<style type="text/css">
#baseRuleta {
    padding-top: 4px;
    background: url(../sicam/plantillas/default/images/fondoRueda.png);
    background-position: center;
    background-repeat: no-repeat;
    background-size:  650px 850px;
}
</style>
<table cellpadding="0" cellspacing="0" border="0" style="text-align:center; width:100%;">
    <tbody>
        <tr>
            <td id="baseRuleta">
                <canvas id='myCanvas' width='701' height='800' style="margin-left: auto; margin-right: auto;"></canvas>
            </td>
        </tr>
    </tbody>
</table>