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Miller SL, Wiebenga-Sanford BP, Rithner CD, Levinger NE. Nanoconfinement Raises the Energy Barrier to Hydrogen Atom Exchange between Water and Glucose. J Phys Chem B 2021; 125:3364-3373. [PMID: 33784460 DOI: 10.1021/acs.jpcb.0c10681] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In bulk aqueous environments, the exchange of protons between labile hydroxyl groups typically occurs easily and quickly. Nanoconfinement can dramatically change this normally facile process. Through exchange spectroscopy (EXSY) NMR measurements, we observe that nanoconfinement of glucose and water within AOT (sodium bis(2-ethylhexyl) sulfosuccinate) reverse micelles raises the energy barrier to labile hydrogen exchange, which suggests a disruption of the hydrogen bond network. Near room temperature, we measure barriers high enough to slow the process by as much as 2 orders of magnitude. Although exchange rates slow with decreasing temperatures in these nanoconfined environments, the barrier we measure below ∼285 K is 3-5 times lower than the barrier measured at room temperature, indicating a change in mechanism for the process. These findings suggest the possibility of hydrogen tunneling at a surprisingly high-temperature threshold. Furthermore, differences in exchange rates depend on the hydroxyl group position on the glucose pyranose ring and suggest a net orientation of glucose at the reverse micelle interface.
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Affiliation(s)
- Samantha L Miller
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | | | - Christopher D Rithner
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
| | - Nancy E Levinger
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States
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2
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Xia ZY, Bruguier C, Dedouit F, Grabherr S, Augsburger M, Liu BB. Oleic Acid (OA), A Potential Dual Contrast Agent for Postmortem MR Angiography (PMMRA): A Pilot Study. Curr Med Sci 2020; 40:786-794. [PMID: 32862391 DOI: 10.1007/s11596-020-2244-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/19/2020] [Indexed: 01/31/2023]
Abstract
Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography (PMMRA). However, in this emerging field, the number of suitable kinds of liquid is still very limited. The objective of this research is to compare MR images of oleic acid (OA) with paraffin oil (PO) in vitro and in ex situ animal hearts, in order to evaluate the feasibility to use OA as a novel contrast agent for PMMRA. In vitro, OA, PO and water (control) were introduced into three tubes separately and T1weighted-spin echo (T1w-SE) and T2w-SE images were acquired on a 1.5T MR scanner. In the second experiment, OA and PO were injected into left coronary artery (LCA) and left ventricle (LV) of ex situ bovine hearts and their T1w-SE, T2w-SE, T1w-multipoint Dixon (T1w-mDixon) and 3DT2w-mDixon images were acquired. The overall results indicate that OA may have a potential to be used as a dual (T1 and T2 based) contrast agent for PMMRA when proper sequence parameters are utilized. However, as the pilot study was based on limited number of animal hearts, more researches using OA in cadavers are needed to validate our findings.
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Affiliation(s)
- Zhi-Yuan Xia
- Institute of Evidence Law and Forensic Science, China University of Political Science and Law (CUPL), Key Laboratory of Evidence Law and Forensic Science, Ministry of Education, Beijing, 100088, China.
| | - Christine Bruguier
- University Center of Legal Medicine, Lausanne-Geneva (CURML), Lausanne, CH1000, Switzerland
| | - Fabrice Dedouit
- Service de Médecine Légale, Hôpital de Rangueil, Toulouse, 50032, France
| | - Silke Grabherr
- University Center of Legal Medicine, Lausanne-Geneva (CURML), Lausanne, CH1000, Switzerland
| | - Marc Augsburger
- University Center of Legal Medicine, Lausanne-Geneva (CURML), Lausanne, CH1000, Switzerland
| | - Bei-Bei Liu
- Dian Research Center for Postmortem Imaging & Angiography, Beijing, 100192, China
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3
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Saini BS, Darby JRT, Portnoy S, Sun L, van Amerom J, Lock MC, Soo JY, Holman SL, Perumal SR, Kingdom JC, Sled JG, Macgowan CK, Morrison JL, Seed M. Normal human and sheep fetal vessel oxygen saturations by T2 magnetic resonance imaging. J Physiol 2020; 598:3259-3281. [PMID: 32372463 DOI: 10.1113/jp279725] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/30/2020] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Human fetal Doppler ultrasound and invasive blood gas measurements obtained by cordocentesis or at the time of delivery reveal similarities with sheep (an extensively used model for human fetal cardiovascular physiology). Oxygen saturation (SO2 ) measurements in human fetuses have been limited to the umbilical and scalp vessels, providing little information about normal regional SO2 differences in the fetus. Blood