reflecting progressive scar maturation at the repair site.
Despite the acknowledged benefits and widespread use of MR imaging in the assessment of the Achilles tendon, there is some debate as to the utility of MRI in examination in this regard. Karjalainen et al. examined 117 Achilles tendons with MRI and documented the overall sensitivity of MR imaging in the detection of abnormalities in cases of painful Achilles tendon to be 94%, with a specificity of 81%, and overall accuracy of 89%. The interobserver agreement for the MR imaging findings evaluated was good in all categories.50 However, several authors demonstrated an overlap of imaging findings in symptomatic and asymptomatic individuals.41,53 Signal heterogeneity and subtle focal increases in intrasubstance signal with distal longitudinal striations or small punctate foci of increased T1 weighted signal may represent normal fascial anatomy or possibly small vessels in normal Achilles tendons.41 This fascicular signal should be less apparent on STIR/T2 weighted images and the tendon should maintain a normal morphologic appearance with a concave anterior surface on axial imaging.54 Areas of mild increased T2 weighted signal visualized within the Achilles tendon in asymptomatic patients have been described and postulated by Haims and co-workers to represent areas of subclinical tendi-nopathy/mucoid degeneration. In contrast, areas of intense T2 weighted signal and thickened tendons were associated with chronic symptoms and tendon tears.53 Unlike ultrasound, Khan et al. did show that graded MRI did correlate with 12-month clinical outcome in patients with tendinopathy.33
In conclusion, the Achilles tendon is the most commonly injured tendon in the foot and ankle, with injuries commonly related to sports/athletic activities. Imaging modalities most commonly employed in the diagnostic assessment of the Achilles include conventional radiography, ultra-sonography, and magnetic resonance imaging. Cross-sectional imaging, including ultrasound and MR imaging, plays an important role in the documentation and staging of disease of the Achilles, and provides a noninvasive means of assessing the tendon's response to therapy or progression of disease.
1. Cheung Y, Rosenberg ZS, Magee T, Chinitz L. Normal anatomy and pathologic conditions of ankle tendons: Current imaging techniques. Radiographics 1992; 12:429-444.
2. Fischer E. Low kilovolt radiography In: Resnick D, Niwayama G, eds., Diagnosis of Bone and Joint Disorders. Philadelphia: WB Saunders, 1981, pp. 367-369.
3. Resnick D, Feingold DPM, Curd J, Niwayama G, Goergen TG. Calcaneal abnormalities in articular disorders: Rheumatoid arthritis, ankylosing spon-dylitis, psoriatic arthritis and Reiter syndrome. Radiology 1977; 125:355-366.
4. Yu JS, Witte D, Resnick D, Pogue W. Ossification of the Achilles tendon: Imaging abnormalities in 12 patients. Skeletal Radiol 1994; 23(2):127-131.
5. Barberie JE, Wong AD, Cooperberg PL, Carson BW. Extended field-of-view sonography in musculoskeletal disorders. AJR Am J Roentgenol 1998; 171(3):751-757.
6. Adler RS. Future and new developments in muscu-loskeletal ultrasound. Radiol Clin North Am 1999; 37:623-631.
7. Bertolotto M, Perrone R, Martinoli C, Rollandi GA, Patetta R, Derchi LE. High resolution ultrasound anatomy of normal Achilles tendon. Br J Radiol 1995; 68(813):986-891.
8. Fornage BD. Achilles tendon: US examination. Radiology 1986; 159(3):759-764.
9. Fornage BD, Rifkin MD. Ultrasound examination of tendons. Radiol Clin North Am 1988; 26(1):87-107.
10. Gibbon WW, Cooper JR, Radcliffe GS. Sonographic incidence of tendon microtears in athletes with chronic Achilles tendinosis. Br J Sports Med 1999; 33:129-130.
11. Hartgerink P, Fessell DP, Jacobson JA, van Holsbeeck MT. Full- versus partial-thickness Achilles tendon tears: Sonographic accuracy and characterization in 26 cases with surgical correlation. Radiology 2001; 220(2):406-412.
12. Kainberger FM, Engel A, Barton P, Huebsch P, Neuhold A, Salomonowitz E. Injury of the Achilles tendon: Diagnosis with sonography. AJR Am J Roentgenol 1990; 155:1031-1036.
13. Kaplan PA, Matamoros A, Anderson JC. Sonogra-phy of the musculoskeletal system. AJR Am J Roentgenol 1990; 155:237-245.
