A sensor guide wire for an intravascular measurement of a physiological variable in a living body may include a sensor element configured to measure the physiological variable based on exposure to fluid in the living body and a cylindrical-shaped jacket forming an interior space housing the sensor element. The jacket comprises an outer circumferential wall with a circumferential surface extending between distal and proximal longitudinal ends of the jacket. The outer circumferential wall of the jacket does not include any apertures along its circumferential surface so as to prevent fluid from passing through the outer circumferential wall and/or the jacket has a constant cross section along its entire length.
