Figure 1
T2-weighted image of the patient's left heel. MRI machines measure proton density; density is proportional to how dark a tissue appears on the scan. 'T1' and 'T2' are technical terms describing the time required for proton relaxation. T2 images make adipose tissue, water, and other fluids bright, thus these images are ideal for detecting tissue edema. On the image, note the intact flexor hallucis longus (filled arrowheads) pulled taught. The flexor hallucis longus is responsible for what little plantar flexion the patient had left. The arrows show the retracted and limp proximal end of the Achilles tendon, with the bright area of signal intensity (open arrowhead) representing inflammation and fluid migration between the severed ends.