Biomed. Eng.-Biomed. Tech. 2014; 59(6): 545–548
Case Report Sylvia Lehmann*, Klaus Tenbrock, Simone Schrading, Robert Pikkemaat, Christoph Hoog Antink, Susana Santos, Jan Wilhelm Spillner, Norbert Wagner and Steffen Leonhardt
Monitoring of lobectomy in cystic fibrosis with electrical impedance tomography – a new diagnostic tool Abstract: Electrical impedance tomography (EIT) is a radiation-free technique generating cross-sectional images of the lung. EIT visualizes global and regional ventilation by illustrating the distribution of electrical bioimpedance. With an electrode belt around the patient’s thorax, rotating injection-couples of a harmless alternating current allow voltage measurement of the remaining electrodes. This enables the reconstruction of a tomogram with highly dynamic changes within ventilation. We report on a female six-year-old patient with cystic fibrosis and complete destruction of the upper and middle lobe of the right lung. Lobectomy, a rare therapeutic option in patients with cystic fibrosis that needs to be considered in cases of severe localized destruction, was performed. We show a pre- and postoperative documentation of static (radiology) and dynamic investigation tools (spirometry) in correlation with EIT as a new non-invasive and radiation-free diagnostic tool for this patient group. Keywords: cystic fibrosis; electrical impedance tomo graphy; imaging; lung function; magnetic resonance frequency. DOI 10.1515/bmt-2014-0019 Received February 21, 2014; accepted June 20, 2014; online first August 5, 2014
*Corresponding author: Sylvia Lehmann, Department of Paediatric Pulmonology, University Hospital RWTH Aachen, Germany, E-mail: [email protected] Klaus Tenbrock and Norbert Wagner: Department of Paediatric Pulmonology, University Hospital RWTH Aachen, Germany Simone Schrading: Department of Radiology, University Hospital RWTH Aachen, Germany Robert Pikkemaat, Christoph Hoog Antink, Susana Santos and Steffen Leonhardt: Department of Medical Information Technology, RWTH Aachen, Germany Jan Wilhelm Spillner: Department of Cardiovascular and Thoracic Surgery and Cardiology, University Hospital RWTH Aachen, Germany
Lung function tests and radiological procedures like chest X-ray and chest computed tomography (CT) are routine diagnostic features for the monitoring of lung disease in patients with cystic fibrosis (CF). A combination of these techniques is common, especially in cases of suspected disease progression. Spirometry is a dynamic investigation and delivers information about airway obstruction and restriction, but lacks topographic localization of bronchial obstruction. Radiologic processes, however, are associated with X-ray exposure and allow only static visualization of the lung. Electrical impedance tomography (EIT) is a new non-invasive and radiation-free imaging tool delivering dynamic images of the lung. A six-year-old female patient with CF and a history of severe non-compliance presented with recurrent infect exacerbations. Chest X-ray demonstrated progressive lung destruction of the right upper and middle lobe with bronchiectasis, infiltrates and atelectasis as the leading trigger of exacerbations. Spirometric data had declined from an average forced expiratory volume in 1 s (FEV1) of 79.06% (standard deviation [SD] ± 18%) to 42.26% (SD ± 8.45%) within one year. A spiral CT of the thorax confirmed mucus plugging and cavernous formation within the bronchiectatic areas of the right upper and middle lobe (Figure 1). EIT showed inhomogeneous distribution of impedance. The right ventral quadrant in particular revealed almost no tidal variation of electrical impedance, which explains only marginal ventilation within this region. As strict antibiotic regimens, forced inhalation and chest physiotherapy did not lead to an improvement, the patient’s right upper and middle lobes were resected. Pathological findings showed no intact lung tissue, distinctive bronchiectasis, intraluminal mucus stasis and florid purulent inflammation. Just five weeks after surgery, an improvement in FEV1 (absolute increase: 10.6%) and forced vital capacity (FVC; absolute increase: 9.6%) was validated during lung function testing, corresponding to clinical findings, chest X-ray, magnetic resonance imaging (MRI) and EIT results.
