Ahmed Sharafeldeen

Dr. Ahmed Sharafeldeen

University of Louisville, Louisville, Kentucky, USA
orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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1 August 2020 in American Journal of Ophthalmology
Verified
Journal Article
Closed access
HSHarpal Singh Sandhu
Harpal Singh Sandhu
MEMOHAMMED Elmogy
MOHAMMED Elmogy
ASAhmed Sharafeldeen
Ahmed Sharafeldeen
Mohamed ElsharkawyMohamed Elsharkawy
Mohamed Elsharkawy
NENabila El-Adawy
Nabila El-Adawy
Ayman El-BazAyman El-Baz
Ayman El-Baz

11 February 2022 in Diagnostics
Verified
Journal Article
Open access
PDF file
Mohamed ElsharkawyMohamed Elsharkawy
Mohamed Elsharkawy
ASAhmed Sharafeldeen
Ahmed Sharafeldeen
Ahmed SolimanAhmed Soliman
Ahmed Soliman
Fahmi KhalifaFahmi Khalifa
Fahmi Khalifa
MOHAMMED GHAZALMOHAMMED GHAZAL
MOHAMMED GHAZAL
Ayman El-BazAyman El-Baz
Ayman El-Baz
Early diagnosis of diabetic retinopathy (DR) is of critical importance to suppress severe damage to the retina and/or vision loss. In this study, an optical coherence tomography (OCT)-based computer-aided diagnosis (CAD) method is proposed to detect DR early using structural 3D retinal scans. This system uses prior shape knowledge to automatically segment all retinal layers of the 3D-OCT scans using an adaptive, appearance-based method. After the segmentation step, novel texture features are extracted from the segmented layers of the OCT B-scans volume for DR diagnosis. For every layer, Markov–Gibbs random field (MGRF) model is used to extract the 2nd-order reflectivity. In order to represent the extracted image-derived features, we employ cumulative distribution function (CDF) descriptors. For layer-wise classification in 3D volume, using the extracted Gibbs energy feature, an artificial neural network (ANN) is fed the extracted feature for every layer. Finally, the classification outputs for all twelve layers are fused using a majority voting schema for global subject diagnosis. A cohort of 188 3D-OCT subjects are used for system evaluation using different k-fold validation techniques and different validation metrics. Accuracy of 90.56%, 93.11%, and 96.88% are achieved using 4-, 5-, and 10-fold cross-validation, respectively. Additional comparison with deep learning networks, which represent the state-of-the-art, documented the promise of our system’s ability to diagnose the DR early.

25 February 2021 in Scientific Reports
Verified
Journal Article
Open access
PDF file
ASAhmed Sharafeldeen
Ahmed Sharafeldeen
Mohamed ElsharkawyMohamed Elsharkawy
Mohamed Elsharkawy
FKF. Khalifa
F. Khalifa
ASA. Soliman
A. Soliman
MGM. Ghazal
M. Ghazal
Ayman El-BazAyman El-Baz
Ayman El-Baz
This study proposes a novel computer assisted diagnostic (CAD) system for early diagnosis of diabetic retinopathy (DR) using optical coherence tomography (OCT) B-scans. The CAD system is based on fusing novel OCT markers that describe both the morphology/anatomy and the reflectivity of retinal layers to improve DR diagnosis. This system separates retinal layers automatically using a segmentation approach based on an adaptive appearance and their prior shape information. High-order morphological and novel reflectivity markers are extracted from individual segmented layers. Namely, the morphological markers are layerthicknessandtortuositywhile the reflectivity markers are the 1st-order reflectivity of the layer in addition to local and global high-order reflectivity based onMarkov-Gibbs random field (MGRF)andgray-level co-occurrence matrix (GLCM), respectively. The extracted image-derived markers are represented using cumulative distribution function (CDF) descriptors. The constructed CDFs are then described using their statistical measures, i.e., the 10th through 90th percentiles with a 10% increment. For individual layer classification, each extracted descriptor of a given layer is fed to a support vector machine (SVM) classifier with a linear kernel. The results of the four classifiers are then fused using a backpropagation neural network (BNN) to diagnose each retinal layer. For global subject diagnosis, classification outputs (probabilities) of the twelve layers are fused using another BNN to make the final diagnosis of the B-scan. This system is validated and tested on 130 patients, with two scans for both eyes (i.e. 260 OCT images), with a balanced number of normal and DR subjects using different validation metrics:2-folds,4-folds,10-folds, andleave-one-subject-out (LOSO)cross-validation approaches. The performance of the proposed system was evaluated usingsensitivity,specificity,F1-score, andaccuracymetrics. The system’s performance after the fusion of these different markers showed better performance compared with individual markers and other machine learning fusion methods. Namely, it achieved $$96.15\%$$96.15% , $$99.23\%$$99.23% , $$97.66\%$$97.66% , and $$97.69\%$$97.69% , respectively, using the LOSO cross-validation technique. The reported results, based on the integration of morphology and reflectivity markers and by using state-of-the-art machine learning classifications, demonstrate the ability of the proposed system to diagnose the DR early.

