Pour tomatoes into a medium saucepan. Fill the can up with water and add it to the tomatoes. Set it to medium low heat and cover. Keep an eye on it. Once it starts to boil, turn the heat to low.
While the tomatoes heat, spray a large deep skillet with cooking spray and put it over medium heat. Remove the sausage from their casings, and add it to the skillet. Cook it, breaking it apart, until it is no longer pink.
Add the arborio rice, and cook for about a minute. Turn the heat to medium low, and add the wine. Stir and allow the arborio rice to soak up the wine.
Once the wine is absorbed, add two cups of the tomato/water mixture. Stir and allow the rice to absorb it. Continue to add the liquid one cup at a time, waiting for it to absorb before adding more.
Once the rice is creamy and tender, remove it from the heat. (You may not need all the liquid.) Stir in the spinach a little at a time, letting it wilt.
Serve, topping with the parmesan cheese, or just sit by yourself and eat the entire pot.