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
546 S. Lehmann et al.: Monitoring of lobectomy in CF with EIT
Figure 1 Preoperative Chest CT (Duale Source Somatom Definition FLASH CT, Siemens Medical Systems, Germany): Coronal (left) view and sagittal (right) view. Severe lung destruction in the right upper and middle lobe with large bronchiectasis and cavernous formation.
Table 1 Results of global and regional spirometry and electrical impedance tomography (EIT) (right quadrant of the lung).
Spirometry FEV1 EIT FEV1 (DZ AU) Spirometry FEV0.5 EIT FEV 0.5 (DZ AU) Spirometry FVC EIT FVC (DZ AU) Spirometry FEV1/FVC EIT FEV1/FVC
Preoperative
Postoperative
Global
Regional
Global
Regional
47.6%/0.41l 11.85 48.3%/0.3l 9.69 46.4%/0.46l 12.35 100.60% 0.96
n. a. 3.57 n. a. 2.66 n. a. 3.45 n. a. 1.03
58.2%/0.54l 13.64 63.2%/0.421 15.08 57.4%/0.6l 15.08 93.40% 0.91
n. a. 6.3 n. a. 8.03 n. a. 8.03 n. a. 0.78
Delta image (postoperative and preoperative) Global
Regional
22.30% 15.11% 30.80% 55.60% 23.70% 22.11% –7.15% –5.20%
n. a. 76.50% n. a. 303% n. a. 233% n. a. –24%
ΔZ AU, difference in impedance in arbitrary units; FEV, forced expiratory volume; FVC, forced vital capacity (1, one minute; 0.5, 30 s); n. a., not available.
Evaluation of the EIT data provided in Table 1 indicated pre- and postoperative global EIT changes that correspond well to the spirometric findings. Data evaluation attested pre- and postoperative global EIT changes corresponding to spirometric findings. Moreover, EIT displayed an improvement of ventilation within the right quadrant due to expansion of the residual right lung (Figure 2) and an expansion of the contralateral left lung. This information was in concordance with postoperative MRI findings that show aeration of the right lung except within the pneumonectomy cave (Figure 3). A comparison of pre- and postoperative radiologic findings was only possible by comparing preoperative CT and postoperative MRI. The comparable quality and sensitivity of these two techniques within CF is documented [4] and pre- and
postoperative changes are visible. Postoperative spirometry demonstrated a decrease of the Tiffeneau index (FEV1/ FVC) obtained during the Tiffeneau maneuver, a forced expiration technique [10] during spirometry. Global EIT– Tiffeneau index results [11, 12] corroborated this decline. Despite this, the regional analysis of the EIT–Tiffeneau Index within the resected area showed an increase of ventilation despite loss of lung volume. Based on a semiquantitative data evaluation, it was possible to calculate the regional change in the EIT–Tiffeneau index within the right quadrant, showing that it was nearly five times smaller than the global change. Due to the severity of the intervention, patients with CF undergoing lobectomy need to be selected carefully [2, 7, 8]. Diagnostic features for the detection of lung
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
S. Lehmann et al.: Monitoring of lobectomy in CF with EIT 547
100 90 20
80 70
40
60 60
50 40
80
30 20
100
10 120 20
40
60
80
100
120
20
40
60
80
100
120
20
40
60
80
100
120
0
Figure 2 Functional EIT images (EIT Evaluation Kit 2, Dräger Medical Lübeck, Germany. EK No. 155/12) indicating distribution of ventilation on a relative scale (rainbow-color scheme in Arbitrary Units). Caudo-cranial view. Increase of ventilation within the right ventral (expansion of the residual lung) and left dorsal quadrant (contralateral expansion of the lung), discrete mediastinal shift during forced ventilation maneuver. Left: Preoperative, middle: postoperative, right: Delta-images (8) between pre- and postoperative situation: Differentiation of 1 and 2. (each after inhalation of Salbutamol).
