Nishant Ravikumar


2024

pdf bib
Enhancing Image-to-Text Generation in Radiology Reports through Cross-modal Multi-Task Learning
Nurbanu Aksoy | Nishant Ravikumar | Serge Sharoff
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)

Image-to-text generation involves automatically generating descriptive text from images and has applications in medical report generation. However, traditional approaches often exhibit a semantic gap between visual and textual information. In this paper, we propose a multi-task learning framework to leverage both visual and non-imaging data for generating radiology reports. Along with chest X-ray images, 10 additional features comprising numeric, binary, categorical, and text data were incorporated to create a unified representation. The model was trained to generate text, predict the degree of patient severity, and identify medical findings. Multi-task learning, especially with text generation prioritisation, improved performance over single-task baselines across language generation metrics. The framework also mitigated overfitting in auxiliary tasks compared to single-task models. Qualitative analysis showed logically coherent narratives and accurate identification of findings, though some repetition and disjointed phrasing remained. This work demonstrates the benefits of multi-modal, multi-task learning for image-to-text generation applications.

2023

pdf bib
Enriching Electronic Health Record with Semantic Features UtilisingPretrained Transformers
Lena AlMutair | Eric Atwell | Nishant Ravikumar
Proceedings of the 20th International Conference on Natural Language Processing (ICON)

Electronic Health Records (EHRs) have revolutionised healthcare by enhancing patient care and facilitating provider communication. Nevertheless, the efficient extraction of valuable information from EHRs poses challenges, primarily due to the overwhelming volume of unstructured data, the wide variability in data formats, and the lack of standardised labels. Leveraging deep learning and concept embeddings, we address the gap in context-aware systems for EHRs. The proposed solution was evaluated on the MIMIC III dataset and demonstrated superior performance compared to other methodologies. We addressed the positive impact of the latent feature combined with the note representation in four different settings. Model performance was evaluated using a case study conducted with BertScore, assessing precision, recall, and F1 scores. The model excels in Medical Natural Language Inference (MedNLI) with an 89.3% accuracy, further boosted to 90.5% through retraining the embeddings using International Classification of Diseases (ICD) codes, which we formally designate as ClinicNarrIR. The ClinicNarrIR was tested with 1000 randomly sampled notes, achieving an N DCG@10 score of approximately 0.54 with accuracy@10 of 0.85. The study also demonstrates a high correlation between the results produced by the proposed representation and medical coders. Notably, in all evaluation cases, the optimal base pretrained model that emerged was BlueBERT.