Sohail Contractor

dblp:357/3492 · DBLP profile ↗
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14ranked-venue papers
0as first author
14since 2021 · last 2026
0009-0002-5742-1642ORCID · conflict

Domains — the database's venue-derived domains; a paper can count in several

Graphics, computer vision, multimedia, augmented reality and games · 13 · 13 since 2021Artificial intelligence and machine learning · 6 · 6 since 2021Applied, interdisciplinary, general and emerging computing · 2 · 2 since 2021
YearPublicationVenuePosition
2026 SDUNet: Shape-Depth Aware Hybrid UNet for Improved Kidney Segmentation in Diffusion-Weighted MRI
Ibrahim Abdelhalim, Mohamed Abou El-Ghar, Moumen T. El-Melegy, Asem M. Ali, Mohammed Ghazal, Ali Mahmoud 0001, Sohail Contractor, Ayman El-Baz
ICPR (11)7
2026 Quantifying Multi-site Heterogeneity in Tractography-Based Regression of SRS Cognition in Autism Spectrum Disorder
Mohamed Khudri, Mostafa Abdelrahim, Moumen T. El-Melegy, Ali Mahmoud 0001, Asem M. Ali, Ahmed Shalaby 0002, Mohammed Ghazal, Fatma Taher, Sohail Contractor, Gregory Barnes 0001, Ayman El-Baz
ICPR (14)9
2026 3D NMIBC Segmentation via Texture-Guided Frequency-Aware Transformer on T2-Weighted MRI
Israa Sharaby, Ahmed Alksas, Osama Ezzat, Amr A. Elsawy, Rasha T. Abouelkheir, Ahmed Elmahdy, Sherry M. Khater, Moumen T. El-Melegy, Asem M. Ali, Ali Mahmoud 0001, Mohammed Ghazal, Sohail Contractor, Mahmoud A. Bazeed, Ahmed Mosbah, Ayman El-Baz
ICPR (15)12
2025 A Novel Automated System for Pathological Lung Segmentation Using Modified Local Binary Patterns and Hierarchical Transformers
abstract
This study proposes a novel deep learning-based automatic segmentation system for accurately delineating pulmonary regions in 3D computed tomography (CT) scans. First, a modified local binary pattern, called cylinder binary pattern (CBP), is introduced, which utilizes concentric cylinders at different radii, to effectively capture intricate textural details at multiple levels. Then, a 3D encoder-decoder deep learning-based network, called VX-Net, is proposed specifically to accurately segment pulmonary regions within 3D CT scans. This network incorporates the hierarchical transformers into its encoder architecture to significantly improve feature extraction process. These transformers replicate Transformer model by integrating 3D convolutions with both larger and smaller kernels. While this network is used for segmenting pulmonary regions, it can also be adapted for various other segmentation tasks. The proposed system is evaluated on 3D CT scans of 26 patients with three different severity levels of COVID-19, using four distinct metrics. These include Dice similarity coefficient (DSC), overlap coefficient, Hausdorff distance (HD), and absolute volume difference (AVD). The proposed system shows remarkable performance, achieving scores of 97.63±0.98%, 95.38±1.86%, 1.99±1.9, and 3.01±1.15, respectively. When compared to various state-of-the-art segmentation methods, the proposed segmentation system showcases its ability to accurately segment both normal and pathological pulmonary regions.
