Hoping to rebound from their road loss to the Eagles, the Cowboys returned home for a Week 6 battle against their in-state rival, the Houston Texans.  In the first quarter, Dallas trailed early when Kris Brown kicked a 19-yard field goal for an early Houston 3-0 lead.  In the second quarter, the Cowboys tied the game at 3-3 when Mike Vanderjagt kicked a 22-yard field goal.  At the end of the first half, Houston regained the lead when Brown kicked a 48-yard field goal.  For the rest of the game, the Dallas defense shut out the Houston Texans.  Drew Bledsoe and Terrell Owens hooked up on two touchdown passes, and Marion Barber ran a 1-yard touchdown, Vanderjagt kicked another 21-yard field goal, and backup quarterback Tony Romo threw another touchdown pass to Owens.  Tony Romo completed his first two NFL passes, including one touchdown.
Question: How many yards shorter was the shortest rushing touchdown compared to the shortest field goal?
Answer: 18