{
 "serie": "s201_STIR_SAG",
 "n_imgs": 18,
 "s": 42.4,
 "respuesta": "**Limited assessment:** Only 18 sampled sagittal STIR images are provided. Cartilage, ligament integrity, and the precise extent of osteochondral abnormalities require the complete multiplanar examination.\n\n### Abnormal findings\n\n| Location | Description | Confidence |\n|---|---|---|\n| **Medial talar dome/medial tibiotalar articulation** | Focal articular–subchondral irregularity with small STIR-bright subchondral foci and mild adjacent marrow signal abnormality, most apparent on images 5–7. Suspicious for a chronic osteochondral lesion with cystic/reactive change. A small opposing medial tibial plafond subchondral abnormality may also be present. Lesion dimensions, cartilage stability, and any fragment cannot be reliably assessed here. | **Medium** |\n| **Tibiotalar joint** | Small effusion, including fluid in the anterior and posterior recesses. | **High** |\n| **Subtalar joint/sinus tarsi** | Small amount of subtalar joint fluid and conspicuous increased STIR signal within the sinus tarsi beneath the talar neck. Some of this signal is lobulated, potentially representing localized cystic/ganglion-type change in addition to edema/synovial fluid. No definite osseous coalition is demonstrated. | **Medium** |\n| **Flexor hallucis longus tendon sheath, posterior ankle** | Prominent fluid tracking along the tendon behind the distal tibia and talus. This may represent sheath distention communicating with the ankle effusion; associated tenosynovitis is possible. No definite tendon discontinuity. | **Medium** |\n| **Dorsolateral midfoot soft tissues** | Mild superficial/subcutaneous STIR hyperintensity, consistent with nonspecific edema. No organized collection identified. | **Medium** |\n\n### Other assessed structures\n- **Bones:** No acute fracture, collapse, or extensive marrow edema identified elsewhere.\n- **Cartilage:** No additional gross osteochondral defect identified; detailed cartilage assessment is limited.\n- **Ligaments:** The lateral ligament complex, syndesmosis, and deltoid ligament are not adequately assessed on these sampled sagittal images. A chronic ligament tear cannot be confidently diagnosed or excluded.\n- **Tendons:** Achilles tendon is intact without convincing tendinopathy. Visualized portions of the other flexor, extensor, and peroneal tendons show no definite tear.\n- **Plantar fascia:** No convincing proximal thickening or perifascial edema.\n\n**Principal concern:** Suspected chronic medial tibiotalar osteochondral abnormality, accompanied by a small ankle effusion and sinus-tarsi/subtalar inflammatory or cystic signal change."
}