{
 "serie": "s2_AX_T1_memp",
 "n_imgs": 24,
 "s": 74.1,
 "respuesta": "**Technical note:** Axial T1-weighted (memp) images of the right ankle, ordered from distal (midfoot/metatarsal bases) to proximal (distal tibia/fibula). Image left = lateral (fibula side), right = medial, bottom = posterior. T1 only – fluid and marrow edema cannot be confidently separated from other low-signal tissue, so several findings are given with limited confidence.\n\n**Bones / marrow**\n- Calcaneus, talus, navicular, cuboid, cuneiforms, metatarsal bases, distal tibia and fibula: marrow shows homogeneous bright fatty signal. No definite T1-hypointense marrow replacement, fracture line, or osteochondral defect of the talar dome identified. (medium confidence – T1 alone is insensitive to edema).\n- A thin oblique low-signal line traversing the calcaneal body on the slices at the level of the sustentaculum/posterior facet (slices ~12–14). Most consistent with the subtalar joint facets / cortical margin of the sustentaculum caught obliquely rather than a fracture, but a subtle calcaneal fracture cannot be fully excluded on T1 alone. (low confidence for pathology)\n- No os trigonum, accessory navicular, or coalition seen. (medium)\n\n**Joints / fluid**\n- Posteromedial to the talus/posterior tibia (slices ~18–20) there is a rounded, well-circumscribed low-signal structure (~1 cm) with a surrounding thin bright fat rim, larger than expected for the FHL tendon alone. This may represent fluid distending the FHL tendon sheath (tenosynovitis) or a distended posterior tibiotalar/subtalar recess; correlation with fluid-sensitive sequences is needed. (low–medium confidence)\n- Tibiotalar joint: no obvious large anterior effusion on T1. Sinus tarsi fat appears preserved with normal interosseous/cervical ligament striations (medium).\n\n**Tendons**\n- Achilles tendon: seen on the posterior \"tail\" of slices ~15–24. Caliber appears within normal limits with a normal low-signal ovoid/crescentic cross-section; small central intermediate signal on some slices most likely represents partial-volume with Kager fat/plantaris. No definite thickening, tear, or retrocalcaneal soft-tissue mass. Pre-Achilles (Kager) fat pad normal. (medium)\n- Peroneal tendons (lateral, along the calcaneus and posterolateral fibula): two normal low-signal ovoid tendons without split, thickening, or obvious peritendinous fluid. (medium)\n- Posterior tibial, FDL and FHL tendons: normal low signal and caliber where visualized; FHL muscle belly normal posterior to the tibia. Apart from the possible FHL sheath fluid noted above, no tendon abnormality. (medium)\n- Anterior tendons (tibialis anterior, EHL, EDL): normal. (medium)\n- Plantar fascia: thin, uniformly low signal at the calcaneal origin; no thickening. (medium)\n\n**Ligaments**\n- Deltoid and lateral ligament complexes are only partially assessable on axial T1; no gross disruption or thickening seen. Spring ligament region normal. (low–medium)\n\n**Soft tissues**\n- Subcutaneous fat, plantar musculature (abductor hallucis, flexor digitorum brevis, quadratus plantae, abductor digiti minimi) show normal signal and bulk; no fatty atrophy, mass, or edema-type signal. Numerous small vascular flow voids in the medial and lateral subcutaneous tissue are normal. No soft-tissue mass. (medium)\n\n**Summary**\n1. Possible fluid in the posteromedial ankle – FHL tendon sheath (tenosynovitis) vs posterior joint recess – low–medium confidence; confirm on T2/STIR.\n2. Equivocal linear low signal through the calcaneal body, most likely normal subtalar facet/sustentacular cortex; fracture considered unlikely (low confidence).\n3. Otherwise no definite bone, tendon (including Achilles and peroneals), ligament, or soft-tissue abnormality on this T1 series."
}