Tendon achilles

1-It is a hypo intense rob in all pulse sequences extend from Gastrocnemius muscle to calcaneal insertion.

2-It is the most strongest and largest tendon in the body.

3-It is the most common injured tendon in the foot.

4-It has no tendon sheath(so does not affected by tenosynovitis, if it is inflammed means tendonitis).

5-It has a flat or concave anterior aspect with posterior convex border(seen in axial view).

6-It has a bursa anterior to its insertion in the calcaneum.

7-It has a uniform low signal in all pulse sequences.

8- If the tendon is injured, you must mention two findings, the first one is how long is the length between the site of insertion and the site of injury, the second one is if there is a gap between cutted edge, you must mention how long is the space between them.

Signs of tear: You will see the tendon enlarged with evidence of  discontinuity(complete tear) and large area of fluid collection.

 

9-It could be injured completely or partially(where there is injured fibers beside normal fibers in a swollen tendon), to judge type of injury look in the axial view.

Partial tear of the tendon.

10-If the tendon is swollen with area of increased intensity inside its parenchyma, look to the color of this intensity, if it is as water in T2,this will be a tear, but if it is grey in color, this will be due to tendonitis.

Insertional Achilles tendonitis

Tendonitis.

11-If the tendon is normal with accumulation of water around it, this will be peri-tendonitis.

12-Lesions affecting Achilles tendon are:

-Complete tear.

-Partial tear.

-Tendonitis(swollen tendon with or without internal signal intensity).

-Peritendonitis. 

-No tenosynovitis as it does not has a sheath.

13-Anterior to the site of insertion of tendon in calcaneus, there is a small bursa normally containing small amount of fluid known as retro calcaneal bursa, if this fluid is increased in amount, this means retro calcaneal bursitis( most commonly seen in patients with rheumatoid).