Table 2. Translation to MRI of the ‘ultrasound classification of medial gastrocnemius injuries’.
| Types | Location of damage | Imaging findings | |
|---|---|---|---|
| US signs | MRI signs | ||
| 1 | Muscular myoaponeurotic injury | Morphologic and echostructural alteration of muscle fascicles and the interposed fibro-adipose septa | Area of feathery edema is observed in the fibers anchored to the aponeurosis in fluid-sensitive sequences |
| 2A | Gastrocnemius aponeurotic injury (<50%) | Morphologic and echostructural alteration of the aponeurosis continuity, as well as evidence of morphologic and echostructural alteration of muscle fascicles. Small hypo-anechoic collection (hematoma). Synchronous motion of the gastrocnemius and soleus muscles | Increased signal area at the myoaponeurotic junction, along with irregularity in the fibrillar pattern of the anchorage and a clear discontinuity in the aponeurosis at that level. Small liquid-signal accumulation (hematoma). Synchronous motion of the gastrocnemius and soleus muscles |
| 2B | Gastrocnemius aponeurosis injury (>50%) | Morphologic and echostructural alteration of the aponeurosis continuity, as well as evidence of morphologic and echostructural alteration of muscle fascicles. Large hypo-anechoic accumulation (hematoma). Usually, asynchronous motion of the gastrocnemius and soleus muscles | Increased signal area at the myoaponeurotic junction, along with irregularity in the fibrillar pattern of the anchorage and a clear discontinuity in the aponeurosis at that level. Large liquid-signal accumulation (hematoma). Usually, asynchronous motion of the gastrocnemius and soleus muscles |
| 3 | FGA injury | Morphologic and echostructural alteration of the FGA. Synchronous motion of the gastrocnemius and soleus muscles | Exclusively a FGA discontinuity, and a small amount of fluid tends to accumulate superficially, although significant hematomas are not present. Synchronous motion of the gastrocnemius and soleus muscles |
| 4 | Mixed injury | Combination of US findings of 2B and 3 types | Combination of MRI findings of 2B and 3 types |
MRI, magnetic resonance imaging; US, ultrasound; FGA, free gastrocnemius aponeurosis.