Type Radio and dinamic items

Good day. 

How to dinamic add items to radio

i want to do that:

{
   type: 'radio',
   id: 'radioFiles',
   label: 'Список файлов для вставки',
   //items: [['1'],['2']],
   items: setItems(),
   style : 'color:green; font-size: 12px',
   setup: function(element){
      this.setItem("1", "dta");
   },
   onClick : function() {
       if(this.getValue())
           alert( 'Current value: ' + this.getValue() );
   }
},
------------------------
function setItems() {
    items = [];
    $.getJSON('/Upload/JsonFiles?type=image', function(data) {
        $.each(data, function(key, val){
            items.push([[val.Name]]);
        });
    });
    return items;
};

But i cannot add some items.

Plz, tell me what I'm doing wrong?