Figure 3 Postoperative MRI of the chest (Achieva 1.5T, Philips, Best, The Netherlands, 32 channel body surface coil). Axial (left) and coronal (right) T2-weighted image. After resection of the right upper and middle lobe MRI shows a mild volume loss of the right lung. No relevant mediastinal shift. Bronchiectasis in both lungs.
destruction in CF patients comprise lung function tests, such as spirometry, multiple breath inert gas washout technique and radiological procedures. Lung function tests are dynamic investigations and deliver global information of airway resistance of small and big bronchi, but a detailed topographic localization of the bronchial obstruction is not deducible. Multiple breath inert gas washout technique is more sensitive than FEV1 and maximal expiratory flow at 25% of FVC to detect the status of early lung disease, but it cannot differentiate between global and regional changes in the affected lung [1, 5].
Radiological investigations, except MRI, are associated with X-ray exposure and deliver regional but static topographic information. The standard radiological tools for monitoring lung disease in patients with CF are chest X-ray and CT; however, improvements and new developments in MRI techniques such as parallel imaging have also improved the use of parenchymal pulmonary MRI imaging. Accordingly, in recent years great improvements have been made in MRI of the lung and MRI is increasingly being used in CF patients instead of CT. MRI of the lung is still technically challenging due to the low proton density
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
548 S. Lehmann et al.: Monitoring of lobectomy in CF with EIT and fast signal decay of the lung parenchyma. Moreover, it is still a non-dynamic investigation. Helium-3-MRI, as a dynamic and topographic investigation is rarely available. MRI seems to have a diagnostic value equal to that of CT in grading the severity of the disease [4]. While radiological procedures show aeration of the lung, EIT displays ventilation changes as electrical impedance changes with air content. EIT cannot, however, differentiate the causes of non-ventilation changes, such as pneumothorax, pleural effusion or pneumectomy. EIT is a radiation-free imaging method [6] with very good temporal resolution. Altogether, CT, MRI and chest X-ray display the entire lung volume, whereas EIT only demonstrates a tomogram of a slice 3 cm thick in adult patients. The EIT-tomogram is examined just as MRI and CT are in a caudo-cranial manner, see Figure 2. While CT is defined by regional tissue absorption of X-rays, EIT shows the distribution of electrical impedance in a tomographic section. Since electrical impedance strongly correlates with air content, EIT offers the possibility of assessing global as well as regional changes in ventilation. Changes of electrical impedance over time (ΔZ in arbitrary units) are measured with a 16-electrode-belt in a transversal section and are converted into a fast image stream [9]. To date it has primarily been used in mechanically-ventilated patients to control and improve ventilation [3]. Studies of EIT in adult patients with CF have shown that EIT offers advantages because it provides additional regional ventilation information compared to spirometry and highresolution CT [13, 14]. In our previous study, we were able to demonstrate an association between spirometry and EIT in asthmatic children. We were also able to perform regional lung function tests with EIT [3]. The present case study documents the utilization of routine diagnostic tools in comparison with EIT and indicates a good correlation. Despite only depicting a cross-section of the lung and having a lower resolution than radiological features, our study indicates that EIT enhanced diagnosis, documenting global, ipsi- and contralateral ventilation changes within a declared region of interest pre- and post lobectomy. Hence, this case report shows that EIT may be able to visualize dynamic changes in air content and lung ventilation. EIT is a non-invasive technique without side effects, allowing repeatable investigations without limits, while the EIT device is small and
mobile. EIT is highly dynamic and may become a supporting tool for diagnostic and therapeutic decisions in pulmonology. The diagnostic potential of EIT should be evaluated in randomized trials.
