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Cui Z, Liu X, Qu H, Wang H. Technical Principles and Clinical Applications of Electrical Impedance Tomography in Pulmonary Monitoring. SENSORS (BASEL, SWITZERLAND) 2024; 24:4539. [PMID: 39065936 PMCID: PMC11281055 DOI: 10.3390/s24144539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/11/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024]
Abstract
Pulmonary monitoring is crucial for the diagnosis and management of respiratory conditions, especially after the epidemic of coronavirus disease. Electrical impedance tomography (EIT) is an alternative non-radioactive tomographic imaging tool for monitoring pulmonary conditions. This review proffers the current EIT technical principles and applications on pulmonary monitoring, which gives a comprehensive summary of EIT applied on the chest and encourages its extensive usage to clinical physicians. The technical principles involving EIT instrumentations and image reconstruction algorithms are explained in detail, and the conditional selection is recommended based on clinical application scenarios. For applications, specifically, the monitoring of ventilation/perfusion (V/Q) is one of the most developed EIT applications. The matching correlation of V/Q could indicate many pulmonary diseases, e.g., the acute respiratory distress syndrome, pneumothorax, pulmonary embolism, and pulmonary edema. Several recently emerging applications like lung transplantation are also briefly introduced as supplementary applications that have potential and are about to be developed in the future. In addition, the limitations, disadvantages, and developing trends of EIT are discussed, indicating that EIT will still be in a long-term development stage before large-scale clinical applications.
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Affiliation(s)
- Ziqiang Cui
- School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China; (X.L.); (H.Q.); (H.W.)
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Gao Z, Yang L, Zhao Z, Dai M, Cao X, Song X, Zhang B, Zhao K. Monitoring of spontaneous pneumothorax using electrical impedance tomography: A case report. Heliyon 2024; 10:e25405. [PMID: 38352735 PMCID: PMC10862679 DOI: 10.1016/j.heliyon.2024.e25405] [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: 10/03/2023] [Revised: 01/20/2024] [Accepted: 01/25/2024] [Indexed: 02/16/2024] Open
Abstract
Pneumothorax is an emergency in thoracic surgeries and respiratory medicine. A technique is warranted for real-time monitoring of pneumothorax at the bedside so that rapid diagnosis and timely intervention can be achieved. We report herein a case in which electrical impedance tomography (EIT) was employed at the bedside to monitor lung ventilation of a patient with spontaneous pneumothorax during treatment. It was found that the affected side/healthy side ventilation ratio and global inhomogeneity were strongly correlated with the severity of pneumothorax. The use of EIT allowed intuitive observation of the effect of pneumothorax on ventilation, which helped the doctors make immediate diagnosis and intervention. After timely and successful treatment, the patient was discharged. This is the first case reporting a complete therapeutic course of spontaneous pneumothorax assessed with EIT. Our case demonstrated that EIT could monitor regional ventilation loss of the affected side of pneumothorax patients at the bedside, and dynamically assess the treatment effect of pneumothorax, which provides an important imaging basis for clinical pneumothorax treatment.
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Affiliation(s)
- Zhijun Gao
- Department of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Lin Yang
- Department of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Zhanqi Zhao
- School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- Department of Critical Care Medicine,Peking Union Medical College Hospital, Beijing, China
| | - Meng Dai
- Department of Biomedical Engineering, Air Force Medical University, Xi'an, China
| | - Xinsheng Cao
- Department of Aerospace Medicine, Air Force Medical University, Xi'an, China
| | - Xuan Song
- Department of Pulmonary and Critical Care Medicine, 986th Hospital of Air Force, Air Force Medical University, Xi'an, China
| | - Binghua Zhang
- Department of Pulmonary and Critical Care Medicine, 986th Hospital of Air Force, Air Force Medical University, Xi'an, China
| | - Ke Zhao
- Department of Pulmonary and Critical Care Medicine, 986th Hospital of Air Force, Air Force Medical University, Xi'an, China
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Zhou R, He C, Chi Y, Yuan S, Tang B, Li Z, Li Q, He H, Long Y. Electrical impedance tomography to aid in the identification of hypoxemia etiology: Massive atelectasis or pneumothorax? A case report. Front Med (Lausanne) 2022; 9:970087. [PMID: 36117985 PMCID: PMC9481296 DOI: 10.3389/fmed.2022.970087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
Background Bedside ultrasound is often used to determine the etiology of hypoxaemia, but not always with definitive results. This case reports the application of electrical impedance tomography (EIT) and saline injection to determine the etiology of hypoxaemia in a complex case that could not be identified by bedside ultrasound. The determination of the etiology of hypoxaemia by EIT and saline injection, regional ventilation and perfusion information can be used as a new clinical diagnostic method. Case presentation A post-cardiac surgery patient under prolonged mechanical ventilation for lung emphysema developed sudden hypoxemia in the intensive care unit (ICU). A line pattern and lung sliding sign abolishment were found in the left lung, but there was no evidence of a lung point sign on bedside ultrasound. Hence, the initial diagnosis was considered to be a massive pneumothorax. To further define the etiology, EIT and saline bolus were used to assess regional ventilation and perfusion. A massive ventilation defect was found in the left lung, in which regional perfusion was maintained, resulting in an intrapulmonary shunt in the left lung. Finally, the conjecture of a pneumothorax was ruled out considering the massive atelectasis. After the diagnosis was clarified, hypoxaemia was corrected by restorative ventilation of the left lung after changing the patient's posture and enhancing sputum drainage with chest physiotherapy. Conclusions This was the clinical case involving EIT and saline bolus to establish the differential diagnosis and guide clinical decisions for patients with acute hypoxemia. This study highlighted that combination regional ventilation, EIT perfusion, and saline bolus provided helpful information for determining the etiology of hypoxemia. The results of this study contribute to the development of emergency patient management.
