specifically targetting borders for gradient fill

Question

let's say I want to take the right border of my image and make it gradient, starting from my background color and going to transparent. Is such a thing achievable? In theory I imagine it something like this

<div class="faded-edges"></div>

.faded-edges {
   border: 25px rgba(147,147,147,1);
   border-right:  (gradient)
   border-left: (gradient)
}