T2 MRI relaxometry presents a non-invasive measure of SO2 in the major fetal vessels. This study presents the first in vivo validation of fetal vessel T2 oximetry against the in vitro T2-SO2 relationship using catheterized sheep fetuses and compares the normal SO2 in the major vessels between the human and sheep fetal circulations. Human fetal vessel SO2 by T2 MRI confirms many similarities with the sheep fetal circulation and is able to demonstrate regional differences in SO2 ; in particular the significantly higher SO2 in the left versus right heart. ABSTRACT Blood T2 magnetic resonance imaging (MRI) relaxometry non-invasively measures oxygen saturation (SO2 ) in major vessels but has not been validated in fetuses in vivo. We compared the blood T2-SO2 relationship in vitro (tubes) and in vivo (vessels) in sheep, and measured SO2 across the normal human and sheep fetal circulations by T2. Singleton pregnant ewes underwent surgery to implant vascular catheters. In vitro and in vivo sheep blood T2 measurements were related to corresponding SO2 measured using a blood gas analyser, as well as relating T2 and SO2 of human fetal blood in vitro. MRI oximetry was performed in the major vessels of 30 human fetuses at 36 weeks (term, 40 weeks) and 10 fetal sheep (125 days; term, 150 days). The fidelity of in vivo fetal T2 oximetry was confirmed through comparison of in vitro and in vivo sheep blood T2-SO2 relationships (P = 0.1). SO2 was similar between human and sheep fetuses, as was the fetal oxygen extraction fraction (human, 33 ± 11%; sheep, 34 ± 7%; P = 0.798). The presence of streaming in the human fetal circulation was demonstrated by the SO2 gradient between the ascending aorta (68 ± 10%) and the main pulmonary artery (49 ± 9%; P < 0.001). Human and sheep fetal vessel MRI oximetry based on T2 is a validated approach that confirms the presence of streaming of umbilical venous blood towards the heart and brain. Streaming is important in ensuring oxygen delivery to these organs and its disruption may have important implications for organ development, especially in conditions such as congenital heart disease and fetal growth restriction.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sharon Portnoy
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Liqun Sun
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Joshua van Amerom
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - John C Kingdom
- Department of Obstetrics and Gynaecology, Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
| | - John G Sled
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher K Macgowan
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
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Webb B, Manninger M, Leoni M, Widek T, Dobrovnik M, Scherr D, Stollberger R, Schwark T. T 2 and T 2∗ mapping in ex situ porcine myocardium: myocardial intravariability, temporal stability and the effects of complete coronary occlusion. Int J Legal Med 2019; 134:679-690. [PMID: 31848700 DOI: 10.1007/s00414-019-02211-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 11/13/2019] [Indexed: 11/25/2022]
Abstract
Diagnosis of ischaemia-related sudden cardiac death in the absence of microscopic and macroscopic ischaemic lesions remains a challenge for medical examiners. Medical imaging techniques increasingly provide support in post-mortem examinations by detecting and documenting internal findings prior to autopsy. Previous studies have characterised MR relaxation times to investigate post-mortem signs of myocardial infarction in forensic cohorts. In this prospective study based on an ex situ porcine heart model, we report fundamental findings related to intramyocardial variability and temporal stability of T2 as well as the effects of permanent coronary occlusion on T2 and T2∗ relaxation in post-mortem myocardium. The ex situ porcine hearts included in this study (n= 19) were examined in two groups (Ss, n= 11 and Si, n= 8). All magnetic resonance imaging (MRI) examinations were performed ex situ, at room temperature and at 3 T. In the Ss group, T2 mapping was performed on slaughterhouse porcine hearts at different post-mortem intervals (PMI) between 7 and 26 h. Regarding the intramyocardial variability, no statistically significant differences in T2 were observed between myocardial segments (p= 0.167). Assessment of temporal stability indicated a weak negative correlation (r=- 0.21) between myocardial T2 and PMI. In the Si group, animals underwent ethanol-induced complete occlusion of the left anterior descending artery. T2 and T2∗ mapping were performed within 3 h of death. Differences between the expected ischaemic and remote regions were statistically significant for T2 (p= 0.007), however not for T2∗ (p= 0.062). Our results provide important information for future assessment of the diagnostic potential of quantitative MRI in the post-mortem detection of early acute myocardial infarction.
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Affiliation(s)
- Bridgette Webb
- Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria.
