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Byrne DP, Studer N, Secombe C, Cieslewicz A, Hosgood G, Raisis A, Adler A, Mosing M. Validation of three-dimensional thoracic electrical impedance tomography of horses during normal and increased tidal volumes. Physiol Meas 2024; 45:035010. [PMID: 38422515 DOI: 10.1088/1361-6579/ad2eb3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 02/29/2024] [Indexed: 03/02/2024]
Abstract
Objective. Data from two-plane electrical impedance tomography (EIT) can be reconstructed into various slices of functional lung images, allowing for more complete visualisation and assessment of lung physiology in health and disease. The aim of this study was to confirm the ability of 3D EIT to visualise normal lung anatomy and physiology at rest and during increased ventilation (represented by rebreathing).Approach. Two-plane EIT data, using two electrode planes 20 cm apart, were collected in 20 standing sedate horses at baseline (resting) conditions, and during rebreathing. EIT data were reconstructed into 3D EIT whereby tidal impedance variation (TIV), ventilated area, and right-left and ventral-dorsal centres of ventilation (CoVRLand CoVVD, respectively) were calculated in cranial, middle and caudal slices of lung, from data collected using the two planes of electrodes.Main results. There was a significant interaction of time and slice for TIV (p< 0.0001) with TIV increasing during rebreathing in both caudal and middle slices. The ratio of right to left ventilated area was higher in the cranial slice, in comparison to the caudal slice (p= 0.0002). There were significant effects of time and slice on CoVVDwhereby the cranial slice was more ventrally distributed than the caudal slice (p< 0.0009 for the interaction).Significance. The distribution of ventilation in the three slices corresponds with topographical anatomy of the equine lung. This study confirms that 3D EIT can accurately represent lung anatomy and changes in ventilation distribution during rebreathing in standing sedate horses.
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Affiliation(s)
- David P Byrne
- School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia
| | | | - Cristy Secombe
- School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia
| | | | - Giselle Hosgood
- School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia
| | - Anthea Raisis
- School of Veterinary Medicine, Murdoch University, Murdoch, Western Australia, Australia
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottowa, ON, Canada
| | - Martina Mosing
- Anaesthesia and Perioperative Intensive Care, Department of Companion Animals and Horses Vetmeduni, Vienna, Austria
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Brabant O, Karpievitch YV, Gwatimba A, Ditcham W, Ho HY, Raisis A, Mosing M. Thoracic electrical impedance tomography identifies heterogeneity in lungs associated with respiratory disease in cattle. A pilot study. Front Vet Sci 2024; 10:1275013. [PMID: 38239750 PMCID: PMC10795053 DOI: 10.3389/fvets.2023.1275013] [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: 08/09/2023] [Accepted: 11/07/2023] [Indexed: 01/22/2024] Open
Abstract
Respiratory disease in cattle is a significant global concern, yet current diagnostic methods are limited, and there is a lack of crush-side tests for detecting active disease. To address this gap, we propose utilizing electrical impedance tomography (EIT), a non-invasive imaging technique that provides real-time visualization of lung ventilation dynamics. The study included adult cattle from farms in Western Australia. The cattle were restrained in a crush. A standardized respiratory scoring system, which combined visual, auscultation, and clinical scores, was conducted by two non-conferring clinicians for each animal. The scores were blinded and averaged. During assessment, an EIT electrode belt was placed around the thorax. EIT recordings of ten suitable breaths were taken for analysis before the cattle were released back to the herd. Based on the combined examination scoring, the cattle were categorized as having healthy or diseased lungs. To allow visual interpretation of each breath and enable the creation of the quartile ventilation ratio (VQR), Flow/Tidal Impedance Variation curves (F/TIV) were generated for each breath. The analysis focused on two EIT variables: The novel VQR over time during inhalation and exhalation and global expiratory impedance (TIVEXP) adjusted by breath length. A mixed effects model was used to compare these variables between healthy and diseased cattle. Ten adult cattle of mixed ages were used in the current analysis. Five cattle were scored as healthy and five as diseased. There was a significant difference in the examination scores between the healthy and diseased group (P = 0.03). A significant difference in VQR during inhalation (P = 0.03) was observed between the healthy and diseased groups. No difference was seen in VQR over time during exhalation (P = 0.3). The TIVEXP was not different between groups (P = 0.36). In this study, EIT was able to detect differences in inhalation mechanics when comparing healthy and diseased cattle as defined via clinical examination, highlighting the clinical utility of EIT.
