1. Cook the fettuccine according to package instructions. Drain and set aside.
2. In a large skillet, heat olive oil over medium heat. Add shrimp and Cajun seasoning. Cook until shrimp is pink and opaque, about 3-4 minutes. Remove shrimp and set aside.
3. In the same skillet, add minced garlic and cook until fragrant, about 1 minute. Pour in heavy cream and bring to a simmer.
4. Stir in Parmesan cheese and lemon juice. Cook until the sauce thickens, about 3-4 minutes.
5. Add the cooked fettuccine and shrimp back into the skillet. Toss to coat everything in the sauce. Season with salt and pepper to taste.
6. Serve immediately, garnished with additional Parmesan cheese if desired.