis, ischemic necrosis, or necrosis-apoptosis cell death continuum), and injured neurons with equivocal degeneration were counted by histopathology. STATISTICAL TESTS Spearman correlations were used to compare MD and FA to normal, degenerating, and injured neurons. T2 injury and neuron counts were evaluated by descriptive analysis. RESULTS The QA insult generated titratable levels of neuronal pathology. In QA, HI, and sham piglets, lower MD correlated with higher ratios of degenerating-to-total neurons (P < 0.05), lower ratios of normal-to-total neurons (P < 0.05), and greater numbers of degenerating neurons (P < 0.05). MD did not correlate with abnormal neurons exhibiting nascent injury (P > 0.99). Neuron counts were not related to FA (P > 0.30) or to qualitative injury from T2 -weighted MRI. DATA CONCLUSION MD is more accurate than FA for detecting neuronal degeneration and loss during acute recovery from neonatal excitotoxic and HI brain injury. MD does not reliably detect nonfulminant, nascent, and potentially reversible neuronal injury. EVIDENCE LEVEL 1 TECHNICAL EFFICACY: Stage 2 J. Magn. Reson. Imaging 2020;52:1216-1226.
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Affiliation(s)
- Jennifer K Lee
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University (JHU), Baltimore, Maryland, USA
| | - Dapeng Liu
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Erika P Raven
- Department of Radiology, New York University (NYU), New York, New York, USA
| | - Dengrong Jiang
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peiying Liu
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Qin Qin
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ewa Kulikowicz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University (JHU), Baltimore, Maryland, USA
| | - Polan T Santos
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University (JHU), Baltimore, Maryland, USA
| | - Shawn Adams
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University (JHU), Baltimore, Maryland, USA
| | - Jiangyang Zhang
- Department of Radiology, New York University (NYU), New York, New York, USA
| | - Raymond C Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University (JHU), Baltimore, Maryland, USA
| | - Lee J Martin
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Aylin Tekes
- Department of Radiology, Johns Hopkins University, Baltimore, Maryland, USA
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Kao YCJ, Oyarzabal EA, Zhang H, Faber JE, Shih YYI. Role of Genetic Variation in Collateral Circulation in the Evolution of Acute Stroke: A Multimodal Magnetic Resonance Imaging Study. Stroke 2017; 48:754-761. [PMID: 28188261 DOI: 10.1161/strokeaha.116.015878] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 12/05/2016] [Accepted: 12/08/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE No studies have determined the effect of differences in pial collateral extent (number and diameter), independent of differences in environmental factors and unknown genetic factors, on severity of stroke. We examined ischemic tissue evolution during acute stroke, as measured by magnetic resonance imaging and histology, by comparing 2 congenic mouse strains with otherwise identical genetic backgrounds but with different alleles of the Determinant of collateral extent-1 (Dce1) genetic locus. We also optimized magnetic resonance perfusion and diffusion-deficit thresholds by using histological measures of ischemic tissue. METHODS Perfusion, diffusion, and T2-weighted magnetic resonance imaging were performed on collateral-poor (congenic-Bc) and collateral-rich (congenic-B6) mice at 1, 5, and 24 hours after permanent middle cerebral artery occlusion. Magnetic resonance imaging-derived penumbra and ischemic core volumes were confirmed by histology in a subset of mice at 5 and 24 hours after permanent middle cerebral artery occlusion. RESULTS Although perfusion-deficit volumes were similar between strains 1 hour after permanent middle cerebral artery occlusion, diffusion-deficit volumes were 32% smaller in collateral-rich mice. At 5 hours, collateral-rich mice had markedly restored perfusion patterns showing reduced perfusion-deficit volumes, smaller infarct volumes, and smaller perfusion-diffusion mismatch volumes compared with the collateral-poor mice (P<0.05). At 24 hours, collateral-rich mice had 45% smaller T2-weighted lesion volumes (P<0.005) than collateral-poor mice, with no difference in perfusion-diffusion mismatch volumes because of penumbral death occurring 5 to 24 hours after permanent middle cerebral artery occlusion in collateral-poor mice. CONCLUSIONS Variation in collateral extent significantly alters infarct volume expansion, transiently affects perfusion and diffusion magnetic resonance imaging signatures, and impacts salvage of ischemic penumbra after stroke onset.
