{
 "serie": "s3_Axial_PD_FS",
 "n_imgs": 24,
 "s": 61.0,
 "respuesta": "**Series: Axial PD FS, right ankle/hindfoot (forefoot → distal tibia). Orientation: posterior (Achilles) at bottom of image, lateral (fibula) on the left.**\n\n**Joint fluid / synovium**\n- Tibiotalar joint effusion: fluid distending the anterior recess (bright ovoid anterior to the distal tibia, slice 21) and fluid in the posterior recess/tibiofibular region (slices 19–21). Moderate effusion – confidence high.\n- Subtalar/sinus tarsi: increased fluid signal in the sinus tarsi and along the talocalcaneal interosseous ligament region (slices 11–13) – sinus tarsi edema/fluid – confidence medium.\n\n**Ligaments**\n- Lateral collateral complex (ATFL/CFL region): extensive fluid/edema lateral to the talus and along the anterolateral capsule (large bright area on slices 10–13, curvilinear fluid tracking around the anterolateral talus). Appearance suggests ATFL sprain/tear with lateral capsular edema – confidence medium‑high.\n- Deltoid ligament: mild increased signal along the medial talus/medial malleolus (slices 15–17) – possible low-grade deltoid sprain – confidence low.\n- Syndesmosis: fluid at the anterior/posterior inferior tibiofibular interval (slices 19–21); cannot exclude AITFL/PITFL involvement – confidence low.\n\n**Tendons**\n- Deep posterior compartment: large, homogeneous fluid‑bright region posterior/posteromedial to the distal tibia between tibia and fibula (slices 21–24), replacing the expected intermediate signal of the FHL muscle belly – edema/fluid within FHL muscle or a distended tenosynovial/fluid collection – confidence medium.\n- Medial flexor tendons (tibialis posterior/FDL/FHL): fluid surrounding tendons posteromedially at the malleolar and talar levels (slices 16–20) – tenosynovitis – confidence medium.\n- Peroneal tendons: thin rim of fluid around the peroneus longus/brevis posterolaterally (slices 15–20) – mild peroneal tenosynovitis – confidence low‑medium.\n- Achilles tendon: normal low signal and thickness; no retrocalcaneal fluid – normal.\n- Extensor tendons: normal.\n\n**Bones / cartilage**\n- Talus: subtle heterogeneous increased marrow signal in the talar body, more medial (slices 15–17) – possible mild bone marrow edema/contusion – confidence low.\n- Tibia, fibula, calcaneus, navicular, cuboid, cuneiforms, metatarsals: no definite marrow edema or fracture line; cortical contours intact.\n- Cartilage: no focal osteochondral defect confidently identified on this fluid‑sensitive series.\n\n**Soft tissues**\n- Diffuse subcutaneous edema: reticular high signal in the plantar and lateral/dorsal subcutaneous fat of the mid/hindfoot (slices 3–9, 10–14), most marked laterally and plantarly – confidence high.\n- Prominent venous structures (branching bright vessels in plantar fat, slice 3) – likely normal/venous congestion, no discrete mass.\n\n**Impression:** Findings most consistent with acute/subacute lateral ankle sprain (ATFL ± CFL) with lateral soft‑tissue edema, moderate tibiotalar effusion, sinus tarsi fluid, medial and peroneal tenosynovitis, and fluid/edema in the deep posterior compartment (FHL). Possible mild talar marrow edema. No fracture or tendon tear identified."
}