Why Avala for Medical Imaging
Medical annotation differs from general computer vision in its tolerance for error — there is essentially none. A missed lesion boundary or misclassified cell type can propagate through the model and affect diagnostic decisions. Avala addresses this with:Precision Annotation Tools
Polygon and segmentation tools with sub-pixel precision for accurate boundary delineation. Keypoint tools for anatomical landmark placement.
Multi-Stage Quality Control
Configurable review pipelines with spot-checking, targeted review, and full review stages. Support for domain expert reviewers with role-based access.
Team Permissions
Fine-grained access controls to restrict who can view, annotate, and review sensitive medical data. Role-based permissions at the organization, team, and project level.
Audit and Compliance
Task lifecycle tracking from assignment through review and approval. Every annotation action is recorded for audit trail requirements.
Data Types
| Modality | Avala Data Type | Typical Annotation |
|---|---|---|
| X-ray | Image | Bounding boxes, polygons, classification |
| CT / MRI slices | Image | Polygons, segmentation masks |
| Pathology slides | Image | Polygon regions, classification |
| Endoscopy video | Video | Frame-level segmentation, tracking |
| Ultrasound | Image, Video | Bounding boxes, polygons |
| Retinal imaging | Image | Segmentation, classification |
Common Tasks
Lesion Detection
Draw bounding boxes or polygons around tumors, nodules, cysts, and other regions of interest. For tasks that require precise boundary delineation (e.g., tumor segmentation for surgical planning), use the polygon tool to trace exact margins. The polygon tool supports:- Freeform vertex placement for irregular shapes
- Edge snapping for clean boundaries
- Vertex editing to refine placement after initial tracing
- Sub-pixel accuracy for high-resolution medical images
Organ Segmentation
Create pixel-level segmentation masks for organs and anatomical structures in CT or MRI slices. Use the segmentation brush for large regions and switch to polygon mode for fine boundary work.Cell Classification
Classify cell types in pathology slides using classification labels and structured attributes. Define a taxonomy that includes:- Primary cell type (e.g., lymphocyte, neutrophil, epithelial)
- Morphological attributes (e.g., size, shape regularity, staining intensity)
- Diagnostic relevance (e.g., normal, atypical, malignant)
Surgical Video Analysis
Track surgical instruments and anatomical landmarks across endoscopy or surgical video frames. Object tracking maintains consistent IDs across frames, making it possible to train models for instrument detection, phase recognition, and activity analysis.Quality Control for Medical Data
Medical annotation quality control goes beyond general-purpose review. Avala’s quality control features support the workflows medical teams require.Multi-Stage Review Pipelines
Configure review pipelines that match your clinical validation process:Annotation Issues
Pin issues to specific annotations in the image. A reviewer can mark a polygon boundary as “too loose at the superior margin” and the annotator sees the issue pinned to the exact location that needs correction.Consensus Workflows
For validation datasets and ground truth creation, assign the same images to multiple domain experts independently. Consensus scoring reveals:- Regions where experts disagree (these need additional review or clearer guidelines)
- Annotators who consistently deviate from the group
- Edge cases where the annotation guideline is ambiguous
Quality Metrics
Monitor annotation quality across your team:| Metric | What It Measures |
|---|---|
| Acceptance rate | Percentage of tasks approved on first submission |
| Annotation time | Average time per task — unusually fast or slow may indicate issues |
| Issue frequency | Rate of flagged problems per task |
| Inter-annotator agreement | Consistency across annotators on the same data |
Compliance Considerations
Medical imaging data often falls under regulatory requirements (HIPAA, GDPR, MDR). While Avala provides the tooling for annotation workflows, your team is responsible for ensuring data handling complies with applicable regulations. Avala features that support compliance workflows:| Requirement | Avala Feature |
|---|---|
| Access control | Role-based team permissions restrict data access to authorized users |
| Audit trail | Task lifecycle tracking records every annotation, review, and status change |
| Data isolation | Datasets and projects are scoped to organizations with membership controls |
| Export control | Exports are generated on demand and can be restricted by permission |
Avala Features Used
| Feature | Purpose | Learn More |
|---|---|---|
| Polygon annotation | Precise boundary delineation for lesions and organs | Polygon Tool |
| Segmentation annotation | Pixel-level masks for anatomical structures | Segmentation Tool |
| Keypoint annotation | Anatomical landmarks for pose and structure | Keypoint Tool |
| Classification | Cell type and tissue classification | Classification Tool |
| Multi-stage review | Configurable review pipelines with expert reviewers | Quality Control |
| Team permissions | Restrict access to sensitive data | Team Permissions |
| API exports | Integration with training pipelines | Exports API |
| Work batches | Distribute annotation work across teams | Work Batches |
Getting Started
Set up your organization
Create an organization and invite your annotation and review teams. Configure team roles so that only authorized users can access medical data.
Upload imaging data
Create a dataset with the appropriate data type (Image for radiology/pathology, Video for endoscopy) and upload your files.
Define your label taxonomy
Set up object classes, attributes, and classification categories that match your clinical annotation guideline. Include clear definitions and reference examples.
Configure quality control
Set up a multi-stage review pipeline. Assign domain expert reviewers and configure acceptance criteria.
Next Steps
Quality Control
Set up multi-stage review workflows with spot-checking and expert review.
Polygon Tool
Precision boundary tracing for lesions, organs, and anatomical structures.
Team Permissions
Configure role-based access controls for your organization.
Label Taxonomy
Design an effective label schema for medical annotation projects.