{
 "serie": "s501_DP_SPAIR_TRA",
 "n_imgs": 24,
 "s": 56.4,
 "respuesta": "**Series: axial PD SPAIR (fat‑suppressed), right ankle, 24 slices ordered from plantar/forefoot (slice 1) to distal tibia/fibula (slice 24).**\n\n**Joint fluid**\n- Tibiotalar joint effusion – moderate. Slices 18–21 show high‑signal fluid distending the anterior recess and extending along the anterolateral and medial gutters; slice 19 shows fluid also tracking into the distal tibiofibular (syndesmotic) recess. Confidence: high.\n- Subtalar / sinus tarsi region – bright fluid signal in the posterior subtalar joint and increased signal in the sinus tarsi soft tissues (slices 12–15, lateral between talus and calcaneus), with loss of the normal dark/fatty sinus tarsi signal. Suggests posterior subtalar effusion / sinus tarsi soft‑tissue edema (sinus tarsi syndrome pattern, compatible with prior sprain). Confidence: medium.\n\n**Tendons**\n- Peroneal tendons: rounded low‑signal tendons posterolateral to the fibula/lateral calcaneus with a rim of high‑signal fluid (slices 14–16 at the retro‑/inframalleolar level, and slice 24 posterior to the fibula) – mild peroneal tenosynovitis. No definite split/tear identified on this sequence. Confidence: medium.\n- Medial flexor tendons (tibialis posterior / FDL / FHL): small amounts of fluid around the posteromedial tendons at slices 22–24. Mild tenosynovitis vs. physiological fluid (FHL communicates with the joint, so this may be secondary to the effusion). Confidence: low–medium.\n- Anterior compartment tendons: small foci of fluid around the anterior tendons (slices 22–24). Likely minor/physiologic. Confidence: low.\n- Achilles tendon: normal calibre and dark signal throughout; no retrocalcaneal bursitis seen. Normal.\n\n**Ligaments**\n- Anterior talofibular ligament (anterolateral gutter, slices 19–20): region appears thickened/ill‑defined with adjacent fluid rather than a crisp low‑signal band – findings compatible with chronic ATFL injury/scarring from the remote sprain. Confidence: low–medium (axial fat‑sat alone is limited; correlate with T1/PD).\n- Deltoid and syndesmotic ligaments: no clear discontinuity identified. Low confidence assessment.\n\n**Bones / marrow**\n- Talar dome, distal tibia, fibula, calcaneus: no convincing focal bone‑marrow edema or osteochondral defect on the sampled slices. A small focus of intra‑osseous high signal in the anterior calcaneus/cuboid region on slice 11 is most likely a vascular channel; a small marrow edema focus cannot be fully excluded. Confidence: low.\n- No fracture line or cyst identified.\n\n**Cartilage**\n- Talar dome cartilage appears grossly preserved on the sampled axial slices; no focal defect seen (limited plane for cartilage assessment). Confidence: low.\n\n**Soft tissues**\n- Linear high signal along the medial aspect of a long bone in the plantar/forefoot slices (slices 4–9) – most likely a normal vessel or physiologic fluid in a flexor tendon sheath; no discrete mass. Confidence: low.\n- No subcutaneous edema, mass or ganglion identified.\n\n**Impression**\n1. Moderate tibiotalar joint effusion (high confidence).\n2. Posterior subtalar fluid with sinus tarsi soft‑tissue edema – sinus tarsi syndrome pattern (medium).\n3. Mild peroneal tenosynovitis (medium); minor fluid around medial flexor tendons (low–medium).\n4. Probable chronic thickening of the anterior talofibular ligament, consistent with the prior sprain (low–medium; correlate with other sequences).\n5. No definite osteochondral lesion or marrow edema on these slices."
}