14. Maffulli N, Regine R, Angelillo M, Capasso G, Filice S. Ultrasound diagnosis of Achilles tendon pathology in runners. Br J Sports Med 1987; 21(4):158-162.
15. Mathieson JR, Connell DG, Cooperberg PL, Lloyd Smith DR. Sonography of the Achilles tendon and adjacent bursae. AJR Am J Roentgenol 1988; 151: 127-131.
16. Rupp S, Tempelhof S, Fritsch E. Ultrasound of the Achilles tendon after surgical repair: Morphology and function. Br J Radiol 1995; 68:454-458.
17. O'Reilly MA, Massouh H. Pictorial review: The sonographic diagnosis of pathology in the Achilles tendon. Clin Radiol 1993; 48(3):202-206.
18. Maffulli N, Dymond NP, Capasso G. Ultrasonographic findings in subcutaneous rupture of Achilles tendon. J Sports Med Phys Fitness 1989; 29:365-368.
19. Lin J, Fessell DP, Jacobson JA, Weadock WJ, Hayes CW. An illustrated tutorial of musculoskeletal sonography: Part 1, introduction and general principles. AJR Am J Roentgenol 2000; 175: 637-645.
20. Dussik KT, Fritch DJ, Kyriazidou M, Sear RS. Measurements of articular tissues with ultrasound. Am J Phys Med 1958; 37(3):160-165.
21. Fornage BD. The hypoechoic normal tendon: A pitfall. J Ultrasound Med 1987; 6:19-22.
22. Martinoli C, Derchi LE, Pastorino C, Bertolotto M, Silvestri E. Analysis of echotexture of tendons with US. Radiology 1993; 186(3):839-843.
23. Frey C, Rosenberg Z, Shereff M, Kim H. The retro-calcaneal bursa: Anatomy and bursography. Foot Ankle 1982; 13:203-207.
24. Civeira F, Castillo JJ, Calvo C, Ferrando J, de Pedro C, Martinez-Rodes P, et al. Achilles tendon size by high resolution sonography in healthy population. Med Clin (Barc) 1998; 111(2):41-44.
25. Koivunen-Niemela T, Parkkola K. Anatomy of the Achilles tendon (tendo calcaneus) with respect to tendon thickness measurements. Surg Radiol Anat 1995; 17:263-268.
26. Äström M, Gentz C-F, Nilsson P, Rausing A, Sjöberg S, Westlin N. Imaging in chronic achilles tendi-nopathy: A comparison of ultrasonography, magnetic resonance imaging and surgical findings in 27 histologically verified cases. Skeletal Radiol 1996; 25:615-620.
27. Kainberger F, Mittermaier F, Seidl G, Parth E, Weinstabl R. Imaging of tendons: Adaptation, degeneration, rupture. Eur J Radiol 1997; 25: 209-222.
28. Paavola M, Paakkala T, Kannus P, Jarvinen M. Ultrasonography in the differential diagnosis of Achilles tendon injuries and related disorders: A comparison between pre-operative ultrasonogra-phy and surgical findings. Acta Radiol 1998; 39(6):612-619.
Patel RS, Fessell DP, Jacobson JA, Hayes CW, van Holsbeeck MT. Artifacts, anatomic variants, and pitfalls in sonography of the foot and ankle. AJR Am J Roentgenol 2002; 178:1247-1254. Hollenberg GM, Adams MJ, Weinberg EP. Sono-graphic appearance of nonoperatively treated Achilles tendon ruptures. Skeletal Radiol 2000; 29:259-264.
Bleakney RR, Tallon C, Wong JK, Lim KP, Maffulli N. Long-term ultrasonographic features of the Achilles tendon after rupture. Clin J Sport Med 2002; 12(5):273-278.
Moller M, Kalebo P, Tiderbrant G, Movin T, Karlsson J. The ultrasonographic appearance of the ruptured Achilles tendon during healing: A longitudinal evaluation of surgical and nonsurgical treatment, with comparisons to MRI appearance. Knee Surg Sports Traumatol Arthrose 2002; 10: 49-56.
