Cristinel Stefan Udristoiu

Mr. Cristinel Stefan Udristoiu

University of Craiova, Department of Computers and Information Technology

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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19 April 2021 in Medicina
Verified
Journal Article
Open access
PDF file
Corina Maria VasileCorina Maria Vasile
Corina Maria Vasile
Anca Loredana UdriștoiuAnca Loredana Udriștoiu
Anca Loredana Udriștoiu
Alice Elena GheneaAlice Elena Ghenea
Alice Elena Ghenea
MPMihaela Popescu
Mihaela Popescu
CGCristian Gheonea
Cristian Gheonea
DADragos Ovidiu Alexandru
Dragos Ovidiu Alexandru
Background and Objectives: At present, thyroid disorders have a great incidence in the worldwide population, so the development of alternative methods for improving the diagnosis process is necessary. Materials and Methods: For this purpose, we developed an ensemble method that fused two deep learning models, one based on convolutional neural network and the other based on transfer learning. For the first model, called 5-CNN, we developed an efficient end-to-end trained model with five convolutional layers, while for the second model, the pre-trained VGG-19 architecture was repurposed, optimized and trained. We trained and validated our models using a dataset of ultrasound images consisting of four types of thyroidal images: autoimmune, nodular, micro-nodular, and normal. Results: Excellent results were obtained by the ensemble CNN-VGG method, which outperformed the 5-CNN and VGG-19 models: 97.35% for the overall test accuracy with an overall specificity of 98.43%, sensitivity of 95.75%, positive and negative predictive value of 95.41%, and 98.05%. The micro average areas under each receiver operating characteristic curves was 0.96. The results were also validated by two physicians: an endocrinologist and a pediatrician. Conclusions: We proposed a new deep learning study for classifying ultrasound thyroidal images to assist physicians in the diagnosis process.

22 November 2021 in Life
Verified
Journal Article
Open access
PDF file
Anca Loredana UdriștoiuAnca Loredana Udriștoiu
Anca Loredana Udriștoiu
Alice Elena GheneaAlice Elena Ghenea
Alice Elena Ghenea
Cristinel Stefan UdristoiuCristinel Stefan Udristoiu
Cristinel Stefan Udristoiu
MNManuela Neaga
Manuela Neaga
OZOvidiu Mircea Zlatian
Ovidiu Mircea Zlatian
Ramona CioboataRamona Cioboata
Ramona Cioboata
(1) Background: The new SARS-COV-2 pandemic overwhelmed intensive care units, clinicians, and radiologists, so the development of methods to forecast the diagnosis’ severity became a necessity and a helpful tool. (2) Methods: In this paper, we proposed an artificial intelligence-based multimodal approach to forecast the future diagnosis’ severity of patients with laboratory-confirmed cases of SARS-CoV-2 infection. At hospital admission, we collected 46 clinical and biological variables with chest X-ray scans from 475 COVID-19 positively tested patients. An ensemble of machine learning algorithms (AI-Score) was developed to predict the future severity score as mild, moderate, and severe for COVID-19-infected patients. Additionally, a deep learning module (CXR-Score) was developed to automatically classify the chest X-ray images and integrate them into AI-Score. (3) Results: The AI-Score predicted the COVID-19 diagnosis’ severity on the testing/control dataset (95 patients) with an average accuracy of 98.59%, average specificity of 98.97%, and average sensitivity of 97.93%. The CXR-Score module graded the severity of chest X-ray images with an average accuracy of 99.08% on the testing/control dataset (95 chest X-ray images). (4) Conclusions: Our study demonstrated that the deep learning methods based on the integration of clinical and biological data with chest X-ray images accurately predicted the COVID-19 severity score of positive-tested patients.

1 November 2024 in Endoscopic Ultrasound
Verified
Journal Article
Open access
Anca Loredana UdriștoiuAnca Loredana Udriștoiu
Anca Loredana Udriștoiu
NPNicoleta Podină
Nicoleta Podină
Bogdan Silviu UngureanuBogdan Silviu Ungureanu
Bogdan Silviu Ungureanu
ACalina constantin
alina constantin
CGClaudia Valentina Georgescu
Claudia Valentina Georgescu
ASAdrian Saftoiu
Adrian Saftoiu
Background: EUS-guided fine-needle biopsy is the procedure of choice for the diagnosis of pancreatic ductal adenocarcinoma (PDAC). Nevertheless, the samples obtained are small and require expertise in pathology, whereas the diagnosis is difficult in view of the scarcity of malignant cells and the important desmoplastic reaction of these tumors. With the help of artificial intelligence, the deep learning architectures produce a fast, accurate, and automated approach for PDAC image segmentation based on whole-slide imaging. Given the effectiveness of U-Net in semantic segmentation, numerous variants and improvements have emerged, specifically for whole-slide imaging segmentation. Methods: In this study, a comparison of 7 U-Net architecture variants was performed on 2 different datasets of EUS-guided fine-needle biopsy samples from 2 medical centers (31 and 33 whole-slide images, respectively) with different parameters and acquisition tools. The U-Net architecture variants evaluated included some that had not been previously explored for PDAC whole-slide image segmentation. The evaluation of their performance involved calculating accuracy through the mean Dice coefficient and mean intersection over union (IoU). Results: The highest segmentation accuracies were obtained using Inception U-Net architecture for both datasets. PDAC tissue was segmented with the overall average Dice coefficient of 97.82% and IoU of 0.87 for Dataset 1, respectively, overall average Dice coefficient of 95.70%, and IoU of 0.79 for Dataset 2. Also, we considered the external testing of the trained segmentation models by performing the cross evaluations between the 2 datasets. The Inception U-Net model trained on Train Dataset 1 performed with the overall average Dice coefficient of 93.12% and IoU of 0.74 on Test Dataset 2. The Inception U-Net model trained on Train Dataset 2 performed with the overall average Dice coefficient of 92.09% and IoU of 0.81 on Test Dataset 1. Conclusions: The findings of this study demonstrated the feasibility of utilizing artificial intelligence for assessing PDAC segmentation in whole-slide imaging, supported by promising scores.

28 November 2025 in Applied Sciences
Verified
Journal Article
Open access
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Anca Loredana UdriștoiuAnca Loredana Udriștoiu
Anca Loredana Udriștoiu
Cristinel Stefan UdristoiuCristinel Stefan Udristoiu
Cristinel Stefan Udristoiu
Technological advancements are accelerating the integration of artificial intelligence (AI) into biomedicine, but also demonstrate the need for solutions to the complex challenges of healthcare