Check whether Image column contains data before retrieving

{% assign track_record = entities['musdyn_track'][request.params.id] %}
{% if track_record.musdyn_artworkid %}
    <script>
        webapi.safeAjax({
            type: "GET",
            url: "/_api/musdyn_tracks({{ request.params.id }})/musdyn_artwork/?size=full",
            contentType:"application/json",
            success: function(res) {
                $('#main').append('<img class="img-responsive" src="data:image/png;base64,' + res.value + '">');
            },
            error: function(xhr, status, error){
                $('#main').append('<img class="img-responsive" src="/artwork-not-found.svg">');
                var errorMessage = xhr.status + ': ' + xhr.statusText;
                console.log(errorMessage);
            }
        });
    </script>
{% endif %}