X17 photographers witnessed Lindsay's g-friend Samantha Ronson rushed to the hospital just an hour ago!

Lindsay and an assistant escorted Sam from her Los Feliz home to a local hospital. Sam and Lindsay were in the back seat of the car - Samantha lying down on Linday's lap the whole time.

Sam was taken from the car into the emergency entrance of the hospital in a wheelchair.

Calls to the hospital have not yet been returned. More details coming ...