# 📐 L2 Spec — Magnetic Resonance Imaging (MRI) — proton-density / T1 / T2 contrast Mismatch-Only Spec
**ID:** `L2-030-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-030`](/artifact/l1/L1-030)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.5 · **Delta tier:** 5
> **⛓ On-chain block:** 41553360
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| H | px | 64 – 1024 |
| W | px | 64 – 1024 |
| Z | — | 16 – 1024 |
| Te ms | ms | 1 – 500 |
| Tr ms | ms | 10 – 10000 |
| Snr db | dB | 0.0 – 40.0 |
| Motion | — | 0.0 – 0.5 |
| Eddy currents | — | 0.0 – 0.2 |
| Undersampling | — | 0.0625 – 1.0 |
| Acceleration r | — | 1 – 16 |
| B0 inhomogeneity | — | 0.0 – 0.3 |
| Coil sensitivity drift | — | 0.0 – 0.2 |
## 2. Tolerance (ε)
**Type:** `fn`
```
20.0 + 0.3 * SNR_dB - 10.0 * B0_inhomogeneity - 8.0 * motion - 5.0 * log2(acceleration_R)
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.5 |
| Delta tier | 5 |
## 4. Fingerprint
`aa08f269769abcffb73765b2b404bab464f5880c06edf212c5a7ab122ecb2848`
## 5. On-chain Registration
- **Chain hash:** `0xfd2ce0c1188c3982034309843acc45207391336d3f4aede5a5ab2ec1a52878e2`
- **Chain tx hash:** `0xdbc039e753f29045e16fb46a841aa4113d4bb68e347654a92a91640d6f3d7d00`
- **Chain block:** `41553360`
---
## File Mapping
This bundle consists of: `L2-030-001.md`, `L2-030-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-030-001.md` | Source of truth — edit this | Human or LLM |
| `L2-030-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-030-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._