The Thin Sagittal Sectional Anatomy Of The Human Foot Correlated With MRI

Objective: To explore morphological variations and MRI signal characteristics oncontinuous thin sagittal plane of the complex anatomy of the foot and thecorresponding MR images and provide imaging evidence for the localization,diagnosis and surgical treatment the diseases in this region.Materials and Methods:3left foot specimens of adult males were obtained fromShandong University School of Medicine, Department of Anatomy. They wereexamined by using a3.0-T MR unit along a scan baseline，which was parallel withlong axis of the the second metatarsal bone and perpendicular to the plantar. Onenormal foot specimens was selected for the study of sectional anatomy by usingComputerized Freezing Milling Technique.At the same time10volunteers wererecruited to perform MRI scanning with the same baseline as the foot specimens.Finally the typical slices of the foot specimens and the corresponding MR images ofvolunteers were selected to investigate anatomical structures.Results: Six typical sagittal slices and corresponding volunteers MR images were selected to study the anatomical characteristics and MRI findings of the bones,joints, ligaments, muscles, blood vessels and nerves of the foot on the continuoussagittal planes.There are six typical sagittal planes from the medial to the lateral ofthe foot. The first sagittal planar views through the first metatarsal bone and medialmalleolus level. The main structures of this level include medial malleolus, naviculartuberosity, the medial cuneiform bone，the first metatarsal bone and sesamoid bone.The posterior tibial tendon is close to the medial malleolus and passes behind it, thenruns forward the bottom of the scaphoid tubercle. The tibialis anterior tendon and theextensor hallucis longus tendon are on the dorsum of the foot.The abductor hallucismuscle，the flexor hallucis muscle and the end of hallucis longus tendon are on thethe Plantar The second sagittal planar views through the inner edge of the secondmetatarsal，talus and calcaneus tuberosity level. On this level we begin to see thesustentaculum tali，the subtalar joint, the middle cuneiform bone, the secondmetatarsal bone and phalanges bones.The flexor hallucis longus tendon passesbehind the sustentaculum tali. The tibialis anterior tendon and the extensor hallucislongus tendon are on the dorsum of the foot. Plantar fascia began to appear in thePlantar. Superior to plantar fascia，we can see digitorum brevis, flexor hallucisbrevis and the end of the flexor hallucis longus tendon from inferior to superior andalso see quadratus plantae and long plantar ligament. The third sagittal planar viewsthrough the outer edge of the second metatarsal bone and the protrusion of calcaneusbone level. On this level we can see the subtalar joint,the posterior subtalar joint andthe innermost section of sinus tarsi between them and only see the base of the second metatarsal bone. Tendo calcaneus and cuboid bone begin to appear. The interosseoustalocalcaneal ligament appears in the tarsal sinus. The tibialis anterior tendon and theextensor digitorum longus tendon are on the dorsum of the foot.On the plantar thereare plantar fascia, flexor digitorum brevis, quadratus plantae, flexor hallucis brevisand the end of peroneus longus tendon from inferior to superior. The fourth sagittalplanar views through the third metatarsal bone,tarsal sinus and tendo calcaneus level.This level is the median sagittal plane of the foot. The main structures include tendocalcaneus, fat pad and tarsal sinus. The cervical ligament appears in tarsal sinus. Onthe dorsum of the foot there is the extensor digitorum brevis superior to navicularbone and lateral cuneiform bone. On the plantar there are abductor digiti minimi,flexor digitorum brevis, transverse head of adductor hallucis and lumbricals fromanterior to posterior. Superior and inferior to the third metatarsal bone are dorsalinterossei muscle and plantar interossei muscle. The fifth sagittal planar viewsthrough the fourth metatarsal bone and lateral tarsal sinus level. On this levelcalcaneocuboid articular surface increased significantly，cuneocuboid joint is formedby lateral cuneiform bone and cuboid bone anterosuperiorly, the fourth metatarsalbone and proximal phalanx shows clearly and we can see part of tendo calcaneus. Onthe dorsum of the foot superior to lateral cuneiform bone and cuboid bone is theextensor digitorum brevis. On the plantar inferior to calcaneus bone is abductor digitiminimi muscle and inferior to cuboid bone is peroneus longus tendon. Superior andinferior to the fourth metatarsal bone are dorsal interossei muscle and plantarinterossei muscle. The sixth sagittal planar views through the fifth metatarsal and fibula level. On this level fibula appears and talus changed significantly small. Thefourth and fifth metatarsal formed inter-metatarsal joints and with cuboid boneposteriorly formed dice metatarsal joint. Plantar fascia and tendo calcaneus disappear.On the dorsum of the foot superior to cuboid bone is the extensor digitorum brevis.On the plantar there are abductor digiti minimi muscle, flexor digiti minimi brevis,transverse head of adductor hallucis and plantar interossei muscle from posterior toanterior. Inferior to cuboid bone is peroneus longus tendon. The results show asignificant correspondence between the sagittal planes of foot specimens and thecorresponding levels MR images of volunteers and it can clearly show themorphological characteristics and imaging features of the foot structures.Conclusions: Computerized freezing milling technique is a significant method tostudy sectional anatomy of the foot specimens.The structural details of the foot onsagittal planes can display in the front-rear direction and the verticaldirection.Compared with the corresponding volunteers MR images, it can provideanatomical evidence for clinical diagnostic imaging and surgical treatment ofdiseases in this region.