Ahmed Sharafeldeen, Fatma Taher, Mohammed Ghazal, Ashraf Khalil, Ali Mahmoud 0001, Sohail Contractor, Ayman El-Baz
ICIP6
2025 A Novel Explainable AI-Based System For Improved Prediction of Breast Cancer Response to Neoadjuvant Chemotherapy
abstract
We propose a novel AI-based system for breast cancer (BCa) assessment to predict response to neoadjuvant chemotherapy (NAC) into one of three responses: Partial Response (PR), Complete Response (CR), and Stationary Disease (SD), providing a full insight for medical experts about treatment regimens. The proposed AI-based system integrates machine learning (ML) and deep learning (DL) approaches to incorporate both global and local markers for more accurate prediction. The ML approach, based on a decision tree model, learns patterns from global markers extracted through pathology assessments to determine molecular subtypes. This analysis incorporates four standard tests: ER, PR, HER2, and Ki-67. Additionally, it integrates global radiomics descriptors, including tumor morphology, lesion count, and radiologist assessments for axillary nodes (benign vs. suspicious). In addition to assessing global markers, we employed a pre-trained Vision Transformer (ViT-b16) with a multihead adaptive self-attention mechanism to extract local markers from the Region of Interest (ROI) around the breast tumor. This approach eliminates the need for segmentation, which could impact the accuracy of the local AI model’s prediction. The outputs of both models are fused using a GradientBoosting algorithm to predict the response to NAC. The proposed system was tested on 736 2D images along with their corresponding radiomics and pathological markers (CR = 156, PR = 353, and SD = 227). The developed AI-based system achieved an accuracy of 98.91%. Explainability was enabled through heatmaps which visually highlight areas with high attention for decision-making. These results demonstrate promising potential for AI-based early assessment in BCa management.
Fatma M. Talaat, Hanaa ZainEldin, Mohamed Shehata 0002, Eman Alnaghy, Reham Alghandour, Khadiga M. Ali, Sohail Contractor, Ayman El-Baz
ICIP7
2025 AI-based non-invasive imaging technologies for early autism spectrum disorder diagnosis: A short review and future directions
Mostafa Abdelrahim, Mohamed Khudri, Ahmed Elnakib, Mohamed Shehata 0002, Kate Weafer, Ashraf Khalil, Gehad A. Saleh, Nihal M. Batouty, Mohammed Ghazal, Sohail Contractor, Gregory Barnes 0001, Ayman El-Baz
Artif. Intell. Medicine10
2024 A Novel Approach for 3D Renal Segmentation Using a Modified GAN Model and Texture Analysis
abstract
This paper introduces a novel framework for renal segmentation of kidney transplant patients suspected of renal rejection. The framework applies image processing techniques for texture analysis utilizing a modified Pix 2 Pix GAN model to capture the varied kidney shapes in the dataset of 36 subject volumes acquired using BOLD MRI scans. For this problem, we built a framework that analyzes the kidney texture based on four steps: (i) calculate the average CDF for each case to map CDF values to their corresponding intensities for contrast enhancement (ii) extract the region of interest for the kidney to focus on the kidney structure, (iii) calculate the probability maps using the histograms of the contours for the kidney and non-kidney regions, (iv) Create a common-layer across the dataset using the masks by calculating the average of the pixel values of the images to accommodate the shared information within the mask images. Finally, stack the three layers to have the RGB channels contain relevant information about the renal dataset as input for the modified GAN model. The proposed framework achieved an average accuracy and Dice Similarity Coefficient: $90.3 \%$, and $83.1 \%$, respectively. The framework’s primary results underscore its efficiency in providing segmentation for renal diagnosis.
Israa Sharaby, Ahmed Alksas, Hossam Magdy Balaha, Ali Mahmoud 0001, Mohammed Ali Badawy, Mohamed Abou El-Ghar, Ashraf Khalil, Mohammed Ghazal, Sohail Contractor, Ayman El-Baz
ICIP9
2024 Automated Segmentation of Lung Regions in 3D CT Scans Using Hybrid Unsupervised-Supervised Models
abstract
This paper introduces an automatic segmentation system designed for precise outlining of the pulmonary area within 3D computed tomography (CT) scans, utilizing a combination of unsupervised and supervised models. Initially, an unsupervised model is utilized to depict the empirical distribution of Hounsfield units in both lung and chest regions within the 3D CT volume. This representation takes the form of a probability model based on a linear combination of Gaussians, determined through a modified expectation maximization (EM) algorithm. Subsequently, the LCG-based segmentation is refined by modeling it with a spatial probabilistic model using a 3D Markov Gibbs random field (MGRF) with analytically estimated potentials. Finally, a supervised deep learning model is introduced and integrated with the proposed unsupervised model to achieve superior segmentation results. The efficacy of the proposed method is assessed using 3D chest scans from 29 patients confirmed with varying degrees of severity in COVID-19. This evaluation employs four distinct metrics: Dice similarity coefficient (DSC), overlap coefficient, Hausdorff distance (HD), and absolute volume difference (AVD), achieving remarkable results of $97.35_{ \pm 1.51} \%, 94.89_{ \pm 2.80} \%$, $3.39_{ \pm 1.61}$, and $2.70_{ \pm 2.88}$, respectively. When compared to four state-of-the-art deep learning-based methods, the proposed system demonstrated outstanding performance in segmenting pathological lung tissues, highlighting its potential and efficacy.