References [1] Aurora P, Gustafsson P, Bush A, et al. Multiple breath inert gas washout as a measure of ventilation distribution in children with cystic fibrosis. Thorax 2004; 59: 1068–1073. [2] Camargos P, Le Bourgeois M, Revillon Y, et al. Lung resection in cystic fibrosis: a survival analysis. Pediatr Pulmonol 2008; 43: 72–76. [3] Costa LVE, Gonzalez Lima R, Amato BPM. Electrical impedance tomography. Curr Opin Crit Care 2009; 15: 18–24. [4] Eichinger M, Optazaite DE, Kopp-Schneider A, et al. Morphologic and functional scoring of cystic fibrosis lung disease using MRI. Eur J Radiol 2012; 81: 1321–1329. [5] Gattinoni L, Caironi P, Valenza F, Carlesso E. The role of CT-scan studies for the diagnosis and therapy of acute respiratory distress syndrome. Clin Chest Med 2006; 27: 559–570. [6] Leonhardt S, Lachmann B. Electrical impedance tomography: the holy grail of ventilation and perfusion monitoring? Intensive Care Med 2012; 38: 1917–1929. [7] Mallory GB, Spray TL. Paediatric lung transplantation. Eur Respir J 2004; 24: 839–845. [8] Mearns MB, Hodson CJ, Jackson AD, et al. Pulmonary resection in cystic fibrosis. Results in 23 cases. Arch Dis Child 1972; 47: 499–508. [9] Meier T, Gehring H, Leonhardt S, et al., Assessment of regional lung recruitment and derecruitment during a PEEP trial based on electrical impedance tomography. Intensive Care Med 2008, 34: 543–550. [10] Miller MR, Hankinson J, Brusasco V, et al. Standardization of Spirometry. Eur Respir J 2005; 26: 319–338. [11] Pikkemaat R, Tenbrock K, Lehmann S, Leonhardt S. Electrical impedance tomography: New diagnositic possibilities using regional time constant maps. Appl Cardiopul P (ACP) 2012; 16: 212–225. [12] Vogt B, Pulletz S, Elke G, et al. Spatial and temporal heterogeneity of regional lung ventilation determined by electrical impedance tomography during pulmonary function testing. J Appl Physiol 2012; 16: 1154–1161. [13] Zhao Z, Fischer R, Frerichs I, Müller-Lisse U, Möller K. Regional ventilation in cystic fibrosis measured by electrical impedance tomography. J Cyst Fibros 2012; 11: 412–418. [14] Zhao Z, Müller-Lisse U, Frerichs I, Fischer R, Möller K. Regional airway obstruction in cystic fibrosis determined by electrical impedance tomography in comparison with high resolution CT. Physiol Meas 2013; 34: 107–114.
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
Case Report Sylvia Lehmann*, Klaus Tenbrock, Simone Schrading, Robert Pikkemaat, Christoph Hoog Antink, Susana Santos, Jan Wilhelm Spillner, Norbert Wagner and Steffen Leonhardt
Monitoring of lobectomy in cystic fibrosis with electrical impedance tomography – a new diagnostic tool Abstract: Electrical impedance tomography (EIT) is a radiation-free technique generating cross-sectional images of the lung. EIT visualizes global and regional ventilation by illustrating the distribution of electrical bioimpedance. With an electrode belt around the patient’s thorax, rotating injection-couples of a harmless alternating current allow voltage measurement of the remaining electrodes. This enables the reconstruction of a tomogram with highly dynamic changes within ventilation. We report on a female six-year-old patient with cystic fibrosis and complete destruction of the upper and middle lobe of the right lung. Lobectomy, a rare therapeutic option in patients with cystic fibrosis that needs to be considered in cases of severe localized destruction, was performed. We show a pre- and postoperative documentation of static (radiology) and dynamic investigation tools (spirometry) in correlation with EIT as a new non-invasive and radiation-free diagnostic tool for this patient group. Keywords: cystic fibrosis; electrical impedance tomo graphy; imaging; lung function; magnetic resonance frequency. DOI 10.1515/bmt-2014-0019 Received February 21, 2014; accepted June 20, 2014; online first August 5, 2014
