Detection of intraventricular blood using EIT in a neonatal piglet model

Sadleir, Rosalind; Tang, Tong; Tucker, Aaron; Borum, Peggy R.; Weiss, Michael D.

doi:10.1109/iembs.2009.5334510

Cited by 13 publications

(10 citation statements)

References 19 publications

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“…While several other EIT research groups have explored the effects of intraperitoneal and intracranial hemorrhage, 22,23,24 to the best of our knowledge, the novel EIT implementation described in this manuscript is at present the only study to show in-vivo , real-time, tomographic reconstructions of mass-effect, hemorrhage, and cessation of blood flow. Wang et.…”

Section: Discussionmentioning

confidence: 99%

Intracranial Electrical Impedance Tomography

Manwaring

Moodie²,

Hartov³

et al. 2013

Anesthesia &Amp; Analgesia

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Background Electrical impedance tomography (EIT) is a method that can render continuous graphical cross-sectional images of the brain’s electrical properties. Because these properties can be altered by variations in water content, shifts in Na+ concentration, bleeding, and mass deformation, EIT has promise as a sensitive instrument for head injury monitoring to improve early recognition of deterioration, and to observe the benefits of therapeutic intervention. This study presents a swine model of head injury used to determine the detection capabilities of an inexpensive bed side EIT monitoring system with a novel intracranial pressure (ICP)/EIT electrode combination sensor on induced intraparenchymal mass effect, intraparenchymal hemorrhage, and cessation of brain blood flow. Conductivity difference images are shown in conjunction with ICP data, confirming the effects. Methods Eight domestic piglets (3–4 weeks old, mean 10kg), under general anesthesia, were subjected to four injuries: induced intraparenchymal mass effect using an inflated, and later, deflated 0.15mL Fogarty catheter; hemorrhage by intraparenchymal injection of 1mL arterial blood; and ischemia/infarction by euthanasia. EIT and ICP data were recorded 10 minutes prior to inducing the injury until 10 minutes post-injury. Continuous EIT and ICP monitoring were facilitated by a ring of circumferentially disposed cranial Ag/AgCl electrodes and one intraparenchymal ICP/EIT sensor-electrode combination. Data were recorded at 100 Hz. Two-dimensional tomographic conductivity difference (Δσ) images, rendered using data before and after an injury, were displayed in real-time on an axial circular mesh. Regions of interest (ROI) within the images were automatically selected as the upper or lower 5% of conductivity data depending upon the nature of the injury. Mean Δσ within the ROIs and background were statistically analyzed. ROI Δσ was compared to the background Δσ after an injury event using an unpaired, unequal variance t-test. Conductivity change within an ROI post- injury was likewise compared to the same ROI prior to the injury utilizing unpaired t-tests with unequal variance. Results Eight animal subjects were studied, each undergoing four injury events including euthanasia. Changes in conductivity due to injury showed expected pathophysiologic effects in an ROI identified within the middle of the left hemisphere; this localization is reasonable given the actual site of injury (left hemisphere) and spatial warping associated with estimating a 3D conductivity distribution in two dimensional space. Results are shown as mean ± 1 SD. When averaged across all eight animals, balloon inflation caused the mean Δσ within the ROI to shift by −11.4 ± 10.9 mS/m; balloon deflation by +9.4 ± 8.8 mS/m; blood injection by +19.5 ± 11.5 mS/m; death by −12.6 ± 13.2 mS/m. All induced injuries were detectable to statistical significance (p < 0.0001). Conclusion This study confirms that the bed-side EIT system with ICP/EIT combination sensor can detect induced trauma....

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Section: Discussionmentioning

confidence: 99%

Intracranial Electrical Impedance Tomography

Manwaring

Moodie²,

Hartov³

et al. 2013

Anesthesia &Amp; Analgesia

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“…In previous papers (Sadleir and Tang 2009, Sadleir et al 2009, Tang et al 2010, Tang and Sadleir 2010, 2011) we described promising results in numerical simulations and phantom experiments. We found that an 16-electrode layout based on the electroencephalograph (EEG) 10–20 layout, combined with a measurement strategy that involved applying a sequence of current patterns with all return paths over the anterior fontanel (the ‘Cz pattern’) was superior to other patterns considered.…”