Khan KM, Forster BB, Robinson J, Cheong Y, Louis L, Maclean L, et al. Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study. Br J Sports Med 2003; 37:149-153. Archambault JM, Wiley JP, Bray RC, Verhoef M, Wiseman DA, Elliott PD. Can sonography predict the outcome in patients with achillodynia? J Clin Ultrasound 1998; 26(7):335-339. Zanetti M, Metzdorf A, Kundert H-P, Zollinger H, Vienne P, Seifert B, et al. Achilles tendons: Clinical relevance of neovascularization diagnosed with power Doppler US. Radiology 2003; 227(2): 556-560.
Nehrer S, Breitenseher M, Brodner W, Kainberger F, Fellinger EJ, Engel A, et al. Clinical and sono-graphic evaluation of the risk of rupture in the Achilles tendon. Areh Orthop Trauma Surg 1997; 116(1-2):14-8.
Weinberg EP, Adams MJ, Hollenberg GM. Color Doppler sonography of patellar tendinosis. AJR Am J Roentgenol 1998; 171(3):743-744. Quinn SF, Murray WT, Clark RA, Cochran CF. Achilles tendon: MR imaging at 1.5 T. Radiology 1987; 164:767-770.
Bencardino JT, Rosenberg ZS, Serrano LF. MR imaging of tendon abnormalities of the foot and ankle. Magn Reson Imaging Clin N Am 2001; 9(3): 475-492.
Rosenberg ZS, Beltran J, Bencardino JT. From the RSNA Refresher Courses. Radiological Society of North America. MR imaging of the ankle and foot. Radiographics 2000; 20:S153-S179. Soila K, Karjalainen P, Aronen HJ, Pihlajamaki HK, Tirman PJ. High-resolution MR imaging of the asymptomatic Achilles tendon: New observations. AJR Am J Roentgenol 1999; 173:323-328.
42. Cheung Y, Rosenberg ZS. MR imaging of the accessory muscles around the ankle. Magn Reson Imaging Clin N Am 2001; 9(3):465-473.
43. Schweitzer ME, Karasick D. MR Imaging of disorders of the Achilles tendon. AJR Am J Roentgenol 2000; 175:613-625.
44. Erickson SJ, Cox IH, Hyde JS, Carrera GF, Strandt JA, Estkowski LD. Effect of tendon orientation on MR imaging signal intensity: A manifestation of the "magic angle" phenomenon. Radiology 1991; 181: 389-392.
45. Erickson SJ, Prost RW, Timins ME. "Magic angle" effect: Background physics and clinical relevance. Radiology 1993; 188:23-25.
46. Marshall H, Howarth C, Larkman DJ, Herlihy AH, Oatridge A, Bydder GM. Contrast-enhanced magic-angle MR imaging of the Achilles tendon. AJR Am J Roentgenol 2002; 179(1):187-192.
47. Oatridge A, Herlihy A, Thomas RW, Wallace AL, Puri BK, Larkman DJ, et al. Magic angle imaging of the achilles tendon in patients with chronic ten-dinopathy. Clin Radiol 2003;58(5): 384-388.
48. Oatridge A, Herlihy AH, Thomas RW, Wallace AL, Curati WL, Hajnal JV, et al. Magnetic resonance: Magic angle imaging of the Achilles tendon. Laneet 2001; 358(9293):1610-1611.
49. Bottger BA, Schweitzer ME, El-Noueam KI, Desai M. MR imaging of the normal and abnormal retro-calcaneal bursae. AJR Am J Roentgenol 1988; 170: 1239-1241.
50. Karjalainen PT, Soila K, Aronen HJ, Pihlajamäki HK, Tynninen O, Paavonen T, et al. MR imaging of overuse injuries of the Achilles tendon. AJR Am J Roentgenol 2000; 175:251-260.
51. Karjalainen PT, Aronen HJ, Pihlajamäki HK, Soila K, Paavonen T, Bostman OM. Magnetic resonance imaging during healing of surgically repaired Achilles tendon ruptures. Am J Sports Med 1997; 25:164-171.
52. Keene JS, Lash EG, Fisher DR, De Smet AA. Magnetic resonance imaging of Achilles tendon ruptures. Am J Sports Med 1989; 17:333-337.
53. Haims AH, Schweitzer ME, Patel RS, Hecht P, Wapner KL. MR imaging of the Achilles tendon: Overlap of findings in symptomatic and asymptomatic individuals. Skeletal Radiol 2000; 29: 640-645.
54. Bencardino JT, Rosenberg ZS. Normal variants and pitfalls in MR imaging of the ankle and foot. Magn Reson Imaging Clin N Am 2001; 9(3):447-463.
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