The "Louis Armstrong New Orleans International Airport":http://www.flymsy.com/ is not in New Orleans proper. It takes approximately 20 minutes to drive from the airport to the Astor Crowne Plaza in the French Quarter.
Directions to Astor Crowne Plaza
Driving from the East on I-10 West bound look for the Canal Street/Claiborne Exit. As you exit the ramp continue straight to Canal Street. At Canal Street take a right and continue for approximately one mile. The hotel is on the corner of Bourbon and Canal Streets and you will pass it on the left side of the street. After passing the hotel on Canal Street, take your first u-turn and circle back to the hotel @ 739 Canal Street.