Findings

Achilles tendon is ruptured. Axial proton density MR images demonstrate edema in the gastrocnemius muscle and thickening of the tendon above the rupture site. 

Discussion

Achilles tendon rupture is commonly a sports related injury, but can also occur in other patient populations who may be affected by diabetes, inflammatory arthritis, gout, fluoroquinolone antibiotics, and calcium metabolism disorders. Patients may report hearing or feeling a “pop.”

Differential Diagnosis

Thickened Achilles tendon without clear measurable focal tear:

• Partial tear (moderate sprain)
• Tendinosis
• Achilles tendon xanthoma (usually bilateral, but occasionally unilateral).