Figure 2. Plantar fibroma. (a) Ultrasound shows a small well definded hypoechoic mass (arrow) related to the plantar fascia (open arrow). (b) T1 weighted sagittal image and (c) transverse T2 weighted image of a larger lesion showing a mass related to the plantar fascia. The mass returns intermediate signal intensity on T1 and low signal intensity on T2 weighted images.
Figure 3. Trevor's disease. (a) Typical ossified mass in the medial portion of the epiphysis (arrow). (b) With time the ossification merges with the ossification centre forming a bony protuberance.
Figure 4. Missed fracture. (a) T1 weighted and (b) short tau inversion recovery image showing an undisplaced fracture of the distal fibula (arrows) that was not apparent on the plain radiograph.
Figure 5. Subtle osteochondral fracture of the lateral corner of the talar dome. (a) The lesion cannot be diagnosed on the frontal view. (b) The fracture is seen on the oblique view (arrow).
Figure 6. Persistent pain following inversion injury. Short tau inversion recovery coronal image. There is an undisplaced fracture of the lateral corner of talar dome (arrows) surrounded by oedema.
Figure 7. Subchondral bone bruise. There is a chondral defect (arrow) and oedema affecting the medial aspect of the talar dome and the mid-portion of the tibial plateau (open arrow). The pattern of bony oedema indicates recent inversion injury with the medial corner of the tilted talus impacting the tibial plafond.
Figure 10. Persistent pain following trauma due to sinus tarsi syndrome. (a) T1 weighted sagittal image showing normal sinus tarsi containing the intertarsal ligament (arrow) and fat. (b) T1 weighted sagittal image in a patient with sinus tarsi syndrome. The sinus is filled with abnormal tissue returning low signal intensity material (arrows).
Figure 12. Typical stress fracture of the medial malleolus. (a) Short tau inversion recovery coronal image showing focal increase signal at the base of the medial malleolus surrounding a small focal low signal lesion extending to the articular surface (arrow). (b) Axial T1 weighted image showing the linear fracture line (arrows). (c) Corresponding CT slice confirms the sclerotic fracture line (arrows).
Figure 13. Stress fracture of the calcaneus. (a) T1 weighted image shows short linear defect (arrow). (b) Corresponding short tau inversion recovery image shows the focal oedema around the lesion.
Figure 14. Osteochondritis dissecans of the talar dome. (a) T1 weighted sagittal image shows low signal intensity lesion at the medial talar dome (arrow). (b) Short tau inversion recovery sagittal image shows high signal line under the lesion (arrows) indicating instability.
Figure 15. Osteochondritis dissecans of the talar dome. (a) T1 weighted coronal image shows a focus of low signal at the medial talar dome (arrow). (b) T2 gradient echo sagittal image shows a defect in the cartilage and small cysts under the lesion (arrow) suggesting that this is an unstable lesion.
Figure 16. Osteochondritis dissecans. (a) Coronal T1 weighted image showing subchondral low signal at the medial corner of the talar dome (arrow). (b) Coronal short tau inversion recovery shows small subchondral cysts surrounded by oedema. The overlying cartilage appears to be intact.
Figure 17. Anterior impingement. (a) Lateral plain film showing spurs arising from the anterior lip of the distal talus and the dorsal aspect of the talus (arrows). (b) Sagittal short tau inversion recovery image shows a spur arising from the anterior aspect of the distal tibia. Note the typical intra-articular position of the spur (arrow). There is also posterior subluxation of the talus indicating instability with incompetent anterior talofibular ligament.
Figure 18. Posterior impingement (os trigonum syndrome). (a) T1 weighted sagittal image showing low signal intensity within the os trigonum representing sclerosis and oedema (arrow). (b) Corresponding short tau inversion recovery image showing oedema in the os trigonum (arrow) and adjacent posterior talus.
Figure 19. Pigmented villonodular synovitis. (a) T1 weighted and (b) short tau inversion recovery (STIR) sagittal images showing mass associated to the flexor hallucis longus tendon. The periphery of the lesion returns low signal intensity on both T1 and STIR images indicating haemosiderin deposition (arrows).
Figure 20. Osteomylelitis of the tibia. (a) Normal plain film (b) T1 weighted and (c) short tau inversion recovery coronal images showing focal metaphyseal lesion with some surrounding oedema.
Figure 21. Osteoid osteoma. (a) T1 weighted and (b) short tau inversion recovery sagittal images showing focal lesion (arrows) on the dorsum of the talar neck with surrounding oedema and an effusion. (c) CT shows characteristic features of a well defined lytic lesion with a sclerotic rim and central calcification (arrow). (d) CT showing radiofrequency ablation.
Figure 22. Achilles tendinosis. (a) Extended field of view ultrasound image showing diffuse fusiform swelling of the tendon (arrows) (C, calcaneus). (b) Sagittal scan with Doppler showing fusiform widening of the tendon. The tendon is hyopechoic and has a heterogeneous internal structure. Power Doppler demonstrates the typical pattern of hypervascularity with vascular channels penetrating the anterior surface of the tendon (arrows).
