Nikolaos Giannakeas

Prof. Nikolaos Giannakeas

University of Ioannina

Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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27 May 2023 in Data
Verified
Journal Article
Open access
PDF file
AMAndreas Miltiadous
Andreas Miltiadous
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Theodora AfrantouTheodora Afrantou
Theodora Afrantou
Panagiotis IoannidisPanagiotis Ioannidis
Panagiotis Ioannidis
NGNikolaos Grigoriadis
Nikolaos Grigoriadis
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Recently, there has been a growing research interest in utilizing the electroencephalogram (EEG) as a non-invasive diagnostic tool for neurodegenerative diseases. This article provides a detailed description of a resting-state EEG dataset of individuals with Alzheimer’s disease and frontotemporal dementia, and healthy controls. The dataset was collected using a clinical EEG system with 19 scalp electrodes while participants were in a resting state with their eyes closed. The data collection process included rigorous quality control measures to ensure data accuracy and consistency. The dataset contains recordings of 36 Alzheimer’s patients, 23 frontotemporal dementia patients, and 29 healthy age-matched subjects. For each subject, the Mini-Mental State Examination score is reported. A monopolar montage was used to collect the signals. A raw and preprocessed EEG is included in the standard BIDS format. For the preprocessed signals, established methods such as artifact subspace reconstruction and an independent component analysis have been employed for denoising. The dataset has significant reuse potential since Alzheimer’s EEG Machine Learning studies are increasing in popularity and there is a lack of publicly available EEG datasets. The resting-state EEG data can be used to explore alterations in brain activity and connectivity in these conditions, and to develop new diagnostic and treatment approaches. Additionally, the dataset can be used to compare EEG characteristics between different types of dementia, which could provide insights into the underlying mechanisms of these conditions.

12 July 2023 in IEEE Access
Verified
Journal Article
Open access
AMAndreas Miltiadous
Andreas Miltiadous
EGEmmanouil Gionanidis
Emmanouil Gionanidis
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Objective: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that affects a significant percentage of the elderly. EEG has emerged as a promising tool for the timely diagnosis and classification of AD or other dementia types. This paper proposes a novel approach to AD EEG classification using a Dual-Input Convolution Encoder Network (DICE-net). Approach: Recordings of 36 AD, 23 Frontotemporal dementia (FTD), and 29 age-matched healthy individuals (CN) were used. After denoising, Band power and Coherence features were extracted and fed to DICE-net, which consists of Convolution, Transformer Encoder, and Feed-Forward layers. Main results: Our results show that DICE-net achieved an accuracy of 83.28% in the AD-CN problem using Leave-One-Subject-Out validation, outperforming several baseline models, and achieving good generalization performance. Significance: Our findings suggest that a convolution transformer network can effectively capture the complex features of EEG signals for the classification of AD patients versus control subjects and may be expanded to other types of dementia, such as FTD. This approach could improve the accuracy of early diagnosis and lead to the development of more effective interventions for AD.

9 August 2021 in Diagnostics
Verified
Journal Article
Open access
PDF file
AMAndreas Miltiadous
Andreas Miltiadous
Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
Markos G. TsipourasMarkos G. Tsipouras
Markos G. Tsipouras
Theodora AfrantouTheodora Afrantou
Theodora Afrantou
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Dementia is the clinical syndrome characterized by progressive loss of cognitive and emotional abilities to a degree severe enough to interfere with daily functioning. Alzheimer’s disease (AD) is the most common neurogenerative disorder, making up 50–70% of total dementia cases. Another dementia type is frontotemporal dementia (FTD), which is associated with circumscribed degeneration of the prefrontal and anterior temporal cortex and mainly affects personality and social skills. With the rapid advancement in electroencephalogram (EEG) sensors, the EEG has become a suitable, accurate, and highly sensitive biomarker for the identification of neuronal and cognitive dynamics in most cases of dementia, such as AD and FTD, through EEG signal analysis and processing techniques. In this study, six supervised machine-learning techniques were compared on categorizing processed EEG signals of AD and FTD cases, to provide an insight for future methods on early dementia diagnosis. K-fold cross validation and leave-one-patient-out cross validation were also compared as validation methods to evaluate their performance for this classification problem. The proposed methodology accuracy scores were 78.5% for AD detection with decision trees and 86.3% for FTD detection with random forests.

29 March 2022 in Diagnostics
Verified
Journal Article
Open access
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Athena DavriAthena Davri
Athena Davri
Effrosyni BirbasEffrosyni Birbas
Effrosyni Birbas
Theofilos KanavosTheofilos Kanavos
Theofilos Kanavos
GNGeorgios Ntritsos
Georgios Ntritsos
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
ABAnna Batistatou
Anna Batistatou
Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men, with an increasing incidence. Pathology diagnosis complemented with prognostic and predictive biomarker information is the first step for personalized treatment. The increased diagnostic load in the pathology laboratory, combined with the reported intra- and inter-variability in the assessment of biomarkers, has prompted the quest for reliable machine-based methods to be incorporated into the routine practice. Recently, Artificial Intelligence (AI) has made significant progress in the medical field, showing potential for clinical applications. Herein, we aim to systematically review the current research on AI in CRC image analysis. In histopathology, algorithms based on Deep Learning (DL) have the potential to assist in diagnosis, predict clinically relevant molecular phenotypes and microsatellite instability, identify histological features related to prognosis and correlated to metastasis, and assess the specific components of the tumor microenvironment.

18 September 2018 in Health and Technology
Verified
Journal Article
Closed access
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Katerina D. TzimourtaKaterina D. Tzimourta
Katerina D. Tzimourta
Alexandros T TzallasAlexandros T Tzallas
Alexandros T Tzallas
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
LALoukas G. Astrakas
Loukas G. Astrakas
DTDimitrios G. Tsalikakis
Dimitrios G. Tsalikakis
Markos G. TsipourasMarkos G. Tsipouras
Markos G. Tsipouras

5 August 2023 in Cancers
Verified
Journal Article
Open access
PDF file
Athena DavriAthena Davri
Athena Davri
Effrosyni BirbasEffrosyni Birbas
Effrosyni Birbas
Theofilos KanavosTheofilos Kanavos
Theofilos Kanavos
GNGeorgios Ntritsos
Georgios Ntritsos
Nikolaos GiannakeasNikolaos Giannakeas
Nikolaos Giannakeas
ABAnna Batistatou
Anna Batistatou
Lung cancer is one of the deadliest cancers worldwide, with a high incidence rate, especially in tobacco smokers. Lung cancer accurate diagnosis is based on distinct histological patterns combined with molecular data for personalized treatment. Precise lung cancer classification from a single H&E slide can be challenging for a pathologist, requiring most of the time additional histochemical and special immunohistochemical stains for the final pathology report. According to WHO, small biopsy and cytology specimens are the available materials for about 70% of lung cancer patients with advanced-stage unresectable disease. Thus, the limited available diagnostic material necessitates its optimal management and processing for the completion of diagnosis and predictive testing according to the published guidelines. During the new era of Digital Pathology, Deep Learning offers the potential for lung cancer interpretation to assist pathologists’ routine practice. Herein, we systematically review the current Artificial Intelligence-based approaches using histological and cytological images of lung cancer. Most of the published literature centered on the distinction between lung adenocarcinoma, lung squamous cell carcinoma, and small cell lung carcinoma, reflecting the realistic pathologist’s routine. Furthermore, several studies developed algorithms for lung adenocarcinoma predominant architectural pattern determination, prognosis prediction, mutational status characterization, and PD-L1 expression status estimation.