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He H, Chi Y, Long Y, Yuan S, Zhang R, Yang Y, Frerichs I, Möller K, Fu F, Zhao Z. Three broad classifications of acute respiratory failure etiologies based on regional ventilation and perfusion by electrical impedance tomography: a hypothesis-generating study. Ann Intensive Care 2021; 11:134. [PMID: 34453622 PMCID: PMC8401348 DOI: 10.1186/s13613-021-00921-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 08/19/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The aim of this study was to validate whether regional ventilation and perfusion data measured by electrical impedance tomography (EIT) with saline bolus could discriminate three broad acute respiratory failure (ARF) etiologies. METHODS Perfusion image was generated from EIT-based impedance-time curves caused by 10 ml 10% NaCl injection during a respiratory hold. Ventilation image was captured before the breath holding period under regular mechanical ventilation. DeadSpace%, Shunt% and VQMatch% were calculated based on lung perfusion and ventilation images. Ventilation and perfusion maps were divided into four cross-quadrants (lower left and right, upper left and right). Regional distribution defects of each quadrant were scored as 0 (distribution% ≥ 15%), 1 (15% > distribution% ≥ 10%) and 2 (distribution% < 10%). Data percentile distributions in the control group and clinical simplicity were taken into consideration when defining the scores. Overall defect scores (DefectV, DefectQ and DefectV+Q) were the sum of four cross-quadrants of the corresponding images. RESULTS A total of 108 ICU patients were prospectively included: 93 with ARF and 15 without as a control. PaO2/FiO2 was significantly correlated with VQMatch% (r = 0.324, P = 0.001). Three broad etiologies of ARF were identified based on clinical judgment: pulmonary embolism-related disease (PED, n = 14); diffuse lung involvement disease (DLD, n = 21) and focal lung involvement disease (FLD, n = 58). The PED group had a significantly higher DeadSpace% [40(24)% vs. 14(15)%, PED group vs. the rest of the subjects; median(interquartile range); P < 0.0001] and DefectQ score than the other groups [1(1) vs. 0(1), PED vs. the rest; P < 0.0001]. The DLD group had a significantly lower DefectV+Q score than the PED and FLD groups [0(1) vs. 2.5(2) vs. 3(3), DLD vs. PED vs. FLD; P < 0.0001]. The FLD group had a significantly higher DefectV score than the other groups [2(2) vs. 0(1), FLD vs. the rest; P < 0.0001]. The area under the receiver operating characteristic (AUC) for using DeadSpace% to identify PED was 0.894 in all ARF patients. The AUC for using the DefectV+Q score to identify DLD was 0.893. The AUC for using the DefectV score to identify FLD was 0.832. CONCLUSIONS Our study showed that it was feasible to characterize three broad etiologies of ARF with EIT-based regional ventilation and perfusion. Further study is required to validate clinical applicability of this method. Trial registration clinicaltrials, NCT04081142. Registered 9 September 2019-retrospectively registered, https://clinicaltrials.gov/show/NCT04081142 .
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Affiliation(s)
- Huaiwu He
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yi Chi
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yun Long
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
| | - Siyi Yuan
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Rui Zhang
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yingying Yang
- Department of Critical Care Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center of Schleswig-Holstein Campus Kiel, Kiel, Germany
| | - Knut Möller
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Feng Fu
- Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China
| | - Zhanqi Zhao
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany. .,Department of Biomedical Engineering, Fourth Military Medical University, 169 Changle Xi Rd, Xi'an, China.
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