Ramzi Mahmoudi

Dr. Ramzi Mahmoudi

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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10 May 2022 in Applied Sciences
Verified
Journal Article
Open access
PDF file
RMRamzi Mahmoudi
Ramzi Mahmoudi
NBNarjes Benameur
Narjes Benameur
Rania MabroukRania Mabrouk
Rania Mabrouk
Mazin Abed MohammedMazin Abed Mohammed
Mazin Abed Mohammed
Begonya Garcia ZapirainBegonya Garcia Zapirain
Begonya Garcia Zapirain
MBMohamed Hedi Bedoui
Mohamed Hedi Bedoui
Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a global threat impacting the lives of millions of people worldwide. Automated detection of lung infections from Computed Tomography scans represents an excellent alternative; however, segmenting infected regions from CT slices encounters many challenges. Objective: Developing a diagnosis system based on deep learning techniques to detect and quantify COVID-19 infection and pneumonia screening using CT imaging. Method: Contrast Limited Adaptive Histogram Equalization pre-processing method was used to remove the noise and intensity in homogeneity. Black slices were also removed to crop only the region of interest containing the lungs. A U-net architecture, based on CNN encoder and CNN decoder approaches, is then introduced for a fast and precise image segmentation to obtain the lung and infection segmentation models. For better estimation of skill on unseen data, a fourfold cross-validation as a resampling procedure has been used. A three-layered CNN architecture, with additional fully connected layers followed by a Softmax layer, was used for classification. Lung and infection volumes have been reconstructed to allow volume ratio computing and obtain infection rate. Results: Starting with the 20 CT scan cases, data has been divided into 70% for the training dataset and 30% for the validation dataset. Experimental results demonstrated that the proposed system achieves a dice score of 0.98 and 0.91 for the lung and infection segmentation tasks, respectively, and an accuracy of 0.98 for the classification task. Conclusions: The proposed workflow aimed at obtaining good performances for the different system’s components, and at the same time, dealing with reduced datasets used for training.

14 March 2021 in IET Image Processing
Verified
Journal Article
Open access
PDF file
AAAsma Ammari
Asma Ammari
RMRamzi Mahmoudi
Ramzi Mahmoudi
BHBadii Hmida
Badii Hmida
RSRachida Saouli
Rachida Saouli
MBMohamed Hédi Bedoui
Mohamed Hédi Bedoui
The right ventricular assessment is crucial to heart disease diagnosis. Unfortunately, its segmentation is quite challenging due to its intricate shape, ill‐defined thin edges, large variability among patients, and pathologies. Besides, it is a very laborious and time‐consuming task to be done manually. Therefore, automated segmentation techniques are very suitable to reduce the strain on the expert. Here, it is attempted to review the taxonomy of the current RV segmentation approaches adopted to handle the afore‐mentioned issues. Enhanced by our expert's interpretation, the results of over forty research papers were evaluated based on several metrics such as the dice metric and the Hausdorff distance. Synthetic tables and charts were also used to discuss the reviewed approaches. The following study shows that none of the existing methods has proved accurate enough to meet all the RV challenging issues. Many misestimated results were reported for several cases. Eventually, global guidance is outlined, which supports combining different methods to enhance the expected results during the MRI short‐axis slice processing.

29 January 2020 in IET Image Processing
Verified
Journal Article
Open access
PDF file
RMRamzi Mahmoudi
Ramzi Mahmoudi
NANarjes Ben Ameur
Narjes Ben Ameur
AAAsma Ammari
Asma Ammari
MAMohamed Akil
Mohamed Akil
RSRachida Saouli
Rachida Saouli
MBMomahed Hedi Bedoui
Momahed Hedi Bedoui
Magnetic resonance imaging (MRI) has emerged as the golden reference for cardiac examination. This modality allows the assessment of human cardiovascular morphology, functioning, and perfusion. Although a couple of challenging issues, such as the cardiac magnetic resonance (MR) image's features and the large variability of images among several patients, still influences the cardiac cavities’ segmentation and needs to be carried out. In this study, the authors have profoundly reviewed and fully compared semi‐automated segmentation methods performed on cardiac cine‐MR short‐axis images for the evaluation of the left ventricular functions. However, the number of parameters handled by the synthesised works is limited if not null. For the sake of ensuring the highest coverage of the left ventricle parameters computing, they have introduced a parallel watershed‐based approach to segment the left ventricular allowing hence the computation of six parameters (end‐diastolic volume, end‐systolic volume, ejection fraction, cardiac output, stroke volume, and left ventricular mass). An algorithm is associated with the main considered measurements. The experimental results that were obtained through studying 20 patients’ MRI data base demonstrate their approach's accuracy in estimating real values of the parameters’ set thanks to a faithful segmentation of the myocardium.



19 September 2024 in International Journal of Imaging Systems and Technology
Verified
Journal Article
Closed access
NANarjes Ben Ameur
Narjes Ben Ameur
ASAmeni Sassi
Ameni Sassi
WOWael Ouarda
Wael Ouarda
RMRamzi Mahmoudi
Ramzi Mahmoudi
YAYounes Arous
Younes Arous
HMHalima Mahjoubi
Halima Mahjoubi