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Sunday, 18 January 2026

MedGemma 1.5: Mastering 3D Medical Imaging and EHR Analysis

Presentational View

Introduction

Artificial Intelligence (AI) in Healthcare is quickly evolving from a point of automating simple processes, such as completing clinical tasks; to meeting the complex needs associated with Clinical Decision Making. Today’s Medical Workflows require more than static verification to sufficiently evaluate the Complete Status and Pathology of a Patient.

Historically, Traditional Models have struggled to support the dynamic and long-term nature of Service Delivery utilized by Artificial Intelligence (AI). The combination of Historic Contexts with Future Progression utilized in assessing Patient Trajectories incorporates a high level of complexity. MedGemma 1.5 provides a New Way to approach this Element of Patient Care through New Technologies that provide Advanced Interpretative Capabilities for Multimodal Volumetric Datasets. Through the integration of 3D Data in conjunction with Printed Texts, MedGemma provides an Innovative Solution for Medical Professionals to create a widely applicable Data Integration Tool to provide holistic approaches to Patient Care through New Evidence based Practice Concepts.

What is MedGemma 1.5?

MedGemma 1.5 is an open multimodal generative AI-oriented system that is designed using the Gemma 3 architecture and is targeted specifically for understanding medical text and image modalities. Unlike previous models of similar capacity, this version 1.5 is designed specifically for working with high-dimensional data like 3D scans and whole slide images with a compute-friendly 4B  parameter size.

Key Features of MedGemma 1.5

  • High-Dimensional Imaging Support: The model goes beyond mere 2D imagery in interpreting 3D volumetric data, representing Computed Tomography and Magnetic Resonance Imaging scans. This allows for a depth and volume assessment not available using flat images.
  • Whole-slide histopathology image integration: It allows for the simultaneous interpretation of several patches from whole-slide images, a fundamental advance of pathology by allowing the model to synthesize information across a large tissue sample rather than view small, isolated segments.
  • Temporal and Spatial Reasoning: Longitudinal assessment, whereby the model has been given the ability to compare current and historical chest X-rays to enable the tracking of disease states over time. Its anatomical localisation via bounding box enables it to focus on specific findings within a radiograph at much higher detail and accuracy.
  • Structured Clinical Data Extraction: A key advantage is the capability to parse unstructured medical records, thereby extracting structured insights like values and units from lab reports that show superior comprehension of Electronic Health Records.
  • Seamless speech-to-text integration: it's designed to be natively compatible with MedASR, a specialized medical speech-to-text model that makes advanced, explicitly reasoned workflows directly driven by voice medical dictation possible.

    MedASR Integration with MedGemma 1.5
    source - https://research.google/blog/next-generation-medical-image-interpretation-with-medgemma-1-5-and-medical-speech-to-text-with-medasr/

Use Cases for MedGemma 1.5

  • Volumetric 3D Radiology Analysis: This represents a major evolution from existing API-based systems where it is possible to provide more than one slice of data from either CT or MRI to get immediate and automatic results of radiological findings.
  • Longitudinal Disease Monitoring: The developers can develop software that enables automated comparison between current and past data for a patient’s chest X-ray images. This can aid in the real-time evaluation of whether there has been stability or progression in a particular disease, which has not been directly related until now, as this was an activity that was performed manually by doctors for comparison purposes.
  • Real-Time Anatomical Localization: The bounding boxes around anatomical structures or pathological findings can be produced in real time when the model is reviewed in live mode. This is very useful for highlighting regions of interest in the radiographs in real time.
  • Automated Pathology Triage: Pathologists can harness the power of the model to examine various patches of a whole slide image together to arrive at a diagnosis, thereby efficiently working on large histology image datasets.
  • Offline Clinical Decision Support: Since it has a very compute-efficient size of 4B, deployment on-device for offline triaging and record parsing is possible. This will be particularly useful in low-connectivity environments and many other scenarios where cloud processing simply is not possible because of stringent data privacy requirements.

How Does MedGemma 1.5 Work?

MedGemma 1.5 is developed upon the Gemma 3 decoder-only transformer architecture, which now meets the stringent multimodal requirements in the medical environment. The core function for the vision component in the model is the SigLIP image encoder. This function extracts the input information into features that the large language model (LLM), the other component, uses for medical inference. To deal with large patient history and high-dimensional inputs, the model applies the Grouped-Query Attention (GQA) technique. This approach would allow the model to consider a context window size of a least 128K.

MedGemma as a developer tool
source - https://research.google/blog/next-generation-medical-image-interpretation-with-medgemma-1-5-and-medical-speech-to-text-with-medasr/

This architecture is better understood in practice from the flow chart describing the intended use of MedGemma as a developer tool. The journey of this operational workflow begins with use case definition, where specific clinical objectives are identified, and then involves model selection from the MedGemma collection to match those objectives. It then advances through a crucial step of validation and adaptation to ensure the model fits the purpose in the intended clinical setting, culminating in scaling on Google Cloud by making use of Vertex AI and Model Garden to take the prototype to the production stage of the medical AI application.

