Round image with style?

Question

css

I am designing the html version of an email. There is the following code: I can't add style to img itself, since it is displayed through the [img] shortcode. Tried rounding like this:
<span><img src="..." /></span>

<span style="border-radius: 50%;"><img src="..." /></span>

but didn't work :(
Question: is there any way to round the image without working directly with the img itself?

Answer 1

<span style="border-radius: 50%;overflow:hidden"><img src="..." /></span>

Answer 2

use css and classes rather than style
html:
css:
.round > img {border-radius: 50%}