digraph structs {
    node [shape=plaintext];

    struct1 [label=<<TABLE>
    <TR><TD><IMG SRC="eqn.gif"/></TD></TR>
    <TR><TD>caption</TD></TR>
    </TABLE>>];
}

digraph structs {
    node [shape=plaintext];

    struct1 [label=<<TABLE>
    <TR><TD><IMG SRC="eqn.png"/></TD></TR>
    <TR><TD>caption</TD></TR>
    </TABLE>>];
}