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Affiliation(s)
- Olivia Brabant
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Yuliya V. Karpievitch
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA, Australia
- School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Alphons Gwatimba
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA, Australia
| | - William Ditcham
- School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Ho Yin Ho
- Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA, Australia
| | - Anthea Raisis
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Martina Mosing
- Anesthesiology and Perioperative Intensive Care, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
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Simões J, Tilley P. Decision Making in Severe Equine Asthma-Diagnosis and Monitoring. Animals (Basel) 2023; 13:3872. [PMID: 38136909 PMCID: PMC10740644 DOI: 10.3390/ani13243872] [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: 10/19/2023] [Revised: 11/22/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Decision making consists of gathering quality data in order to correctly assess a situation and determine the best course of action. This process is a fundamental part of medicine and is what enables practitioners to accurately diagnose diseases and select appropriate treatment protocols. Despite severe equine asthma (SEA) being a highly prevalent lower respiratory disease amongst equids, clinicians still struggle with the optimization of routine diagnostic procedures. The use of several ancillary diagnostic tests has been reported for disease identification and monitoring, but many are only suitable for research purposes or lack practicality for everyday use. The aim of this paper is to assist the equine veterinarian in the process of decision making associated with managing SEA-affected patients. This review will focus on disease diagnosis and monitoring, while also presenting a flow-chart which includes the basic data that the clinician must obtain in order to accurately identify severely asthmatic horses in their everyday routine practice. It is important to note that European and American board-certified specialists on equine internal medicine can provide assistance in the diagnosis and treatment plan of SEA-affected horses.
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Affiliation(s)
- Joana Simões
- Equine Health and Welfare Academic Division, Faculty of Veterinary Medicine, Lusófona University, Campo Grande 376, 1749-024 Lisbon, Portugal
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal;
- Associate Laboratory for Animal and Veterinary Sciences (AL4Animals), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
| | - Paula Tilley
- CIISA-Centre for Interdisciplinary Research in Animal Health, Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal;
- Associate Laboratory for Animal and Veterinary Sciences (AL4Animals), Faculty of Veterinary Medicine, University of Lisbon, 1300-477 Lisbon, Portugal
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Byrne DP, Keeshan B, Hosgood G, Adler A, Mosing M. Comparison of electrical impedance tomography and spirometry-based measures of airflow in healthy adult horses. Front Physiol 2023; 14:1164646. [PMID: 37476683 PMCID: PMC10354512 DOI: 10.3389/fphys.2023.1164646] [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: 02/13/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023] Open
Abstract
Electrical impedance tomography (EIT) is a non-invasive diagnostic tool for evaluating lung function. The objective of this study was to compare respiratory flow variables calculated from thoracic EIT measurements with corresponding spirometry variables. Ten healthy research horses were sedated and instrumented with spirometry via facemask and a single-plane EIT electrode belt around the thorax. Horses were exposed to sequentially increasing volumes of apparatus dead space between 1,000 and 8,500 mL, in 5-7 steps, to induce carbon dioxide rebreathing, until clinical hyperpnea or a tidal volume of 150% baseline was reached. A 2-min stabilization period followed by 2 minutes of data collection occurred at each timepoint. Peak inspiratory and expiratory flow, inspiratory and expiratory time, and expiratory nadir flow, defined as the lowest expiratory flow between the deceleration of flow of the first passive phase of expiration and the acceleration of flow of the second active phase of expiration were evaluated with EIT and spirometry. Breathing pattern was assessed based on the total impedance curve. Bland-Altman analysis was used to evaluate the agreement where perfect agreement was indicated by a ratio of EIT:spirometry of 1.0. The mean ratio (bias; expressed as a percentage difference from perfect agreement) and the 95% confidence interval of the bias are reported. There was good agreement between EIT-derived and spirometry-derived peak inspiratory [-15% (-46-32)] and expiratory [10% (-32-20)] flows and inspiratory [-6% (-25-18)] and expiratory [5% (-9-20)] times. Agreement for nadir flows was poor [-22% (-87-369)]. Sedated horses intermittently exhibited Cheyne-Stokes variant respiration, and a breath pattern with incomplete expiration in between breaths (crown-like breaths). Electrical impedance tomography can quantify airflow changes over increasing tidal volumes and changing breathing pattern when compared with spirometry in standing sedated horses.