- BioTechMed, Graz, Austria.
| | - Martin Manninger
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Marlene Leoni
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - Thomas Widek
- Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria
- BioTechMed, Graz, Austria
| | - Martin Dobrovnik
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
| | - Daniel Scherr
- Division of Cardiology, Department of Medicine, Medical University of Graz, Graz, Austria
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Rudolf Stollberger
- BioTechMed, Graz, Austria
- Institute of Medical Engineering, Graz University of Technology, Graz, Austria
| | - Thorsten Schwark
- Ludwig Boltzmann Institute for Clinical Forensic Imaging, Graz, Austria
- Institute of Forensic Medicine, Medical University Graz, Graz, Austria
- Laboratoire National de Santé, Dudelange, Luxembourg
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Cheng CA, Chen W, Zhang L, Wu HH, Zink JI. A Responsive Mesoporous Silica Nanoparticle Platform for Magnetic Resonance Imaging-Guided High-Intensity Focused Ultrasound-Stimulated Cargo Delivery with Controllable Location, Time, and Dose. J Am Chem Soc 2019; 141:17670-17684. [PMID: 31604010 DOI: 10.1021/jacs.9b07591] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Magnetic resonance imaging (MRI) is an essential modality for clinical diagnosis, and MRI-guided high-intensity focused ultrasound (MRgHIFU) is a powerful technology for targeted therapy. Clinical applications of MRgHIFU primarily utilize hyperthermia and ablation to treat cancerous tissue, but for drug delivery applications thermal damage is undesirable. A biofriendly MRgHIFU-responsive mesoporous silica nanoparticle (MSN) platform that is stimulated within a physiological safe temperature range has been developed, reducing the possibility of thermal damage to the surrounding healthy tissues. Biocompatible polyethylene glycol (PEG) was employed to cap the pores of MSNs, and the release of cargo molecules by HIFU occurs without substantial temperature increase (∼4 °C). To visualize by MRI and measure the stimulated delivery in situ, a U.S. Food and Drug Administration (FDA)-approved gadolinium-based contrast agent, gadopentetate dimeglumine (Gd(DTPA)2-), was used as the imageable cargo. Taking advantage of the three-dimensional (3-D) imaging and targeting capabilities of MRgHIFU, the release of Gd(DTPA)2- stimulated by HIFU was pinpointed at the HIFU focal point in 3-D space in a tissue-mimicking gel phantom. The amount of Gd(DTPA)2- released was controlled by HIFU stimulation times and power levels. A positive correlation between the amount of Gd(DTPA)2- released and T1 was found. The MRgHIFU-stimulated cargo release was further imaged in a sample of ex vivo animal tissue. With this technology, the biodistribution of the nanocarriers can be tracked and the MRgHIFU-stimulated cargo release can be pinpointed, opening up an opportunity for future image-guided theranostic applications.
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Affiliation(s)
- Chi-An Cheng
- Department of Bioengineering , University of California Los Angeles , Los Angeles , California 90095 , United States.,California NanoSystems Institute , University of California Los Angeles , Los Angeles 90095 , California , United States
| | - Wei Chen
- Department of Chemistry & Biochemistry , University of California Los Angeles , Los Angeles , California 90095 , United States.,California NanoSystems Institute , University of California Los Angeles , Los Angeles 90095 , California , United States
| | - Le Zhang
- Department of Radiological Sciences, David Geffen School of Medicine , University of California Los Angeles , Los Angeles , California 90095 , United States
| | - Holden H Wu
- Department of Bioengineering , University of California Los Angeles , Los Angeles , California 90095 , United States.,Department of Radiological Sciences, David Geffen School of Medicine , University of California Los Angeles , Los Angeles , California 90095 , United States
| | - Jeffrey I Zink
- Department of Chemistry & Biochemistry , University of California Los Angeles , Los Angeles , California 90095 , United States.,California NanoSystems Institute , University of California Los Angeles , Los Angeles 90095 , California , United States
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6
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Solids Content of Black Liquor Measured by Online Time-Domain NMR. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9102169] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Black liquor, a valuable by-product of the pulp production process, is used for the recovery of chemicals and serves as an energy source for the pulp mill. Before entering the recovery unit, black liquor runs through several stages of evaporation, wherein the solids content (SC) can be used to control the evaporation effectiveness. In the current study, the time-domain nuclear magnetic resonance (TD-NMR) technique was applied to determine the SC of black liquor. The TD-NMR system was modified for flowing samples, so that the black liquor could be pumped through the system, followed by the measurement of the spin-spin relaxation rate, R2. A temperature correction was also applied to reduce deviations in the R2 caused by the sample temperature. The SC was calculated based on a linear model between the R2 and the SC values determined gravimetrically, where good agreement was shown. The online TD-NMR system was tested at a pulp mill for the SC estimation of weak black liquor over seven days without any fouling, which demonstrated the feasibility of the method in a harsh industrial environment. Therefore, the potential of the TD-NMR technology as a technique for controlling the black liquor evaporation process was demonstrated.
