Cook rigatoni according to package directions., Meanwhile, in a large skillet, cook sausage over medium heat 4-6 minutes or until no longer pink, breaking into crumbles; drain and remove sausage from pan., In same skillet, heat butter over medium heat. Add mushrooms, garlic, salt and pepper; cook, covered, 4 minutes, stirring occasionally. Uncover; cook and stir 2-3 minutes or until mushrooms are tender and liquid is evaporated., Stir in cream; bring to a boil. Reduce heat; cook, uncovered, 8-10 minutes or until slightly thickened. Return sausage to skillet; heat through. Drain pasta; serve with sauce. If desired, sprinkle with parsley.