# ScolioVis API - Test Report

## Overview

| Property | Value |
|----------|-------|
| **Repository** | scoliovis-api |
| **Source** | https://github.com/blankeos/scoliovis-api |
| **Paper** | "ScolioVis: Automated Cobb Angle Measurement using Keypoint RCNN" |
| **Model** | Keypoint R-CNN (ResNet50-FPN backbone) |
| **Output** | Vertebra landmarks (4 corners each) + 3 Cobb angles |
| **Pretrained Weights** | Yes (227 MB) |

---

## Purpose

ScolioVis detects **vertebra corners** and calculates **Cobb angles** from the detected landmarks:
- Outputs 4 keypoints per vertebra (corners)
- Calculates PT, MT, TL angles from vertebra orientations
- Provides interpretable results (can visualize detected vertebrae)

---

## Test Results (OUTPUT_TEST_1)

### Test Configuration

- **Test Dataset**: Spinal-AI2024 subset5 (test set)
- **Images Tested**: 5 (016001.jpg - 016005.jpg)
- **Weights**: Pretrained (keypointsrcnn_weights.pt)
- **Device**: CPU

### Results Comparison

| Image | GT PT | Pred PT | GT MT | Pred MT | GT TL | Pred TL | Verts |
|-------|-------|---------|-------|---------|-------|---------|-------|
| 016001.jpg | 0.0° | - | 4.09° | - | 12.45° | - | 6 (failed) |
| 016002.jpg | 7.77° | 0.0° | 21.09° | 17.2° | 24.34° | 24.1° | 9 |
| 016003.jpg | 5.8° | 0.0° | 11.17° | 11.9° | 15.37° | 15.8° | 8 |
| 016004.jpg | 0.0° | - | 11.94° | - | 20.01° | - | 2 (failed) |
| 016005.jpg | 9.97° | 0.0° | 16.88° | 10.6° | 20.77° | 16.2° | 11 |

**GT = Ground Truth, Pred = Predicted, Verts = Vertebrae Detected**

### Error Analysis (Successful Predictions Only)

| Image | PT Error | MT Error | TL Error | Mean Error |
|-------|----------|----------|----------|------------|
| 016002.jpg | -7.8° | -3.9° | -0.2° | 4.0° |
| 016003.jpg | -5.8° | +0.7° | +0.4° | 2.3° |
| 016005.jpg | -10.0° | -6.3° | -4.6° | 7.0° |

**Average Error: 4.4°** (on successful predictions)

### Success Rate

- **3/5 images** (60%) successfully calculated angles
- **2/5 images** failed (too few vertebrae detected)

---

## Output Files

```
OUTPUT_TEST_1/
├── 016001_result.png    # Visualization (6 verts, failed)
├── 016002_result.png    # Visualization (9 verts, success)
├── 016003_result.png    # Visualization (8 verts, success)
├── 016004_result.png    # Visualization (2 verts, failed)
├── 016005_result.png    # Visualization (11 verts, success)
└── results.json         # JSON results
```

---

## How It Works

```
Input Image (JPG/PNG)
        │
        ▼
┌─────────────────────────┐
│  Keypoint R-CNN         │
│  (ResNet50-FPN)         │
│  - Detect vertebrae     │
│  - Predict 4 corners    │
└─────────────────────────┘
        │
        ▼
┌─────────────────────────┐
│  Post-processing        │
│  - Filter by score >0.5 │
│  - NMS (IoU 0.3)        │
│  - Sort by Y position   │
│  - Keep top 17 verts    │
└─────────────────────────┘
        │
        ▼
┌─────────────────────────┐
│  Cobb Angle Calculation │
│  - Compute midpoint     │
│    lines per vertebra   │
│  - Find max angles      │
│  - Classify S vs C      │
└─────────────────────────┘
        │
        ▼
Output: {
  landmarks: [...],
  angles: {pt, mt, tl},
  curve_type: "S" | "C"
}
```

---

## Strengths

1. **Pretrained weights available** - Ready to use
2. **Interpretable output** - Can visualize detected vertebrae
3. **Good accuracy** - 4.4° average error when detection succeeds
4. **Curve type detection** - Identifies S-curve vs C-curve

## Limitations

1. **Detection failures** - 40% failure rate on test set
2. **Requires sufficient vertebrae** - Needs ~8+ vertebrae for reliable angles
3. **Synthetic image challenges** - May perform differently on real X-rays
4. **PT angle often 0** - Model tends to underestimate proximal thoracic

---

## Usage

```bash
# Activate venv
.\venv\Scripts\activate

# Run test script
python test_subset5.py

# Or start FastAPI server
uvicorn main:app --reload
# Then POST image to /v2/getprediction
```

---

## Comparison with Seg4Reg

| Metric | ScolioVis | Seg4Reg (no weights) |
|--------|-----------|---------------------|
| Avg Error | **4.4°** | 35.7° |
| Success Rate | 60% | 100% |
| Interpretable | **Yes** | No |
| Pretrained | **Yes** | No |

**Winner**: ScolioVis (when detection succeeds)

---

## Conclusion

ScolioVis with pretrained weights produces **clinically reasonable results** (4.4° average error) when vertebra detection succeeds. The main limitation is detection reliability on synthetic images - 40% of test images had too few vertebrae detected.

**Recommendation**: Good for real X-rays; may need fine-tuning for synthetic Spinal-AI2024 images.

---

*Report generated: January 2026*
*Test data: Spinal-AI2024 subset5*