Section: Introductionmentioning

confidence: 82%

In vivoquantification of intraventricular hemorrhage in a neonatal piglet model using an EEG-layout based electrical impedance tomography array

et al. 2016

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Intraventricular hemorrhage (IVH) is a common occurrence in the days immediately after premature birth. It has been correlated with outcomes such as periventricular leukomalacia (PVL), cerebral palsy and developmental delay. The causes and evolution of IVH are unclear; it has been associated with fluctuations in blood pressure, damage to the subventricular zone and seizures. At present, ultrasound is the most commonly used method for detection of IVH, but is used retrospectively. Without the presence of adequate therapies to avert IVH, the use of a continuous monitoring technique may be somewhat moot. While treatments to mitigate the damage caused by IVH are still under development, the principal benefit of a continuous monitoring technique will be in investigations into the etiology of IVH, and its associations with periventricular injury and blood pressure fluctuations. Electrical impedance tomography (EIT) is potentially of use in this context as accumulating blood displaces higher conductivity cerebrospinal fluid (CSF) in the ventricles. We devised an electrode array and EIT measurement strategy that performed well in detection of simulated ventricular blood in computer models and phantom studies. In this study we describe results of pilot in vivo experiments on neonatal piglets, and show that EIT has high sensitivity and specificity to small quantities of blood (<1 ml) introduced into the ventricle. EIT images were processed to an index representing the quantity of accumulated blood (the ‘quantity index’, QI). We found that QI values were linearly related to fluid quantity, and that the slope of the curve was consistent between measurements on different subjects. Linear discriminant analysis showed a false positive rate of 0%, and receiver operator characteristic analysis found area under curve values greater than 0.98 to administered volumes between 0.5, and 2.0 ml. We believe our study indicates that this method may be well suited to quantitative monitoring of IVH in newborns, simultaneously or interleaved with electroencephalograph assessments.

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“…Xu et al, Manwaring et al, Dowrick et al, Sadleir et al, and Dai et al established different animal models of intracranial hemorrhage (ICH), including intraparenchymal hemorrhage (IPH), subarachnoid hemorrhage (SAH) and intraventricular hemorrhage (IVH). They found that EIT could accurately reflect the real-time impedance change caused by ICH, even though the blood volume was much smaller than that of the brain, as in the case of the IPH pig model with 5 ml blood injection [30][31][32][33][34]. Moreover, Shuai et al explored the ability of EIT to monitor intraperitoneal hemorrhage in a pig model and observed that the intraperitoneal blood volume changes could be continuously identified by the observation of EIT images throughout the bleeding progression [35].…”

Section: Introductionmentioning

confidence: 99%

Real‐Time Detection of Hemothorax and Monitoring its Progression in a Piglet Model by Electrical Impedance Tomography: A Feasibility Study

Yang

Zhang

Liu

et al. 2020

BioMed Research International

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Hemothorax is a serious medical condition that can be life-threatening if left untreated. Early diagnosis and timely treatment are of great importance to produce favorable outcome. Although currently available diagnostic techniques, e.g., chest radiography, ultrasonography, and CT, can accurately detect hemothorax, delayed hemothorax cannot be identified early because these examinations are often performed on patients until noticeable symptoms manifest. Therefore, for early detection of delayed hemothorax, real-time monitoring by means of a portable and noninvasive imaging technique is needed. In this study, we employed electrical impedance tomography (EIT) to detect the onset of hemothorax in real time on eight piglet hemothorax models. The models were established by injection of 60 ml fresh autologous blood into the pleural cavity, and the subsequent development of hemothorax was monitored continuously. The results showed that EIT was able to sensitively detect hemothorax as small as 10 ml in volume, as well as its location. Also, the development of hemothorax over a range of 10 ml up to 60 ml was well monitored in real time, with a favorable linear relationship between the impedance change in EIT images and the volume of blood injected. These findings demonstrated that EIT has a unique potential for early diagnosis and continuous monitoring of hemothorax in clinical practice, providing medical staff valuable information for prompt identification and treatment of delayed hemothorax.

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Detection of intraventricular blood using EIT in a neonatal piglet model

Cited by 13 publications

References 19 publications

Intracranial Electrical Impedance Tomography

Intracranial Electrical Impedance Tomography

In vivoquantification of intraventricular hemorrhage in a neonatal piglet model using an EEG-layout based electrical impedance tomography array

Real‐Time Detection of Hemothorax and Monitoring its Progression in a Piglet Model by Electrical Impedance Tomography: A Feasibility Study

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