Figure 23. Achilles tendinosis. (a) Sagittal T2 weighted image showing focal area of high signal in keeping with mucoid degeneration. (b) Sagittal T1 weighted image of a different case showing diffuse swelling of the tendon with an ill-defined anterior border indicating tendinosis with associated paratenonitis. There is evidence of pre achilles bursitis (arrow).
Figure 24. Insertional tendinopathy. (a) Ultrasound showing widening of the tendon and a partial tear (arrow). (b) T1 weighted image of a different case. (c) Corresponding short tau inversion recovery image (note prominent posterosuperior corner of the calcaneus (arrow) which is impinging on the tendon) showing oedema in the calcaneus at the insertion and bursitis of the pre-Achilles (arrow) and retrocalcaneal (open arrow) bursae.
Figure 25. Tendinopathy secondary to seronegative arthropathy. (a) Ultrasound shows marked widening of the distal portion of the tendon which is diffusely hypoechoic (arrows) (C, calcaneus). (b) Short tau inversion recovery sagittal MRI in a different case showing fluid in the pre-achilles bursa (arrow). Note also inflammatory change in the plantar fascia (open arrow) and associated oedema in the calcaneus (arrow heads).
Figure 28. Complete tear of the achilles tendon with intact plantaris tendon. (a) Axial image through the region of an acute tear. The intact plantaris tendon is seen lying on the medial side of the tear (arrow) within the paratenon (open arrows) (AT, torn achilles tendon). (b) Longitudinal scan demonstrates the intact plantaris (arrows).
Figure 29. Tibialis posterior tendinosis. (a) Axial ultrasound showing a minor widening of the tendon (arrow) with a hypoechoic rim representing tenosynovitis (open arrow). (b) Longitudinal section shows a widened tendon with fluid in the tendon sheath (arrow) and synovial hypertrophy (open arrow). (c) Power Doppler shows hypervascularity in the tendon and surrounding synovium.
Figure 30. Tibialis posterior tendinosis. Axial T2 weighted image distal to the malleolus showing a widened tendon (arrow) and fluid in the tendon sheath. There is no abnormal intratendinous signal.
Figure 31. Longitudinal split of tibialis posterior tendon. Sagittal T2 weighted image showing linear high signal within the tendon (arrow) (FD, flexor digitorum longus).
Figure 32. Tibialis posterior tendinosis. T1 weighted axial image showing increased signal within the tendon (arrow) and surrounding synovitis. Note the secondary bony spur arising from the tibia just medial to the tendon (open arrow).
Figure 33. Complete chronic tear of the tibialis posterior tendon. (a) T1 weighted axial image showing a small amount of scar tissue at the expected site of the tendon (arrow) (FD, flexor digitorum longus). (b) Sagittal image showing the widened retracted proximal free end of the tendon (arrow).
Figure 35. Peroneal dislocation. (a) Axial ultrasound showing peroneus longus tendon lying on the anterolateral aspect of the fibula (arrow). Peroneus brevis is lying in the normal position behind the fibula (open arrow). The stripped reinaculum can be seen (arrowheads) (F, fibula).
Figure 38. Talocalcaneal coalition. (a) T1 weighted coronal showing a non-bony coalition. There is a wide irregular middle subtalar joint (arrow). (b) Marked bony oedema is seen on the short tau inversion recovery sequence.
Figure 41. Osteonecrosis of the lateral part of the navicular. (a) Frontal and (b) lateral views show the typical appearances with a small triangular shaped residual medial portion (arrows) displaced medially and dorsally. More laterally the talus articulates with the cuneiforms (open arrow).
Figure 42. Morton's neuroma. (a) Sagittal ultrasound showing typical rounded hypoechoic lesion (arrow). Deep to the lesion there is some fluid seen in the intermetatarsal bursa (open arrow). (b) Axial T1 weighted image showing small intermediate signal intensity mass between the 3rd and 4th metatarsals (arrow).
Figure 43. Osteonecrosis of the sesamoid. (a) T1 weighted axial scan showing diffuse low signal intensity in the lateral sesamoid (arrow). (b) Short tau inversion recovery axial image showing low signal laterally in the sesamoid (arrow) and oedema related to secondary osteoarthritis more medially (open arrow).
Figure 45. Bone marrow oedema syndrome. (a) T1 weighted and (b) short tau inversion recovery sagittal images showing diffuse oedema within the talus with an ankle joint effusion.
Figure 46. Diabetic neuropathy. (a) T1 weighted sagittal image showing disorganization of the midcarpal bones and extensive low signal intensity. (b) There is high signal on the short tau inversion recovery image indicating that the process is still active.
Figure 47. Diabetic osteomyelitis. (a) T1 and (b) short tau inversion recovery sagittal images showing focal erosion and oedema in the posterior aspect of the calcaneus which is communicating with an ulcer (arrow). There is also some inflammation of the Achilles tendon and pre-Achilles bursa.