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7
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Xu Y, Guo X, Yang S, Li L, Zhang P, Sun W, Liu C, Mi S. Construction of bionic tissue engineering cartilage scaffold based on three-dimensional printing and oriented frozen technology. J Biomed Mater Res A 2018; 106:1664-1676. [DOI: 10.1002/jbm.a.36368] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 01/11/2018] [Accepted: 02/01/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Yuanyuan Xu
- Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, Department of Mechanical Engineering; Tsinghua University; Beijing China
- Biomanufacturing Engineering Laboratory; Graduate School at Shenzhen, Tsinghua University; Shenzhen Guangdong China
| | - Xiao Guo
- Biomanufacturing Engineering Laboratory; Graduate School at Shenzhen, Tsinghua University; Shenzhen Guangdong China
| | - Shuaitao Yang
- Biomanufacturing Engineering Laboratory; Graduate School at Shenzhen, Tsinghua University; Shenzhen Guangdong China
| | - Long Li
- Center for translational medicine, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences; Shenzhen Guangdong China
| | - Peng Zhang
- Center for translational medicine, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences; Shenzhen Guangdong China
| | - Wei Sun
- Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, Department of Mechanical Engineering; Tsinghua University; Beijing China
- Biomanufacturing Engineering Laboratory; Graduate School at Shenzhen, Tsinghua University; Shenzhen Guangdong China
- Tsinghua-Berkeley Shenzhen Institute; Shenzhen Guangdong China
- Department of Mechanical Engineering; Drexel University; Philadelphia 19104 Pennsylvania
| | - Changyong Liu
- Additive Manufacturing Research Institute, College of Mechatronics and Control Engineering; Shenzhen University; Shenzhen Guangdong China
| | - Shengli Mi
- Biomanufacturing Engineering Laboratory; Graduate School at Shenzhen, Tsinghua University; Shenzhen Guangdong China
- Open FIESTA Center, Tsinghua University; Shenzhen Guangdong China
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Post-mortem MR angiography: quantitative investigation and intravascular retention of perfusates in ex situ porcine hearts. Int J Legal Med 2018; 132:579-587. [PMID: 29344721 PMCID: PMC5807516 DOI: 10.1007/s00414-017-1763-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 12/12/2017] [Indexed: 11/13/2022]
Abstract
As the implementation of minimally invasive imaging techniques in both forensic and pathological practice increases, research in this area focuses on addressing recognised diagnostic weaknesses of current approaches. Assessment of sudden cardiac death (SCD) can be considered one such area in which post-mortem imaging still shows diagnostic weaknesses. We hypothesise that magnetic resonance imaging (MRI) with an angiographic adjunct may improve the visualisation and interpretation of cardiac pathologies in a post-mortem setting. To systematically investigate this hypothesis, selected perfusates (paraffin oil, Gadovist®;-doped physiological solution and polyethylene glycol (PEG)) were injected into the left anterior descending (LAD) artery of ex situ porcine hearts to assess the visualisation of perfusates in MRI as well as their intravascular retention over 12 h. Morphological images were acquired and quantitative T1 maps were generated from inversion recovery data. Visualisation of vascular structure and image quality were assessed using signal-to-noise and contrast-to-noise ratios. Intravascular retention was assessed both visually and statistically using a volume of interest (VOI) approach to analyse significant changes in signal intensity in and around the filled LAD artery, as well as changes in the longitudinal relaxation time (T1) in adjacent myocardium. In addition to presenting possible mechanisms explaining perfusate extravasation given the increased permeability of post-mortem vessels, the potential diagnostic consequences of this phenomenon and the importance of contrast stability and extended intravascular retention are discussed. In light of our findings and these considerations, paraffin oil emerged as the preferred perfusate for use in post-mortem MR angiography.
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Postmortale Magnetresonanztomographie-Angiographie nach Multiphasen-Computertomographie-Angiographie. Rechtsmedizin (Berl) 2017. [DOI: 10.1007/s00194-017-0188-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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