*Corresponding author: Sylvia Lehmann, Department of Paediatric Pulmonology, University Hospital RWTH Aachen, Germany, E-mail: [email protected] Klaus Tenbrock and Norbert Wagner: Department of Paediatric Pulmonology, University Hospital RWTH Aachen, Germany Simone Schrading: Department of Radiology, University Hospital RWTH Aachen, Germany Robert Pikkemaat, Christoph Hoog Antink, Susana Santos and Steffen Leonhardt: Department of Medical Information Technology, RWTH Aachen, Germany Jan Wilhelm Spillner: Department of Cardiovascular and Thoracic Surgery and Cardiology, University Hospital RWTH Aachen, Germany
Lung function tests and radiological procedures like chest X-ray and chest computed tomography (CT) are routine diagnostic features for the monitoring of lung disease in patients with cystic fibrosis (CF). A combination of these techniques is common, especially in cases of suspected disease progression. Spirometry is a dynamic investigation and delivers information about airway obstruction and restriction, but lacks topographic localization of bronchial obstruction. Radiologic processes, however, are associated with X-ray exposure and allow only static visualization of the lung. Electrical impedance tomography (EIT) is a new non-invasive and radiation-free imaging tool delivering dynamic images of the lung. A six-year-old female patient with CF and a history of severe non-compliance presented with recurrent infect exacerbations. Chest X-ray demonstrated progressive lung destruction of the right upper and middle lobe with bronchiectasis, infiltrates and atelectasis as the leading trigger of exacerbations. Spirometric data had declined from an average forced expiratory volume in 1 s (FEV1) of 79.06% (standard deviation [SD] ± 18%) to 42.26% (SD ± 8.45%) within one year. A spiral CT of the thorax confirmed mucus plugging and cavernous formation within the bronchiectatic areas of the right upper and middle lobe (Figure 1). EIT showed inhomogeneous distribution of impedance. The right ventral quadrant in particular revealed almost no tidal variation of electrical impedance, which explains only marginal ventilation within this region. As strict antibiotic regimens, forced inhalation and chest physiotherapy did not lead to an improvement, the patient’s right upper and middle lobes were resected. Pathological findings showed no intact lung tissue, distinctive bronchiectasis, intraluminal mucus stasis and florid purulent inflammation. Just five weeks after surgery, an improvement in FEV1 (absolute increase: 10.6%) and forced vital capacity (FVC; absolute increase: 9.6%) was validated during lung function testing, corresponding to clinical findings, chest X-ray, magnetic resonance imaging (MRI) and EIT results.
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
546 S. Lehmann et al.: Monitoring of lobectomy in CF with EIT
Figure 1 Preoperative Chest CT (Duale Source Somatom Definition FLASH CT, Siemens Medical Systems, Germany): Coronal (left) view and sagittal (right) view. Severe lung destruction in the right upper and middle lobe with large bronchiectasis and cavernous formation.
Table 1 Results of global and regional spirometry and electrical impedance tomography (EIT) (right quadrant of the lung).
Spirometry FEV1 EIT FEV1 (DZ AU) Spirometry FEV0.5 EIT FEV 0.5 (DZ AU) Spirometry FVC EIT FVC (DZ AU) Spirometry FEV1/FVC EIT FEV1/FVC
Preoperative
Postoperative
Global
Regional
Global
Regional
47.6%/0.41l 11.85 48.3%/0.3l 9.69 46.4%/0.46l 12.35 100.60% 0.96
n. a. 3.57 n. a. 2.66 n. a. 3.45 n. a. 1.03
58.2%/0.54l 13.64 63.2%/0.421 15.08 57.4%/0.6l 15.08 93.40% 0.91
n. a. 6.3 n. a. 8.03 n. a. 8.03 n. a. 0.78
Delta image (postoperative and preoperative) Global
Regional
22.30% 15.11% 30.80% 55.60% 23.70% 22.11% –7.15% –5.20%
n. a. 76.50% n. a. 303% n. a. 233% n. a. –24%
ΔZ AU, difference in impedance in arbitrary units; FEV, forced expiratory volume; FVC, forced vital capacity (1, one minute; 0.5, 30 s); n. a., not available.