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Affiliation(s)
- Yu-Chieh Jill Kao
- From the Department of Neurology (Y.-C.J.K., E.A.O.), Biomedical Research Imaging Center (Y.-C.J.K., E.A.O., Y.-Y.I.S.), Neurobiology Curriculum (E.A.O., J.E.F.), Department of Cell Biology and Physiology (H.Z., J.E.F.), McAllister Heart Institute (H.Z., J.E.F., Y.-Y.I.S.), and Department of Biomedical Engineering (Y.-Y.I.S.), University of North Carolina, Chapel Hill; and Translational Imaging Research Center (Y.-C.J.K.) and Department of Radiology, School of Medicine (Y.-C.J.K.), College of Medicine, Taipei Medical University, Taiwan
| | - Esteban A Oyarzabal
- From the Department of Neurology (Y.-C.J.K., E.A.O.), Biomedical Research Imaging Center (Y.-C.J.K., E.A.O., Y.-Y.I.S.), Neurobiology Curriculum (E.A.O., J.E.F.), Department of Cell Biology and Physiology (H.Z., J.E.F.), McAllister Heart Institute (H.Z., J.E.F., Y.-Y.I.S.), and Department of Biomedical Engineering (Y.-Y.I.S.), University of North Carolina, Chapel Hill; and Translational Imaging Research Center (Y.-C.J.K.) and Department of Radiology, School of Medicine (Y.-C.J.K.), College of Medicine, Taipei Medical University, Taiwan
| | - Hua Zhang
- From the Department of Neurology (Y.-C.J.K., E.A.O.), Biomedical Research Imaging Center (Y.-C.J.K., E.A.O., Y.-Y.I.S.), Neurobiology Curriculum (E.A.O., J.E.F.), Department of Cell Biology and Physiology (H.Z., J.E.F.), McAllister Heart Institute (H.Z., J.E.F., Y.-Y.I.S.), and Department of Biomedical Engineering (Y.-Y.I.S.), University of North Carolina, Chapel Hill; and Translational Imaging Research Center (Y.-C.J.K.) and Department of Radiology, School of Medicine (Y.-C.J.K.), College of Medicine, Taipei Medical University, Taiwan
| | - James E Faber
- From the Department of Neurology (Y.-C.J.K., E.A.O.), Biomedical Research Imaging Center (Y.-C.J.K., E.A.O., Y.-Y.I.S.), Neurobiology Curriculum (E.A.O., J.E.F.), Department of Cell Biology and Physiology (H.Z., J.E.F.), McAllister Heart Institute (H.Z., J.E.F., Y.-Y.I.S.), and Department of Biomedical Engineering (Y.-Y.I.S.), University of North Carolina, Chapel Hill; and Translational Imaging Research Center (Y.-C.J.K.) and Department of Radiology, School of Medicine (Y.-C.J.K.), College of Medicine, Taipei Medical University, Taiwan
| | - Yen-Yu Ian Shih
- From the Department of Neurology (Y.-C.J.K., E.A.O.), Biomedical Research Imaging Center (Y.-C.J.K., E.A.O., Y.-Y.I.S.), Neurobiology Curriculum (E.A.O., J.E.F.), Department of Cell Biology and Physiology (H.Z., J.E.F.), McAllister Heart Institute (H.Z., J.E.F., Y.-Y.I.S.), and Department of Biomedical Engineering (Y.-Y.I.S.), University of North Carolina, Chapel Hill; and Translational Imaging Research Center (Y.-C.J.K.) and Department of Radiology, School of Medicine (Y.-C.J.K.), College of Medicine, Taipei Medical University, Taiwan.
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