Wash artichokes by plunging up and down in cold water. Cut off stem ends; trim about 1/2 inch from top of each artichoke. Remove any loose bottom leaves. With scissors, trim one-fourth off top of each outer leaf.
Place artichokes in a Dutch oven; add water to depth of 1 inch. Add lemon juice. Bring to a boil; cover, reduce heat, and simmer 25 minutes or until almost tender. Drain; cool. Spread leaves apart; discard inner leaves. Scrape out fuzzy choke with a spoon. Set artichokes aside.
Coat a large nonstick skillet with cooking spray; place over medium-high heat until hot. Add pork, shallot, and carrot. Cook 5 minutes, stirring to crumble pork. Add mushrooms and garlic; cook, stirring often, 2 minutes. Add beef broth and next 3 ingredients. Simmer 4 to 5 minutes or until liquid is absorbed and mushrooms are tender. Combine flour and milk, stirring to dissolve flour. Add to mushroom mixture. Simmer 3 minutes or until thickened. Stir in rice and parsley.
Spoon about 1/2 cup mixture into center of each reserved artichoke. Combine Parmesan cheese and breadcrumbs. Sprinkle 1 tablespoon Parmesan cheese mixture on top of mushroom mixture in each artichoke. Coat Parmesan cheese mixture with cooking spray.
Bake at 350° for 25 minutes or until tops are lightly browned.