Evaluation of the EIT data provided in Table 1 indicated pre- and postoperative global EIT changes that correspond well to the spirometric findings. Data evaluation attested pre- and postoperative global EIT changes corresponding to spirometric findings. Moreover, EIT displayed an improvement of ventilation within the right quadrant due to expansion of the residual right lung (Figure 2) and an expansion of the contralateral left lung. This information was in concordance with postoperative MRI findings that show aeration of the right lung except within the pneumonectomy cave (Figure 3). A comparison of pre- and postoperative radiologic findings was only possible by comparing preoperative CT and postoperative MRI. The comparable quality and sensitivity of these two techniques within CF is documented [4] and pre- and
postoperative changes are visible. Postoperative spirometry demonstrated a decrease of the Tiffeneau index (FEV1/ FVC) obtained during the Tiffeneau maneuver, a forced expiration technique [10] during spirometry. Global EIT– Tiffeneau index results [11, 12] corroborated this decline. Despite this, the regional analysis of the EIT–Tiffeneau Index within the resected area showed an increase of ventilation despite loss of lung volume. Based on a semiquantitative data evaluation, it was possible to calculate the regional change in the EIT–Tiffeneau index within the right quadrant, showing that it was nearly five times smaller than the global change. Due to the severity of the intervention, patients with CF undergoing lobectomy need to be selected carefully [2, 7, 8]. Diagnostic features for the detection of lung
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
S. Lehmann et al.: Monitoring of lobectomy in CF with EIT 547
100 90 20
80 70
40
60 60
50 40
80
30 20
100
10 120 20
40
60
80
100
120
20
40
60
80
100
120
20
40
60
80
100
120
0
Figure 2 Functional EIT images (EIT Evaluation Kit 2, Dräger Medical Lübeck, Germany. EK No. 155/12) indicating distribution of ventilation on a relative scale (rainbow-color scheme in Arbitrary Units). Caudo-cranial view. Increase of ventilation within the right ventral (expansion of the residual lung) and left dorsal quadrant (contralateral expansion of the lung), discrete mediastinal shift during forced ventilation maneuver. Left: Preoperative, middle: postoperative, right: Delta-images (8) between pre- and postoperative situation: Differentiation of 1 and 2. (each after inhalation of Salbutamol).
Figure 3 Postoperative MRI of the chest (Achieva 1.5T, Philips, Best, The Netherlands, 32 channel body surface coil). Axial (left) and coronal (right) T2-weighted image. After resection of the right upper and middle lobe MRI shows a mild volume loss of the right lung. No relevant mediastinal shift. Bronchiectasis in both lungs.
destruction in CF patients comprise lung function tests, such as spirometry, multiple breath inert gas washout technique and radiological procedures. Lung function tests are dynamic investigations and deliver global information of airway resistance of small and big bronchi, but a detailed topographic localization of the bronchial obstruction is not deducible. Multiple breath inert gas washout technique is more sensitive than FEV1 and maximal expiratory flow at 25% of FVC to detect the status of early lung disease, but it cannot differentiate between global and regional changes in the affected lung [1, 5].
Radiological investigations, except MRI, are associated with X-ray exposure and deliver regional but static topographic information. The standard radiological tools for monitoring lung disease in patients with CF are chest X-ray and CT; however, improvements and new developments in MRI techniques such as parallel imaging have also improved the use of parenchymal pulmonary MRI imaging. Accordingly, in recent years great improvements have been made in MRI of the lung and MRI is increasingly being used in CF patients instead of CT. MRI of the lung is still technically challenging due to the low proton density
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
