{
 "serie": "s201_STIR_SAG",
 "n_imgs": 18,
 "s": 69.5,
 "respuesta": "**Limited assessment: sagittal STIR sequence only; axial/coronal and non–fat-suppressed sequences would be needed for definitive ligament/cartilage/tendon characterization.**\n\n## Abnormal findings identified\n\n| Category | Location | Description | Confidence |\n|---|---|---|---|\n| **Bone / osteochondral** | **Medial-to-central talus, centered in the talar body/dome-neck region** | Lobulated focal STIR-hyperintense marrow signal/cystic change with surrounding marrow edema. This appears subchondral/juxta-articular and is suspicious for chronic osteochondral/subchondral cystic change, possibly related to prior injury. No obvious collapse or displaced fragment is seen on these images. | **High** for abnormal talar marrow/cystic signal; **Medium** for exact osteochondral origin/location |\n| **Cartilage / articular surface** | **Talar dome / adjacent talar articular region** | Overlying cartilage is not well assessed on STIR alone. There may be subtle associated articular surface irregularity, but a definite full-thickness cartilage defect cannot be confirmed from this series. | **Low–Medium** |\n| **Subtalar / sinus tarsi region** | **Sinus tarsi / tarsal canal and subtalar joint region** | Increased STIR-bright fluid/edema in the sinus tarsi region with partial loss of expected fat signal. This may reflect chronic sinus tarsi synovitis/scarring and/or injury of the interosseous/cervical talocalcaneal ligament complex. | **Medium** |\n| **Joint fluid / synovitis** | **Tibiotalar and subtalar joints** | Small amount of joint fluid, greatest around the posterior subtalar/tibiotalar recesses. Mild synovitis/effusion is possible. | **Medium** |\n| **Tendons** | **Posteromedial ankle, likely flexor hallucis longus tendon sheath region** | Mild linear fluid signal around a posteromedial tendon course, possibly mild FHL tenosynovitis; difficult to confirm on sagittal STIR alone. | **Low–Medium** |\n| **Soft tissues** | **Subcutaneous tissues about ankle/foot** | Mild nonspecific STIR-bright subcutaneous edema, most apparent around the hindfoot/ankle margins. No focal fluid collection seen. | **Low** |\n\n## Structures that look grossly intact on this sequence\n\n- **Achilles tendon:** grossly intact; no tear or marked tendinosis evident.\n- **Plantar fascia:** no convincing plantar fascial tear or marked perifascial edema.\n- **Major flexor/extensor/peroneal tendons:** no gross tendon discontinuity on this sagittal STIR series.\n- **Ligaments:** ATFL/CFL/deltoid/spring ligament are not well evaluated on sagittal STIR alone; no gross acute ligament disruption is visible here."
}