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Affiliation(s)
- David P. Byrne
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Ben Keeshan
- Department of Systems and Computer Engineering, Carleton University, Ottawa, ON, Canada
| | - Giselle Hosgood
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, ON, Canada
| | - Martina Mosing
- Anaesthesiology and Perioperative Intensive Care, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
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Brabant OA, Byrne DP, Sacks M, Moreno Martinez F, Raisis AL, Araos JB, Waldmann AD, Schramel JP, Ambrosio A, Hosgood G, Braun C, Auer U, Bleul U, Herteman N, Secombe CJ, Schoster A, Soares J, Beazley S, Meira C, Adler A, Mosing M. Thoracic Electrical Impedance Tomography-The 2022 Veterinary Consensus Statement. Front Vet Sci 2022; 9:946911. [PMID: 35937293 PMCID: PMC9354895 DOI: 10.3389/fvets.2022.946911] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Electrical impedance tomography (EIT) is a non-invasive real-time non-ionising imaging modality that has many applications. Since the first recorded use in 1978, the technology has become more widely used especially in human adult and neonatal critical care monitoring. Recently, there has been an increase in research on thoracic EIT in veterinary medicine. Real-time imaging of the thorax allows evaluation of ventilation distribution in anesthetised and conscious animals. As the technology becomes recognised in the veterinary community there is a need to standardize approaches to data collection, analysis, interpretation and nomenclature, ensuring comparison and repeatability between researchers and studies. A group of nineteen veterinarians and two biomedical engineers experienced in veterinary EIT were consulted and contributed to the preparation of this statement. The aim of this consensus is to provide an introduction to this imaging modality, to highlight clinical relevance and to include recommendations on how to effectively use thoracic EIT in veterinary species. Based on this, the consensus statement aims to address the need for a streamlined approach to veterinary thoracic EIT and includes: an introduction to the use of EIT in veterinary species, the technical background to creation of the functional images, a consensus from all contributing authors on the practical application and use of the technology, descriptions and interpretation of current available variables including appropriate statistical analysis, nomenclature recommended for consistency and future developments in thoracic EIT. The information provided in this consensus statement may benefit researchers and clinicians working within the field of veterinary thoracic EIT. We endeavor to inform future users of the benefits of this imaging modality and provide opportunities to further explore applications of this technology with regards to perfusion imaging and pathology diagnosis.
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Affiliation(s)
- Olivia A. Brabant
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - David P. Byrne
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Muriel Sacks
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | | | - Anthea L. Raisis
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Joaquin B. Araos
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Andreas D. Waldmann
- Department of Anaesthesiology and Intensive Care Medicine, Rostock University Medical Centre, Rostock, Germany
| | - Johannes P. Schramel
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Aline Ambrosio
- Department of Surgery, Faculty of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | - Giselle Hosgood
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Christina Braun
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Ulrike Auer
- Department of Anaesthesiology and Perioperative Intensive Care Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Ulrike Bleul
- Clinic of Reproductive Medicine, Department of Farm Animals, Vetsuisse-Faculty University Zurich, Zurich, Switzerland
| | - Nicolas Herteman
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Cristy J. Secombe
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
| | - Angelika Schoster
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Joao Soares
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Shannon Beazley
- Department of Small Animal Clinical Sciences, Western College Veterinary Medicine, Saskatoon, SK, Canada
| | - Carolina Meira
- Department of Clinical Diagnostics and Services, Anaesthesiology, Vetsuisse-Faculty, University of Zurich, Zurich, Switzerland
| | - Andy Adler
- Department of Systems and Computer Engineering, Carleton University, Ottawa, ON, Canada
| | - Martina Mosing
- School of Veterinary Medicine, Murdoch University, Perth, WA, Australia
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Herteman N, Mosing M, Waldmann AD, Gerber V, Schoster A. Exercise-induced airflow changes in horses with asthma measured by electrical impedance tomography. J Vet Intern Med 2021; 35:2500-2510. [PMID: 34505734 PMCID: PMC8478024 DOI: 10.1111/jvim.16260] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Equine asthma (EA) causes airflow impairment, which increases in severity with exercise. Electrical impedance tomography (EIT) is an imaging technique that can detect airflow changes in standing healthy horses during a histamine provocation test. OBJECTIVES To explore EIT-calculated flow variables before and after exercise in healthy horses and horses with mild-to-moderate (MEA) and severe equine asthma (SEA). ANIMALS Nine healthy horses 9 horses diagnosed with MEA and 5 with SEA were prospectively included. METHODS Recordings were performed before and after 15 minutes of lunging. Absolute values from global and regional peak inspiratory (PIF, positive value) and expiratory (PEF, negative value) flows were calculated. Data were analyzed using a mixed model analysis followed by Bonferroni's multiple comparisons test to evaluate the impact of exercise and diagnosis on flow indices. RESULTS Control horses after exercise had significantly lower global PEF and PIF compared to horses with SEA (mean difference [95% confidence interval, CI]: 0.0859 arbitrary units [AU; 0.0339-0.1379], P < .001 and 0.0726 AU [0.0264-0.1188], P = .001, respectively) and horses with MEA (0.0561 AU [0.0129-0.0994], P = .007 and 0.0587 AU [0.0202-0.0973], P = .002, respectively). No other significant differences were detected. CONCLUSIONS AND CLINICAL IMPORTANCE Electrical impedance tomography derived PIF and PEF differed significantly between healthy horses and horses with SEA or MEA after exercise, but not before exercise. Differences between MEA and SEA were not observed, but the study population was small.
