Enhancing Reliability in Deep Learning Diagnosis of Brain Tumors Using Grad-CAM

Öz

While deep learning models in medical imaging have gained popularity as a means to enhance patient outcomes and diagnostic accuracy recently, one of their main issues is interpretability, which is essential to understanding and debugging the model. Explainable Artificial Intelligence (XAI) is a recent rising research direction that aims to explain this black box part of the deep learning models. For quick identification, clinical evaluations and imaging methods such as Magnetic Resonance Imaging (MRI) scans, are frequently utilized; nevertheless, manual analysis has challenges such as subjectivity and delays. On the other hand, AI-based models convey a more rapid and reliable approach to classifying and detecting brain tumors. In this work, we present a transparent and explainable framework of pre-trained Convolutional Neural Network (CNN) models combined with Gradient Weighted Class Activation Mapping (Grad-CAM) for the classification of brain MRI images. We compare the effectiveness of ResNet50, DenseNet121, MobileNetV2 and ConvNeXtTiny architectures. We obtained a test accuracy of 100% and precision-recall scores above 99.90%, highlighting the model's effectiveness in identifying whether a tumor is present. The results illustrate how the models have enhanced localization skills by visualizing the regions of focus in the predictions through the application of the Grad-CAM method. This blend of interpretability offers a promising step toward creating more reliable and understandable tools for diagnosing brain tumors.

Anahtar Kelimeler

• Tumor Detection
• Grad-CAM
• Deep Learning

Derin Öğrenme ile Beyin Tümörlerinin Teşhisinde Grad-CAM Kullanarak Güvenilirliğin Artırılması

Öz

Tıbbi görüntülemede derin öğrenme modelleri, hasta sonuçlarını ve tanı doğruluğunu iyileştirmenin bir yolu olarak son zamanlarda popülerlik kazanmış olsa da, bu modellerin temel sorunlarından biri, modeli anlamak ve hata ayıklamak için gerekli olan yorumlanabilirliktir. Açıklanabilir Yapay Zeka (XAI), derin öğrenme modellerinin bu kara kutu kısmını açıklamayı amaçlayan, son zamanlarda yükselen bir araştırma yönüdür. Hızlı tanımlama için, manyetik rezonans görüntüleme (MRI) taramaları gibi klinik değerlendirmeler ve görüntüleme yöntemleri sıklıkla kullanılır; ancak manuel analiz, öznellik ve gecikmeler gibi zorluklar içerir. Öte yandan, yapay zeka tabanlı modeller, beyin tümörlerini sınıflandırma ve tespit etme konusunda daha hızlı ve güvenilir bir yaklaşım sunar. Bu çalışmada, beyin MRI görüntülerinin sınıflandırılması için önceden eğitilmiş Evrişimli Sinir Ağı (CNN) modellerinin Gradyen Ağırlıklı Sınıf Aktivasyon Haritalama (Grad-CAM) ile birleştirildiği şeffaf ve açıklanabilir bir çerçeve sunuyoruz. ResNet50, DenseNet121, MobileNetV2 ve ConvNeXtTiny mimarilerinin etkinliğini karşılaştırıyoruz. %100 test doğruluğu ve %99,90'ın üzerinde hassasiyet-geri çağırma puanları elde ettik, bu da modelin tümörün varlığını tespit etmedeki etkinliğini vurgulamaktadır. Sonuçlar, Grad-CAM yönteminin uygulanmasıyla tahminlerde odaklanılan bölgeleri görselleştirerek modellerin lokalizasyon becerilerini nasıl geliştirdiğini göstermektedir. Bu yorumlanabilirlik özelliği, beyin tümörlerini teşhis etmek için daha güvenilir ve anlaşılır araçlar oluşturma yolunda umut verici bir adımdır.

Anahtar Kelimeler

• Tümör Teşhisi
• Derin Öğrenme
• Grad-CAM

Kaynakça

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