{
 "serie": "s6_COR_2D_MERGE",
 "n_imgs": 22,
 "s": 60.0,
 "respuesta": "**Series: Coronal 2D MERGE (GRE, fluid/cartilage bright, marrow dark), right ankle – 22 slices anterior → posterior**\n\n**Bones**\n- Tibia, fibula, talus, calcaneus, navicular/cuboid: normal contour, no cortical step‑off or fracture line identified. No osteochondral defect of the talar dome (medial and lateral dome subchondral plate smooth on slices 6–10). Confidence high for absence of gross fracture; medium for OCL exclusion (GRE is insensitive to marrow edema).\n- No os trigonum or accessory ossicle identified. Marrow edema cannot be reliably assessed on this sequence.\n\n**Cartilage**\n- Tibiotalar and posterior subtalar articular cartilage appears as a continuous bright band of uniform thickness; no focal full‑thickness defect seen. Confidence medium.\n\n**Joint fluid**\n- Small tibiotalar joint effusion: fluid distending the medial and lateral gutters (slices 6–9) and a discrete bright fluid pocket in the posterior tibiotalar recess just above the posterior talus/calcaneus (slices 14–17). Confidence medium.\n- Mild fluid signal along the posterior subtalar joint (slices 10–13). Confidence low.\n\n**Ligaments**\n- Deltoid (deep tibiotalar) fibers seen as low‑signal tissue in the medial gutter; anterior talofibular / calcaneofibular ligaments not well profiled on this coronal set. No definite ligament tear identified. Confidence low (limited plane).\n- Sinus tarsi: intermediate/bright signal in the sinus tarsi fat (slices 6–8) – possible mild sinus tarsi fluid/synovitis vs normal fat on GRE. Confidence low.\n\n**Tendons**\n- Achilles tendon: uniform low signal, normal thickness, normal calcaneal insertion (slices 17–21). No retrocalcaneal bursal fluid of significance. Confidence high.\n- Medial flexor tendons (posterior tibial, FDL, FHL): small amount of bright signal adjacent to the tendons at the level of the sustentaculum/posterior talus (slices 12–15) – possible minimal tenosynovial fluid, most likely FHL sheath communicating with the ankle joint. Confidence low.\n- Peroneal tendons: no visible split or sheath distension on the visualized slices. Confidence low–medium.\n\n**Soft tissues**\n- Plantar/medial heel fat pad is lobulated with thin septa – normal appearance on GRE (bright fat). No plantar fascia thickening identified at the calcaneal origin. Confidence medium.\n- No soft‑tissue mass, no subcutaneous edema, no Kager fat pad abnormality.\n\n**Summary**\n1. Small tibiotalar joint effusion with fluid in the posterior recess (medium confidence).\n2. Possible mild posterior subtalar fluid and minimal medial flexor (likely FHL) tenosynovial fluid (low confidence).\n3. Possible mild sinus tarsi signal change (low confidence).\n4. No fracture, osteochondral lesion, or tendon tear identified; Achilles normal. Marrow edema and ligament integrity are incompletely evaluated on this single GRE coronal sequence – correlate with fluid‑sensitive fat‑suppressed and axial images."
}