Bring a large pot of lightly salted water to a boil. Add pasta and cook as package directs, adding asparagus 6 minutes before pasta will be done.
Meanwhile heat butter in a large nonstick skillet over medium-high heat. Add shrimp; sauté 3 to 4 minutes until cooked through. Remove with a slotted spoon to a plate.
Add sherry and white part of scallions to skillet. Bring to a boil, reduce heat and simmer uncovered until liquid is reduced by half. Add Alfredo sauce and reserved juice from tomatoes; stir until blended and hot.
Drain pasta and asparagus; return to pot. Add Sauce, shrimp and tomatoes; toss to mix and coat. Sprinkle with green part of scallions.