The aforementioned solutions will work to implement max-width/height in IE, but just wanted to mention that if performance is an issue, you might want to look into generating actual thumbnail images instead of relying on HTML/CSS sizing.
Thumbnails would result in a smaller filesize, and you could potentially crop them to improve your visual direction. It would also get around the need for JavaScript and/or the negative performance implications of CSS Expressions.
Might not be feasible from a maintenance standpoint, but I figured I would mention it...