how to remove particular image in list

Question

cntitem = 0;

DirectoryInfo dirst = new DirectoryInfo(MapPath("~/images"));

FileInfo[] file = dirst.GetFiles();

ArrayList list = new ArrayList();

foreach (FileInfo file2 in file)

{

list.Add("/Images/"+file2);

cntitem++;

}

///below code is working but i dnt want this type ("~/images/blank.gif" i want this image only remove)

list.RemoveAt(2);//we can delete using index particular iamge

list.RemoveAt(3);//

Session["cnt"] = cntitem;