Ahmed Sharafeldeen, Adel Khelifi, Mohammed Ghazal, Maha Yaghi, Sohail Contractor, Ayman El-Baz
ICIP5
2024 A New AI System for Precise Grading of HCC Based on Analyzing DW-MRI Radiomics and Alpha-fetoprotein as Liver Cancer Clinical Marker
abstract
Hepatocellular carcinoma (HCC), – the main form of liver cancer –, is the second global leading cause of cancer-related mortality. LI-RADS is considered the worldwide non-invasive standard method for imaging interpretation and reporting in patients with HCC eliminating the need for biopsy. However, it might be prone to interpretation subjectivity. Therefore, we develop an objective non-invasive AI-based grading system for HCC for appropriate etiology treatment plans. The developed system integrates potential image-based markers that represent the tumor’s morphology, functionality, and appearance/texture with the associated clinical biomarkers. The study encompasses 117 patients diagnosed with HCC and was divided into three different groups (group 1: benign low-grade (LR 1,2), N = 41; group 2: malignant high-grade (LR 4,5), N = 39; and group 3: malignant not HCC (LR-M), N = 37). Diffusion-weighted magnetic resonance imaging (DWI) was acquired for imaging-based markers identification. The developed grading system pipeline includes: i) estimation of morphological markers using a new parametric spherical harmonic model, ii) estimation of appearance/textural markers using a novel rotation invariant circular binary pattern model, iii) calculation of the functional markers by constructing the representative cumulative distribution functions of the estimated apparent diffusion coefficients, and iv) integrating the aforementioned imaging-based markers with the associated clinical biomarkers, known as Alpha-fetoprotein. The integrated markers were optimized to train and test multiple machine learning (ML) classifiers and a hyper-tuned custom CNN. On a randomly stratified train (80%) test (20%) split scheme, the developed obtained an overall accuracy of 88% in differentiating between the three groups using the integrated markers along with the CatBoost classifier, surpassing the diagnostic performance of individual marker sets, other ML classifiers, and the CNN as well. The obtained results demonstrate the feasibility of the developed system as a novel tool for non-invasive and objective HCC grading.
