• Neurological Diseases Diagnosis with Electrical Impedance Tomography
  • Mohammadreza Nazarian,1,*
    1. Student Research Committee, Ahvaz Jundishapur University of Medical Science, Ahvaz, Iran.


  • Introduction: Most brain diseases have high mortality and disability rates. For instance, cerebral edema is a common response to various forms of brain injury and stroke has a sudden onset and rapid progression, so they need quick and timely identification. Advanced diagnostic techniques such as computed tomography (CT) scans and magnetic resonance imaging (MRI) are used. However, these techniques are limited due to size, cost, and the risk of exposure to ionizing radiation in CT scans. In addition, the ultrasound device cannot be used because, due to the particular structure of the skull, ultrasonic rays cannot penetrate it. Hence, A new and secure imaging system is required. An innovative medical imaging method called electrical impedance tomography (EIT) measures the voltage across the human skin while delivering a safe excitation current, and it reconstructs the image using a predetermined imaging algorithm. Additionally, EIT is beneficial because it is a small, portable device, non-invasive, radiation-free, and can be used for functional imaging. It also has great potential for the early detection of intracranial conditions in patients with brain diseases. In this review, we investigated the use of EIT for diagnosing brain abnormalities.
  • Methods: The Web of Science, Science Direct, PubMed, and Google Scholar databases were searched up to July 2024, utilizing various keyword combinations: stroke, electrical impedance tomography, edema, brain diseases, neurological diseases, and tissue impedance.
  • Results: Impedance spectra analysis revealed significant differences between normal, ischemic, and hemorrhagic brain tissue. The characteristic frequency-dependent changes in impedance enabled the differentiation of tissue types. EIT has shown promise in imaging and diagnosing stroke, with the potential for early detection and monitoring of thrombolysis. Moreover, EIT has been shown to detect functional brain changes associated with ischemia, with studies reporting significant impedance increases in ischemic brain tissue. Another study on stroke in anesthetized rats found that cerebral ischemia led to a 60% increase in impedance, while cortical electrodes detected a 10–20% increase. Researchers demonstrated the feasibility of utilizing a generic head mesh for EIT imaging in post-traumatic stroke monitoring, eliminating the need for patient-specific models. Furthermore, they incorporated a Jacobian matrix-based electrode movement correction method to enhance image quality. The progression of brain edema is closely linked to the brain's water content, which is indicated by the intracranial pressure. Studies have shown the potential of EIT for real-time monitoring and differentiation of cerebral edema types in the brain. Investigators have explored the possibility of using EIT to track changes in brain water content associated with brain edema. It has been shown that EIT could be a useful non-invasive imaging technique for early detection of cerebral edema and assessing the effects of mannitol dehydration.
  • Conclusion: EIT has made significant advancements in brain imaging, which is expected to aid in the early detection and identification of neurological diseases, ensuring timely patient treatment.
  • Keywords: stroke, "electrical impedance tomography", edema, and "neurological diseases"