Retrieve cached image and display image in page using javascript

I have server side code that retrieved  images from table and  stores them in a Dictionary array and Cache like:

   Cache("files") = New Dictionary(Of String, String)()

The 'Of string' key is identity number of image to add and the String() value contain the corresponding image in Base64string format.

I now would like to be able to retrieve a particular image from Dictionary array by passing ID number to javascript function and load that image in a image element on page.