Future Horizons: Dynamic & Federated AI

Looking ahead, the smooth integration of MedGemma 1.5 with MedASR heralds a direction toward real-time, multimodal feedback loops. Can we envision a system where a clinician's spoken dictation during image review generates not only a report but also an immediate, active signal for learning? This would allow such a model to dynamically adjust its bounding boxes or diagnostic summaries based on spoken corrections, turning what is currently static validation into a conversational fine-tuning process that continually refines clinical reasoning without manual curation of data.

Moreover, this model's architecture is compute-efficient and primed for deployment with federated learning. The model could update its weights on sensitive, high-dimensional volumetric data with training distributed across decentralized networks of hospitals, without that data ever leaving the secure local environment. This would not only solve some very critical issues in data sovereignty but also allow institution-specific adaptation at scale, creating a self-evolving ecosystem of medical AI that becomes more robust and representative demographically with every deployment.

Performance Evaluation

The output of MedGemma 1.5 is a huge step forward in terms of spatial understanding, especially with respect to Anatomical Localization. On the Chest ImaGenome dataset, which is a benchmark designed to measure localization capability - how well an algorithm is able to locate a specific finding on a radiograph - version 1.5 of MedGemma reportedly reached an Intersection over Union (IoU) of 38%. This is an absolute jump of 35% over its predecessor, which had an IoU of 3%, a clear indicator of how the system has matured from a pure classification tool into a system with a strong spatial understanding capability.

Benchmark -  several forms of Medical Image Interpretation
source - https://research.google/blog/next-generation-medical-image-interpretation-with-medgemma-1-5-and-medical-speech-to-text-with-medasr/

In Electronic Health Record Comprehension, too, there has been approximately similar performance increases by the model. In medical document comprehension, for extracting structured data from unstructured medical reports, there was a 78% retrieval macro F1 score enhancement (18% increase over the predecessor on that particular task with 60% performance), and also, for answering questions on medical documents, as assessed by EHRQA, a test for question-answering on medical documents, MedGemma 1.5 has reached a 90% accuracy level, a 22% relative increase from the original  model with just 68% accuracy.

Benchmark - Medical Text Tasks
source - https://research.google/blog/next-generation-medical-image-interpretation-with-medgemma-1-5-and-medical-speech-to-text-with-medasr/

Further testing has reaffirmed the technical soundness of the model. Radiology classification improved by the good margin of 14% on the detection of MRI evidence and a further 3% on the accuracy of CT. Regarding medical reasoning, it got a 69% mark on the benchmark MedQA test, beating the previous highest of 64%. Most important of all, the generative fidelity of its histopathology (estimated through ROUGE-L) increased dramatically from the insignificant value of 0.02 to the value of 0.49.

How to Access and Use It?

The model can be accessed at the MedGemma GitHub repo, which is the central place where code, inference Jupyter notebooks, and fine-tuning lessons can be found. The weights of the model are located on Hugging Face and can be accessed at the Google Cloud Model Garden. Although the model can be used commercially and for research purposes, it has to be used under the acceptance of the Health AI Developer Foundations terms of use. The model has a unique license framework that, among other things, supports on-premises use on private infrastructure.

Limitations

It should be remembered here that MedGemma 1.5 is a developer-level tool and not a medical device. The results derived from this model should be validated and verified by a professional. It should not be attempted to use this model for the purpose of ruling out a medical condition or disease. The developer community needs to take particular care to make this model generalize well on a non-public dataset concerning medical concepts. Future research may probably work on improving this model on the multimodal front.

Conclusion

By assembling compute efficiency, high-dimensional imaging, and an awareness that drives temporal behavior into one efficient solution, it gives developers and engineers working with health tech the keys to provide all-important care pathways that for once understand patient trajectories. For those developing next-generation health tech, this solution has opened a gateway that leads from fragmented data and complex understandings to clarity.


Sources:
Blog: https://research.google/blog/next-generation-medical-image-interpretation-with-medgemma-1-5-and-medical-speech-to-text-with-medasr/
Model Details: https://developers.google.com/health-ai-developer-foundations/medgemma/model-card
Developer Guide: https://developers.google.com/health-ai-developer-foundations/medgemma
Model Weight: https://huggingface.co/google/medgemma-1.5-4b-it
GitHub Repo: https://github.com/google-health/medgemma


Disclaimer - This article is intended purely for informational purposes. It is not sponsored or endorsed by any company or organization, nor does it serve as an advertisement or promotion for any product or service. All information presented is based on publicly available resources and is subject to change. Readers are encouraged to conduct their own research and due diligence.

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MedGemma 1.5: Mastering 3D Medical Imaging and EHR Analysis

Introduction Artificial Intelligence (AI) in Healthcare is quickly evolving from a point of automating simple processes, such as completing ...