548 S. Lehmann et al.: Monitoring of lobectomy in CF with EIT and fast signal decay of the lung parenchyma. Moreover, it is still a non-dynamic investigation. Helium-3-MRI, as a dynamic and topographic investigation is rarely available. MRI seems to have a diagnostic value equal to that of CT in grading the severity of the disease [4]. While radiological procedures show aeration of the lung, EIT displays ventilation changes as electrical impedance changes with air content. EIT cannot, however, differentiate the causes of non-ventilation changes, such as pneumothorax, pleural effusion or pneumectomy. EIT is a radiation-free imaging method [6] with very good temporal resolution. Altogether, CT, MRI and chest X-ray display the entire lung volume, whereas EIT only demonstrates a tomogram of a slice 3 cm thick in adult patients. The EIT-tomogram is examined just as MRI and CT are in a caudo-cranial manner, see Figure 2. While CT is defined by regional tissue absorption of X-rays, EIT shows the distribution of electrical impedance in a tomographic section. Since electrical impedance strongly correlates with air content, EIT offers the possibility of assessing global as well as regional changes in ventilation. Changes of electrical impedance over time (ΔZ in arbitrary units) are measured with a 16-electrode-belt in a transversal section and are converted into a fast image stream [9]. To date it has primarily been used in mechanically-ventilated patients to control and improve ventilation [3]. Studies of EIT in adult patients with CF have shown that EIT offers advantages because it provides additional regional ventilation information compared to spirometry and highresolution CT [13, 14]. In our previous study, we were able to demonstrate an association between spirometry and EIT in asthmatic children. We were also able to perform regional lung function tests with EIT [3]. The present case study documents the utilization of routine diagnostic tools in comparison with EIT and indicates a good correlation. Despite only depicting a cross-section of the lung and having a lower resolution than radiological features, our study indicates that EIT enhanced diagnosis, documenting global, ipsi- and contralateral ventilation changes within a declared region of interest pre- and post lobectomy. Hence, this case report shows that EIT may be able to visualize dynamic changes in air content and lung ventilation. EIT is a non-invasive technique without side effects, allowing repeatable investigations without limits, while the EIT device is small and
mobile. EIT is highly dynamic and may become a supporting tool for diagnostic and therapeutic decisions in pulmonology. The diagnostic potential of EIT should be evaluated in randomized trials.
References [1] Aurora P, Gustafsson P, Bush A, et al. Multiple breath inert gas washout as a measure of ventilation distribution in children with cystic fibrosis. Thorax 2004; 59: 1068–1073. [2] Camargos P, Le Bourgeois M, Revillon Y, et al. Lung resection in cystic fibrosis: a survival analysis. Pediatr Pulmonol 2008; 43: 72–76. [3] Costa LVE, Gonzalez Lima R, Amato BPM. Electrical impedance tomography. Curr Opin Crit Care 2009; 15: 18–24. [4] Eichinger M, Optazaite DE, Kopp-Schneider A, et al. Morphologic and functional scoring of cystic fibrosis lung disease using MRI. Eur J Radiol 2012; 81: 1321–1329. [5] Gattinoni L, Caironi P, Valenza F, Carlesso E. The role of CT-scan studies for the diagnosis and therapy of acute respiratory distress syndrome. Clin Chest Med 2006; 27: 559–570. [6] Leonhardt S, Lachmann B. Electrical impedance tomography: the holy grail of ventilation and perfusion monitoring? Intensive Care Med 2012; 38: 1917–1929. [7] Mallory GB, Spray TL. Paediatric lung transplantation. Eur Respir J 2004; 24: 839–845. [8] Mearns MB, Hodson CJ, Jackson AD, et al. Pulmonary resection in cystic fibrosis. Results in 23 cases. Arch Dis Child 1972; 47: 499–508. [9] Meier T, Gehring H, Leonhardt S, et al., Assessment of regional lung recruitment and derecruitment during a PEEP trial based on electrical impedance tomography. Intensive Care Med 2008, 34: 543–550. [10] Miller MR, Hankinson J, Brusasco V, et al. Standardization of Spirometry. Eur Respir J 2005; 26: 319–338. [11] Pikkemaat R, Tenbrock K, Lehmann S, Leonhardt S. Electrical impedance tomography: New diagnositic possibilities using regional time constant maps. Appl Cardiopul P (ACP) 2012; 16: 212–225. [12] Vogt B, Pulletz S, Elke G, et al. Spatial and temporal heterogeneity of regional lung ventilation determined by electrical impedance tomography during pulmonary function testing. J Appl Physiol 2012; 16: 1154–1161. [13] Zhao Z, Fischer R, Frerichs I, Müller-Lisse U, Möller K. Regional ventilation in cystic fibrosis measured by electrical impedance tomography. J Cyst Fibros 2012; 11: 412–418. [14] Zhao Z, Müller-Lisse U, Frerichs I, Fischer R, Möller K. Regional airway obstruction in cystic fibrosis determined by electrical impedance tomography in comparison with high resolution CT. Physiol Meas 2013; 34: 107–114.
Brought to you by | Western University Authenticated Download Date | 6/10/15 4:53 PM