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Affiliation(s)
- Nicolas Herteman
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse Faculty, University of Zurich, Switzerland
| | - Martina Mosing
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Perth, Australia
| | - Andreas D Waldmann
- Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Rostock, Germany
| | - Vinzenz Gerber
- Equine Clinic, Swiss Institute of Equine Medicine, University of Bern and Agroscope, Berne, Switzerland
| | - Angelika Schoster
- Clinic for Equine Internal Medicine, Equine Hospital, Vetsuisse Faculty, University of Zurich, Switzerland
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Secombe C, Adler A, Hosgood G, Raisis A, Mosing M. Can bronchoconstriction and bronchodilatation in horses be detected using electrical impedance tomography? J Vet Intern Med 2021; 35:2035-2044. [PMID: 33977584 PMCID: PMC8295671 DOI: 10.1111/jvim.16152] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Electrical impedance tomography (EIT) generates images of the lungs based on impedance change and was able to detect changes in airflow after histamine challenge in horses. OBJECTIVES To confirm that EIT can detect histamine-provoked changes in airflow and subsequent drug-induced bronchodilatation. Novel EIT flow variables were developed and examined for changes in airflow. METHODS Bronchoconstriction was induced using stepwise histamine bronchoprovocation in 17 healthy sedated horses. The EIT variables were recorded at baseline, after saline nebulization (control), at the histamine concentration causing bronchoconstriction (Cmax ) and 2 and 10 minutes after albuterol (salbutamol) administration. Peak global inspiratory (PIFEIT ) and peak expiratory EIT (PEFEIT ) flow, slope of the global expiratory flow-volume curve (FVslope ), steepest FVslope over all pixels in the lung field, total impedance change (surrogate for tidal volume; VTEIT ) and intercept on the expiratory FV curve normalized to VTEIT (FVintercept /VTEIT ) were indexed to baseline and analyzed for a difference from the control, at Cmax , 2 and 10 minutes after albuterol. Multiple linear regression explored the explanation of the variance of Δflow, a validated variable to evaluate bronchoconstriction using all EIT variables. RESULTS At Cmax , PIFEIT , PEFEIT , and FVslope significantly increased whereas FVintercept /VT decreased. All variables returned to baseline 10 minutes after albuterol. The VTEIT did not change. Multivariable investigation suggested 51% of Δflow variance was explained by a combination of PIFEIT and PEFEIT . CONCLUSIONS AND CLINICAL IMPORTANCE Changes in airflow during histamine challenge and subsequent albuterol administration could be detected by various EIT flow volume variables.
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Affiliation(s)
- Cristy Secombe
- School of Veterinary Medicine, Murdoch UniversityPerthAustralia
| | - Andy Adler
- Systems and Computer Engineering, Carleton UniversityOttawaCanada
| | - Giselle Hosgood
- School of Veterinary Medicine, Murdoch UniversityPerthAustralia
| | - Anthea Raisis
- School of Veterinary Medicine, Murdoch UniversityPerthAustralia
| | - Martina Mosing
- School of Veterinary Medicine, Murdoch UniversityPerthAustralia
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