30 October 2023 in Cancers
Verified
Journal Article
Open access
PDF file
GSGehad Ahmad Saleh
Gehad Ahmad Saleh
NBNihal M Batouty
Nihal M Batouty
AGAbdelrahman Gamal
Abdelrahman Gamal
Ahmed ElnakibAhmed Elnakib
Ahmed Elnakib
OHOmar Hamdy
Omar Hamdy
Ayman El-BazAyman El-Baz
Ayman El-Baz
Breast cancer stands out as the most frequently identified malignancy, ranking as the fifth leading cause of global cancer-related deaths. The American College of Radiology (ACR) introduced the Breast Imaging Reporting and Data System (BI-RADS) as a standard terminology facilitating communication between radiologists and clinicians; however, an update is now imperative to encompass the latest imaging modalities developed subsequent to the 5th edition of BI-RADS. Within this review article, we provide a concise history of BI-RADS, delve into advanced mammography techniques, ultrasonography (US), magnetic resonance imaging (MRI), PET/CT images, and microwave breast imaging, and subsequently furnish comprehensive, updated insights into Molecular Breast Imaging (MBI), diagnostic imaging biomarkers, and the assessment of treatment responses. This endeavor aims to enhance radiologists’ proficiency in catering to the personalized needs of breast cancer patients. Lastly, we explore the augmented benefits of artificial intelligence (AI), machine learning (ML), and deep learning (DL) applications in segmenting, detecting, and diagnosing breast cancer, as well as the early prediction of the response of tumors to neoadjuvant chemotherapy (NAC). By assimilating state-of-the-art computer algorithms capable of deciphering intricate imaging data and aiding radiologists in rendering precise and effective diagnoses, AI has profoundly revolutionized the landscape of breast cancer radiology. Its vast potential holds the promise of bolstering radiologists’ capabilities and ameliorating patient outcomes in the realm of breast cancer management.

4 May 2022 in Sensors
Verified
Journal Article
Open access
PDF file
Mohamed ElsharkawyMohamed Elsharkawy
Mohamed Elsharkawy
MEMostafa Elrazzaz
Mostafa Elrazzaz
ASAhmed Sharafeldeen
Ahmed Sharafeldeen
MAMarah Talal Alhalabi
Marah Talal Alhalabi
Fahmi KhalifaFahmi Khalifa
Fahmi Khalifa
Ayman El-BazAyman El-Baz
Ayman El-Baz
Diabetic retinopathy (DR) is a devastating condition caused by progressive changes in the retinal microvasculature. It is a leading cause of retinal blindness in people with diabetes. Long periods of uncontrolled blood sugar levels result in endothelial damage, leading to macular edema, altered retinal permeability, retinal ischemia, and neovascularization. In order to facilitate rapid screening and diagnosing, as well as grading of DR, different retinal modalities are utilized. Typically, a computer-aided diagnostic system (CAD) uses retinal images to aid the ophthalmologists in the diagnosis process. These CAD systems use a combination of machine learning (ML) models (e.g., deep learning (DL) approaches) to speed up the diagnosis and grading of DR. In this way, this survey provides a comprehensive overview of different imaging modalities used with ML/DL approaches in the DR diagnosis process. The four imaging modalities that we focused on are fluorescein angiography, fundus photographs, optical coherence tomography (OCT), and OCT angiography (OCTA). In addition, we discuss limitations of the literature that utilizes such modalities for DR diagnosis. In addition, we introduce research gaps and provide suggested solutions for the researchers to resolve. Lastly, we provide a thorough discussion about the challenges and future directions of the current state-of-the-art DL/ML approaches. We also elaborate on how integrating different imaging modalities with the clinical information and demographic data will lead to promising results for the scientists when diagnosing and grading DR. As a result of this article’s comparative analysis and discussion, it remains necessary to use DL methods over existing ML models to detect DR in multiple modalities.

15 October 2022 in Sensors
Verified
Journal Article
Open access
PDF file
Mahmoud ElgafiMahmoud Elgafi
Mahmoud Elgafi
ASAhmed Sharafeldeen
Ahmed Sharafeldeen
Ahmed ElnakibAhmed Elnakib
Ahmed Elnakib
AEAhmed Elgarayhi
Ahmed Elgarayhi
NANorah Saleh Alghamdi
Norah Saleh Alghamdi
Ayman El-BazAyman El-Baz
Ayman El-Baz
Diabetic retinopathy (DR) is a major health problem that can lead to vision loss if not treated early. In this study, a three-step system for DR detection utilizing optical coherence tomography (OCT) is presented. First, the proposed system segments the retinal layers from the input OCT images. Second, 3D features are extracted from each retinal layer that include the first-order reflectivity and the 3D thickness of the individual OCT layers. Finally, backpropagation neural networks are used to classify OCT images. Experimental studies on 188 cases confirm the advantages of the proposed system over related methods, achieving an accuracy of 96.81%, using the leave-one-subject-out (LOSO) cross-validation. These outcomes show the potential of the suggested method for DR detection using OCT images.