Abdelrhman Elkhouly, Ahmed Alksas, Gehad A. Saleh, Mohamed Shehata 0002, Abdelrahman Karawia, Mohammed Ghazal, Sohail Contractor, Ayman El-Baz
ICPR (27)7
2024 Unsupervised Segmentation of Pulmonary Regions in 3D CT Scans Optimized Using Transformer Model
Ahmed Sharafeldeen, Adel Khelifi, Mohammed Ghazal, Maha Yaghi, Ali Mahmoud 0001, Sohail Contractor, Ayman El-Baz
ICPR (23)6
2024 A New Non-invasive AI-Based Diagnostic System for Automated Diagnosis of Acute Renal Rejection in Kidney Transplantation: Analysis of ADC Maps Extracted from Matched 3D Iso-Regions of the Transplanted Kidney
Ibrahim Abdelhalim, Mohamed Abou El-Ghar, Amy C. Dwyer, Rosemary Ouseph, Sohail Contractor, Ayman El-Baz
MICCAI (12)5
2024 IHRRB-DINO: Identifying High-Risk Regions of Breast Masses in Mammogram Images Using Data-Driven Instance Noise (DINO)
Mahmoud SalahEldin Kasem, Abdelrahman Abdallah, Ibrahim Abdelhalim, Norah Saleh Alghamdi, Sohail Contractor, Ayman El-Baz
MICCAI (1)5
2023 Early Diagnosis of Prostate Cancer Using Parametric Estimation of IVIM from DW-MRI
abstract
Prostate cancer (PCa) is a widespread type of cancer that leads to numerous fatalities and a high financial cost. The chance of survival for PCa patients increases when the disease is detected at an early stage. This study discusses the development of a non-invasive computer-aided diagnosis (CAD) system that utilizes intravoxel incoherent motion (IVIM) parameters to detect and diagnose prostate cancer. The study focuses on IVIM, which can separate the diffusion of water molecules in capillaries from the molecular diffusion outside of the vessels, and its diagnostic efficacy in the central and peripheral zones of prostate cancer. The study proposes a two-step segmentation approach for tumor detection, starting with the precise localization of the prostate gland using a robust level-sets technique and then using an Attention U-Net to extract the tumor-containing region of interest (ROI) from the segmented image. The study evaluates the performance of the CAD system, the best classifier and IVIM parameters for differentiation, and the diagnostic value of IVIM parameters compared to ADC. The results of this study contribute to the development of non-invasive methods for early prostate cancer detection and diagnosis. The IVIM (CZ + PZ) parameters that utilized the extra trees classifier (ETC) and were implemented without principal component analysis (PCA) and standardization scaling achieved the best metrics. They produced an accuracy of 84.62%, a balanced accuracy of 82.58%, a precision of 80%, a specificity of 67.86%, a sensitivity of 97.30%, an F1-score of 87.12%, an IoU of 78.26%, a ROC of 83.88%, and a weighted sum metric (WSM) of 82.79%.
Hossam Magdy Balaha, Sarah M. Ayyad, Ahmed Alksas, Ali E. Takieldeen, Mohamed A. Badawy, Mohamed Shehata 0002, Mohamed Abou El-Ghar, Mohammed Ghazal, Ali Mahmoud 0001, Sohail Contractor, Ayman El-Baz
ICIP10
2023 Accurate Segmentation for Pathological Lung Based on Integration of 3D Appearance and Surface Models
abstract
A novel unsupervised-based segmentation method is introduced to accurately delineate the lung region in 3D CT images based on appearance and geometric models. First, a probabilistic model that utilized a linear combination of Gaussian (LCG) tuned by a modified expectation maximization (EM) algorithm, is employed to model the density distribution of 3D CT chest volume. Subsequently, the initial labeling of the 3D CT chest volume is mapped to a probability distribution based on a 3D Markov Gibbs random field (MGRF) for refining. Finally, a geometric model is employed to refine the proposed segmentation by interpolating/connecting two points on its boundary with high curvature. The effectiveness of the proposed approach on 3D computed tomography (CT) chest scans of 26 patients diagnosed with different severity of coronavirus disease 2019 (COVID-19) is evaluated using four different metrics: overlap coefficient, Dice similarity coefficient (DSC), absolute lung volume difference (ALVD), and 95th-percentile bidirectional Hausdorff distance (95thHD). The proposed method achieved 94.89%±2.39%, 97.36%±1.27%, 1.79±1.89, and 4.75±2.3, respectively. Compared to three state-of-the-art methods based on deep learning approaches, the proposed method achieved superior performance in segmenting pathological lung tissues, demonstrating the promising of the proposed segmentation system.
Ahmed Sharafeldeen, Ahmed Alksas, Mohammed Ghazal, Maha Yaghi, Adel Khelifi, Ali Mahmoud 0001, Sohail Contractor, Eric Vanbogaert, Ayman El-Baz
ICIP7