Looks complex, and the greyscale values don't match the height values inflate uses to make a model. You would need to paint a new greyscale image with height values to inflate, then add the original image as a texture map.
If you try to do too much with a single inflate it will get messy.
That said - all those tubes and cylinder shapes would be best drawn individually as curvy shapes. And use inflate on individual pieces that are more oblong.
i would make a few simple rectangular blocks and project the picture onto them.
If you give an example illustration of an existing t-shirt I might be able to give a better answer.